Simple dichotomous assessment of cranial artery inflammation by conventional 18F-FDG PET/CT shows high accuracy for the diagnosis of giant cell arteritis: a case-control study

Abstract

Purpose

To estimate the diagnostic accuracy of conventional 18F-FDG PET/CT of cranial arteries in the diagnosis of giant cell arteritis (GCA).

Methods

The study was a retrospective case-control study. The reference diagnosis was fulfillment of the 1990 ACR criteria for GCA. All patients had new-onset GCA. Conventional 18F-FDG PET/CT was performed before glucocorticoid treatment. Controls were age- and sex-matched patients with a previous history of malignant melanoma (MM) undergoing surveillance PET/CT >6 months after MM resection. PET images were evenly cropped to include only head and neck and were assessed in random order by four nuclear medicine physicians blinded to reference diagnosis. Temporal (TA), maxillary (MA) and vertebral (VA) arteries were visually rated for 18F-FDG uptake. Interreader agreement was evaluated by Fleiss kappa.

Results

A total of 44 patients and 44 controls were identified. In both groups, the mean age was 69 years (p = 0.45) and 25/44 were women. 35/41 GCA patients were temporal artery biopsy positive (TAB). Considering only FDG uptake in TA and/or MA, diagnostic sensitivity and specificity was 64 and 100%. Including VA, sensitivity increased to 82% and specificity remained 100%. Interreader agreement was 91% and Fleiss kappa 0.82 for the PET diagnosis based on the cranial arteries.

Conclusion

Conventional 18F-FDG PET/CT is an accurate and reliable tool to diagnose cranial arteritis in glucocorticoid-naïve GCA patients. The high diagnostic specificity suggests that TAB can be omitted in patients with 18F-FDG uptake in cranial arteries. 18F-FDG PET/CT performed in patients with suspected vasculitis should always include the head and neck.

https://ift.tt/2OuAeCx

Antitumor virotherapy using syngeneic or allogeneic mesenchymal stem cell carriers induces systemic immune response and intratumoral leukocyte infiltration in mice

Abstract

Oncolytic virotherapy uses oncolytic viruses that selectively replicate in cancer cells. The use of cellular vehicles with migration ability to tumors has been considered to increase their delivery to target sites. Following this approach, the antitumor efficacy of the treatment Celyvir (mesenchymal stem cells infected with the oncolytic adenovirus ICOVIR-5) has been demonstrated in patients with neuroblastoma. However, the better efficacy of syngeneic or allogeneic mesenchymal stem cells as cell carriers and the specific role of the immune system in this therapy are still unknown. In this study we use our virotherapy Celyvir with syngeneic and allogeneic mouse mesenchymal stem cells to determine their antitumor efficacy in a C57BL/6 murine adenocarcinoma model. Adoptive transfer of splenocytes from treated mice to new tumor-bearing mice followed by a secondary adoptive transfer to a third group was performed. Similar reduction of tumor growth and systemic activation of the innate and adaptive immune system was observed in groups treated with syngeneic or allogeneic mesenchymal stem cells loaded with ICOVIR-5. Moreover, a different pattern of infiltration was observed by immunofluorescence in Celyvir-treated groups. While non-treated tumors presented higher density of infiltrating immune cells in the periphery of the tumor, both syngeneic and allogeneic Celyvir-treated groups presented higher infiltration of CD45+ cells in the core of the tumor. Therefore, these results suggest that syngeneic and allogeneic Celyvir induce systemic activation of the immune system, similar antitumor effect and a higher intratumoral infiltration of leukocytes.

https://ift.tt/2vqwtFE

Processing number and length in the parietal cortex: sharing resources, not a common code

Publication date: Available online 31 July 2018

Source: Cortex

Author(s): Valentina Borghesani, Maria Dolores de Hevia, Arnaud Viarouge, Pedro Pinheiro Chagas, Evelyn Eger, Manuela Piazza

Abstract

A current intense discussion in numerical cognition concerns the relationship between the processing of numerosity and other non-numerical quantities. In particular, it is a matter of debate whether number and other quantities (e.g. size, length) are represented separately in the brain or whether they share a common generalized magnitude representation. We acquired high-resolution functional MRI data while adult subjects engaged in a magnitude comparison task involving either numerosity (i.e., which of the two sets has more elements?) or line length (i.e., which of the two lines is longer?). We compared the activation evoked by the two different types of quantity and observed a common recruitment of a vast portion of occipital and parietal cortices. Using MVPA, we demonstrated that some of the commonly activated regions represented the discrete and continuous quantities via a similar distance-dependent magnitude code. However, we found no effect of distance across the two quantity representations, failing to support the existence of a common, dimension invariant, generalized quantity code. Taken together, these findings indicate that although the processing of number and length is supported by partially overlapping neural resources, representations within these regions do not appear to be based on a common neural code.

https://ift.tt/2mXiWkU

Cognitive and neural markers of super-recognisers’ face processing superiority and enhanced cross-age effect

Publication date: Available online 31 July 2018

Source: Cortex

Author(s): Elena Belanova, Josh P. Davis, Trevor Thompson

Abstract

Super-recognisers inhabit the extreme high end of an adult face processing ability spectrum in the population. While almost all research in this area has evaluated those with poor or mid-range abilities, evaluating whether super-recognisers' superiority generates distinct electrophysiological brain activity, and transcends to different age group faces (i.e., children's) is important for enhancing theoretical understanding of normal and impaired face processing. It may also be crucial for policing, as super-recognisers may be deployed to operations involving child identification and protection. In Experiment 1, super-recognisers (n = 315) outperformed controls (n = 499) at adult and infant face recognition, while also displaying larger cross-age effects. These findings were replicated in Experiment 2 (super-recognisers, n = 19; controls, n = 28), although one SR with frequent infant exposure showed no cross-age effect. Compared to controls, super-recognisers also generated significantly greater electrophysiological activity in event-related potentials associated with pictorial processing (P1) and explicit recognition (P600). Experiment 3, employing an upright and inverted sequential matching design found super-recognisers (n = 24) outperformed controls (n = 20) at adult and infant face matching, but showed no upright cross-age matching effects. Instead, they displayed larger inversion effects, and cross-age inversion effects, implicating the role of holistic processing in their perceptual superiority. Larger cross-age effects in recognition, but not matching suggests that super-recognisers' adult face recognition is partly driven by experience. However, their enhanced infant face recognition suggest super-recognisers' superiority is also experience-independent, results that have implications for policing and for models of face recognition.

https://ift.tt/2M5tCZF

Arithmetic learning modifies the functional connectivity of the fronto-parietal network

Publication date: Available online 31 July 2018

Source: Cortex

Author(s): Hui Zhao, Xiaoxi Li, Vyacheslav Karolis, Yi Feng, Haijing Niu, Brian Butterworth

Abstract

How Resting-State Functional Connectivity (RSFC) is modified by learning is an important but rarely asked question. Here we used functional near-infrared spectroscopy (fNIRS) to measure changes in RSFC after learning novel subtraction and multiplication facts by forty-one young adult volunteers. We also measured changes in regional hemoglobin concentration. Fronto-parietal RSFC was modified by arithmetic learning and the fronto-parietal RSFC configuration before learning predicted the effectiveness of arithmetic learning. We also found a significant learning effect indicated by a monotonic decrease in reaction time and an increase in accuracy. Regional task-dependent oxy-hemoglobin concentration differentiated subtraction from multiplication learning supporting previous fMRI findings. These results suggest the sensitivity and importance of fronto-parietal connectivity to arithmetic learning.

https://ift.tt/2mXvicI

The cerebellar topography of attention sub-components in spinocerebellar ataxia type 2

Publication date: Available online 31 July 2018

Source: Cortex

Author(s): M. Lupo, G. Olivito, C. Iacobacci, S. Clausi, S. Romano, M. Masciullo, M. Molinari, M. Cercignani, M. Bozzali, M. Leggio

Abstract

Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominant neurodegenerative disease characterized by a progressive cerebellar syndrome and multiple-domain cognitive impairments. The cerebellum is known to contribute to distinct functional networks related to higher-level functions. The aims of the present study were to investigate the different sub-components of attention and to analyse possible correlations between attention deficits and specific cerebellar regions in SCA2 patients.

To this purpose, 11 SCA2 patients underwent an exhaustive attention battery that evaluated several attention sub-components. The SCA2 group performed below the normal range in tasks assessing selective attention, divided attention, and sustained attention, obtaining negative Z-scores. These results were confirmed by non-parametric Mann-Whitney U tests that showed significant differences between SCA2 and control subjects in the same sub-components of the attention battery, allowing us to speculate on cerebellar involvement when a high cognitive demand is required (i.e., multisensory integration, sequencing, prediction of events, and inhibition of inappropriate response behaviours).

The voxel-based morphometry analysis showed a pattern of significantly reduced grey matter volume in specific cerebellar lobules. In particular, the SCA2 patients showed significant grey matter loss in bilateral regions of the anterior cerebellar hemisphere (I-V) and in the posterior lobe (VI-IX) and posterior vermis (VI-IX).

Statistical analysis found significant correlations between grey matter reductions in the VIIb/VIIIa cerebellar lobules and impairments in Sustained and Divided Attention tasks and between grey matter reduction in the vermal VI lobule and impairment in the Go/NoGo task.

For the first time, the study demonstrated the involvement of specific cerebellar lobules in different sub-components of the attention domain, giving further support to the inclusion of the cerebellum within the attention network.

https://ift.tt/2KdHPBV

Neural signatures of inhibitory control in bilingual spoken production

Publication date: Available online 31 July 2018

Source: Cortex

Author(s): Eleonora Rossi, Sharlene Newman, Judith F. Kroll, Michele Diaz

Abstract

Bilinguals activate both languages when they intend to speak even one language alone (e.g., Kroll et al., 2006). At the same time, they are able to select the language they intend to speak and switch back and forth between languages rapidly, with few production errors. Previous research utilizing behavioral (Linck et al., 2009) and neuroimaging techniques (ERPs and fMRI; Guo et al., 2011; Misra et al., 2012) suggest that successful bilingual speech production is enabled by active inhibition of the language not in use. Results showing an asymmetric switching cost for the L1 compared to the L2 (with a larger cost -reflected in longer naming latencies-when switching from the L2 to the L1) have been taken as evidence that the L1 (usually the dominant language for bilinguals who learned their second language later in life) may need to be inhibited when speaking in the L2. However, there is still little research on the scope of this inhibitory process. The goal of this event-related functional magnetic resonance imaging study is to understand how the recruitment of neural areas implicated during bilingual language processing are shaped by the scope of language use. The results show that bilinguals engage a wide functional control network that is hierarchically engaged in local control for single lexical items, but extends further to the broader semantic level, and finally to the whole language. This functional network is modulated by proficiency in the L2.

https://ift.tt/2LHgii7