JNM Ahead of Print
Scaling of GFR and SUV for body size: the curious conflict of whole body metric preferences
Peters, A. M., Keramida, G. · Friday, June 10, 2016, 8:10
Tags: Neurology
Latest Results for Child's Nervous System
Excellent response to deep brain stimulation in a young girl with GNAO1 -related progressive choreoathetosis
Friday, June 10, 2016, 7:50
Tags: Neurology
Neuro-Oncology
First report on spinal metastasis in childhood-onset craniopharyngioma
Thursday, June 09, 2016, 15:15
Tags: Cancer, Neurology
Neuro-Oncology
Comment on: Adjuvant chemotherapy in adult medulloblastoma: is it an option for average-risk patients?
Thursday, June 09, 2016, 15:15
Tags: Cancer, Neurology
Journal of Neuroscience Methods
Novel approach to automatically classify rat social behavior using a video tracking system
Thursday, June 09, 2016, 11:30
Publication date: 1 August 2016
Source:Journal of Neuroscience Methods, Volume 268
Author(s): Suzanne M. Peters, Ilona J. Pinter, Helen H.J. Pothuizen, Raymond C. de Heer, Johanneke E. van der Harst, Berry M. Spruijt
Background In the past, studies in behavioral neuroscience and drug development have relied on simple and quick readout parameters of animal behavior to assess treatment efficacy or to understand underlying brain mechanisms. The predominant use of classical behavioral tests has been repeatedly criticized during the last decades because of their poor reproducibility, poor translational value and the limited explanatory power in functional terms. New method We present a new method to monitor social behavior of rats using automated video tracking. The velocity of moving and the distance between two rats were plotted in frequency distributions. In addition, behavior was manually annotated and related to the automatically obtained parameters for a validated interpretation. Results Inter-individual distance in combination with velocity of movement provided specific behavioral classes, such as moving with high velocity when "in contact" or "in proximity". Human observations showed that these classes coincide with following (chasing) behavior. In addition, when animals are "in contact", but at low velocity, behaviors such as allogrooming and social investigation were observed. Also, low dose treatment with morphine and short isolation increased the time animals spent in contact or in proximity at high velocity. Comparison with existing methods Current methods that involve the investigation of social rat behavior are mostly limited to short and relatively simple manual observations. Conclusion A new and automated method for analyzing social behavior in a social interaction test is presented here and shows to be sensitive to drug treatment and housing conditions known to influence social behavior in rats.
Source:Journal of Neuroscience Methods, Volume 268
Author(s): Suzanne M. Peters, Ilona J. Pinter, Helen H.J. Pothuizen, Raymond C. de Heer, Johanneke E. van der Harst, Berry M. Spruijt
Background In the past, studies in behavioral neuroscience and drug development have relied on simple and quick readout parameters of animal behavior to assess treatment efficacy or to understand underlying brain mechanisms. The predominant use of classical behavioral tests has been repeatedly criticized during the last decades because of their poor reproducibility, poor translational value and the limited explanatory power in functional terms. New method We present a new method to monitor social behavior of rats using automated video tracking. The velocity of moving and the distance between two rats were plotted in frequency distributions. In addition, behavior was manually annotated and related to the automatically obtained parameters for a validated interpretation. Results Inter-individual distance in combination with velocity of movement provided specific behavioral classes, such as moving with high velocity when "in contact" or "in proximity". Human observations showed that these classes coincide with following (chasing) behavior. In addition, when animals are "in contact", but at low velocity, behaviors such as allogrooming and social investigation were observed. Also, low dose treatment with morphine and short isolation increased the time animals spent in contact or in proximity at high velocity. Comparison with existing methods Current methods that involve the investigation of social rat behavior are mostly limited to short and relatively simple manual observations. Conclusion A new and automated method for analyzing social behavior in a social interaction test is presented here and shows to be sensitive to drug treatment and housing conditions known to influence social behavior in rats.
Tags: Neurology
Journal of Neuroscience Methods
Automated quantitative analysis to assess motor function in different rat models of impaired coordination and ataxia
Thursday, June 09, 2016, 11:30
Publication date: 1 August 2016
Source:Journal of Neuroscience Methods, Volume 268
Author(s): Elisavet I. Kyriakou, Jan G. van der Kieft, Raymond C. de Heer, Andrew Spink, Huu Phuc Nguyen, Judith R. Homberg, Johanneke E. van der Harst
Background An objective and automated method for assessing alterations in gait and motor coordination in different animal models is important for proper gait analysis. The CatWalk system has been used in pain research, ischemia, arthritis, spinal cord injury and some animal models for neurodegenerative diseases. New method Our goals were to obtain a comprehensive gait analysis of three different rat models and to identify which motor coordination parameters are affected and are the most suitable and sensitive to describe and detect ataxia with a secondary focus on possible training effects. Results Both static and dynamic parameters showed significant differences in all three models: enriched housed rats show higher walking and swing speed and longer stride length, ethanol-induced ataxia affects mainly the hind part of the body, and the SCA17 rats show coordination disturbances. Coordination changes were revealed only in the case of the ethanol-induced ataxia and the SCA17 rat model. Although training affected some gait parameters, it did not obscure group differences when those were present. Comparison with existing methods To our knowledge, a comparative gait assessment in rats with enriched housing conditions, ethanol-induced ataxia and SCA17 has not been presented before. Conclusions There is no gold standard for the use of CatWalk. Dependent on the specific effects expected, the protocol can be adjusted. By including all sessions in the analysis, any training effect should be detectable and the development of the performance over the sessions can provide insight in effects attributed to intervention, treatment or injury.
Source:Journal of Neuroscience Methods, Volume 268
Author(s): Elisavet I. Kyriakou, Jan G. van der Kieft, Raymond C. de Heer, Andrew Spink, Huu Phuc Nguyen, Judith R. Homberg, Johanneke E. van der Harst
Background An objective and automated method for assessing alterations in gait and motor coordination in different animal models is important for proper gait analysis. The CatWalk system has been used in pain research, ischemia, arthritis, spinal cord injury and some animal models for neurodegenerative diseases. New method Our goals were to obtain a comprehensive gait analysis of three different rat models and to identify which motor coordination parameters are affected and are the most suitable and sensitive to describe and detect ataxia with a secondary focus on possible training effects. Results Both static and dynamic parameters showed significant differences in all three models: enriched housed rats show higher walking and swing speed and longer stride length, ethanol-induced ataxia affects mainly the hind part of the body, and the SCA17 rats show coordination disturbances. Coordination changes were revealed only in the case of the ethanol-induced ataxia and the SCA17 rat model. Although training affected some gait parameters, it did not obscure group differences when those were present. Comparison with existing methods To our knowledge, a comparative gait assessment in rats with enriched housing conditions, ethanol-induced ataxia and SCA17 has not been presented before. Conclusions There is no gold standard for the use of CatWalk. Dependent on the specific effects expected, the protocol can be adjusted. By including all sessions in the analysis, any training effect should be detectable and the development of the performance over the sessions can provide insight in effects attributed to intervention, treatment or injury.
Tags: Neurology
Journal of Neuroscience Methods
Optimization and pharmacological validation of a set-shifting procedure for assessing executive function in rats
Thursday, June 09, 2016, 11:30
Publication date: 1 August 2016
Source:Journal of Neuroscience Methods, Volume 268
Author(s): R. Troudet, E. Detrait, E. Hanon, Y. Lamberty
Background Set-shifting tests represent a reliable paradigm to assess executive functions in humans and animals. In the rat, set-shifting in a cross-maze is a recognized method. In this test, rats must learn an egocentric rule to locate food reinforcement. Once acquired, a second rule, based on visual-cue strategy, allows the location of the food. Ability of rats to shift from the first to the second rule is considered to reflect cognitive flexibility. New method This study aimed at optimizing the most currently used set-shifting protocol in a cross-maze for standardized drug testing by modulating the parameters related to caloric restriction, reward preference, and by redefining the notion of turn bias and classification of errors sub-types, i.e. perseverative vs. regressive. The new protocol has then been used to assess rats treated by sub-chronic phencyclidine administration and investigate the potential reversal effect of tolcapone, a brain penetrant catechol-O-methyl transferase inhibitor. Results The new procedure resulted in a decreased total duration and a re-definition of turn bias and error subtypes. Despite preferences for sweet rewards, caloric restriction had to be maintained to motivate animals. Overall, sub-chronic PCP-treated rats made mostly perseverative errors compared to controls and required more trials to shift between the two rules. Tolcapone partly reversed impairments observed in PCP-treated rats. Conclusion The new protocol has improved the reliability of key parameters and has contributed to the decrease of the test duration. PCP-treated rats submitted to this protocol have been shown to have significant deficits that could be reversed by tolcapone.
Source:Journal of Neuroscience Methods, Volume 268
Author(s): R. Troudet, E. Detrait, E. Hanon, Y. Lamberty
Background Set-shifting tests represent a reliable paradigm to assess executive functions in humans and animals. In the rat, set-shifting in a cross-maze is a recognized method. In this test, rats must learn an egocentric rule to locate food reinforcement. Once acquired, a second rule, based on visual-cue strategy, allows the location of the food. Ability of rats to shift from the first to the second rule is considered to reflect cognitive flexibility. New method This study aimed at optimizing the most currently used set-shifting protocol in a cross-maze for standardized drug testing by modulating the parameters related to caloric restriction, reward preference, and by redefining the notion of turn bias and classification of errors sub-types, i.e. perseverative vs. regressive. The new protocol has then been used to assess rats treated by sub-chronic phencyclidine administration and investigate the potential reversal effect of tolcapone, a brain penetrant catechol-O-methyl transferase inhibitor. Results The new procedure resulted in a decreased total duration and a re-definition of turn bias and error subtypes. Despite preferences for sweet rewards, caloric restriction had to be maintained to motivate animals. Overall, sub-chronic PCP-treated rats made mostly perseverative errors compared to controls and required more trials to shift between the two rules. Tolcapone partly reversed impairments observed in PCP-treated rats. Conclusion The new protocol has improved the reliability of key parameters and has contributed to the decrease of the test duration. PCP-treated rats submitted to this protocol have been shown to have significant deficits that could be reversed by tolcapone.
Tags: Neurology
Journal of Neuroscience Methods
The development of a non-invasive behavioral model of thermal heat stress in laboratory mice (Mus musculus)
Thursday, June 09, 2016, 11:30
Publication date: 1 August 2016
Source:Journal of Neuroscience Methods, Volume 268
Author(s): J.T. Mufford, M.J. Paetkau, N.J. Flood, G. Regev-Shoshani, C.C. Miller, J.S. Church
Background Many behavioral and physiological studies of laboratory mice employ invasive methods such as radio telemetry to measure key aspects of behavior and physiology. Radio telemetry requires surgical implants, which may impact mouse health and behavior, and thus reduce the reliability of the data collected. New method We developed a method to measure key aspects of thermoregulatory behavior without compromising animal welfare. We examined the thermoregulatory response to heat stress in a custom-built arena that permitted the use of simultaneous and continuous infrared thermography (IRT) and video capture. This allowed us to measure changes in surface body temperature and determine total distance traveled using EthoVision XT animal tracking software. Results Locomotor activity and surface body temperature differed between heat-stressed mice and mice kept within their thermal comfort zone. The former had an increase in surface body temperature and a decline in locomotor activity, whereas the latter had a stable surface body temperature and showed greater activity levels. Methods Surface body temperature and locomotor activity are conventionally quantified by measurements taken at regular intervals, which limit the use and accuracy of the data. We obtained data of high resolution (i.e., recorded continuously) and accuracy that allowed for the examination of key physiological measurements such as energy expenditure and peripheral vasomotor tone. Conclusions This novel experimental method for studying thermoregulatory behavior in mice using non-invasive tools has advantages over radio-telemetry and represents an improvement in laboratory animal welfare.
Source:Journal of Neuroscience Methods, Volume 268
Author(s): J.T. Mufford, M.J. Paetkau, N.J. Flood, G. Regev-Shoshani, C.C. Miller, J.S. Church
Background Many behavioral and physiological studies of laboratory mice employ invasive methods such as radio telemetry to measure key aspects of behavior and physiology. Radio telemetry requires surgical implants, which may impact mouse health and behavior, and thus reduce the reliability of the data collected. New method We developed a method to measure key aspects of thermoregulatory behavior without compromising animal welfare. We examined the thermoregulatory response to heat stress in a custom-built arena that permitted the use of simultaneous and continuous infrared thermography (IRT) and video capture. This allowed us to measure changes in surface body temperature and determine total distance traveled using EthoVision XT animal tracking software. Results Locomotor activity and surface body temperature differed between heat-stressed mice and mice kept within their thermal comfort zone. The former had an increase in surface body temperature and a decline in locomotor activity, whereas the latter had a stable surface body temperature and showed greater activity levels. Methods Surface body temperature and locomotor activity are conventionally quantified by measurements taken at regular intervals, which limit the use and accuracy of the data. We obtained data of high resolution (i.e., recorded continuously) and accuracy that allowed for the examination of key physiological measurements such as energy expenditure and peripheral vasomotor tone. Conclusions This novel experimental method for studying thermoregulatory behavior in mice using non-invasive tools has advantages over radio-telemetry and represents an improvement in laboratory animal welfare.
Tags: Neurology
Journal of NeuroEngineering and Rehabilitation - Latest Articles
Powered robotic exoskeletons in post-stroke rehabilitation of gait: a scoping review
Dennis R. Louie And Janice J. Eng · Thursday, June 09, 2016, 11:25
Powered robotic exoskeletons are a potential intervention for gait rehabilitation in stroke to enable repetitive walking practice to maximize neural recovery. As this is a relatively new technology for stroke,...
Tags: Neurology
Journal of NeuroEngineering and Rehabilitation - Latest Articles
Instrumental indices for upper limb function assessment in stroke patients: a validation study
Maria Longhi, Andrea Merlo, Paolo Prati, Meris Giacobbi And Davide Mazzoli · Thursday, June 09, 2016, 11:25
Robotic exoskeletons are increasingly being used in objective and quantitative assessment of upper limb (UL) movements. A set of instrumental indices computed during robot-assisted reaching tasks with the Arme...
Tags: Neurology
The New England Journal of Medicine: Neurology\Neurosurgery
A Woman with Dyspnea and Altered Mental Status
Thursday, June 09, 2016, 11:21
A 59-year-old black woman with systemic lupus erythematosus (SLE) presented to the emergency department with new-onset lethargy and shortness of breath. She had dreceived a diagnosis of SLE 15 years earlier, after presenting with joint pain and swelling, and was treated with azathioprine. The…
Tags: Neurology
The New England Journal of Medicine: Neurology\Neurosurgery
Intensive Blood-Pressure Lowering in Patients with Acute Cerebral Hemorrhage
Thursday, June 09, 2016, 3:21
An acute hypertensive response in patients with intracerebral hemorrhage is common and may be associated with hematoma expansion and increased mortality. The second Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial (INTERACT2) included patients with spontaneous intracerebral…
Tags: Neurology
Behavioural Brain Research
An interplay of fusiform gyrus and hippocampus enables prototype- and exemplar-based category learning
Wednesday, June 08, 2016, 22:59
Publication date: 15 September 2016
Source:Behavioural Brain Research, Volume 311
Author(s): Robert K. Lech, Onur Güntürkün, Boris Suchan
The aim of the present study was to examine the contributions of different brain structures to prototype- and exemplar-based category learning using functional magnetic resonance imaging (fMRI). Twenty-eight subjects performed a categorization task in which they had to assign prototypes and exceptions to two different families. This test procedure usually produces different learning curves for prototype and exception stimuli. Our behavioral data replicated these previous findings by showing an initially superior performance for prototypes and typical stimuli and a switch from a prototype-based to an exemplar-based categorization for exceptions in the later learning phases. Since performance varied, we divided participants into learners and non-learners. Analysis of the functional imaging data revealed that the interaction of group (learners vs. non-learners) and block (Block 5 vs. Block 1) yielded an activation of the left fusiform gyrus for the processing of prototypes, and an activation of the right hippocampus for exceptions after learning the categories. Thus, successful prototype- and exemplar-based category learning is associated with activations of complementary neural substrates that constitute object-based processes of the ventral visual stream and their interaction with unique-cue representations, possibly based on sparse coding within the hippocampus.
Source:Behavioural Brain Research, Volume 311
Author(s): Robert K. Lech, Onur Güntürkün, Boris Suchan
The aim of the present study was to examine the contributions of different brain structures to prototype- and exemplar-based category learning using functional magnetic resonance imaging (fMRI). Twenty-eight subjects performed a categorization task in which they had to assign prototypes and exceptions to two different families. This test procedure usually produces different learning curves for prototype and exception stimuli. Our behavioral data replicated these previous findings by showing an initially superior performance for prototypes and typical stimuli and a switch from a prototype-based to an exemplar-based categorization for exceptions in the later learning phases. Since performance varied, we divided participants into learners and non-learners. Analysis of the functional imaging data revealed that the interaction of group (learners vs. non-learners) and block (Block 5 vs. Block 1) yielded an activation of the left fusiform gyrus for the processing of prototypes, and an activation of the right hippocampus for exceptions after learning the categories. Thus, successful prototype- and exemplar-based category learning is associated with activations of complementary neural substrates that constitute object-based processes of the ventral visual stream and their interaction with unique-cue representations, possibly based on sparse coding within the hippocampus.
Tags: Neurology
Behavioural Brain Research
Mice deficient for striatal Vesicular Acetylcholine Transporter (VAChT) display impaired short-term but normal long-term object recognition memory
Wednesday, June 08, 2016, 22:59
Publication date: 15 September 2016
Source:Behavioural Brain Research, Volume 311
Author(s): Daniel Palmer, Samantha Creighton, Vania F. Prado, Marco A.M. Prado, Elena Choleris, Boyer D. Winters
Substantial evidence implicates Acetylcholine (ACh) in the acquisition of object memories. While most research has focused on the role of the cholinergic basal forebrain and its cortical targets, there are additional cholinergic networks that may contribute to object recognition. The striatum contains an independent cholinergic network comprised of interneurons. In the current study, we investigated the role of this cholinergic signalling in object recognition using mice deficient for Vesicular Acetylcholine Transporter (VAChT) within interneurons of the striatum. We tested whether these striatal VAChTD2−Cre−flox/flox mice would display normal short-term (5 or 15min retention delay) and long-term (3h retention delay) object recognition memory. In a home cage object recognition task, male and female VAChTD2−Cre−flox/flox mice were impaired selectively with a 15min retention delay. When tested on an object location task, VAChTD2−Cre−flox/flox mice displayed intact spatial memory. Finally, when object recognition was tested in a Y-shaped apparatus, designed to minimize the influence of spatial and contextual cues, only females displayed impaired recognition with a 5min retention delay, but when males were challenged with a 15min retention delay, they were also impaired; neither males nor females were impaired with the 3h delay. The pattern of results suggests that striatal cholinergic transmission plays a role in the short-term memory for object features, but not spatial location.
Source:Behavioural Brain Research, Volume 311
Author(s): Daniel Palmer, Samantha Creighton, Vania F. Prado, Marco A.M. Prado, Elena Choleris, Boyer D. Winters
Substantial evidence implicates Acetylcholine (ACh) in the acquisition of object memories. While most research has focused on the role of the cholinergic basal forebrain and its cortical targets, there are additional cholinergic networks that may contribute to object recognition. The striatum contains an independent cholinergic network comprised of interneurons. In the current study, we investigated the role of this cholinergic signalling in object recognition using mice deficient for Vesicular Acetylcholine Transporter (VAChT) within interneurons of the striatum. We tested whether these striatal VAChTD2−Cre−flox/flox mice would display normal short-term (5 or 15min retention delay) and long-term (3h retention delay) object recognition memory. In a home cage object recognition task, male and female VAChTD2−Cre−flox/flox mice were impaired selectively with a 15min retention delay. When tested on an object location task, VAChTD2−Cre−flox/flox mice displayed intact spatial memory. Finally, when object recognition was tested in a Y-shaped apparatus, designed to minimize the influence of spatial and contextual cues, only females displayed impaired recognition with a 5min retention delay, but when males were challenged with a 15min retention delay, they were also impaired; neither males nor females were impaired with the 3h delay. The pattern of results suggests that striatal cholinergic transmission plays a role in the short-term memory for object features, but not spatial location.
Tags: Neurology
Cortex
Meta-analytical and electrophysiological evidence for executive dysfunction in primary dystonia
Wednesday, June 08, 2016, 19:54
Publication date: Available online 8 June 2016
Source:Cortex
Author(s): Florian Lange, Caroline Seer, Carolin Salchow, Reinhard Dengler, Dirk Dressler, Bruno Kopp
Impaired motor control in primary dystonia has been linked to cortico-basal ganglia alterations that may also give rise to changes in executive functioning. However, no conclusive evidence for executive dysfunction in patients with primary dystonia has been reported yet. We conducted a meta-analysis of the relationship between primary dystonia and performance on the Wisconsin Card Sorting Test (WCST), an established test of executive functioning. Its results revealed a significant effect of medium size, indicating that primary dystonia is associated with moderate performance deficits on the WCST. Building on this finding, we conducted an event-related potential (ERP) study to elucidate the cognitive and neural mechanisms underlying executive dysfunction in primary dystonia. Eighteen patients with blepharospasm, a common form of primary focal dystonia, and 34 healthy matched controls completed a computerized version of the WCST. We specifically compared indicators of two distinct components of executive functioning: set shifting and rule inference. On a behavioral level, blepharospasm patients seemed to have particular difficulty integrating information to infer the correct task rule. In addition, P3a amplitude (as an electrophysiological marker of rule-inference processes) was selectively attenuated in blepharospasm patients. Executive dysfunction in blepharospasm can thus rather be attributed to a rule-inference deficit, whereas set-shifting abilities appear to be relatively unaffected by the disease. Moreover, P3a amplitude attenuation was related to disease duration, indicating that this ERP might serve as a neural indicator of disease progression and executive dysfunction in primary dystonia. These results demonstrate for the first time that pathophysiological alterations in primary dystonia might affect cortical activation for executive functioning.
Source:Cortex
Author(s): Florian Lange, Caroline Seer, Carolin Salchow, Reinhard Dengler, Dirk Dressler, Bruno Kopp
Impaired motor control in primary dystonia has been linked to cortico-basal ganglia alterations that may also give rise to changes in executive functioning. However, no conclusive evidence for executive dysfunction in patients with primary dystonia has been reported yet. We conducted a meta-analysis of the relationship between primary dystonia and performance on the Wisconsin Card Sorting Test (WCST), an established test of executive functioning. Its results revealed a significant effect of medium size, indicating that primary dystonia is associated with moderate performance deficits on the WCST. Building on this finding, we conducted an event-related potential (ERP) study to elucidate the cognitive and neural mechanisms underlying executive dysfunction in primary dystonia. Eighteen patients with blepharospasm, a common form of primary focal dystonia, and 34 healthy matched controls completed a computerized version of the WCST. We specifically compared indicators of two distinct components of executive functioning: set shifting and rule inference. On a behavioral level, blepharospasm patients seemed to have particular difficulty integrating information to infer the correct task rule. In addition, P3a amplitude (as an electrophysiological marker of rule-inference processes) was selectively attenuated in blepharospasm patients. Executive dysfunction in blepharospasm can thus rather be attributed to a rule-inference deficit, whereas set-shifting abilities appear to be relatively unaffected by the disease. Moreover, P3a amplitude attenuation was related to disease duration, indicating that this ERP might serve as a neural indicator of disease progression and executive dysfunction in primary dystonia. These results demonstrate for the first time that pathophysiological alterations in primary dystonia might affect cortical activation for executive functioning.
Tags: Neurology
Cortex
Behavioural and neuroimaging correlates of impaired self-awareness of hypo- and hyperkinesia in Parkinson's disease
Wednesday, June 08, 2016, 19:54
Publication date: Available online 8 June 2016
Source:Cortex
Author(s): Franziska Maier, Kim L. Williamson, Masoud Tahmasian, Luisa Rochhausen, Anna L. Ellereit, George P. Prigatano, Lutz Kracht, Chris C. Tang, Damian M. Herz, Gereon R. Fink, Lars Timmermann, Carsten Eggers
Introduction Anosognosia or impaired self-awareness of motor symptoms (ISAm) has been rarely investigated in Parkinson's disease (PD). We here studied the relationship between ISAm during periods with and without dopaminergic medication (ON- and OFF-state), and clinical, neuropsychological, and neuroimaging data to further elucidate behavioural aspects and the neurobiological underpinnings of ISAm. Methods Thirty-one right-handed, non-demented, non-depressed PD patients were included. ISAm was evaluated using a recently developed scale that assesses awareness of dyskinesia, resting tremor, and bradykinesia. The test was applied during both ON- and OFF-states. Multiple correlation analyses between ISAm and behavioural data were conducted. In addition, imaging of glucose metabolism using 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) was performed to investigate the neural basis of ISAm. A multiple regression approach was applied to investigate metabolism alterations related to ISAm. Results In the OFF-state, higher ISAm was associated with left-sided disease onset, older age, and shorter disease duration. Concerning FDG-PET data, there was a significant negative correlation between higher OFF-state ISAm and decreased glucose metabolism in the right inferior frontal gyrus. In the ON-state, ISAm was not significantly correlated with clinical or behavioural data. However, there was a significant correlation between higher ISAm and an increased metabolism in the bilateral medial frontal gyrus, left inferior frontal gyrus, right superior frontal gyrus and right precentral gyrus. Conclusion The results support the role of the right hemisphere in awareness of motor symptoms in the OFF-state. In the ON-state, dopaminergic medication and dyskinesia influence ISAm and relate to metabolism changes in bilateral frontal regions.
Source:Cortex
Author(s): Franziska Maier, Kim L. Williamson, Masoud Tahmasian, Luisa Rochhausen, Anna L. Ellereit, George P. Prigatano, Lutz Kracht, Chris C. Tang, Damian M. Herz, Gereon R. Fink, Lars Timmermann, Carsten Eggers
Introduction Anosognosia or impaired self-awareness of motor symptoms (ISAm) has been rarely investigated in Parkinson's disease (PD). We here studied the relationship between ISAm during periods with and without dopaminergic medication (ON- and OFF-state), and clinical, neuropsychological, and neuroimaging data to further elucidate behavioural aspects and the neurobiological underpinnings of ISAm. Methods Thirty-one right-handed, non-demented, non-depressed PD patients were included. ISAm was evaluated using a recently developed scale that assesses awareness of dyskinesia, resting tremor, and bradykinesia. The test was applied during both ON- and OFF-states. Multiple correlation analyses between ISAm and behavioural data were conducted. In addition, imaging of glucose metabolism using 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) was performed to investigate the neural basis of ISAm. A multiple regression approach was applied to investigate metabolism alterations related to ISAm. Results In the OFF-state, higher ISAm was associated with left-sided disease onset, older age, and shorter disease duration. Concerning FDG-PET data, there was a significant negative correlation between higher OFF-state ISAm and decreased glucose metabolism in the right inferior frontal gyrus. In the ON-state, ISAm was not significantly correlated with clinical or behavioural data. However, there was a significant correlation between higher ISAm and an increased metabolism in the bilateral medial frontal gyrus, left inferior frontal gyrus, right superior frontal gyrus and right precentral gyrus. Conclusion The results support the role of the right hemisphere in awareness of motor symptoms in the OFF-state. In the ON-state, dopaminergic medication and dyskinesia influence ISAm and relate to metabolism changes in bilateral frontal regions.
Tags: Neurology
Cortex
Multi-factorial modulation of hemispheric specialization and plasticity for language in healthy and pathological conditions: a review
Wednesday, June 08, 2016, 19:54
Publication date: Available online 7 June 2016
Source:Cortex
Author(s): Nathalie Tzourio-Mazoyer, Marcela Perrone-Bertolotti, Gael Jobard, Bernard Mazoyer, Monica Baciu
This review synthesizes anatomo-functional variability of language hemispheric representation and specialization (hemispheric specialization for language, HSL) as well as its modulation by several variables (demographic, anatomical, developmental, genetic, clinical, and psycholinguistic) in physiological and pathological conditions. The left hemisphere (LH) dominance for language, observed in approximately 90% of healthy individuals and in 70% of patients, is grounded by intra-hemispheric connections mediated by associative bundles such as the arcuate fasciculus and inter-hemispheric transcallosal connections mediated by the corpus callosum that connects homotopic regions of the left and right hemispheres (RH). In typical brains, inter-hemispheric inhibition, exerted from the LH to the RH, permits the LH to maintain language dominance. In pathological conditions, inter- and intra-hemispheric inhibition is decreased, inducing modifications on the degree of HSL and of language networks. HSL evaluation is classically performed in clinical practice with the Wada test and electro-cortical stimulation, gold standard methods. The advent of functional neuroimaging has allowed a more detailed assessment of the language networks and their lateralization, consistent with the results provided by the gold standard methods. In the first part, we describe anatomo-functional support for HSL in healthy conditions, its developmental course, its relationship with cognitive skills, and the various modulatory factors acting on HSL. The second section is devoted to the assessment of HSL in patients with focal and drug-resistant epilepsy (FDRE). FDRE is considered a neurological model associated with patterns of language plasticity, both before and after surgery: FDRE patients show significant modification of language networks induced by changes mediated by transcallosal connections (explaining inter-hemispheric patterns of language reorganization) or collateral connections (explaining intra-hemispheric patterns of language reorganization). Finally, we propose several predictive and explicative models of language organization and reorganization.
Source:Cortex
Author(s): Nathalie Tzourio-Mazoyer, Marcela Perrone-Bertolotti, Gael Jobard, Bernard Mazoyer, Monica Baciu
This review synthesizes anatomo-functional variability of language hemispheric representation and specialization (hemispheric specialization for language, HSL) as well as its modulation by several variables (demographic, anatomical, developmental, genetic, clinical, and psycholinguistic) in physiological and pathological conditions. The left hemisphere (LH) dominance for language, observed in approximately 90% of healthy individuals and in 70% of patients, is grounded by intra-hemispheric connections mediated by associative bundles such as the arcuate fasciculus and inter-hemispheric transcallosal connections mediated by the corpus callosum that connects homotopic regions of the left and right hemispheres (RH). In typical brains, inter-hemispheric inhibition, exerted from the LH to the RH, permits the LH to maintain language dominance. In pathological conditions, inter- and intra-hemispheric inhibition is decreased, inducing modifications on the degree of HSL and of language networks. HSL evaluation is classically performed in clinical practice with the Wada test and electro-cortical stimulation, gold standard methods. The advent of functional neuroimaging has allowed a more detailed assessment of the language networks and their lateralization, consistent with the results provided by the gold standard methods. In the first part, we describe anatomo-functional support for HSL in healthy conditions, its developmental course, its relationship with cognitive skills, and the various modulatory factors acting on HSL. The second section is devoted to the assessment of HSL in patients with focal and drug-resistant epilepsy (FDRE). FDRE is considered a neurological model associated with patterns of language plasticity, both before and after surgery: FDRE patients show significant modification of language networks induced by changes mediated by transcallosal connections (explaining inter-hemispheric patterns of language reorganization) or collateral connections (explaining intra-hemispheric patterns of language reorganization). Finally, we propose several predictive and explicative models of language organization and reorganization.
Tags: Neurology
ScienceDirect Publication: Brain Research Bulletin
Ghrelin attenuates brain injury in septic mice via PI3K/Akt signaling activation
Wednesday, June 08, 2016, 15:35
Publication date: Available online 7 June 2016
Source:Brain Research Bulletin
Author(s): Ning Sun, Hui Wang, Li Ma, Ping Lei, Qiang Zhang
Brain injury has been reported to occur in sepsis and can lead to high mortality among septic patients. Previous studies suggest that ghrelin is protective for the brain, but whether ghrelin protects brain from sepsis remains unclear. Therefore, the aim of this study is to investigate the protective effect of ghrelin against sepsis-induced brain injury. Cecal ligation and puncture was performed in male C57BL/6J mice to establish the sepsis model. Ghrelin was administrated intraperitoneally at a dose of 80μg/kg. The blood-brain barrier (BBB) integrity, brain water content, inflammatory cytokines (TNF-α and IL-1β), oxidative stress (SOD and MDA) and neuronal apoptosis were assessed. In addition, the expression levels of Akt, phospho-Akt (Ser473) (p-Akt), Bcl-2 and Bax were detected by Western blot. Our results suggested that ghrelin attenuated brain edema, neuronal apoptosis and enhanced BBB integrity. Ghrelin decreased the production of TNF-α and IL-1β. Ghrelin increased the activity of SOD and decreased MDA production. Additionally, ghrelin increased the expression of p-Akt and Bcl-2 and decreased the Bax expression. The protective effects of ghrelin mentioned above were abolished by LY294002 (LY), a PI3K inhibitor. In conclusion, our results demonstrate that ghrelin attenuates brain injury in sepsis via PI3K/Akt signaling activation.
Source:Brain Research Bulletin
Author(s): Ning Sun, Hui Wang, Li Ma, Ping Lei, Qiang Zhang
Brain injury has been reported to occur in sepsis and can lead to high mortality among septic patients. Previous studies suggest that ghrelin is protective for the brain, but whether ghrelin protects brain from sepsis remains unclear. Therefore, the aim of this study is to investigate the protective effect of ghrelin against sepsis-induced brain injury. Cecal ligation and puncture was performed in male C57BL/6J mice to establish the sepsis model. Ghrelin was administrated intraperitoneally at a dose of 80μg/kg. The blood-brain barrier (BBB) integrity, brain water content, inflammatory cytokines (TNF-α and IL-1β), oxidative stress (SOD and MDA) and neuronal apoptosis were assessed. In addition, the expression levels of Akt, phospho-Akt (Ser473) (p-Akt), Bcl-2 and Bax were detected by Western blot. Our results suggested that ghrelin attenuated brain edema, neuronal apoptosis and enhanced BBB integrity. Ghrelin decreased the production of TNF-α and IL-1β. Ghrelin increased the activity of SOD and decreased MDA production. Additionally, ghrelin increased the expression of p-Akt and Bcl-2 and decreased the Bax expression. The protective effects of ghrelin mentioned above were abolished by LY294002 (LY), a PI3K inhibitor. In conclusion, our results demonstrate that ghrelin attenuates brain injury in sepsis via PI3K/Akt signaling activation.
Tags: Neurology
ScienceDirect Publication: Brain Research Bulletin
Local administration of resveratrol inhibits excitability of nociceptive wide-dynamic range neurons in rat trigeminal spinal nucleus caudalis
Wednesday, June 08, 2016, 15:35
Publication date: Available online 7 June 2016
Source:Brain Research Bulletin
Author(s): Yoshihito Shimazu, Eri Shibuya, Shiori Takehana, Kenta Sekiguchi, Katsuo Oshima, Hiroaki Kamata, Hiroyuki Karibe, Mamoru Takeda
Although we recently reported that intravenous administration of resveratrol suppresses trigeminal nociception, the precise peripheral effect of resveratrol on nociceptive and non-nociceptive mechanical stimulation-induced trigeminal neuron activity in vivo remains to be determined. The aim of the present study was to investigate whether local subcutaneous administration of resveratrol attenuates mechanical stimulation-induced excitability of trigeminal spinal nucleus caudalis (SpVc) neuron activity in rats, in vivo. Extracellular single-unit recordings were made of SpVc wide-dynamic range (WDR) neuron activity in response to orofacial mechanical stimulation in pentobarbital-anesthetized rats. Neurons responded to non-noxious and noxious mechanical stimulation applied to the orofacial skin. Local subcutaneous administration of resveratrol (1–10mM) into the orofacial skin dose dependently and significantly reduced the mean number of SpVc WDR neurons firing in response to both non-noxious and noxious mechanical stimuli, with the maximal inhibition of discharge frequency in response to both stimuli being seen within 5min. These inhibitory effects were no longer evident after approximately 20min. The mean magnitude of inhibition by resveratrol (10mM) of SpVc neuron discharge frequency was almost equal to that of the local anesthetic 1% lidocaine (37mM). These results suggest that local injection of resveratrol into the peripheral receptive field suppresses the excitability of SpVc neurons, possibly via inhibition of Na+channels in the nociceptive nerve terminals of trigeminal ganglion neurons. Therefore, local subcutaneous administration of resveratrol may provide relief of trigeminal nociceptive pain, without side effects, thus contributing to the suite of complementary and alternative medicines used as local anesthetic agents.
Source:Brain Research Bulletin
Author(s): Yoshihito Shimazu, Eri Shibuya, Shiori Takehana, Kenta Sekiguchi, Katsuo Oshima, Hiroaki Kamata, Hiroyuki Karibe, Mamoru Takeda
Although we recently reported that intravenous administration of resveratrol suppresses trigeminal nociception, the precise peripheral effect of resveratrol on nociceptive and non-nociceptive mechanical stimulation-induced trigeminal neuron activity in vivo remains to be determined. The aim of the present study was to investigate whether local subcutaneous administration of resveratrol attenuates mechanical stimulation-induced excitability of trigeminal spinal nucleus caudalis (SpVc) neuron activity in rats, in vivo. Extracellular single-unit recordings were made of SpVc wide-dynamic range (WDR) neuron activity in response to orofacial mechanical stimulation in pentobarbital-anesthetized rats. Neurons responded to non-noxious and noxious mechanical stimulation applied to the orofacial skin. Local subcutaneous administration of resveratrol (1–10mM) into the orofacial skin dose dependently and significantly reduced the mean number of SpVc WDR neurons firing in response to both non-noxious and noxious mechanical stimuli, with the maximal inhibition of discharge frequency in response to both stimuli being seen within 5min. These inhibitory effects were no longer evident after approximately 20min. The mean magnitude of inhibition by resveratrol (10mM) of SpVc neuron discharge frequency was almost equal to that of the local anesthetic 1% lidocaine (37mM). These results suggest that local injection of resveratrol into the peripheral receptive field suppresses the excitability of SpVc neurons, possibly via inhibition of Na+channels in the nociceptive nerve terminals of trigeminal ganglion neurons. Therefore, local subcutaneous administration of resveratrol may provide relief of trigeminal nociceptive pain, without side effects, thus contributing to the suite of complementary and alternative medicines used as local anesthetic agents.
Tags: Neurology
NeuroReport - Published Ahead-of-Print
Postnatal high-fat diet leads to spatial deficit, obesity, and central and peripheral inflammation in prenatal dexamethasone adult offspring rats.
Hsieh, Chih-sung; Li, Shih-wen; Sheen, Jiunn-ming; Yu, Hong-ren; Tiao, Mao-meng; Tain, You-lin; Su, Chung-hao; Huang, Li-tung · Wednesday, June 08, 2016, 10:54
Synthetic glucocorticoids are frequently used in clinical practice for treating pregnant women at risk of preterm delivery, but their long-term effects on the infant brain are largely unknown. Pregnant Sprague-Dawley rats were administered vehicle or dexamethasone between gestational days 14 and 21. Male offspring were then weaned onto either a standard chow or a high-fat diet. The postnatal levels of insulin-like growth factor I (IGF-1), tumor necrosis factor-[alpha] (TNF-[alpha]), and asymmetric dimethylarginine (ADMA) in the plasma, liver, and brain were examined, as well as the possible effects of prenatal dexamethasone on cognition. We found that a postnatal high-fat diet led to spatial deficits detected by the Morris water maze in adult offspring administered dexamethasone prenatally. The spatial deficit was accompanied by decreased IGF-1 mRNA and increased ADMA levels in the dorsal hippocampus. In peripheral systems, a postnatal high-fat diet resulted in decreased plasma IGF-1, increased plasma corticosterone, increased concentrations of transaminases, TNF-[alpha] mRNA, and ADMA in the liver, and associated obesity in adult offspring administered prenatal dexamethasone. In conclusion, a postnatal high-fat diet led to spatial deficits, obesity, and altered levels of IGF-1, TNF-[alpha], and ADMA in the plasma, liver, or brain. (C) 2016 Wolters Kluwer Health | Lippincott Williams & Wilkins
Tags: Neurology
NeuroReport - Published Ahead-of-Print
Age-related oscillatory theta modulation of multisensory integration in frontocentral regions.
Yan, Tianyi; Bi, Xiaoshan; Zhang, Mengmeng; Wang, Wenhui; Yao, Zhiqi; Yang, Weiping; Wu, Jinglong · Wednesday, June 08, 2016, 10:54
This study used electroencephalogram measurements to investigate the effects of aging on oscillatory theta modulation during an audiovisual discrimination task. By a wavelet-based time-frequency analysis, age-related theta oscillation response differences were observed within a relatively restricted time range (0-500 ms) over frontal-central regions. Older adults showed stronger theta spectral power during visual and audiovisual stimuli in the left frontal regions; however, young adults showed stronger theta spectral power during auditory and audiovisual stimuli in the central regions. These findings suggest that multisensory oscillatory theta responses differ according to age, which further proves that the left frontal regions play an important role in audiovisual integration. (C) 2016 Wolters Kluwer Health | Lippincott Williams & Wilkins
Tags: Neurology
Journal of Neurotrauma
Adolescent Traumatic Brain Injury Induces Chronic Mesolimbic Neuroinflammation with Concurrent Enhancement in the Rewarding Effects of Cocaine in Mice during Adulthood
Steven F. Merkel · Wednesday, June 08, 2016, 7:54
Journal of Neurotrauma , Vol. 0, No. 0.
Tags: Neurology
Journal of Neurotrauma
Neuropsychiatric Symptom Modeling in Male and Female C57BL/6J Mice after Experimental Traumatic Brain Injury
Laura B. Tucker · Wednesday, June 08, 2016, 7:54
Journal of Neurotrauma , Vol. 0, No. 0.
Tags: Neurology
World Neurosurgery
Does Modern Management of Malignant Extracranial Disease Prolong Survival in Patients with ≥3 Brain Metastases?
Wednesday, June 08, 2016, 3:56
Publication date: August 2016
Source:World Neurosurgery, Volume 92
Author(s): Bengt Karlsson, Masaaki Yamamoto, Patrick Hanssens, Guus Beute, Takuya Kawabe, Takao Koiso, Michael Söderman, Keith Lim, Charles L. Rosen, Tseng Tsai Yeo
Objective To assess if modern management of extracranial malignant diseases has prolonged the survival times for patients with more than 2 brain metastases (BM). Methods Data from 2385 patients treated with Gamma Knife surgery (GKS) for ≥3 BM between 1982 and 2011 were retrospectively analyzed. The patients were divided into 6 groups based on the treatment year and the median and 10% survival times were compared with the median and mean treatment dates in each group. Results The later the treatment date, the longer the median as well as the 10% survival times. The relation between the median treatment date and both the 10% and median survival times could be accurately expressed by a linear as well as an exponential curve fit. The median and 10% survival times increased by around 80% and 150%, respectively, between 1990 and 2010. Conclusions Both the median and 10% survival times have increased in recent years among patients with more than 2 BM treated with GKS. Both linear and exponential regressions accurately expressed the increase in both median and 10% survival times during the years 1990–2010. Findings from other published data support the observation of longer survival times among patients treated more recently, independent of the patients being treated with GKS or with whole-brain radiation therapy with or without radiosurgery. Thus, earlier findings of short survival times for patients with multiple BM are no longer valid, at least not for patients deemed suitable for radiosurgery. Aggressive management is thus warranted for these patients.
Source:World Neurosurgery, Volume 92
Author(s): Bengt Karlsson, Masaaki Yamamoto, Patrick Hanssens, Guus Beute, Takuya Kawabe, Takao Koiso, Michael Söderman, Keith Lim, Charles L. Rosen, Tseng Tsai Yeo
Objective To assess if modern management of extracranial malignant diseases has prolonged the survival times for patients with more than 2 brain metastases (BM). Methods Data from 2385 patients treated with Gamma Knife surgery (GKS) for ≥3 BM between 1982 and 2011 were retrospectively analyzed. The patients were divided into 6 groups based on the treatment year and the median and 10% survival times were compared with the median and mean treatment dates in each group. Results The later the treatment date, the longer the median as well as the 10% survival times. The relation between the median treatment date and both the 10% and median survival times could be accurately expressed by a linear as well as an exponential curve fit. The median and 10% survival times increased by around 80% and 150%, respectively, between 1990 and 2010. Conclusions Both the median and 10% survival times have increased in recent years among patients with more than 2 BM treated with GKS. Both linear and exponential regressions accurately expressed the increase in both median and 10% survival times during the years 1990–2010. Findings from other published data support the observation of longer survival times among patients treated more recently, independent of the patients being treated with GKS or with whole-brain radiation therapy with or without radiosurgery. Thus, earlier findings of short survival times for patients with multiple BM are no longer valid, at least not for patients deemed suitable for radiosurgery. Aggressive management is thus warranted for these patients.
Tags: Neurology
World Neurosurgery
The AVICH Score: A Novel Grading System to Predict Clinical Outcome in Arteriovenous Malformation–Related Intracerebral Hemorrhage
Wednesday, June 08, 2016, 3:56
Publication date: August 2016
Source:World Neurosurgery, Volume 92
Author(s): Marian C. Neidert, Michael T. Lawton, Marius Mader, Burkhardt Seifert, Antonios Valavanis, Luca Regli, Oliver Bozinov, Jan-Karl Burkhardt
Objective To establish an arteriovenous malformation (AVM) grading score for patients with ruptured AVM and associated intracerebral hemorrhage (ICH) to predict clinical outcome. Methods Patient data from January 2006 to December 2013 with newly diagnosed ICH caused by ruptured AVM and a modified Rankin Scale (mRS) score <2 before ICH were included for this analysis. Clinical outcome was dichotomized in favorable (mRS score, 0–2) and unfavorable (mRS score, 3–6) to find predictors for outcome and to establish a new score based on the areas under the receiver-operating characteristic curves (AUROC) at 3 months, 1 year, and at last follow-up (mean, 31 months). Results A total of 67 patients (mean age, 41 years; 66% male) were analyzed including 39 patients with favorable and 28 with unfavorable outcome. Intraventricular hemorrhage (P = 0.048), ICH score (P = 0.003), AVM size (P < 0.001), Spetzler-Martin grade (P < 0.001), nidus structure (P = 0.005), Lawton-Young grade (P = 0.015), and supplemented Spetzler-Martin score (P < 0.001) were significant predictors for clinical outcome in ruptured AVMs. Based on these results, we created a new score named the AVICH (AVM-related ICH) score, which showed an AUROC of 0.842 compared to 0.789 for the supplemented Spetzler-Martin grading system and 0.703 for the ICH score regarding clinical outcome at last follow-up. Conclusions Based on the AUROC analysis, the AVICH score predicts outcome of patients with ruptured AVM and associated ICH better than the ICH score, the Spetzler-Martin, or the supplemented Spetzler-Martin grading system. An external validation is needed before the AVICH score is tested in a prospective multicenter cohort.
Source:World Neurosurgery, Volume 92
Author(s): Marian C. Neidert, Michael T. Lawton, Marius Mader, Burkhardt Seifert, Antonios Valavanis, Luca Regli, Oliver Bozinov, Jan-Karl Burkhardt
Objective To establish an arteriovenous malformation (AVM) grading score for patients with ruptured AVM and associated intracerebral hemorrhage (ICH) to predict clinical outcome. Methods Patient data from January 2006 to December 2013 with newly diagnosed ICH caused by ruptured AVM and a modified Rankin Scale (mRS) score <2 before ICH were included for this analysis. Clinical outcome was dichotomized in favorable (mRS score, 0–2) and unfavorable (mRS score, 3–6) to find predictors for outcome and to establish a new score based on the areas under the receiver-operating characteristic curves (AUROC) at 3 months, 1 year, and at last follow-up (mean, 31 months). Results A total of 67 patients (mean age, 41 years; 66% male) were analyzed including 39 patients with favorable and 28 with unfavorable outcome. Intraventricular hemorrhage (P = 0.048), ICH score (P = 0.003), AVM size (P < 0.001), Spetzler-Martin grade (P < 0.001), nidus structure (P = 0.005), Lawton-Young grade (P = 0.015), and supplemented Spetzler-Martin score (P < 0.001) were significant predictors for clinical outcome in ruptured AVMs. Based on these results, we created a new score named the AVICH (AVM-related ICH) score, which showed an AUROC of 0.842 compared to 0.789 for the supplemented Spetzler-Martin grading system and 0.703 for the ICH score regarding clinical outcome at last follow-up. Conclusions Based on the AUROC analysis, the AVICH score predicts outcome of patients with ruptured AVM and associated ICH better than the ICH score, the Spetzler-Martin, or the supplemented Spetzler-Martin grading system. An external validation is needed before the AVICH score is tested in a prospective multicenter cohort.
Tags: Neurology
World Neurosurgery
Expanding the Horizon of the Suboccipital Retrosigmoid Approach to the Middle Incisural Space by Cutting the Tentorium Cerebelli: Anatomic Study and Illustration of 2 Cases
Wednesday, June 08, 2016, 3:56
Publication date: August 2016
Source:World Neurosurgery, Volume 92
Author(s): Roberto Colasanti, Al-Rahim Abbasali Tailor, Jun Zhang, Mario Ammirati
Objective Complex skull base approaches are often used to treat lesions within the middle incisural space; yet the well-known retrosigmoid route may provide an effective avenue to this difficult-to-reach region. The purpose of this study was to quantify the exposure advantages on the middle incisural space provided by cutting of the tentorium cerebelli via a standard suboccipital retrosigmoid approach (i.e., via the cerebellopontine cistern route). Also, 2 illustrative cases are presented. Methods A suboccipital retrosigmoid approach to the middle incisural space was performed bilaterally in 3 specimens in the semisitting position. A quantitative analysis of the brainstem surface exposed above the origin of the trigeminal nerve was performed before and after tentorial incision. Results Tentorial cutting significantly improved the exposure of the middle incisural space cisternal structures such as the oculomotor and trochlear nerves and the superior cerebellar and posterior cerebral arteries. The mean brainstem surface exposed more than doubled (2.13-fold increase) after tentorial incision with an average increase from 73.18 mm2 to 155.76 mm2. When the endoscope was used, it was possible to follow the entire course of the cisternal, infratentorial trochlear nerve segment during the opening of the tentorial free edge, facilitating its preservation. In the illustrative cases, 2 cerebellopontine angle meningiomas with supratentorial and infratentorial extension were removed without any postoperative complication. Conclusions Tentorial incision may be useful to extend the rostral exposure of the middle incisural space via a simple retrosigmoid approach, avoiding the need for more complex skull base routes.
Source:World Neurosurgery, Volume 92
Author(s): Roberto Colasanti, Al-Rahim Abbasali Tailor, Jun Zhang, Mario Ammirati
Objective Complex skull base approaches are often used to treat lesions within the middle incisural space; yet the well-known retrosigmoid route may provide an effective avenue to this difficult-to-reach region. The purpose of this study was to quantify the exposure advantages on the middle incisural space provided by cutting of the tentorium cerebelli via a standard suboccipital retrosigmoid approach (i.e., via the cerebellopontine cistern route). Also, 2 illustrative cases are presented. Methods A suboccipital retrosigmoid approach to the middle incisural space was performed bilaterally in 3 specimens in the semisitting position. A quantitative analysis of the brainstem surface exposed above the origin of the trigeminal nerve was performed before and after tentorial incision. Results Tentorial cutting significantly improved the exposure of the middle incisural space cisternal structures such as the oculomotor and trochlear nerves and the superior cerebellar and posterior cerebral arteries. The mean brainstem surface exposed more than doubled (2.13-fold increase) after tentorial incision with an average increase from 73.18 mm2 to 155.76 mm2. When the endoscope was used, it was possible to follow the entire course of the cisternal, infratentorial trochlear nerve segment during the opening of the tentorial free edge, facilitating its preservation. In the illustrative cases, 2 cerebellopontine angle meningiomas with supratentorial and infratentorial extension were removed without any postoperative complication. Conclusions Tentorial incision may be useful to extend the rostral exposure of the middle incisural space via a simple retrosigmoid approach, avoiding the need for more complex skull base routes.
Tags: Neurology
World Neurosurgery
Presigmoid Approach to Vertebrobasilar Artery Aneurysms: A Series of 31 Patients and Review of the Literature
Wednesday, June 08, 2016, 3:56
Publication date: August 2016
Source:World Neurosurgery, Volume 92
Author(s): Mardjono Tjahjadi, Mika Niemelä, Juri Kivelev, Joseph Serrone, Hidetsugu Maekawa, Behnam Rezai Jahromi, Oleg Kerro, Ahmad Hafez, Hanna Lehto, Riku Kivisaari, Juha Hernesniemi
Objective The presigmoid approach can be used to treat vertebrobasilar artery aneurysms when circumstances require more operative exposure. High morbidity and mortality in these cases have been reported. In this study, we describe our modified presigmoid approach for vertebrobasilar artery aneurysms and our clinical results. Methods This series includes patients with vertebrobasilar aneurysms clipped via the modified presigmoid approach at the Department of Neurosurgery at Helsinki University Hospital from 1998 to 2014. Data were collected from the operating record books, patients' medical records, and a radiologic database server. Results Thirty-three presigmoid procedures of 31 patients were performed to treat 34 aneurysms (14 ruptured, 20 unruptured). The aneurysms had a mean distance from the posterior clinoid process to the aneurysm neck of 12.2 mm (range, 0–26.6 mm). A favorable outcome was achieved in 21 patients (64%). A favorable outcome was achieved in 74% of unruptured and good-grade patients, whereas favorable outcome was achieved in only 36% of poor-grade patients. Complete or near-complete occlusion was achieved in 79%. Larger aneurysms, fusiform morphology, and anterior dome projection had lower occlusion rates. Conclusions We have described our experiences of using the presigmoid approach to treat vertebrobasilar aneurysms. The clinical and radiographic results are acceptable given the complex location and configuration of the treated aneurysms. Unfavorable outcomes are related to the poor admission Hunt and Hess grade, aneurysm morphology, and aneurysm size.
Source:World Neurosurgery, Volume 92
Author(s): Mardjono Tjahjadi, Mika Niemelä, Juri Kivelev, Joseph Serrone, Hidetsugu Maekawa, Behnam Rezai Jahromi, Oleg Kerro, Ahmad Hafez, Hanna Lehto, Riku Kivisaari, Juha Hernesniemi
Objective The presigmoid approach can be used to treat vertebrobasilar artery aneurysms when circumstances require more operative exposure. High morbidity and mortality in these cases have been reported. In this study, we describe our modified presigmoid approach for vertebrobasilar artery aneurysms and our clinical results. Methods This series includes patients with vertebrobasilar aneurysms clipped via the modified presigmoid approach at the Department of Neurosurgery at Helsinki University Hospital from 1998 to 2014. Data were collected from the operating record books, patients' medical records, and a radiologic database server. Results Thirty-three presigmoid procedures of 31 patients were performed to treat 34 aneurysms (14 ruptured, 20 unruptured). The aneurysms had a mean distance from the posterior clinoid process to the aneurysm neck of 12.2 mm (range, 0–26.6 mm). A favorable outcome was achieved in 21 patients (64%). A favorable outcome was achieved in 74% of unruptured and good-grade patients, whereas favorable outcome was achieved in only 36% of poor-grade patients. Complete or near-complete occlusion was achieved in 79%. Larger aneurysms, fusiform morphology, and anterior dome projection had lower occlusion rates. Conclusions We have described our experiences of using the presigmoid approach to treat vertebrobasilar aneurysms. The clinical and radiographic results are acceptable given the complex location and configuration of the treated aneurysms. Unfavorable outcomes are related to the poor admission Hunt and Hess grade, aneurysm morphology, and aneurysm size.
Tags: Neurology
World Neurosurgery
Preoperative and Postoperative Factors and Laboratory Values Predicting Outcome in Patients Undergoing Lumbar Fusion Surgery
Wednesday, June 08, 2016, 3:56
Publication date: August 2016
Source:World Neurosurgery, Volume 92
Author(s): Severina Leu, Maria Kamenova, Arne Mehrkens, Luigi Mariani, Stefan Schären, Jehuda Soleman
Objective To determine whether complications in lumbar fusion surgery could be estimated from patient factors and perioperative laboratory values. In addition, risk scores for detection of patients prone to complications were defined. Methods We retrospectively collected data of patients undergoing lumbar fusion surgery between 2013 and 2015. The patients were divided into group A (no complications) and group B (systemic and infectious complications within 30 days postoperatively). Patient-related factors and levels of perioperative laboratory values were compared between the groups and analyzed for possible impact on complications and length of stay (LOS) in the hospital. Results Data of 132 consecutive patients (74 women [56.1%]; median age, 68.5 years) were analyzed. Postoperative complications occurred in 29.5%. Higher postoperative creatine kinase (CK) and C-reactive protein and lower postoperative hemoglobin and thrombocyte values, as well as higher differences between preoperative and postoperative CK, C-reactive protein, and hemoglobin values were associated with postoperative complications. Among others, the combinations of advanced age and elevated body mass index (P = 0.0062, odds ratio: 3.018), or advanced age, elevated body mass index, and postoperative CK >166 U/L (P = 0.0016, odds ratio: 3.637) revealed patients with a threefold risk for complications. The combination of advanced age, American Society of Anesthesiologists score >2, and preoperative hemoglobin <12.9 g/dL was associated with a LOS of 20.3 versus 11 days (P = 0.01). Conclusions Patients with postoperative complications and extended LOS seem to show significant differences in various perioperative laboratory values and patient factors. Perioperative risk assessments using cut-off values and risk scores may help identify patients prone to complications and extended resource use.
Source:World Neurosurgery, Volume 92
Author(s): Severina Leu, Maria Kamenova, Arne Mehrkens, Luigi Mariani, Stefan Schären, Jehuda Soleman
Objective To determine whether complications in lumbar fusion surgery could be estimated from patient factors and perioperative laboratory values. In addition, risk scores for detection of patients prone to complications were defined. Methods We retrospectively collected data of patients undergoing lumbar fusion surgery between 2013 and 2015. The patients were divided into group A (no complications) and group B (systemic and infectious complications within 30 days postoperatively). Patient-related factors and levels of perioperative laboratory values were compared between the groups and analyzed for possible impact on complications and length of stay (LOS) in the hospital. Results Data of 132 consecutive patients (74 women [56.1%]; median age, 68.5 years) were analyzed. Postoperative complications occurred in 29.5%. Higher postoperative creatine kinase (CK) and C-reactive protein and lower postoperative hemoglobin and thrombocyte values, as well as higher differences between preoperative and postoperative CK, C-reactive protein, and hemoglobin values were associated with postoperative complications. Among others, the combinations of advanced age and elevated body mass index (P = 0.0062, odds ratio: 3.018), or advanced age, elevated body mass index, and postoperative CK >166 U/L (P = 0.0016, odds ratio: 3.637) revealed patients with a threefold risk for complications. The combination of advanced age, American Society of Anesthesiologists score >2, and preoperative hemoglobin <12.9 g/dL was associated with a LOS of 20.3 versus 11 days (P = 0.01). Conclusions Patients with postoperative complications and extended LOS seem to show significant differences in various perioperative laboratory values and patient factors. Perioperative risk assessments using cut-off values and risk scores may help identify patients prone to complications and extended resource use.
Tags: Neurology
World Neurosurgery
Study of Changing Intracranial Venous Drainage Patterns in Petroclival Meningioma
Wednesday, June 08, 2016, 3:56
Publication date: August 2016
Source:World Neurosurgery, Volume 92
Author(s): Kazuhide Adachi, Motoharu Hayakawa, Kohei Ishihara, Tukasa Ganaha, Shinya Nagahisa, Mituhiro Hasegawa, Yuichi Hirose
Objective To elucidate venous drainage patterns to avoid damage to the venous drainage route in the middle cranial fossa and superior petrosal sinus when employing the transpetrosal approach. Methods Venous drainage patterns were assessed using three-dimensional computed tomography venography in 22 hemispheres of petroclival meningioma (PCM) cases from patients who underwent primary surgery and 40 hemispheres of control cases. Intracranial venous drainage patterns were compared between control cases and PCM cases. Results The proportion of hemispheres with complete and medial superior petrosal sinus drainage patterns was lower in PCM cases. With regard to the superficial middle cerebral vein drainage pattern, the proportion of hemispheres with the cavernous sinus capture type was lower and the proportion with the emissary type was higher in PCM cases. The proportion of hemispheres with multiple greater anastomoses of the superficial middle cerebral vein was higher in PCM cases without the emissary-type and cavernous sinus capture-type patterns. When the venous drainage route of the cavernous sinus capture type and/or emissary type was disturbed, in particular, greater anastomosis via the vein of Labbè and the vein of Trolard was needed to control venous drainage flow. Conclusions In cases of venous drainage impairment secondary to PCM progression, the drainage route changed to the pterygoid plexus route through the emissary foramen and/or superior sagittal sinus and to the transverse sinus route through the greater anastomosis of the superficial middle cerebral vein. In the anterior transpetrosal approach, peeling off the dura propria of the trigeminal nerve of the foramen rotundum for petrous apex exposure may be associated with the potential risk of pterygoid plexus drainage route impairment.
Source:World Neurosurgery, Volume 92
Author(s): Kazuhide Adachi, Motoharu Hayakawa, Kohei Ishihara, Tukasa Ganaha, Shinya Nagahisa, Mituhiro Hasegawa, Yuichi Hirose
Objective To elucidate venous drainage patterns to avoid damage to the venous drainage route in the middle cranial fossa and superior petrosal sinus when employing the transpetrosal approach. Methods Venous drainage patterns were assessed using three-dimensional computed tomography venography in 22 hemispheres of petroclival meningioma (PCM) cases from patients who underwent primary surgery and 40 hemispheres of control cases. Intracranial venous drainage patterns were compared between control cases and PCM cases. Results The proportion of hemispheres with complete and medial superior petrosal sinus drainage patterns was lower in PCM cases. With regard to the superficial middle cerebral vein drainage pattern, the proportion of hemispheres with the cavernous sinus capture type was lower and the proportion with the emissary type was higher in PCM cases. The proportion of hemispheres with multiple greater anastomoses of the superficial middle cerebral vein was higher in PCM cases without the emissary-type and cavernous sinus capture-type patterns. When the venous drainage route of the cavernous sinus capture type and/or emissary type was disturbed, in particular, greater anastomosis via the vein of Labbè and the vein of Trolard was needed to control venous drainage flow. Conclusions In cases of venous drainage impairment secondary to PCM progression, the drainage route changed to the pterygoid plexus route through the emissary foramen and/or superior sagittal sinus and to the transverse sinus route through the greater anastomosis of the superficial middle cerebral vein. In the anterior transpetrosal approach, peeling off the dura propria of the trigeminal nerve of the foramen rotundum for petrous apex exposure may be associated with the potential risk of pterygoid plexus drainage route impairment.
Tags: Neurology
World Neurosurgery
Neuroendoscopy in Kuwait: Evolution, Current Status, and Future Directions
Wednesday, June 08, 2016, 3:56
Publication date: August 2016
Source:World Neurosurgery, Volume 92
Author(s): Waleed A. Azab, Ahmed Y. Abdelrahman, Tarik M. Alsheikh, Mostafa M. Najibullah
An overview of the development of neuroendoscopy at the neurosurgery department, Ibn Sina Hospital in Kuwait, is presented with an outline of difficulties and obstacles faced by the field until it reached its current status. The factors and solutions that helped us overcome these problems are also elaborated on. After a modest beginning few years ago, endoscopic skull base procedures, intraventricular neuroendoscopy, and spinal endoscopy are regularly performed in the department. Although neuroendoscopy is not per se a neurosurgical subspecialty, it is an area that requires special training. Achieving an appropriate level of care necessitates these highly trained neurosurgeons to collaborate together and with other specialties to create teamsgeared towards offering such treatment options topatients. Importantly, a multitude of essential facilities should be available to make such a pattern of practice possible. In our experience, this was made possible through continued efforts that have finally paid off and gradually led to a complete shift of the face of neuroendoscopic practice in our department. Our future endeavors aim at further development of neuroendoscopy in the department to create a center of excellence.
Source:World Neurosurgery, Volume 92
Author(s): Waleed A. Azab, Ahmed Y. Abdelrahman, Tarik M. Alsheikh, Mostafa M. Najibullah
An overview of the development of neuroendoscopy at the neurosurgery department, Ibn Sina Hospital in Kuwait, is presented with an outline of difficulties and obstacles faced by the field until it reached its current status. The factors and solutions that helped us overcome these problems are also elaborated on. After a modest beginning few years ago, endoscopic skull base procedures, intraventricular neuroendoscopy, and spinal endoscopy are regularly performed in the department. Although neuroendoscopy is not per se a neurosurgical subspecialty, it is an area that requires special training. Achieving an appropriate level of care necessitates these highly trained neurosurgeons to collaborate together and with other specialties to create teamsgeared towards offering such treatment options topatients. Importantly, a multitude of essential facilities should be available to make such a pattern of practice possible. In our experience, this was made possible through continued efforts that have finally paid off and gradually led to a complete shift of the face of neuroendoscopic practice in our department. Our future endeavors aim at further development of neuroendoscopy in the department to create a center of excellence.
Tags: Neurology
Latest Results for Child's Nervous System
The deepithelialized skin flap for closure of large myelomeningoceles: a common plastic surgery technique for a novel neurosurgery application
Tuesday, June 07, 2016, 23:42
Abstract
Purpose
The study aims to demonstrate proof of principle of a common plastic surgery technique of deepithelialization for repair of large myelomeningoceles (MMCs). Whereas repair typically consists of a watertight dural closure followed by a muscle or fasciocutaeneous layer, excess skin, however, need not be discarded and can be deepithelialized to augment or, in selective cases, replace the muscle repair.
Methods
The study was performed through a retrospective chart review of two patients.
Results
Step-by-step figures illustrate the technique. Two patients each born with large MMCs measuring 10 × 11 cm and 6 × 9 cm, respectively, were reviewed. Excess skin was deepithelialized to create an additional layer of vascularized tissue over the muscle repair. There were no post-operative complications at 3-month follow-up.
Conclusions
In large MMCs with excess skin, the use of a deepithelialized skin flap can potentially be an alternative or adjunct to a muscle flap to buttress the dural repair.
Tags: Neurology
Latest Results for Child's Nervous System
Extensive miRNA expression analysis in craniopharyngiomas
Tuesday, June 07, 2016, 23:42
Abstract
Purpose
Craniopharyngiomas are benign tumors of the sellar or parasellar regions. They arise from the remnants of Rathke's pouch and are considered a "developmental disease." microRNAs are short non-coding RNAs that play a key regulatory role in the control of expression of entire gene networks. We performed an extensive analysis of miRNAs in craniopharyngiomas aiming to identify a miRNA expression signature that might aid in the prognosis of disease progression and outcome.
Methods
Thirty-seven craniopharyngioma samples from twenty-three patients, ten age-matched controls from autopsy, and ten infant controls from the developing pituitary from autopsy were evaluated for the expression of 754 miRNAs using TaqMan® Low Density Arrays (TLDAs) v2.0 (Applied Biosystems, Foster City, CA).
Results
Among the most differentially expressed miRNAs, downregulation of miR-132 appears to be a marker of aggressiveness and also plays a role in epithelial–mesenchymal transition.
Conclusions
This is the first time that an extensive study of miRNA expression has been performed in craniopharyngiomas. Further research needs to be performed to investigate the potential role of miR-132 in the development and progression of craniopharyngiomas, and its value as a prognostic marker of aggressiveness.
Tags: Neurology
Neuro-Oncology
Impact of IDH1 mutation status on outcome in clinical trials for recurrent glioblastoma
Tuesday, June 07, 2016, 23:14
Abstract
IDH1 mutated glioblastoma (GB) has a better prognosis than IDH1 wildtype GB. However, it remains unknown whether patients (pts) with IDH1 mutated GB have a higher 6-month progression free survival (PFS6) or radiographic response (RR) rate on clinical trials for recurrence. Retrospective review of GB pts at MDACC between 2006 and 2012 identified 330 patients in recurrent GB trials. 93 patients (28 %) had either PFS6 or a complete/partial RR per RANO criteria. 49/93 (53 %) patients with PFS6 or a complete/partial RR had tumor tissue for IDH1 testing. A matched cohort of 49 patients on recurrent GB clinical trials that failed to achieve PFS6 or RR (also with tissue for IDH1 testing) was identified for comparison. IDH1 status was obtained in 92/98 (94 %) patients of which 17 (18 %) had an IDH1 mutation. PFS6 was seen in 26/49 (53 %) patients. IDH status was unknown in two of these patients. 5/24 (21 %) were IDH1 mutated compared to 5/24 (21 %) of their matched cohort without PFS6. RR was found in 47/49 (94 %) patients. IDH status was unknown in four of these patients. IDH1 mutation was present in 7/43 (16 %) patients with RR compared to 10/43 (23 %) in the matched cohort without RR (p = 0.48). Median OS for trials at first recurrence was 9.8 months for IDH1 wildtype GB vs. 19.32 months for IDH1 mutated GB (p = 0.14). IDH1 mutation status was not predictive of PFS6 or RR in recurrent GB trials for this data set. However, further examination in larger randomized prospective studies is needed.
Tags: Cancer, Neurology
Behavioural Brain Research
The anatomy of empathy: Vicarious experience and disorders of social cognition
Tuesday, June 07, 2016, 22:58
Publication date: 15 September 2016
Source:Behavioural Brain Research, Volume 311
Author(s): Patricia L. Lockwood
Empathy, the ability to vicariously experience and to understand the affect of other people, is fundamental for successful social-cognitive ability and behaviour. Empathy is thought to be a critical facilitator of prosocial behaviour and is disrupted in a number of psychiatric and neurological disorders. Research has begun to uncover the neural basis of such 'vicarious experience', which has been studied as a proxy measure of empathy. Together, these studies have identified portions of the insula and anterior cingulate cortex as critically involved. A key debate is whether overlapping or non-overlapping brain areas respond to personal and vicarious experience. This review will highlight emerging evidence for both types of brain response. Importantly, animal models have suggested that there are central divisions between the anterior cingulate gyrus and anterior cingulate sulcus that may be crucial for understanding social behaviour. Attention to this specific anatomy of vicarious processing could therefore help shed light on the functional profile of empathy. Studies in individuals with psychopathy and autism spectrum disorders have found that vicarious experience is atypical. However, the precise nature of these atypicalities is mixed. Understanding the mechanisms of vicarious experience can enhance our knowledge of the neural basis of empathy and, ultimately, help those with disorders of social cognition and behaviour.
Source:Behavioural Brain Research, Volume 311
Author(s): Patricia L. Lockwood
Empathy, the ability to vicariously experience and to understand the affect of other people, is fundamental for successful social-cognitive ability and behaviour. Empathy is thought to be a critical facilitator of prosocial behaviour and is disrupted in a number of psychiatric and neurological disorders. Research has begun to uncover the neural basis of such 'vicarious experience', which has been studied as a proxy measure of empathy. Together, these studies have identified portions of the insula and anterior cingulate cortex as critically involved. A key debate is whether overlapping or non-overlapping brain areas respond to personal and vicarious experience. This review will highlight emerging evidence for both types of brain response. Importantly, animal models have suggested that there are central divisions between the anterior cingulate gyrus and anterior cingulate sulcus that may be crucial for understanding social behaviour. Attention to this specific anatomy of vicarious processing could therefore help shed light on the functional profile of empathy. Studies in individuals with psychopathy and autism spectrum disorders have found that vicarious experience is atypical. However, the precise nature of these atypicalities is mixed. Understanding the mechanisms of vicarious experience can enhance our knowledge of the neural basis of empathy and, ultimately, help those with disorders of social cognition and behaviour.
Tags: Neurology
Behavioural Brain Research
Insulin potentiates the therapeutic effect of memantine against central STZ-induced spatial learning and memory deficit
Tuesday, June 07, 2016, 22:58
Publication date: 15 September 2016
Source:Behavioural Brain Research, Volume 311
Author(s): Abbas Bahramian, Karim Rastegar, Mohammad Reza Namavar, Maryam Moosavi
Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder. Memantine has been approved for moderate to severe AD, but evidence indicates that it does not modify disease progression. Recently insulin has been found to exert some beneficial effects on cognition. This study aimed to compare the protective effects of memantine and insulin in an animal model of memory deficit. It also evaluated the effects of combination therapy of these drugs. Adult male Sprague-Dawely rats approximately 8–10 weeks old were used. The canules were implanted bilaterally into lateral ventricles. STZ was administered on days 1 and 3 (3mg/kg in divided doses) and Memantine (5 or 10mg/kg/ip) or/and Insulin (3 or 6mU/icv) were started from day 4 and continued till day 13. The animal's learning and memory capability was assessed on days 14–16 using Morris water maze. On day 17 a visible platform test was done to assess the animals' visuomotor ability. After completion of behavioral studies the brain sections were stained with hematoxylin and eosin for routine histological evaluation. The results show that memantine in doses 5 and 10mg/kg improved memory at day 3 of training and memantine 5mg/kg was more potent than memantine 10mg/kg. Insulin in dose 3mU, but not 6 mU, reversed STZ-induced memory deficit from day 2 of training. When insulin was added to memantine, it increased the potency of memantine 5mg/kg in preventing a memory deficit, but surprisingly was not successful in impeding STZ-induced amnesia, in combination with memantine 10mg/kg. This research work revealed that insulin act more efficiently than memantine in reversing STZ-induced memory impairment. Additionally combination of insulin and memantine seems to act better than memantine alone, providing that a dose adjustment has been done. This study suggests considering the combination therapy of memantine and insulin in dementia and AD.
Source:Behavioural Brain Research, Volume 311
Author(s): Abbas Bahramian, Karim Rastegar, Mohammad Reza Namavar, Maryam Moosavi
Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder. Memantine has been approved for moderate to severe AD, but evidence indicates that it does not modify disease progression. Recently insulin has been found to exert some beneficial effects on cognition. This study aimed to compare the protective effects of memantine and insulin in an animal model of memory deficit. It also evaluated the effects of combination therapy of these drugs. Adult male Sprague-Dawely rats approximately 8–10 weeks old were used. The canules were implanted bilaterally into lateral ventricles. STZ was administered on days 1 and 3 (3mg/kg in divided doses) and Memantine (5 or 10mg/kg/ip) or/and Insulin (3 or 6mU/icv) were started from day 4 and continued till day 13. The animal's learning and memory capability was assessed on days 14–16 using Morris water maze. On day 17 a visible platform test was done to assess the animals' visuomotor ability. After completion of behavioral studies the brain sections were stained with hematoxylin and eosin for routine histological evaluation. The results show that memantine in doses 5 and 10mg/kg improved memory at day 3 of training and memantine 5mg/kg was more potent than memantine 10mg/kg. Insulin in dose 3mU, but not 6 mU, reversed STZ-induced memory deficit from day 2 of training. When insulin was added to memantine, it increased the potency of memantine 5mg/kg in preventing a memory deficit, but surprisingly was not successful in impeding STZ-induced amnesia, in combination with memantine 10mg/kg. This research work revealed that insulin act more efficiently than memantine in reversing STZ-induced memory impairment. Additionally combination of insulin and memantine seems to act better than memantine alone, providing that a dose adjustment has been done. This study suggests considering the combination therapy of memantine and insulin in dementia and AD.
Tags: Neurology
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from #Med Blogs by Alexandros G.Sfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/1ZNLAjY
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