MR Imaging Findings in Anti-Leucine-Rich Glioma Inactivated Protein 1 Encephalitis: A Systematic Review and Meta-analysis.

BACKGROUND: Antibodies against leucine-rich glioma inactivated protein 1 (LGI1) constitute a common form of autoimmune encephalitis. On MR imaging, it may show T2 FLAIR hyperintensities of the medial temporal lobe (T2 FLAIR-MTL), involve the basal ganglia, or be unremarkable. PURPOSE: We performed a systematic review and meta-analysis to obtain prevalence estimates of abnormal findings on MR imaging in anti-LGI1 encephalitis. A human brain map of the LGI1 microarray gene expression was derived from the Allen Human Brain Atlas. DATA SOURCES: PubMed and Web of Science were searched with the terms "LGI1" and "encephalitis" from inception to April 7, 2022. STUDY SELECTION: Thirty-one research publications, encompassing case series and retrospective cohort and case-control studies, with >10 patients with anti-LGI1 encephalitis and MR imaging data were included. DATA ANALYSIS: Pooled prevalence estimates were calculated using Freeman-Tukey double-arcsine transformation. Meta-analysis used DerSimonian and Laird random effects models. DATA SYNTHESIS: Of 1318 patients in 30 studies, T2 FLAIR-MTL hyperintensities were present in 54% (95% CI, 0.48-0.60; I2 = 76%). Of 394 patients in 13 studies, 27% showed bilateral (95% CI, 0.19-0.36; I2 = 71%) and 24% unilateral T2 FLAIR-MTL abnormalities (95% CI, 0.17-0.32; I2 = 61%). Of 612 patients in 15 studies, basal ganglia abnormalities were present in 10% (95% CI, 0.06-0.15; I2 = 67%). LGI1 expression was highest in the amygdala, hippocampus, and caudate nucleus. LIMITATIONS: Only part of the spectrum of MR imaging abnormalities in anti-LGI1 encephalitis could be included in a meta-analysis. MR imaging findings were not the main outcomes in most studies, limiting available information. I2 values ranged from 62% to 76%, representing moderate-to-large heterogeneity. CONCLUSIONS: T2 FLAIR-MTL hyperintensities were present in around one-half of patients with anti-LGI1. The prevalence of unilateral and bilateral presentations was similar, suggesting unilaterality should raise the suspicion of this disease in the appropriate clinical context. Around 10% of patients showed basal ganglia abnormalities, indicating that special attention should be given to this region. LGI1 regional expression coincided with the most frequently reported abnormal findings on MR imaging. Regional specificity might be partially determined by expression levels of the target protein.

Neurological Involvement in a Portuguese Cohort of IgG4-Related Disease.

INTRODUCTION: Neurological involvement in immunoglobulin G4-related disease (IgG4-RD) is increasingly recognized. Its diagnosis can be challenging due to clinical mimics and difficulty in obtaining nervous system biopsies. The aim of this study was to describe a cohort of neurological IgG4-RD patients. METHODS: Patients were recruited from a neuroimmunology tertiary center. Clinical, laboratory, neuroimaging and histological data were reviewed. RESULTS: Fifteen patients (60% women), with a median age of 53 years (48.5 - 65.0) were included: 13 (86.7%) classified as possible IgG4-RD, one (6.7%) as probable and one (6.7%) as definitive. The most common neurological phenotypes were meningoencephalitis (26.7%), orbital pseudotumor (13.3%), cranial neuropathies (13.3%), peripheral neuropathy (13.3%), and longitudinally extensive transverse myelitis (LTEM) (13.3%). Median serum IgG4 concentration was 191.5 (145.0 - 212.0) mg/dL. Seven in 14 patients had CSF pleocytosis (50.0%) and oligoclonal bands restricted to the intrathecal compartment, while most cases presented elevated CSF proteins (64.3%). Magnetic resonance imaging abnormalities included white matter lesions in four (26.7%), hypertrophic pachymeningitis in two (13.3%), and LETM in two (13.3%). Two patients had biopsy-proven IgG4-RD in extra-neurological sites. CONCLUSION: This study highlights the phenotypical variability of the neurological IgG4-RD. Biopsy inaccessibility reinforces the importance of new criteria for the diagnosis of this subset of patients.

Anti-titin antibodies in a cohort of myasthenia gravis patients.

Background: Anti-titin antibodies have been previously associated with thymoma-associated myasthenia gravis (MG) and a more clinically severe form of MG. While currently only serving as a disease biomarker, its possible utility as an indicator of underlying thymus malignancy may be of value in clinical practice. Methods: Data was retrospectively collected and analyzed from 2013 to 2022 using an institutional record of MG patients. Anti-titin antibodies were assessed using Line Blot immunoassay. Results: From 130 MG cases, 32 (24.6%) were anti-titin positive. Anti-titin positive cases were associated with older age of disease onset [median (IQR): 63.0 (44.3-70.8) vs. 35.5 (24.8-60.8) years] (P<0.01). Thymectomy was performed in 46 (35.4%) MG patients, 12 of which anti-titin positive (26.1%). Thymectomy samples from anti-titin positive patients comprised 10 (83.3%) cases of thymoma and 2 (16.7%) cases of thymus hyperplasia. There was a tendency towards anti-titin positive patients having more thymoma while anti-titin negative displayed more hyperplasia (P<0.01). Anti-titin positivity correlated with thymoma in patients with age of onset bellow 50 years (P=0.028). Anti-titin positivity was significantly associated with generalized MG in the late-onset group (P=0.005). Conclusions: The presence of anti-titin antibodies appears to correlate with underlying thymoma in early-onset MG cases and with generalized MG in late-onset cases. Prospective studies are needed to further study this association.

Treatment strategies and treatment-related adverse events in MG according to the age of onset.

Introduction: Early-onset (EOMG) and late-onset (LOMG) are distinct groups of MG patients. It is unclear if treatment strategies and treatment-related adverse events may differ according to the age of MG onset. Methods: This single-center retrospective study includes all MG patients followed at a tertiary center since 2007. We reviewed the electronic clinical records. Results: In total, 212 patients were identified, 142 (67.0%) females, with a median disease duration of 10 years. The median age of symptom onset was 42.0 (26.0-64.5) years, with 130 (61.3%) EOMG cases and 82 (38.7%) LOMG. EOMG were more frequently female, had longer disease duration and often more generalized MG (p < 0.001). Comorbidities were significantly more frequent in LOMG (67.1%) compared to EOMG (53.1%) (p = 0.002). Steroid-related adverse effects motivating the switch to steroid-sparing agents (82.0%) were different between groups, with hypertension, hypercholesterolemia, diabetes mellitus and malignancies being more common in LOMG. At the same time, osteoporosis and dyspepsia were more frequent in EOMG (p < 0.001). The most common first-line choice was azathioprine (45.8%), and rituximab was used in 4 patients (1.9%). Conclusion: Our study shows that treatment modalities are similar between EOMG and LOMG, while steroid-related adverse events appear to be distinct.

Blood and CSF anti-neuronal antibodies testing in psychotic syndromes: a retrospective analysis from a tertiary psychiatric hospital.

A Consensus of Psychoimmunology Experts (Pollak et al., 2019) established a set of red flags and proposed diagnostic criteria for psychosis of autoimmune origin (AIP). Previous studies on AIP are limited by the scarcity of CSF analysis, preventing the valorization of blood anti-neuronal antibodies (Ab). The aims of this study are to determine the relative frequency and characterize AIP in a cohort of psychotic patients that underwent CSF workup. This work is a retrospective study in a tertiary psychiatric hospital. Clinical and paraclinical data were collected from medical records, and patients were classified according to Pollak et al. (2019) criteria. From 68 patients, ten (14.7%) had positive anti-neuronal antibodies (Ab): n = 5 in CSF and blood (n = 4 anti-NMDAr, n = 1 -GAD65), and n = 5 in blood only (n = 1 anti-GABAb, n = 1 -GAD65, n = 1 -SOX1, n = 1 -NMDAr, n = 1 -zic4). After 5- (2-10)-year follow-up, n = 6/68 (8.8%) had AIP diagnosis in context of autoimmune encephalitis (AE), and the remaining (n = 4/10, blood-only Ab) alternative diagnoses (n = 2 dementia, n = 1 schizophrenia, n = 1 intellectual disability). Ten of the 13 patients that fulfilled criteria for possible AIP were mimics, and only three AE had criteria for probable AIP. All AIP developed neurological manifestations (mostly cognitive dysfunction); EEG was usually abnormal (66.7%), and all had normal MRI. We found statistically significant associations between AIP/AE and systemic autoimmune disease, presentation with seizures and EEG abnormalities. All AE developed neurological symptoms alongside psychosis. Ab positivity occurred predominantly in AE but also in other neuropsychiatric disorders. Clinical suspicion based on the knowledge of the described presentations of established Ab is crucial in the psychotic patient approach.

Distinct phenotypes in a cohort of anti-CASPR2 associated neurological syndromes.

INTRODUCTION: Anti-contactin-associated protein-like 2 (CASPR2) is classically associated with limbic encephalitis (LE), Morvan syndrome and peripheral nerve hyperexcitability (PNH). Additional clinical features have been previously recognized. OBJECTIVE: To describe a cohort of patients with anti-CASPR2-associated neurological syndromes from a tertiary referral centre. METHODS: Retrospective analysis of patients with positive serum anti-CASPR2 antibodies in the period between 2014 and 2021. RESULTS: Nineteen patients were identified, 11 (57.9%) male, with a median age at symptom onset of 49.0 (31.3-63.0) years and a median time to diagnosis of 1.0 (0.0-1.8) years. The most common clinical syndromes were LE (7 cases, 36.8%), Morvan syndrome (4, 21.1%) and PNH (2, 10.5%). Six patients presented with atypical phenotypes (31.6%), comprising dysautonomia (orthostatic hypotension and Adie's Pupil), motor tics/stereotypies, obsessive-compulsive disorder, and brainstem involvement. The most common presenting symptoms were seizures (31.6%), PNH (21.1%) and cognitive dysfunction (15.8%). One LE patient had a disease duration of 2,5 years and was initially diagnosed with dementia. CSF was normal in most cases. Brain MRI showed temporal lobe hyperintensities in 4 LE cases (57.1%). All PNH cases had myokymic discharges of fasciculations in the electromyography. Two patients had associated thymoma and 1 had lung adenocarcinoma. Eight patients (42.1%) received treatment during the acute phase and 26.3% maintenance treatment. Approximately half of the treated cases improved or stabilised, with 4 (21.1%) deaths in the whole cohort. CONCLUSION: Anti-CASPR2-associated neurological disorders may present with isolated atypical phenotypes, a slowly progressive clinical course, and with normal CSF or imaging findings.

Hydrocephalus: a rare complication of primary central nervous system vasculitis.

Hydrocephalus is a known complication of central nervous system (CNS) vasculitis secondary to infectious diseases. We present an unusual case of primary CNS vasculitis (PCNSV) complicated by communicating hydrocephalus. A patient in their 50s with a few months' history of headache, psychomotor slowing and frequent falls presented with an acute left temporo-parieto-occipital infarction. Angiography revealed multiple arterial irregularities in the anterior circulation bilaterally, CSF was inflammatory and the remaining study was negative, fulfilling criteria for possible PCNSV. One month after successful treatment with corticosteroid, there was worsening of gait, urinary incontinence and neuropsychiatric symptoms. The investigation was remarkable only for active hydrocephalus. An external ventricular shunt was placed, followed by a ventriculoperitoneal shunt, and cyclophosphamide was started with subsequent recovery. Our discussion is that communicating hydrocephalus in PCNSV, due to impaired CSF flow, should be considered on subacute/chronic worsening of patients with PCNSV.

Different relationships between epilepsy syndromes and autoimmune diseases.

OBJECTIVE: Our objective was to study the relationship between epilepsy and autoimmune diseases in two different types of epilepsy: idiopathic generalized epilepsies (IGEs) and mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). The contribution of the human leukocyte antigen (HLA) system to this relationship was analyzed. METHODS: Adult patients with IGEs and MTLE-HS at a tertiary epilepsy center were consecutively enrolled between January 2016 and December 2020. RESULTS: A total of 664 patients, 422 with IGEs and 242 with MTLE-HS, were included. Patients with IGEs were 15 years younger, on average, than patients with MTLE-HS (p < .001). The frequency of autoimmune diseases was 5.5% (n = 23) and 4.5% (n = 11) in patients with IGEs and MTLE-HS, respectively (p = .716). The mean age of autoimmune disease onset was 20 ± 15.6 years in patients with IGEs and 36.7 ± 16.5 years in patients with MTLE-HS (p < .05). Clinical manifestations of autoimmune diseases preceded epilepsy onset in 30.4% of patients with IGEs (i.e., in early childhood); in the other patients, epilepsy appeared before autoimmune disease onset. In all but one patient with MTLE-HS and autoimmune diseases, the autoimmune diseases appeared after epilepsy onset from adolescence onward. SIGNIFICANCE: Our study indicates two relationship patterns: a bidirectional association between IGEs and autoimmune diseases and a unidirectional relationship between MTLE-HS and autoimmune diseases. The involvement of genetic susceptibility factors (such as the HLA system), autoinflammatory mechanisms, female sex, and antiseizure medications in these relationships are discussed.

Characterization of a late-onset multiple sclerosis Portuguese cohort.

BACKGROUND: Late-onset multiple sclerosis (LOMS) is defined as the onset of symptoms above 50 years, corresponding to an increasingly recognized subset of MS. This study aimed at comparing demographic and clinical data of patients with LOMS to those of early-onset MS (EOMS) from a Portuguese cohort. METHODS: Retrospective chart review of an MS cohort from a Portuguese tertiary center. RESULTS: From 746 patients with MS (61.7% female), we identified 39 cases with presentation after 50 years of age (22 males and 17 females), corresponding to 5.3%. The mean age at onset was 55.4 (±5.0) for LOMS and 29.5 (±8.9) for EOMS. There was no significant difference in disease duration. The most common type was relapsing-remitting MS, accounting for 51.5% and 83.9% of LOMS and EOMS patients, respectively. Primary-progressive MS (PPMS) was significantly more represented in the LOMS group (41.0%) (p < 0.01). The median EDSS was significantly higher in the LOMS group (4.75, 0.0-7.5) when compared to the EOMS group (2.0, 0.0-9,0). The most frequent presenting feature was myelitis in both LOMS (48.7%) and EOMS patients (47.4%), resulting in significantly higher EDSS (p = 0.003). CONCLUSIONS: LOMS is associated with higher EDSS when considering the same disease duration, translating into increased disability.

Pediatric Multiple Sclerosis-Experience of a Tertiary Care Center.

BACKGROUND: Pediatric-onset multiple sclerosis (POMS) accounts for 3 to 10% of all MS diagnoses. POMS is usually characterized by prominent disease activity, and patients are at higher risk of developing physical disability and cognitive impairment. OBJECTIVE: This article characterizes a cohort of POMS patients followed at the pediatric neurology unit of a Portuguese tertiary hospital. METHODS: Retrospective observational study. Clinical records of all patients with POMS between 2011 and 2020 were revised. RESULTS: A total of 21 patients, with a female:male ratio of 11:10 and a mean age of onset of 14.8 years were included. Clinical manifestations at presentation included myelitis in eight patients (two with associated brainstem syndrome), optic neuritis in six (one with associated cerebellar syndrome), supratentorial symptoms in four, and isolated brainstem syndrome in two. Twenty patients had oligoclonal immunoglobulin G bands in cerebrospinal fluid. Supra- and infratentorial involvement was identified in the first brain magnetic resonance imaging of nine patients. Initial relapses were treated with intravenous steroids in 19 patients. The mean time for diagnosis was 2.8 months. Eleven patients were on first-line treatment (nine on ß-interferon, two on teriflunomide) and 10 on second-line treatment (six on natalizumab, three on fingolimod, one on ocrelizumab). The mean annual relapse rate was 0.29 (range, 0.01-3), and the median Expanded Disability Status Scale was 1. Four patients reported learning disabilities and/or cognitive deficits. CONCLUSION: About half of patients in this cohort were on second-line disease-modifying treatment, with 19% showing cognitive impairment. Efforts to establish an early diagnosis are crucial to improving these patients' outcomes.

Circulating cell-free DNA methylation mirrors alterations in cerebral patterns in epilepsy.

BACKGROUND: DNA methylation profiling of circulating cell-free DNA (cfDNA) has rapidly become a promising strategy for biomarker identification and development. The cell-type-specific nature of DNA methylation patterns and the direct relationship between cfDNA and apoptosis can potentially be used non-invasively to predict local alterations. In addition, direct detection of altered DNA methylation patterns performs well as a biomarker. In a previous study, we demonstrated marked DNA methylation alterations in brain tissue from patients with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). RESULTS: We performed DNA methylation profiling in cfDNA isolated from the serum of MTLE patients and healthy controls using BeadChip arrays followed by systematic bioinformatic analysis including deconvolution analysis and integration with DNase accessibility data sets. Differential cfDNA methylation analysis showed an overrepresentation of gene ontology terms and transcription factors related to central nervous system function and regulation. Deconvolution analysis of the DNA methylation data sets ruled out the possibility that the observed differences were due to changes in the proportional contribution of cortical neurons in cfDNA. Moreover, we found no overrepresentation of neuron- or glia-specific patterns in the described cfDNA methylation patterns. However, the MTLE-HS cfDNA methylation patterns featured a significant overrepresentation of the epileptic DNA methylation alterations previously observed in the hippocampus. CONCLUSIONS: Our results support the use of cfDNA methylation profiling as a rational approach to seeking non-invasive and reproducible epilepsy biomarkers.

Mesial Temporal Lobe Epilepsy (MTLE) Drug-Refractoriness Is Associated With P2X7 Receptors Overexpression in the Human Hippocampus and Temporal Neocortex and May Be Predicted by Low Circulating Levels of miR-22.

Objective: ATP-gated ionotropic P2X7 receptors (P2X7R) actively participate in epilepsy and other neurological disorders. Neocortical nerve terminals of patients with Mesial Temporal Lobe Epilepsy with Hippocampal Sclerosis (MTLE-HS) express higher P2X7R amounts. Overexpression of P2X7R bolsters ATP signals during seizures resulting in glial cell activation, cytokines production, and GABAergic rundown with unrestrained glutamatergic excitation. In a mouse model of status epilepticus, increased expression of P2X7R has been associated with the down-modulation of the non-coding micro RNA, miR-22. MiR levels are stable in biological fluids and normally reflect remote tissue production making them ideal disease biomarkers. Here, we compared P2X7R and miR-22 expression in epileptic brains and in the serum of patients with MTLE-HS, respectively. Methods: Quantitative RT-PCR was used to evaluate the expression of P2X7R in the hippocampus and anterior temporal lobe of 23 patients with MTLE-HS and 10 cadaveric controls. Confocal microscopy and Western blot analysis were performed to assess P2X7R protein amounts. MiR-22 expression was evaluated in cell-free sera of 40 MTLE-HS patients and 48 healthy controls. Results: Nerve terminals of the hippocampus and neocortical temporal lobe of MTLE-HS patients overexpress (p < 0.05) an 85 kDa P2X7R protein whereas the normally occurring 67 kDa receptor protein dominates in the brain of the cadaveric controls. Contrariwise, miR-22 serum levels are diminished (p < 0.001) in MTLE-HS patients compared to age-matched control blood donors, a situation that is more evident in patients requiring multiple (>3) anti-epileptic drug (AED) regimens. Conclusion: Data show that there is an inverse relationship between miR-22 serum levels and P2X7R expression in the hippocampus and neocortex of MTLE-HS patients, which implies that measuring serum miR-22 may be a clinical surrogate of P2X7R brain expression in the MTLE-HS. Moreover, the high area under the ROC curve (0.777; 95% CI 0.629-0.925; p = 0.001) suggests that low miR-22 serum levels may be a sensitive predictor of poor response to AEDs among MTLE-HS patients. Results also anticipate that targeting the miR-22/P2X7R axis may be a good strategy to develop newer AEDs.

Auditory verbal learning test can lateralize hippocampal sclerosis.

The ability of the Auditory Verbal Learning Test (AVLT) to lateralize hippocampal sclerosis (HS) in mesial temporal lobe epilepsy (MTLE) was explored in a sample of 50 patients with MTLE-HS (23 right and 27 left). Patients' AVLT scores were adjusted to the demographic characteristics of each individual in accordance with the Portuguese normative data. The laterality of the HS was determined by consensus by two neuroradiologists. ROC curves were used to identify the best AVLT cutoff scores to differentiate right vs. left HS. Diagnostic statistics were applied to different AVLT measures. The study results revealed that four AVLT scores can correctly classify the laterality of HS in the total sample and a sub-group of 39 right-handed patients (Edinburgh Laterality Inventory +100): delayed recall trial (76 and 80%, respectively), delayed recognition trial (64 and 67%, respectively), learning over trials index (64 and 74%, respectively), and long-term percent retention index (68 and 72%, respectively). In right-handed patients, the diagnostic capability of the delayed recall trial was improved by pairing it with the learning over trials index (accuracy of 85%). In sum, AVLT measures of verbal memory differentiate left from right HS in MTLE. The delayed recall trial demonstrated good diagnostic capacity.

SARS-CoV-2 infection in patients with neuroimmunological disorders in a tertiary referral centre from the north of Portugal.

INTRODUCTION: The impact of COVID-19 in patients with neuroimmunological disorders is not fully established. There is some evidence suggesting an increased risk of more severe infection associated with the use of immunosuppressors in this population. OBJECTIVE: To characterize SARS-CoV-2 infection in patients followed in the neuroimmunology outpatient clinic of a tertiary centre from the north of Portugal. METHODS: Retrospective analysis of neuroimmunological patients with PCR-proven SARS-CoV-2 infection during the observational period of 20 months. RESULTS: Ninety-one patients were infected, 68.1% female, with a mean age of 48.9±16.7 years. The median disease duration was 11.0 (IQR 6.0-19.0) years. Sixty-one patients (67.0%) had Multiple Sclerosis, of which 50 with relapsing-remitting course, 12 (13.2%) Myasthenia Gravis (MG), 6 (6.6%) Autoimmune Encephalitis and 6 (6.6%) Chronic Inflammatory Demyelinating Polyneuropathy. Seventy-six patients (83.5%) were taking disease-modifying therapy, 77.6% of which were on immunosuppressants, including anti-CD20 in 12 (13.2%). Most patients had mild COVID-19 (84.6%), with 3 cases (3.3%) of severe disease and, 7 cases (7.7%) of critical disease being reported. In total, 13 patients were hospitalized and 4 died. Patients with severe to critical disease were significantly older than patients with milder forms (69.4±21.0 versus 46.5±14.4 years, p<0.01). MG was also associated with more severe disease (p=0.02). There was no association between comorbidities or use of immunosuppressors (including anti-CD20) and COVID-19 severity. CONCLUSIONS: Greater age and MG were associated with severe or critical COVID-19. We found no association between a specific DMT, including anti-CD20, and outcome. Clinical recovery was achieved by 93.4%.

Late onset neuromyelitis optica spectrum disorders (LONMOSD) from a nationwide Portuguese study: Anti-AQP4 positive, anti-MOG positive and seronegative subgroups.

INTRODUCTION: Several neuroimmunological disorders have distinct phenotypes according to the age of onset, as in multiple sclerosis or myasthenia gravis. It is also described that late onset NMOSD (LONMOSD) has a different phenotype. OBJECTIVE: To describe the clinical/demographic characteristics of the LONMOSD and distinguish them from those with early onset (EONMOSD). METHODS: From a nationwide Portuguese NMOSD study we analyzed the clinical/demographic characteristics of the LONMOSD. RESULTS: From the 180 Portuguese patients 45 had disease onset after 50 years old, 80% were female. 23 had anti-AQP4 antibodies (51.1%), 13 anti-MOG antibodies (28.9%) and 9 were double seronegative (20.0%). The most common presenting phenotypes in LONMOSD were transverse myelitis (53.3%) and optic neuritis (26.7%), without difference from EONMOSD (p = 0.074). The mean EDSS for LONMOSD was 6.0 (SD=2.8), after a mean follow-up time of 4.58 (SD=4.47) years, which was significantly greater than the mean EDSS of EONMOSD (3.25, SD=1.80)(p = 0.022). Anti-AQP4 antibodies positive LONMOSD patients had increased disability compared to anti-MOG antibodies positive LONMOSD (p = 0.022). The survival analysis showed a reduced time to use a cane for LONMOSD, irrespective of serostatus (p<0.001). CONCLUSIONS: LONMOSD has increased disability and faster progression, despite no differences in the presenting clinical phenotype were seen in our cohort.

Autoimmune encephalitis: suspicion in clinical practice and mimics.

Despite the existence of well-established diagnostic criteria for autoimmune encephalitis, there are diseases capable of mimicking it. This study sought to retrospectively evaluate the reasons for testing and the final diagnosis of patients admitted to a Neurology ward tested for anti-NMDAR antibodies and estimate sensitivity and specificity of current diagnostic criteria. The threshold for testing was lower than that of the prevailing diagnostic criteria, and the proportion of autoimmune encephalitis mimics was high. Searching for alternative diagnoses is of pivotal importance in cases of autoimmune encephalitis suspicion, and diagnostic criteria may need expanding so that no autoimmune encephalitis is missed.

Pediatric neuromyelitis optica spectrum disorders in Portugal: A multicentre retrospective study.

INTRODUCTION: Neuromyelitis optica spectrum disorders (NMOSD) are more prevalent in adulthood, with few cases reported in pediatric age (<18 years). In this group, anti-aquaporin 4 (AQP4) antibodies are less frequent, while antibodies against myelin oligodendrocyte glycoprotein (MOG) are more commonly detectable than in adults. OBJECTIVE AND METHODS: Description of pediatric NMOSD cases identified in a national multicentric NMOSD Portuguese registry. RESULTS: Twenty (11.1%) NMOSD cases were diagnosed in pediatric age. Twelve (60%) were female, with a median age of onset of 12.5 (6.8-16.5) years. The presenting feature was transverse myelitis in 10 (50%), 4 of which with simultaneous optic neuritis and 2 with concomitant brainstem syndrome. Nine patients (45%) had pleocytosis in the CSF. Six (30.0%) exhibited anti-AQP4 antibodies, 13 (65.0%) anti-MOG antibodies, and one was seronegative for both. Four anti-AQP4 antibodies-positive patients had ≥1 relapse. Most anti-MOG-positive cases were monophasic (53.8%). In the acute phase, all patients received IV methylprednisolone, nine received IVIg and four plasma exchange. One anti-AQP4-positive patient died. Ten patients (5 anti-AQP4-positive/5 anti-MOG-positive) were on maintenance immunosuppressive therapy at the time of data collection. CONCLUSION: NMOSD may present in pediatric age. It is essential to establish the diagnosis and promptly start therapy to improve the prognosis.

Cognitive dysfunction and mortality in multiple sclerosis: Long-term retrospective review.

BACKGROUND: Cognitive dysfunction as a predictor of clinical progression and mortality in multiple sclerosis (MS) is still a matter of debate. OBJECTIVE: The aim of this study was to explore the long-term outcome associated with neuropsychological performance in a cohort of patients with MS. METHODS: A series of 408 MS patients had previously undergone a comprehensive neuropsychological assessment and a contemporaneous neurological evaluation (T1). A retrospective review of the clinical records was conducted 102-192 months after T1. Demographic and clinical data regarding the last clinical appointment with EDSS measurement (T2) were collected and the date of the last clinical contact or death (TS) was recorded. RESULTS: This review revealed that cognitive dysfunction (T1) was associated with higher odds of transitioning from relapsing-remitting course to a progressive disease course (adjusted odds ratio (OR) = 2.29, p = 0.043) and higher hazard of death in the total sample (adjusted hazard ratio (HR) = 3.07, p = 0.006) and the progressive disease course subgroup (adjusted HR = 3.68, p = 0.007), even when adjusting for other covariates. DISCUSSION: The study results demonstrate that cognitive dysfunction in MS is predictive of poorer prognosis and mortality.