Occurrence of area postrema syndrome during follow-up: phenotype and influence over NMOSD activity in LATAM in real-world settings.

INTRODUCTION: We aimed to assess the frequency, duration, and severity of area postrema syndrome (APS) during follow-up in neuromyelitis optica spectrum disorder (NMOSD) patients, as well as its association with inflammatory activity and prognostic factors of APS severity in a real-world setting. METHODS: We conducted a retrospective study on a cohort of Latin American (LATAM) NMOSD patients who had experienced APS during their follow-up. Patients from Mexico, Peru, Brazil, Colombia, Panama, Chile and Argentina patients who met 2015 NMOSD criteria were included. We evaluated data on symptom type (nausea, vomiting and/or hiccups), frequency, duration, severity (measured by APS severity scale), association with other NMOSD core relapses, and acute treatments (symptomatic and immunotherapy or plasmapheresis). Logistic regression was conducted to evaluate factors associated with APS severity (vs. mild-moderate). RESULTS: Out of 631 NMOSD patients, 116 (18.3%) developed APS during their follow-up. The most common APS phenotype was severe. Inflammatory activity (i.e., relapses) significantly decreased after the onset of APS. Half of the patients experienced isolated APS with a median duration of 10 days, and the most frequently used acute treatment was IV steroids. All three symptoms were present in 44.6% of the patients. APS symptoms resolved following immunotherapy. Logistic regression did not identify independent factors associated with the severity of APS. CONCLUSIONS: Our findings indicate that 18.3% of NMOSD patients developed APS during the follow-up period, with most patients fulfilling criteria for severe APS. The inflammatory activity decreased after the onset of APS compared to the previous year.

Frequency of diminished ovarian reserve in women with multiple sclerosis in Chile: An exploratory study.

INTRODUCTION: Multiple Sclerosis (MS) is a chronic disease affecting around 2.8 million people worldwide. Two-thirds are women, and the mean age at diagnosis is about 30 years old. Social trends are moving towards older age at first pregnancy, both in women with and without MS. OBJECTIVES: To determine the frequency of diminished ovarian reserve (DOR) through anti-Mullerian Hormone (AMH) measurement in women with MS at fertile age and Healthy Females (HF) in Chile. METHODS: Case-control, multicentric, cross-sectional study including relapsing-remitting people with MS (pwMS) between 18 and 40 years and sex and age-matched HF. We obtained a blood sample to determine AMH levels. We defined DOR as AMH <1.5 ng/mL and very-low AMH levels as <0.5 ng/mL. Also, we performed questions regarding reproductive decision-making. RESULTS: We included 79 sex and age-matched HF and 92 pwMS, median age 32(19-40) years, median disease duration 6 (1-17)years, median EDSS 1.0 (0-6), 95% were receiving disease-modifying therapy (DMT), 70% high-efficacy DMT and 37% with a treatment that contraindicates pregnancy. DOR was observed in 24% (n = 22) of the pwMS, compared to 14% (n = 11) of the HF (p = 0.09), while very-low AMH levels were observed in 7.6% (n = 7) of pwMS and none of the HF (p = 0.0166). We observed an inverse correlation between age and AMH levels. Age was the only significant risk factor for low AMH levels in pwMS (OR 1.14 95%CI(1.00-1-31), p = 0.04), including smoking, body mass index (BMI), hormonal contraception, autoimmune comorbidity, high/low-moderate efficacy DMT, and active disease as covariables. We did not find statistically significant differences in age at diagnosis, BMI, disease duration, EDSS, autoimmune comorbidity, use of hormonal contraception, or percentage of active disease between MS women with normal vs DOR. Over 70% of pwMS desired to become pregnant in the future, while 60% considered that the diagnosis of MS was a limitation for pregnancy planning. CONCLUSIONS: No differences in DOR, measured by levels of AMH, were observed between pwMS MS and HF in Chile. As expected, AMH levels were correlated only with ageing. This information may be evaluated early during the disease course to help patients and neurologists with fertility counselling and family planning considerations regarding DMT use.

Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease (MOGAD) in Chile: lessons learned from challenging cases.

BACKGROUND: Anti-Myelin Oligodendrocyte Glycoprotein (MOG) Antibody Associated Disease (MOGAD) is an emerging disorder recognized as a clinical entity distinct from Multiple Sclerosis and Aquaporin-4-positive Neuromyelitis Optica Spectrum Disorders (NMOSD-AQP4+), and its phenotypic spectrum continues to expand. Most information about its clinical course has emerged from retrospective studies, and treatment response both in acute and chronic-relapsing disease is still limited. We aimed to describe the clinical and paraclinical characteristics of monophasic and relapsing, paediatric and adult patients with MOGAD under regular clinical care in Chile, highlighting some challenging cases that are far from being considered benign. METHODS: Observational, retrospective, and prospective longitudinal multicentre study including patients with positive serum MOG-IgG assessed by cell-based assay. RESULTS: We include 35 patients, 71% women, median age at onset 30 years (range 1-68), 23% had paediatric onset, with a median disease-duration 24 months (range 12-348). In the whole cohort, the most frequent symptoms at onset were isolated optic neuritis (ON) (34%) and myelitis (22%). Encephalitis with seizures or encephalomyelitis was the most common presentation in paediatric-onset patients 75% (n = 6), compared to 11% (n = 3) of the adult-onset patients (p < 0.001). A relapsing course was observed in 34%, these patients were younger (25 vs. 34 years, p = 0.004) and with a longer disease duration (64 vs. 6 months, p = 0.004) compared to monophasic patients. Two patients developed encephalitis with seizures/status epilepticus, with concomitant positive CSF anti-NMDAR-IgG. Chronic immunotherapy was ever prescribed in 77%, the most frequent was rituximab (35%). Relapses under chronic immunotherapy occurred in 5/27 patients (18.5%), two of them under rituximab, one paediatric patient who started combined therapy with monthly IVIG and one adult patient that switched to satralizumab plus mycophenolate. The median EDSS at the last follow-up was 1.5 (range 0-6.0). CONCLUSION: In Chile, patients with MOGAD exhibit a wide spectrum of clinical presentations at disease onset and during relapses. Close monitoring is needed, particularly in younger patients with short follow-up periods.

Practical issues concerning the use of Magnetic Resonance Imaging in Multiple Sclerosis in Latin America: Discussion from 16 centres on behalf of the Foro Latam EM Study Group.

MAGNIMS-CMSC-NAIMS consensus recommendations on the use of MRI in patients with multiple sclerosis have been recently published, and they have been fundamental for improving patient care. Implementation of these and previous MAGNIMS recommendations have not been established in many countries. Addressing the local limitations behind these difficulties is needed. A panel of 14 MS neurologists from 16 different reference centres from Chile, Argentina, Mexico, Colombia, Ecuador, Panamá, Perú and Brazil met to discuss the current situation regarding the use of MRI in MS including a) Access and availability, b) Standardized acquisition protocols and reports, and c) Multicentric research potential.

Safety and humoral response rate of inactivated and mRNA vaccines against SARS-CoV-2 in patients with Multiple Sclerosis.

BACKGROUND: Safety and effectiveness outcomes in Multiple Sclerosis (MS) patients receiving different disease-modifying therapies (DMT) and different types of vaccines against SARS-CoV-2 are limited. Growing evidence coming mainly from Israel, Europe and North America using mRNA and adenoviral vector vaccines has been published. OBJECTIVES: To assess the safety and humoral response of inactivated virus and mRNA vaccines against SARS-CoV-2 in patients with MS. METHODS: Ongoing, multicentric, prospective, observational study performed between February and September 2021. Humoral response (antibodies against spike-1 protein) was determined at least 4 weeks after the complete schedule of anti-SARS-CoV-2 vaccines. Categorical outcome (positive/negative) and total antibody titres were recorded. Adverse events supposedly attributable to vaccination (AESAV) were collected. RESULTS: 178 patients, 68% women, mean age 39.7 ± 11.2 years, 123 received inactivated (Coronavac-Sinovac), 51 mRNA (Pfizer-BioNtech), and 4 adenoviral vector vaccines (CanSino n = 2, Jonhson&Johnson-Jannsen n = 1, Oxford-AstraZeneca n = 1). Six patients had a history of COVID-19 before vaccination. Overall humoral response was observed in 66.9% (62.6% inactivated vs. 78.4% mRNA, p = 0.04). Positive anti-S1-antibodies were observed in 100% of patients with no DMT (n = 3), 100% with interferon/glatiramer-acetate (n = 11), 100% with teriflunomide/dimethyl-fumarate (n = 16), 100% with natalizumab (n = 10), 100% with alemtuzumab (n = 8), 90% with cladribine (n = 10), and 88% with fingolimod (n = 17), while 43% of patients receiving antiCD20 (n = 99) were positive (38% inactivated vaccine vs. 59% mRNA vaccine, p = 0.05). In the multivariate analysis including antiCD20 patients, the predictors for a positive humoral response were receiving the mRNA vaccine (OR 8.11 (1.79-36.8), p = 0.007) and a lower number of total infusions (OR 0.44 (0.27-0.74) p = 0.002. The most frequent AESAV was local pain (14%), with 4 (2.2%) patients experiencing mild-moderate relapses within 8 weeks of first vaccination compared to 11 relapses (6.2%) within the 8 weeks before vaccination (Chi-squared 3.41, p = 0.06). DISCUSSION: A higher humoral response rate was observed using the mRNA compared to the inactivated vaccine, while patients using antiCD20 had a significantly lower response rate, and patients using antiCD20 and fingolimod had lower antibody titres. In this MS patient cohort, inactivated and mRNA vaccines against SARS-CoV-2 appear to be safe, with no increase in relapse rate. This information may help guidelines including booster shots and types of vaccines in selected populations.

Regional brain atrophy is related to social cognition impairment in multiple sclerosis.

BACKGROUND: Multiple sclerosis exhibits specific neuropathological phenomena driving to both global and regional brain atrophy. At the clinical level, the disease is related to functional decline in cognitive domains as the working memory, processing speed, and verbal fluency. However, the compromise of social-cognitive abilities has concentrated some interest in recent years despite the available evidence suggesting the risk of disorganization in social life. Recent studies have used the MiniSEA test to assess the compromise of social cognition and have found relevant relationships with memory and executive functions, as well as with the level of global and regional brain atrophy. OBJECTIVE: The present article aimed to identify structural changes related to socio-cognitive performance in a sample of patients with relapsing-remitting multiple sclerosis. METHODS: 68 relapsing-remitting multiple sclerosis Chilean patients and 50 healthy control subjects underwent MRI scans and neuropsychological evaluation including social-cognition tasks. Total brain, white matter, and gray matter volumes were estimated. Also, voxel-based morphometry was applied to evaluate regional structural changes. RESULTS: Patients exhibited lower scores in all neuropsychological tests. Social cognition exhibited a significant decrease in this group mostly related to the declining social perception. Normalized brain volume and white matter volume were significantly decreased when compared to healthy subjects. The regional brain atrophy analysis showed that changes in the insular cortex and medial frontal cortices are significantly related to the variability of social-cognitive performance among patients. CONCLUSIONS: In the present study, social cognition was only correlated with the deterioration of verbal fluency, despite the fact that previous studies have reported its link with memory and executive functions. The identification of specific structural correlates supports the comprehension of this phenomenon as an independent source of cognitive disability in these patients.

Regional brain atrophy is related to social cognition impairment in multiple sclerosis / La atrofia cerebral regional se relaciona con el deterioro de la cognición social en sclerosis múltiple

ABSTRACT Background: Multiple sclerosis exhibits specific neuropathological phenomena driving to both global and regional brain atrophy. At the clinical level, the disease is related to functional decline in cognitive domains as the working memory, processing speed, and verbal fluency. However, the compromise of social-cognitive abilities has concentrated some interest in recent years despite the available evidence suggesting the risk of disorganization in social life. Recent studies have used the MiniSEA test to assess the compromise of social cognition and have found relevant relationships with memory and executive functions, as well as with the level of global and regional brain atrophy. Objective: The present article aimed to identify structural changes related to socio-cognitive performance in a sample of patients with relapsing-remitting multiple sclerosis. Methods: 68 relapsing-remitting multiple sclerosis Chilean patients and 50 healthy control subjects underwent MRI scans and neuropsychological evaluation including social-cognition tasks. Total brain, white matter, and gray matter volumes were estimated. Also, voxel-based morphometry was applied to evaluate regional structural changes. Results: Patients exhibited lower scores in all neuropsychological tests. Social cognition exhibited a significant decrease in this group mostly related to the declining social perception. Normalized brain volume and white matter volume were significantly decreased when compared to healthy subjects. The regional brain atrophy analysis showed that changes in the insular cortex and medial frontal cortices are significantly related to the variability of social-cognitive performance among patients. Conclusions: In the present study, social cognition was only correlated with the deterioration of verbal fluency, despite the fact that previous studies have reported its link with memory and executive functions. The identification of specific structural correlates supports the comprehension of this phenomenon as an independent source of cognitive disability in these patients.

RESUMEN Antecedentes: La esclerosis múltiple presenta fenómenos neuropatológicos específicos que conducen a la atrofia cerebral global y regional. A nivel clínico, la enfermedad está relacionada con el deterioro funcional de los dominios cognitivos como la memoria de trabajo, la velocidad de procesamiento y la fluidez verbal. Sin embargo, el compromiso de las habilidades socio-cognitivas ha concentrado cierto interés en los últimos años debido a la evidencia disponible que sugiere el riesgo de desorganización en la vida social. Estudios recientes han utilizado la prueba MiniSEA para evaluar el compromiso de la cognición social y han encontrado relaciones relevantes con la memoria y funciones ejecutiva, así como con el nivel de atrofia cerebral global y regional. Objetivo: El presente artículo tiene como objetivo identificar cambios estructurales relacionados con el rendimiento sociocognitivo en una muestra de pacientes con esclerosis múltiple recurrente-remitente. Métodos: 68 pacientes Chilenos con esclerosis múltiple recurrente-remitente y 50 sujetos de control sanos se sometieron a resonancias magnéticas y evaluación neuropsicológica, incluidas las tareas de cognición social. Se estimaron los volúmenes cerebrales totales, de materia blanca y materia gris. Además, se aplicó la morfometría basada en vóxel para evaluar los cambios estructurales regionales. Resultados: Los pacientes muestran puntuaciones más bajas en todas las pruebas neuropsicológicas. La cognición social exhibe una disminución significativa en este grupo principalmente relacionada con la disminución de la percepción social. El volumen normalizado del cerebro y el volumen de la materia blanca disminuyeron significativamente en comparación con los sujetos sanos. El análisis regional de atrofia cerebral mostró que los cambios en la corteza insular y la corteza frontal medial están significativamente relacionados con la variabilidad del rendimiento sociocognitivo entre los pacientes. Conclusiones: En el presente estudio, la cognición social sólo se correlacionó con el deterioro de la fluencia verbal, a pesar de que estudios previos han reportado su vinculación con la memoria y funciones ejecutivas. La identificación de correlatos estructurales específicos apoya la comprensión de este fenómeno como una fuente independiente de discapacidad cognitiva en estos pacientes.

Coronavirus disease 2019 in Latin American patients with multiple sclerosis.

Patients with multiple sclerosis (MS) who present coronavirus disease 2019 (COVID-19) are of particular interest to neurologists. These patients have a neuroimmune disease and receive immunomodulatory or immunosuppressive therapies in the long-term. We present here data from 73 patients with MS and a confirmed diagnosis of COVID-19 from five Latin American countries. Fifteen patients (20.5%) were hospitalized and two patients died. The use of anti-CD20 therapies was the only risk factor associated to hospitalization and death. Despite the small sample size, this study highlights the awareness regarding therapeutic options for MS during the pandemic.

Status of the neuromyelitis optica spectrum disorder in Latin America.

BACKGROUND: Neuromyelitis optica spectrum disorders (NMOSD) is an increasing diagnostic and therapeutic challenge in Latin America (LATAM). Despite the heterogeneity of this population, ethnic and socioeconomic commonalities exist, and epidemiologic studies from the region have had a limited geographic and population outreach. Identification of some aspects from the entire region are lacking. OBJECTIVES: To determine ethnic, clinical characteristics, and utilization of diagnostic tools and types of therapy for patients with NMOSD in the entire Latin American region. METHODS: The Latin American Committee for Treatment and Research in MS (LACTRIMS) created an exploratory investigational survey addressed by Invitation to NMOSD Latin American experts identified through diverse sources. Data input closed after 30 days from the initial invitation. The questionnaire allowed use of absolute numbers or percentages. Multiple option responses covering 25 themes included definition of type of practice; number of NMOSD cases; ethnicity; utilization of the 2015 International Panel criteria for the diagnosis of Neuromyelitis optica (IPDN); clinical phenotypes; methodology utilized for determination of anti-Aquaporin-4 (anti- AQP4) antibodies serological testing, and if this was performed locally or processed abroad; treatment of relapses, and long-term management were surveyed. RESULTS: We identified 62 investigators from 21 countries reporting information from 2154 patients (utilizing the IPDN criteria in 93.9% of cases), which were categorized in two geographical regions: North-Central, including the Caribbean (NCC), and South America (SA). Ethnic identification disclosed Mestizos 61.4% as the main group. The most common presenting symptoms were concomitant presence of optic neuritis and transverse myelitis in 31.8% (p=0.95); only optic neuritis in 31.4% (more common in SA), p<0.001); involvement of the area postrema occurred in 21.5% and brain stem in 8.3%, both were more frequent in the South American cases (p<0.001). Anti-AQP4 antibodies were positive in 63.9% and anti-Myelin Oligodendrocyte Glycoprotein (MOG) antibodies in 4.8% of total cases. The specific laboratorial method employed was not known by 23.8% of the investigators. Acute relapses were identified in 81.6% of cases, and were treated in 93.9% of them with intravenous steroids (IVS); 62.1% with plasma exchange (PE), and 40.9% with intravenous immunoglobulin-G (IVIG). Therapy was escalated in some cases due to suboptimal initial response. Respondents favored Rituximab as long-term therapy (86.3%), whereas azathioprine was also utilized on 81.8% of the cases, either agent used indistinctly by the investigators according to treatment accessibility or clinical judgement. There were no differences among the geographic regions. CONCLUSIONS: This is the first study including all countries of LATAM and the largest cohort reported from a multinational specific world area. Ethnic distributions and phenotypic features of the disease in the region, challenges in access to diagnostic tools and therapy were identified. The Latin American neurological community should play a determinant role encouraging and advising local institutions and health officials in the availability of more sensitive and modern diagnostic methodology, in facilitating the the access to licensed medications for NMOSD, and addressing concerns on education, diagnosis and management of the disease in the community.

Pregnancy outcomes in women with Multiple Sclerosis.

INTRODUCTION: Women represent two-thirds of the MS population and are usually diagnosed during childbearing age. Collection of local information about pregnancy outcomes is fundamental to support individual decision-making. OBJECTIVE: To explore the trends in pregnancy decision making and pregnancy outcomes before (PreMS) and after (PostMS) MS diagnosis. METHODS: We developed a questionnaire for retrospective assessment of pregnancy outcomes in PreMS and PostMS patients under regular care at the Programa de Esclerosis Multiple UC in Chile. RESULTS: From the 218 women who responded to the questionnaire, 67 women did not have pregnancies. The total number of pregnancies registered was 299, 223 were PreMS (97 women, mean 2.5 ± 1.3 per/woman), and 76 PostMS (59 women, mean 1.9 ± 1.1 per/woman, p = 0.003). Mean age at first pregnancy was 27.6 ± 6.2 in PreMS, and 32.6 ± 4.6 years in PostMS women (p < 0.001). Significant differences between PreMS and PostMS pregnancy outcomes were cesarean section (37% vs. 66%; OR 2.74 95%CI(1.5-52), p=0.002), suspected relapse during 6 months after birth (7% vs. 18%, p<0.001), and breastfeeding (83% vs 67%, p=0.005). Gestational age, weight/size at birth, were not different between groups. Major malformations were observed similarly in both groups. CONCLUSIONS: Changes in pregnancy decision-making after MS diagnosis occur, having fewer children and at an older age. It also changes obstetrician decisions for cesarean sections, with a 3 fold increase. Regarding newborn outcomes, there were no differences between groups.

Prevalence of comorbidities in Multiple Sclerosis and impact on physical disability according to disease phenotypes.

BACKGROUND: Comorbidities are prevalent among Multiple Sclerosis (MS) patients. Few studies have characterized their prevalence and impact in Latin American populations. OBJECTIVE: We aim to assess the prevalence of comorbidities and their impact on the risk of physical disability across different MS phenotypes. METHODS: Cross-sectional multicenter study of patients under regular clinical care at the Programa de Esclerosis Múltiple UC and Hospital Dr. Sótero del Río in Chile. Prevalence of comorbidities was estimated from the retrospective assessment of electronic medical charts. Disease phenotypes were categorized into two groups: clinically isolated syndrome/relapsing-remitting (inflammatory group) and primary/secondary progressive MS patients (progressive group). A multivariable analysis using binary logistic regression for assessing the risk of EDSS ≥ 6.0 in each group was performed. RESULTS: A total of 453 patients was included, 71% female, mean age at onset 31 years, mean disease duration 10 years, and median EDSS 2.0 (range 0-10). In the whole sample, most prevalent comorbidities were ever-smoking (42.2%), depression/anxiety (34.9%), thyroid disease (15.7%), hypertension (11.3%) and insulin resistance/type 2 diabetes mellitus (11.0%). When assessing the risk of EDSS ≥ 6, in the inflammatory group (N = 366), age at onset (OR 1.06, 95%CI(1.02-1.11), p = 0.008), disease duration (OR 1.06, 95%CI(1.00-1.12), p = 0.039) and epilepsy comorbidity (OR 5.36, 95%CI(1.33-21.5), p = 0.018) were associated with a higher risk of disability. In the progressive group (N = 87), disease duration was a risk factor (OR 1.08 95%CI(1.02-1.16), p = 0.014), while shorter diagnostic delay (OR 0.91 95%CI(0.85-0.99), p = 0.025) and insulin resistance/type 2 diabetes mellitus comorbidity were protective factors (OR 0.18 95%CI(0.04-0.83), p = 0.028), 72% of these patients were receiving metformin. CONCLUSIONS: Comorbidities are common across different MS disease phenotypes. Epilepsy seems particularly related with a higher risk of physical disability in relapsing-remitting patients, while the role of insulin resistance/type 2 diabetes mellitus or the impact of metformin use as a protective factor should be further studied. Prospective and larger studies are still needed in order to assess the real impact of comorbidities and their management in MS outcomes.

Forecasting Seizure Freedom After Epilepsy Surgery Assessing Concordance Between Noninvasive and StereoEEG Findings.

BACKGROUND: Accurate localization of the probable Epileptogenic Zone (EZ) from presurgical studies is crucial for achieving good prognosis in epilepsy surgery. OBJECTIVE: To evaluate the degree of concordance at a sublobar localization derived from noninvasive studies (video electroencephalography, EEG; magnetic resonance imaging, MRI; 18-fluorodeoxyglucose positron emission tomography FDG-PET, FDG-PET) and EZ estimated by stereoEEG, in forecasting seizure recurrence in a long-term cohort of patients with focal drug-resistant epilepsy. METHODS: We selected patients with a full presurgical evaluation and with postsurgical outcome at least 1 yr after surgery. Multivariate Cox regression analysis for seizure freedom (Engel Ia) was performed. RESULTS: A total of 74 patients were included, 62.2% were in Engel class Ia with a mean follow-up of 2.8 + 2.4 yr after surgery. In the multivariate analysis for Engel Ia vs >Ib, complete resection of the EZ found in stereoEEG (hazard ratio, HR: 0.24, 95%CI: 0.09-0.63, P = .004) and full concordance between FDG-PET and stereoEEG (HR: 0.11, 95%CI: 0.02-0.65, P = .015) portended a more favorable outcome. Most of our results were maintained when analyzing subgroups of patients. CONCLUSION: The degree of concordance between noninvasive studies and stereoEEG may help to forecast the likelihood of cure before performing resective surgery, particularly using a sublobar classification and comparing the affected areas in the FDG-PET with EZ identified with stereoEEG.

Multiple sclerosis and related disorders: Short report peripheral vascular events in a real-world cohort of multiple sclerosis patients using Fingolimod.

BACKGROUND: Fingolimod is a high-efficacy disease-modifying therapy for multiple sclerosis (MS) and was the first oral treatment approved for the disease. Adverse events include bradyarrhythmia, hypertension, macular oedema and increased risk of infections, mainly due to its main mechanism of action, the non-selective modulation of sphingosine-1-phosphate receptor. METHODS AND RESULTS: We report the baseline characteristics, effectiveness outcomes and adverse events of a prospective cohort of 177 patients with a median treatment duration of 24 months, in which four patients (2.3%) presented with otherwise non-provoked peripheral vascular events (PVE). CONCLUSIONS: Further studies are still needed to evaluate the frequency and severity of PVE in fingolimod patients.

Social cognition in Multiple Sclerosis is associated to changes in brain connectivity: A resting-state fMRI study.

BACKGROUND: Multiple Sclerosis produces changes in the functional connectivity of the brain. Resting-State fMRI is a useful tool for the study of functional changes in the human brain, and its metrics can be related to clinical findings involved in clinical decline. Social cognition has focused increasing interest because patients are exposed to experiencing social disorganization during the progression of the disease. fMRI has proved to be a useful tool for studying brain connectivity and its relation with social cognition both in resting-state and during socio-cognitive tasks. OBJECTIVE: to identify functional changes during rest in Relapsing-Remitting Multiple Sclerosis patients and look for a correlation with social cognition. METHODS: 45 patients with Relapsing-Remitting Multiple Sclerosis and 47 control subjects were recruited to perform a neuropsychological evaluation of the social cognition performance and to acquire resting-state fMRI. RESULTS: Patients exhibited lower performance in social cognition tasks, mostly related to face emotion recognition. Decreased functional connectivity in patients is seen concerning the right anterior insula, middle frontal, and occipital regions while increased connectivity is mostly related to the occipital and visual areas. The connectivity of the fusiform cortex and the amygdala is related to the performance in emotion recognition and Theory of Mind tasks respectively. CONCLUSION: Social cognition compromise was found in this sample. Functional connectivity changes during rest were detected and correlated with social cognition changes in patients.

Frontoparietal connectivity correlates with working memory performance in multiple sclerosis.

Working Memory (WM) impairment is the most common cognitive deficit of patients with Multiple Sclerosis (MS). However, evidence of its neurobiological mechanisms is scarce. Here we recorded electroencephalographic activity of twenty patients with relapsing-remitting MS and minimal cognitive deficit, and 20 healthy control (HC) subjects while they solved a WM task. In spite of similar performance, the HC group demonstrated both a correlation between temporoparietal theta activity and memory load, and a correlation between medial frontal theta activity and successful memory performances. MS patients did not show theses correlations leading significant differences between groups. Moreover, cortical connectivity analyses using granger causality and phase-amplitude coupling between theta and gamma revealed that HC group, but not MS group, presented a load-modulated progression of the frontal-to-parietal connectivity. This connectivity correlated with working memory capacity in MS groups. This early alterations in the oscillatory dynamics underlaying working memory could be useful for plan therapeutic interventions.