Adaptation of The Scenario Test for Greek-speaking people with aphasia: A reliability and validity study.

BACKGROUND: Evidence-based assessments for people with aphasia (PWA) in Greek are predominantly impairment based. Functional communication (FC) is usually underreported and neglected by clinicians. This study explores the adaptation and psychometric testing of the Greek (GR) version of The Scenario Test. The test assesses the everyday FC of PWA in an interactive multimodal communication setting. AIMS: To determine the reliability and validity of The Scenario Test-GR and discuss its clinical value. METHODS & PROCEDURES: The Scenario Test-GR was administered to 54 people with chronic stroke (6+ months post-stroke): 32 PWA and 22 stroke survivors without aphasia. Participants were recruited from Greece and Cyprus. All measures were administered in an interview format. Standard psychometric criteria were applied to evaluate reliability (internal consistency, test-retest, and interrater reliability) and validity (construct and known-groups validity) of The Scenario Test-GR. OUTCOMES & RESULTS: The Scenario Test-GR shows high levels of reliability and validity. High scores of internal consistency (Cronbach's α = 0.95), test-retest reliability (intra-class coefficients (ICC) = 0.99), and interrater reliability (ICC = 0.99) were found. Interrater agreement in scores on individual items ranged from good to excellent levels of agreement. Correlations with a tool measuring language function in aphasia, a measure of FC, two instruments examining the psychosocial impact of aphasia and a tool measuring non-verbal cognitive skills revealed good convergent validity (all ps < 0.05). Results showed good known-groups validity (Mann-Whitney U = 96.5, p < 0.001), with significantly higher scores for participants without aphasia compared with those with aphasia. CONCLUSIONS & IMPLICATIONS: The psychometric qualities of The Scenario Test-GR support the reliability and validity of the tool for the assessment of FC in Greek-speaking PWA. The test can be used to assess multimodal FC, promote aphasia rehabilitation goal-setting at the activity and participation levels, and be used as an outcome measure of everyday communication abilities.

Harmonizing neuropsychological assessment for mild neurocognitive disorders in Europe.

INTRODUCTION: Harmonized neuropsychological assessment for neurocognitive disorders, an international priority for valid and reliable diagnostic procedures, has been achieved only in specific countries or research contexts. METHODS: To harmonize the assessment of mild cognitive impairment in Europe, a workshop (Geneva, May 2018) convened stakeholders, methodologists, academic, and non-academic clinicians and experts from European, US, and Australian harmonization initiatives. RESULTS: With formal presentations and thematic working-groups we defined a standard battery consistent with the U.S. Uniform DataSet, version 3, and homogeneous methodology to obtain consistent normative data across tests and languages. Adaptations consist of including two tests specific to typical Alzheimer's disease and behavioral variant frontotemporal dementia. The methodology for harmonized normative data includes consensus definition of cognitively normal controls, classification of confounding factors (age, sex, and education), and calculation of minimum sample sizes. DISCUSSION: This expert consensus allows harmonizing the diagnosis of neurocognitive disorders across European countries and possibly beyond.

First and Second Language at Hand: A Chronometric Transcranial-Magnetic Stimulation Study on Semantic and Motor Resonance.

According to embodied theories, motor and language processing bidirectionally interact: Motor activation modulates behavior in lexico-semantic tasks (semantic resonance), and understanding motor-related words entails activation of the corresponding motor brain areas (motor resonance). Whereas many studies investigated such interaction in the first language (L1), only few did so in a second language (L2), focusing on motor resonance. Here, we directly compared L1 and a late L2, for the first time both in terms of semantic and motor resonance and both in terms of magnitude and timing, by taking advantage of single-pulse TMS. Twenty-five bilinguals judged, in each language, whether hand motor-related ("grasp") and non-motor-related verbs ("believe"), were physical or mental. Meanwhile, we applied TMS on the hand motor cortex at 125, 275, 350, and 500 msec post verb onset, and recorded behavioral responses and TMS-induced motor evoked potentials. TMS induced faster responses for L1 versus L2 motor and nonmotor verbs at 125 msec (three-way interaction ß = -0.0442, 95% CI [0.0814, -0.0070]), showing a semantic resonance effect at an early stage of word processing in L1 but not in L2. Concerning motor resonance, TMS-induced motor evoked potentials at 275 msec revealed higher motor cortex excitability for L2 versus L1 processing (two-way interaction ß = 0.095, 95% CI [0.017, 0.173]). These findings confirm action-language interaction at early stages of word recognition, provide further evidence that L1 and L2 are differently embodied, and call for an update of existing models of bilingualism and embodiment, concerning both language representations and processing.

Fear and depression during the COVID-19 outbreak in Cameroon: a nation-wide observational study.

BACKGROUND: The COVID-19 pandemic has been associated with significant psychological and social distress worldwide. We investigated fear and depression among adults in Cameroon during different phases of the COVID-19 outbreak. METHODS: An online survey was conducted in Cameroon from June-December 2020 using a structured questionnaire. Socio-demographic data and information regarding COVID-19 history were obtained. Fear and depressive symptoms were assessed using the Fear of COVID-19 score (FCV-19S) and the Patient Health Questionnaire (PHQ-9), respectively. Responses were clustered in weeks to better appreciate their evolution over time. RESULTS: Overall, 7381 responses from all ten regions of Cameroon were analysed (median age: 30 years, 73.3% male). The prevalence of depression (PHQ-9 score ≥ 10) was 8.4%, and that of high fear of COVID-19 (FCV-19S scores ≥19) was 57.4%. These rates were similar across genders, age-groups, and region of residence. While mean weekly PHQ-9 scores remained fairly stable throughout the study period (range: 2.53-3.21; p = 0.101), mean FCV-19S scores were highest during the early weeks but decreased significantly thereafter (from 20.31 to 18.34; p <  0.001). Multivariate analyses revealed that having a postgraduate degree, a history of quarantine, flu-like symptoms during the past 14 days, and higher FCV-19S scores were associated with more severe depressive symptoms, while obtaining COVID-19 information from various sources reduced the odds for depression. CONCLUSION: Depression amidst the COVID-19 crisis is less prevalent in Cameroon than in other countries. Prompt and widespread dissemination of adequate COVID-19 information may reduce the risks for depression by dispelling fear and anxiety among Cameroonians.

[Status epilepticus: clinical management by adults in emergency department]. / État de mal épileptique de l'adulte : prise en charge aux urgences.

Status epilepticus is a feared complication in patients with epilepsy with a mortality rate of almost 10%. It is important to recognize this clinical entity quickly. A delay in diagnosis or treatment has significant consequences on mortality and morbidity. This article is a review of the current literature and aims to provide management of status epilepticus in the emergency department by adults.

L'état de mal épileptique est une complication redoutée chez le patient épileptique avec un taux de mortalité de presque 10 %. Il est important de reconnaître cette entité clinique rapidement. Un retard de diagnostic ou de prise en charge a des conséquences non négligeables sur la mortalité et la morbidité. Cet article est une revue de la littérature actuelle et a pour but de synthétiser la prise en charge de l'état de mal épileptique aux urgences chez l'adulte.

[The Swiss Brain Health Registry : a national infrastructure for Alzheimer's research]. / Le Registre suisse pour la santé du cerveau - Une infrastructure nationale pour la recherche sur la maladie d'Alzheimer.

The Memory Centres of several Swiss hospitals have set up a national online registry for Alzheimer's research, called www.BHR-suisse.org. This type of registry already exists in the United States (www.brainhealthregistry.org/) and the Netherlands (https://hersenonderzoek.nl/). It contributes, as do these initiating sites, to the creation of a global database of research partnersb who wish to contribute by participating in studies on neurodegenerative diseases and more particularly on Alzheimer's disease. By registering, they provide a certain amount of information and become potential research partners. Researchers can then select a panel of volunteers according to the selection and exclusion criteria of their studies, contact them and include them in their studies.

Les centres de la mémoire de plusieurs hôpitaux suisses ont créé un Registre national suisse en ligne pour la recherche sur Alzheimer, intitulé www.bhr-suisse.org. Ce type de registre existe déjà aux États-Unis (www.brainhealthregistry.org/) et aux Pays-Bas (hersenonderzoek.nl/). Il contribue, au même titre que ces sites initiateurs, à constituer une base de données globale de partenaires de recherchea qui souhaitent apporter leur contribution en participant à des études sur les maladies neurodégénératives et, plus particulièrement, sur la maladie d'Alzheimer. En s'inscrivant, ces derniers apportent un certain nombre d'informations et deviennent de potentiels partenaires de recherche. Les chercheurs peuvent ensuite sélectionner un panel suivant les critères de sélection et d'exclusion de leurs études, contacter les volontaires et les intégrer dans ces études.

The right thalamic ventral posterolateral nucleus seems to be determinant for macrosomatognosia: a case report.

BACKGROUND: Macrosomatognosiais the illusory sensation of a substantially enlarged body part. This disorder of the body schema, also called "Alice in wonderland syndrome" is still poorly understood and requires careful documentation and analysis of cases. The patient presented here is unique owing to his unusual macrosomatognosia phenomenology, but also given the unreported localization of his most significant lesion in the right thalamus that allowed consistent anatomo-clinical analysis. CASE PRESENTATION: This 45-years old man presented mainly with long-lasting and quasi-delusional macrosomatognosia associated to sensory deficits, both involving the left upper-body, in the context of a right thalamic ischemic lesion most presumably located in the ventral posterolateral nucleus. Fine-grained probabilistic and deterministic tractography revealed the most eloquent targets of the lesion projections to be the ipsilateral precuneus, superior parietal lobule,but also the right primary somatosensory cortex and, to a lesser extent, the right primary motor cortex. Under stationary neurorehabilitation, the patient slowly improved his symptoms and could be discharged back home and, later on, partially return to work. CONCLUSION: We discuss deficient neural processing and integration of sensory inputs within the right ventral posterolateral nucleus lesion as possible mechanisms underlying macrosomatognosia in light of observed anatomo-clinical correlations. On the other hand, difficulty to classify this unique constellation of Alice in wonderland syndrome calls for an alternative taxonomy of cognitive and psychic aspects of illusory body-size perceptions.

Effects of Continuous Theta Burst Stimulation Over the Left Dlpfc on Mother Tongue and Second Language Production In Late Bilinguals: A Behavioral and ERP Study.

Clinical, neuroimaging, and non-invasive brain stimulation studies have associated the dorsolateral prefrontal cortex (DLPFC) with the multilingual language control system. Here, we investigated if this role is increased during the processing of the non-dominant language due to the higher cognitive/attentional demands. We used an inhibitory repetitive transcranial magnetic stimulation (rTMS) protocol over the left DLPFC and investigated the behavioral and electrophysiological effects on (i) picture naming in the mother tongue and second language, (ii) forward and backward translation and (iii) non-verbal inhibition. To this end, we compared the effects of inhibitory rTMS (cTBS) vs sham-rTMS using a single-blind within-subject design including 22 late bilinguals. Behaviorally, response times were longer after cTBS compared to sham-rTMS in the picture naming task independent of language, while response times were not affected for the word translation task. These results were mirrored on the electrophysiological level showing an effect of stimulation in the picture naming task starting at 547 ms post-stimulus onset, but not in the translation task. This late time range is likely associated with processes of conflict resolution and initiation of the articulation of the word rather than processes related to lexical selection or language switching. For the non-verbal inhibition task, behavioral outcome was not affected despite electrophysiological stimulation-induced changes. Overall, the results suggest that the DLPFC plays a role in top-down cognitive control in language production, but that this role is not increased with higher cognitive demand such as naming in a second language or in language switching during word translation.

Epilepsy-associated neurocognitive disorders (EAND) in an onchocerciasis-endemic rural community in Cameroon: A population-based case-control study.

BACKGROUND: Epilepsy affects at least 50 million individuals worldwide, especially in sub-Saharan Africa (sSA). Cognitive impairment is common in people with epilepsy (PWE) yet, little is known on the burden of cognitive impairment in people with epilepsy in sSA. This study was thus designed to assess cognitive impairment in PWE or epilepsy-associated neurocognitive disorders (EAND) in a rural population in Cameroon. METHODS: This was a case-control study including PWE and age/sex-matched healthy controls from July to September 2017 in Bilomo, a village in the Mbam and Kim Division. The Montreal Cognitive Assessment (MoCA), International HIV Dementia Scale (IHDS), Dubois' Five Word testing, Frontal Assessment Battery (FAB), Isaac's Set Test and the Clock drawing test were administered to the study participants to evaluate global and specific cognitive functions. RESULTS: Eighty participants were included (40 cases and 40 controls) with a mean age of 25.78 years. Using the MoCA, 87.5% of cases had cognitive impairment, against 37.5% of controls (p < 0.001; OR 11.67; CI 3.40-45.09). Using the IHDS, the prevalence of global cognitive impairment was 84.6% among the cases against 40% for the controls (p = <0.001; OR 7.07; CI 2.29-29.19). Specifically, executive function deficits (92.5% of cases vs 40.0% of controls p = <0.001 OR = 18.50 CI; 4.48-105.08) and decreased verbal fluency (100% of cases against 45% of controls p < 0.001) were the most affected cognitive domains. Longer duration of epilepsy and higher seizure frequency were associated with global cognitive impairment. Low level of education was associated with both decreased verbal fluency and executive dysfunction while a longer stay in Bilomo correlated with poor results on the Isaac's Set Test. CONCLUSION: The prevalence of cognitive impairment appears to be much higher in PWE in the Mbam valley, particularly decreased executive function and verbal fluency, than in people without epilepsy. Longer disease duration, higher seizure frequency, low level of education and length of stay in Bilomo are associated with poorer cognitive performance. More studies are needed to refine evaluation tools to better characterize and manage EAND in sSA.

Eye Gaze Behavior at Turn Transition: How Aphasic Patients Process Speakers' Turns during Video Observation.

The human turn-taking system regulates the smooth and precise exchange of speaking turns during face-to-face interaction. Recent studies investigated the processing of ongoing turns during conversation by measuring the eye movements of noninvolved observers. The findings suggest that humans shift their gaze in anticipation to the next speaker before the start of the next turn. Moreover, there is evidence that the ability to timely detect turn transitions mainly relies on the lexico-syntactic content provided by the conversation. Consequently, patients with aphasia, who often experience deficits in both semantic and syntactic processing, might encounter difficulties to detect and timely shift their gaze at turn transitions. To test this assumption, we presented video vignettes of natural conversations to aphasic patients and healthy controls, while their eye movements were measured. The frequency and latency of event-related gaze shifts, with respect to the end of the current turn in the videos, were compared between the two groups. Our results suggest that, compared with healthy controls, aphasic patients have a reduced probability to shift their gaze at turn transitions but do not show significantly increased gaze shift latencies. In healthy controls, but not in aphasic patients, the probability to shift the gaze at turn transition was increased when the video content of the current turn had a higher lexico-syntactic complexity. Furthermore, the results from voxel-based lesion symptom mapping indicate that the association between lexico-syntactic complexity and gaze shift latency in aphasic patients is predicted by brain lesions located in the posterior branch of the left arcuate fasciculus. Higher lexico-syntactic processing demands seem to lead to a reduced gaze shift probability in aphasic patients. This finding may represent missed opportunities for patients to place their contributions during everyday conversation.

The Role of the Cognitive Control System in Recovery from Bilingual Aphasia: A Multiple Single-Case fMRI Study.

Aphasia in bilingual patients is a therapeutic challenge since both languages can be impacted by the same lesion. Language control has been suggested to play an important role in the recovery of first (L1) and second (L2) language in bilingual aphasia following stroke. To test this hypothesis, we collected behavioral measures of language production (general aphasia evaluation and picture naming) in each language and language control (linguistic and nonlinguistic switching tasks), as well as fMRI during a naming task at one and four months following stroke in five bilingual patients suffering from poststroke aphasia. We further applied dynamic causal modelling (DCM) analyses to the connections between language and control brain areas. Three patients showed parallel recovery in language production, one patient improved in L1, and one improved in L2 only. Language-control functions improved in two patients. Consistent with the dynamic view of language recovery, DCM analyses showed a higher connectedness between language and control areas in the language with the better recovery. Moreover, similar degrees of connectedness between language and control areas were found in the patients who recovered in both languages. Our data suggest that engagement of the interconnected language-control network is crucial in the recovery of languages.

Language specificity of lexical-phonological therapy in bilingual aphasia: A clinical and electrophysiological study.

Based on findings for overlapping representations of bilingual people's first (L1) and second (L2) languages, unilingual therapies of bilingual aphasia have been proposed to benefit the untrained language. However, the generalisation patterns of intra- and cross-language and phonological therapy and their neural bases remain unclear. We tested whether the effects of an intensive lexical-phonological training (LPT) in L2 transferred to L1 word production in a Persian-French bilingual stroke patient with Broca's aphasia. Language performance was assessed using the Bilingual Aphasia Test, a 144-item picture naming (PN) task and a word-picture verification (WPV) task. Electroencephalography (EEG) was recorded during PN and WPV in both languages before and after an LPT in French on a wordlist from the PN task. After the therapy, naming improved only for the treated L2 items. The naming performance improved neither in the untrained L2 items nor in the corresponding items in L1. EEG analyses revealed a Language x Session topographic interaction at 540 ms post-stimulus, driven by a modification of the electrophysiological response to the treated L2 but not L1 items. These results indicate that LPT modified the brain networks engaged in the phonological-phonetic processing during naming only in the trained language for the trained items.

[Age-related cognitive impairment: conceptual changes and diagnostic strategies]. / Troubles cognitifs liés au vieillissement: évolution récente des concepts et stratégies diagnostiques.

The actual field of dementia encompasses also the pre-symptomatic phase, which may evolve for decades. Early detection and appropriate diagnosis decrease patient's and family's anxiety, improve patient's global care and allow better legal patient's protection. General Practitioners have at hand several available tools to screen a neurocognitive disorder, with up to 80% of sensitivity and specificity, to complete their clinical evaluation. An accurate diagnosis requires then a complete medical, neurological neuropsychological and neuroradiological evaluation in a Memory Clinic. Other investigations, such as functional cerebral imagery and spinal tap can be critical in unusual situations. Despite mood improvement after diagnostic announcement, increased suicidal risk in the 3 first months should be screened.

Experience-based Auditory Predictions Modulate Brain Activity to Silence as do Real Sounds.

Interactions between stimuli's acoustic features and experience-based internal models of the environment enable listeners to compensate for the disruptions in auditory streams that are regularly encountered in noisy environments. However, whether auditory gaps are filled in predictively or restored a posteriori remains unclear. The current lack of positive statistical evidence that internal models can actually shape brain activity as would real sounds precludes accepting predictive accounts of filling-in phenomenon. We investigated the neurophysiological effects of internal models by testing whether single-trial electrophysiological responses to omitted sounds in a rule-based sequence of tones with varying pitch could be decoded from the responses to real sounds and by analyzing the ERPs to the omissions with data-driven electrical neuroimaging methods. The decoding of the brain responses to different expected, but omitted, tones in both passive and active listening conditions was above chance based on the responses to the real sound in active listening conditions. Topographic ERP analyses and electrical source estimations revealed that, in the absence of any stimulation, experience-based internal models elicit an electrophysiological activity different from noise and that the temporal dynamics of this activity depend on attention. We further found that the expected change in pitch direction of omitted tones modulated the activity of left posterior temporal areas 140-200 msec after the onset of omissions. Collectively, our results indicate that, even in the absence of any stimulation, internal models modulate brain activity as do real sounds, indicating that auditory filling in can be accounted for by predictive activity.

Assessment of Social Cognition and Theory of Mind: Initial Validation of the Geneva Social Cognition Scale.

BACKGROUND: Social cognition is widely studied in neurology. At present, such evaluations are designed for research or for specific diseases and simple general clinical tools are lacking. We propose a clinical evaluation tool for social cognition, the Geneva Social Cognition Scale (GeSoCS). METHODS: The GeSoCS is a 100-point scale composed of 6 subtests (theory of mind stories, recognition of social emotions, false beliefs, inferences, absurdity judgement and planning abilities) chosen from different validated tests of social and cognitive evaluation. Eighty-four patients with neurological disorders and 52 controls participated in the study. Evaluation duration lasted 20-60 min. RESULTS: Mean scores were 92.6 ± 4.5 for controls and 76.5 ± 15.3 for patients and differentiate patients and controls in all subtests. With a cut-off score of 84, the scale had a sensitivity of 62% and a specificity of 94%. In our stroke subgroup, right CVAs failed in cartoons, inferences, 'mind in the eyes', and in the temporal rule task while left CVAs were impaired in verbal/discourse tasks (social cognition, inferences, absurd stories, and cartoons. CONCLUSIONS: The GeSoCS is a medium duration assessment tool that appears to detect and characterize significant social impairment in neurological patients.

Feasibility of a multiple-choice mini mental state examination for chronically critically ill patients.

OBJECTIVES: Following treatment in an ICU, up to 70% of chronically critically ill patients present neurocognitive impairment that can have negative effects on their quality of life, daily activities, and return to work. The Mini Mental State Examination is a simple, widely used tool for neurocognitive assessment. Although of interest when evaluating ICU patients, the current version is restricted to patients who are able to speak. This study aimed to evaluate the feasibility of a visual, multiple-choice Mini Mental State Examination for ICU patients who are unable to speak. DESIGN: The multiple-choice Mini Mental State Examination and the standard Mini Mental State Examination were compared across three different speaking populations. The interrater and intrarater reliabilities of the multiple-choice Mini Mental State Examination were tested on both intubated and tracheostomized ICU patients. SETTING: Mixed 36-bed ICU and neuropsychology department in a university hospital. SUBJECTS: Twenty-six healthy volunteers, 20 neurological patients, 46 ICU patients able to speak, and 30 intubated or tracheostomized ICU patients. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Multiple-choice Mini Mental State Examination results correlated satisfactorily with standard Mini Mental State Examination results in all three speaking groups: healthy volunteers: intraclass correlation coefficient = 0.43 (95% CI, -0.18 to 0.62); neurology patients: 0.90 (95% CI, 0.82-0.95); and ICU patients able to speak: 0.86 (95% CI, 0.70-0.92). The interrater and intrarater reliabilities were good (0.95 [0.87-0.98] and 0.94 [0.31-0.99], respectively). In all populations, a Bland-Altman analysis showed systematically higher scores using the multiple-choice Mini Mental State Examination. CONCLUSIONS: Administration of the multiple-choice Mini Mental State Examination to ICU patients was straightforward and produced exploitable results comparable to those of the standard Mini Mental State Examination. It should be of interest for the assessment and monitoring of the neurocognitive performance of chronically critically ill patients during and after their ICU stay. The multiple-choice Mini Mental State Examination tool's role in neurorehabilitation and its utility in monitoring neurocognitive functions in ICU should be assessed in future studies.

High and low stimulus-driven conflict engage segregated brain networks, not quantitatively different resources.

Task-irrelevant information is constantly present in our environment and may interfere with the processing of the information necessary to achieve goal-directed behavior. While task goals determine which information must be suppressed, the demand for inhibitory control depends on the strength of the interference induced by incoming, task-irrelevant information. Whether the same or distinct inhibitory processes are engaged to suppress various degrees of interference from task-irrelevant information remains largely unresolved. We investigated this question by manipulating the strength of the conflict induced by automatic word reading in a classical color Stroop task. High conflict was induced by presenting words in participant's native language and low conflict by presenting words in a less familiar language. Behavioral performance and electrical neuroimaging analyses of event-related potentials to the words were analyzed following a two-by-two within-subject design with factors conflict strength (high; low) and color word/word ink congruency (congruent; incongruent). Behaviorally, we observed a significant conflict strength × congruency driven by a smaller Stroop effect in the low- than high conflict condition. Electrophysiologically, we observed a significant conflict strength × congruency interaction at the topographic level during the period of the N450 components, indicative of the engagement of distinct configurations of brain networks. No such interaction was found at the level of response strength. Electrical sources analyses localized the topographic effect within the anterior cingulate cortex and basal ganglia, left middle frontal and occipital areas. We interpret our results in terms of qualitatively distinct executive mechanisms for reactive inhibitory control in conditions of high versus low stimulus-driven conflict.

Inter- and intrahemispheric dissociations in ideomotor apraxia: a large-scale lesion-symptom mapping study in subacute brain-damaged patients.

Pantomimes of object use require accurate representations of movements and a selection of the most task-relevant gestures. Prominent models of praxis, corroborated by functional neuroimaging studies, predict a critical role for left parietal cortices in pantomime and advance that these areas store representations of tool use. In contrast, lesion data points to the involvement of left inferior frontal areas, suggesting that defective selection of movement features is the cause of pantomime errors. We conducted a large-scale voxel-based lesion-symptom mapping analyses with configural/spatial (CS) and body-part-as-object (BPO) pantomime errors of 150 left and right brain-damaged patients. Our results confirm the left hemisphere dominance in pantomime. Both types of error were associated with damage to left inferior frontal regions in tumor and stroke patients. While CS pantomime errors were associated with left temporoparietal lesions in both stroke and tumor patients, these errors appeared less associated with parietal areas in stroke than in tumor patients and less associated with temporal in tumor than stroke patients. BPO errors were associated with left inferior frontal lesions in both tumor and stroke patients. Collectively, our results reveal a left intrahemispheric dissociation for various aspects of pantomime, but with an unspecific role for inferior frontal regions.

Does Diglossia Impact Brain Structure? Data from Swiss German Early Diglossic Speakers.

(1) Background: Bilingualism has been reported to shape the brain by inducing cortical changes in cortical and subcortical language and executive networks. Similar yet different to bilingualism, diglossia is common in Switzerland, where the German-speaking population switches between an everyday spoken Swiss German (CH-GER) dialect and the standard German (stGER) used for reading and writing. However, no data are available for diglossia, defined as the use of different varieties or dialects of the same language, regarding brain structure. The aim of our study is to investigate if the presence of this type of diglossia has an impact on the brain structure, similar to the effects seen in bilingualism. (2) Methods: T1-weighted anatomical MRI scans of participants were used to compare the grey matter density and grey matter volume of 22 early diglossic CH-GER-speaking and 20 non-diglossic French-speaking right-handed university students, matched for age, linguistics and academic background. The images were processed with Statistical Parametric Mapping SPM12 and analyzed via voxel- and surface-based morphometry. (3) Results: A Bayesian ANCOVA on the whole brain revealed no differences between the groups. Also, for the five regions of interest (i.e., planum temporale, caudate nucleus, ACC, DLPFC and left interior parietal lobule), no differences in the cortical volume or thickness were found using the same statistical approach. (4) Conclusion: The results of this study may suggest that early diglossia does not shape the brain structure in the same manner as bilingualism.

Principal components of functional connectivity: a new approach to study dynamic brain connectivity during rest.

Functional connectivity (FC) as measured by correlation between fMRI BOLD time courses of distinct brain regions has revealed meaningful organization of spontaneous fluctuations in the resting brain. However, an increasing amount of evidence points to non-stationarity of FC; i.e., FC dynamically changes over time reflecting additional and rich information about brain organization, but representing new challenges for analysis and interpretation. Here, we propose a data-driven approach based on principal component analysis (PCA) to reveal hidden patterns of coherent FC dynamics across multiple subjects. We demonstrate the feasibility and relevance of this new approach by examining the differences in dynamic FC between 13 healthy control subjects and 15 minimally disabled relapse-remitting multiple sclerosis patients. We estimated whole-brain dynamic FC of regionally-averaged BOLD activity using sliding time windows. We then used PCA to identify FC patterns, termed "eigenconnectivities", that reflect meaningful patterns in FC fluctuations. We then assessed the contributions of these patterns to the dynamic FC at any given time point and identified a network of connections centered on the default-mode network with altered contribution in patients. Our results complement traditional stationary analyses, and reveal novel insights into brain connectivity dynamics and their modulation in a neurodegenerative disease.