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.

Stroke frequency, associated factors, and clinical features in primary systemic vasculitis: a multicentric observational study.

OBJECTIVES: The cerebral vessels may be affected in primary systemic vasculitis (PSV), but little is known about cerebrovascular events (CVEs) in this population. This study aimed to determine the frequency of CVEs at the time of diagnosis of PSV, to identify factors associated with CVEs in PSV, and to explore features and outcomes of stroke in patients with PSV. METHODS: Data from adults newly diagnosed with PSV within the Diagnostic and Classification Criteria in VASculitis (DCVAS) study were analysed. Demographics, risk factors for vascular disease, and clinical features were compared between patients with PSV with and without CVE. Stroke subtypes and cumulative incidence of recurrent CVE during a prospective 6-month follow-up were also assessed. RESULTS: The analysis included 4828 PSV patients, and a CVE was reported in 169 (3.50%, 95% CI 3.00-4.06): 102 (2.13% 95% CI 1.73-2.56) with stroke and 81 (1.68% 95% CI 1.33-2.08) with transient ischemic attack (TIA). The frequency of CVE was highest in Behçet's disease (9.5%, 95% CI 5.79-14.37), polyarteritis nodosa (6.2%, 95% CI 3.25-10.61), and Takayasu's arteritis (6.0%, 95% CI 4.30-8.19), and lowest in microscopic polyangiitis (2.2%, 95% CI 1.09-3.86), granulomatosis with polyangiitis (2.0%, 95% CI 1.20-3.01), cryoglobulinaemic vasculitis (1.9%, 95% CI 0.05-9.89), and IgA-vasculitis (Henoch-Schönlein) (0.4%, 95% CI 0.01-2.05). PSV patients had a 11.9% cumulative incidence of recurrent CVE during a 6-month follow-up period. CONCLUSION: CVEs affect a significant proportion of patients at time of PSV diagnosis, and the frequency varies widely among different vasculitis, being higher in Behçet's. Overall, CVE in PSV is not explained by traditional vascular risk factors and has a high risk of CVE recurrence.

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.

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.

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.

[Diagnosis and Treatment of Neuro-Behçet: A Clinical Update]. / Diagnóstico e Tratamento do Neuro-Behçet: Uma Actualização Clínica.

Behçet's disease is a relapsing multisystemic inflammatory syndrome characterized by recurrent oral and/or genital ulcers, uveitis, arthritis, skin lesions, and gastrointestinal and neurological involvement. Neuro-Behçet corresponds to nervous system involvement and is one of the most severe complications of Behçet disease. It occurs in 3% to 30% of cases and is categorized into parenchymal (most common) or non-parenchymal disease. The most common manifestation of parenchymal neuro-Behçet is meningoencephalitis with involvement of the brainstem, where patients present with cranial neuropathies, encephalopathy, sensory-motor syndromes, epilepsy, or myelitis. The main non-parenchymal manifestation is cerebral venous thrombosis. Neuro-Behçet has a predominantly subacute course, with remission within weeks, or clinical progression in one third of the cases. The diagnosis is essentially clinical and diagnostic tests help to corroborate the suspicion, distinguish from differential diagnoses, and exclude complications. Brain magnetic resonance imaging allows the identification of acute lesions (hypointense or isointense on T2-weighted and hypointense on T1-weighted sequences) contrast-enhanced, and chronic lesions characterized by non-contrast enhanced small lesions and brainstem atrophy. If non-parenchymal involvement is suspected, cerebral veno-magnetic resonance imaging /computed tomography should be performed. Cerebrospinal fluid shows elevated proteinorachia and pleocytosis in parenchymal and no changes in non-parenchymal neuro-Behçet (except increased opening pressure). Outbursts of parenchymal disease should be treated with high dose intravenous corticosteroid therapy, with subsequent switch to oral corticoids, followed by biologic therapy, usually an anti-TNF. The treatment of cerebral venous thrombosis is controversial and may consist of a combination of corticosteroids and anticoagulation.

A doença de Behçet é uma síndrome inflamatória multissistémica recidivante, caraterizada por úlceras orais e/ou genitais recorrentes, uveítes, artrite, lesões cutâneas e envolvimento gastrointestinal e neurológico. O neuro-Behçet corresponde ao envolvimento do sistema nervoso e é uma das complicações mais graves da doença de Behçet. Ocorre em 3% a 30% dos casos e categoriza-se em doença parenquimatosa (mais frequente) ou não-parenquimatosa. A manifestação mais comum do neuro-Behçet parenquimatoso é a meningoencefalite com acometimento do tronco cerebral, sendo que os doentes se apresentam com neuropatias cranianas, encefalopatia, síndromes sensitivo-motoras, epilepsia ou mielite. A principal manifestação não-parenquimatosa é a trombose venosa cerebral. O neuro-Behçet apresenta uma evolução maioritariamente subaguda, com remissão em semanas, ou com progressão clínica, em um terço dos casos. O diagnóstico é essencialmente clínico e os exames complementares auxiliam a corroborar a suspeita, a diferenciar de diagnósticos diferenciais e a excluir complicações. A ressonância magnética cerebral permite observar lesões agudas (hipo ou isointensas em T2 e hipointensas em T1) que captam contraste, e lesões crónicas caraterizadas por pequenas lesões que não captam contraste e atrofia do tronco cerebral. Na suspeita de envolvimento não-parenquimatoso deve ser realizada venoressonância magnética/tomografia computorizada cerebral. O líquido cefalorraquidiano apresenta elevação da proteinorraquia e da pleocitose no neuro-Behçet parenquimatoso e não tem alterações no não-parenquimatoso (exceto aumento da pressão de abertura). Os surtos de doença parenquimatosa devem ser tratados com corticoterapia endovenosa em alta dose, com posterior desmame para corticoterapia oral, seguida de terapêutica biológica, habitualmente anti-TNF. O tratamento da trombose venosa cerebral é controverso, podendo consistir na associação de corticoterapia e anticoagulação.

Inflammatory Optic Neuropathy as a Presenting Feature of Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy.

Background: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is commonly associated with early-onset stroke, migraine and vascular dementia. However, optic nerve involvement has been previously recognised. Results: We report a case of a 21-year-old female presenting with right inferior temporal scotoma, dyschromatopsia, relative pupillary afferent defect and bilateral disk oedema in the fundoscopic examination. Visual evoked potential latencies were bilaterally increased, suggesting optic neuropathy. Cerebrospinal fluid (CSF) evaluation showed 11 leukocytes, .45 mg/dL proteins, elevated IgG (4.55 mg/dL) and 2 oligoclonal bands (OCB) restricted to the CSF. ESR was 17 mm/h and CRP 5 mg/dL. Anti-Aquaporin4 anti-MOG antibodies were negative. The MRI showed right optic nerve hyperintensity, enhancing after the administration of contrast product, and multiple FLAIR focal lesions present throughout the white matter, with a noticeable confluence in the anterior temporal horns. She improved after IV high-dose methylprednisolone. Because the lesions of the white matter were highly atypical for an inflammatory disease and highly suggestive of CADASIL genetic testing was requested. A heterozygous pathogenic variant c994C>T p (Arg332Cys) in the exon 6 of the NOTCH3 gene, compatible with the diagnosis of CADASIL was found. Conclusions: This case highlights isolated optic nerve involvement as a presenting feature of CADASIL, possibly reflecting an inflammatory process associated with this hereditary vasculopathy.

Rapidly Progressive Corticobasal Degeneration Mimicking Brainstem Encephalitis.

Background: Corticobasal degeneration (CBD) may have a rapidly progressive (RP) clinical course, mimicking other neurological conditions. Objectives: To describe a neuropathologically proven case of RP-CBD in a patient initially diagnosed with immune-mediated brainstem encephalitis. Methods: Retrospective data collection from electronic records and authorized video material. Results: A 51-year-old man presented with bilateral ptosis, diplopia, and dysphagia. The diagnostic workup was negative for myasthenic syndromes. He progressively developed cognitive dysfunction with frontal release signs and asymmetric parkinsonism. Cerebrospinal fluid evaluation revealed 4 leukocytes/uL, 0.32 g/L proteins, 0.85 g/L glucose, and absent oligoclonal bands. Weakly positive anti-PNMA2 (Ma2/Ta) antibodies were present, and magnetic resonance imaging showed a T2 hyperintensity involving the midbrain and pons. Based on these features, the diagnosis of immune-mediated brainstem encephalitis was considered. The patient did not improve after several cycles of methylprednisolone, intravenous immunoglobulin, and plasma exchange. At 1 year after onset, he developed horizontal and vertical gaze limitation and worsening of the parkinsonism and cognitive dysfunction. By age 53, he was severely disabled, requiring percutaneous gastrostomy for feeding. Anti-IgLON5 was negative. He fulfilled the clinical criteria for probable progressive supranuclear palsy. He died from pneumonia at age 54. The neuropathological examination revealed a 4-repeat tauopathy with features of CBD with extensive involvement of the brainstem. Conclusions: RP-CBD may resemble brainstem encephalitis. The severity of brainstem and upper spinal cord pathology in the postmortem examination correlated with the clinical and imaging features.

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.

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.

External Ophthalmoplegia and Brainstem White Matter Lesions: Presentation of Myotonic Dystrophy Type 1.

INTRODUCTION: Myotonic dystrophy type 1 (DM1) is an autosomal dominant condition which phenotype can be extremely variable considering its multisystem involvement, including the central nervous system. Neuromuscular findings are facial and distal extremities muscle weakness, muscle atrophy and myotonia. Standard diagnosis is obtained with molecular testing to detect CTG expansions in the myotonic dystrophy protein of the kinase gene. Brain magnetic resonance imaging typically shows characteristic subcortical white matter (WM) abnormalities located within anterior temporal lobes. CASE REPORT: We present a 39-year-old male patient with a progressive external ophthalmoplegia, facial and limb muscle weakness, percussion myotonia and atypical brain magnetic resonance imaging findings, showing confluent brainstem WM lesions, affecting the pons, a rare radiologic feature in this disorder. Genetic testing confirmed the diagnosis for DM1. CONCLUSION: This presentation with external ophthalmoplegia and brainstem WM loss in DM1 can show an important correlation with clinical findings and have an important diagnostic and prognostic value.

Factors associated with the severity of COVID-19 outcomes in people with neuromuscular diseases: Data from the International Neuromuscular COVID-19 Registry.

BACKGROUND AND PURPOSE: Clinical outcome information on patients with neuromuscular diseases (NMDs) who have been infected with SARS-CoV-2 is limited. The aim of this study was to determine factors associated with the severity of COVID-19 outcomes in people with NMDs. METHODS: Cases of NMD, of any age, and confirmed/presumptive COVID-19, submitted to the International Neuromuscular COVID-19 Registry up to 31 December 2021, were included. A mutually exclusive ordinal COVID-19 severity scale was defined as follows: (1) no hospitalization; (2) hospitalization without oxygenation; (3) hospitalization with ventilation/oxygenation; and (4) death. Multivariable ordinal logistic regression analyses were used to estimate odds ratios (ORs) for severe outcome, adjusting for age, sex, race/ethnicity, NMD, comorbidities, baseline functional status (modified Rankin scale [mRS]), use of immunosuppressive/immunomodulatory medication, and pandemic calendar period. RESULTS: Of 315 patients from 13 countries (mean age 50.3 [±17.7] years, 154 [48.9%] female), 175 (55.5%) were not hospitalized, 27 (8.6%) were hospitalized without supplemental oxygen, 91 (28.9%) were hospitalized with ventilation/supplemental oxygen, and 22 (7%) died. Higher odds of severe COVID-19 outcomes were observed for: age ≥50 years (50-64 years: OR 2.4, 95% confidence interval [CI] 1.33-4.31; >64 years: OR 4.16, 95% CI 2.12-8.15; both vs. <50 years); non-White race/ethnicity (OR 1.81, 95% CI 1.07-3.06; vs. White); mRS moderately severe/severe disability (OR 3.02, 95% CI 1.6-5.69; vs. no/slight/moderate disability); history of respiratory dysfunction (OR 3.16, 95% CI 1.79-5.58); obesity (OR 2.24, 95% CI 1.18-4.25); ≥3 comorbidities (OR 3.2, 95% CI 1.76-5.83; vs. ≤2; if comorbidity count used instead of specific comorbidities); glucocorticoid treatment (OR 2.33, 95% CI 1.14-4.78); and Guillain-Barré syndrome (OR 3.1, 95% CI 1.35-7.13; vs. mitochondrial disease). CONCLUSIONS: Among people with NMDs, there is a differential risk of COVID-19 outcomes according to demographic and clinical characteristics. These findings could be used to develop tailored management strategies and evidence-based recommendations for NMD patients.

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.

Anti-NMDAr Encephalitis and COVID-19 in a Patient With Systemic pANCA-Vasculitis and Recurrent Varicella Zoster Infection.

Introduction: There is a complex interplay between systemic autoimmunity, immunosuppression, and infections. Any or all of these can result in neurologic manifestations, requiring diligence on the part of neurologists. Case report: We herein report a case of a patient on immunosuppressive treatment for a vasculitis that resulted in zoster meningoencephalitis. This was further complicated by the development of anti-NMDAr encephalitis, the etiology of which is undetermined and further discussed in this paper. The patient eventually developed COVID-19 during hospitalization, succumbing to the respiratory infection. Conclusion: This case emphasizes that post-infectious autoimmune disorders are becoming increasingly recognized and that they should still be considered in patients who are on immunosuppression. Practitioners should be aware of the complex relationship between autoimmunity and immunosuppression and consider both throughout the disease course.