Encephalitis associated with anti-mGluR5 antibodies.

A 30-year-old woman had 5 days of visual hallucinations, nystagmus, memory impairment and mutism. On examination, she was disorientated with reduced attention span, gaze-evoked nystagmus, paratonia and abnormal frontal reflexes. Cerebrospinal fluid (CSF) showed 80 cells, protein 0.41 g/L and glucose 3.2 mmol/L (plasma glucose 5.0 mmol/L). MR scan of the brain showed involvement of limbic and extra-limbic regions and brainstem. Commercial cell-based assays were negative, but tissue-based assays showed neuropil staining, and cell-based assays for anti-metabotropic glutamate receptor 5 (mGluR5) antibodies were positive in serum and CSF. Six months later, she was diagnosed with Hodgkin's lymphoma. This case emphasises the broader clinical spectrum of anti-mGluR5 encephalitis, challenging its initial characterisation as Ophelia syndrome. It underscores the significance of interpreting commercial cell-based assays and advocates for tissue-based assay testing followed by cell-based assay testing in serum and CSF for diagnosing rare autoimmune encephalitis.

Acute disseminated encephalomyelitis following Saint Louis encephalitis virus infection.

Saint Louis encephalitis virus (SLEV) infection is an arbovirosis associated with a broad spectrum of neurological complications. We present a case of a 55-year-old man hailing from Manaus, a city situated in the heart of the Amazon Rainforest, who exhibited symptoms of vertigo, tremors, urinary and fecal retention, compromised gait, and encephalopathy 3 weeks following SLEV infection. Neuroaxis MRI revealed diffuse, asymmetric, and poorly defined margins hyperintense lesions with peripheral and ring enhancement in subcortical white matter, as well as severe spinal cord involvement. Serology for SLEV was positive both on serum and cerebrospinal fluid. To the best of our knowledge, the present report is the first to show brain lesions along with myelitis as a post-infectious complication of SLEV infection.

Neurocysticercosis: diagnosis via metagenomic next-generation sequencing.

A 68-year-old Brazilian woman had 3 months of progressive fatigue, difficulty walking and 18 kg weight loss. On examination, there was gait apraxia and executive dysfunction. MR scan of brain showed communicating hydrocephalus and a cerebrospinal fluid showed 105 white cells/µL (≤5), predominantly lymphocytes, protein of 1.35 g/L (0.15-0.45) and the glucose content of 0.06 mmol/L (3.3-4.4). We suspected an infective cause and used of metagenomic next-generation sequencing to diagnose neurocysticercosis. This case highlights the challenge of diagnosing chronic meningitis and the relevance of genetic approaches in diagnosing neurological infections.

Prevalence of neuromyelitis optica spectrum disorder in Belo Horizonte, Southeast Brazil.

BACKGROUND: Studies on the prevalence of neuromyelitis optica spectrum disorder (NMOSD) are still scarce. The aim of the current study was to determine the prevalence rate of NMOSD in Belo Horizonte, southeast Brazil, where the prevalence rate of multiple sclerosis (MS) has already been established. METHODS: For this observational study, eligible patients had to meet the 2015 International Panel for Neuromyelitis Optica Diagnosis, be seen at the study center between January 2000 and February 2019 and live in Belo Horizonte. The prevalence rate of NMOSD was estimated based on the number of MS and NMOSD patients seen at same Center during the same period, and the previously established prevalence of MS in Belo Horizonte. RESULTS: During the study period, there were 69 patients with NMOSD, 60 (87.0%) of whom were females, and 44 (63.8%) non-whites. The median age at disease onset was 36.7 (4-72) years, the mean EDSS score 4.78±2.36, and the mean ARR 0.57±0.43. Anti-aquaporin-4 immunoglobulin testing was available for 61 (88.4%) patients, of whom 41 (67.2%) had a positive result. During the same period, 280 MS patients were seen. Considering the local known prevalence rate of MS of 18.1/100,000 inhabitants, the estimated NMOSD prevalence rate in Belo Horizonte was 4.52/100,000 (95% CI 3.72-5.43) inhabitants. CONCLUSION: The prevalence rate of NMOSD in Belo Horizonte is high as compared with those found in most of the studies reported to date.

Neuromyelitis optica spectrum disorder associated with dengue virus infection.

Dengue virus infection is a disease with high incidence in some tropical and subtropical countries. A variety of neurological complications of dengue fever (DF) has been described including two cases with the phenotype of neuromyelitis optica spectrum disorder (NMOSD). However, aquaporin-4 serostatus was unknown or negative in these patients. We report two patients with NMOSD occurring in association with DF. The first patient presented with brainstem symptoms and the second one with isolated unilateral optic neuritis. Both patients tested positive for serum AQP4-antibody. This report shows that DF may trigger seropositive NMOSD.

Myelitis and cauda equina involvement following dengue fever. A case report and review of the literature.

Dengue fever (DF) is a common arbovirosis in tropical and subtropical countries and may be associated with a wide range of neurological complications. We describe a 41-year-old man who developed weakness in the right arm and lower limbs, paresthesia in the upper and lower limbs, and sphincter disturbance four weeks following DF. Examination disclosed a wheel-chair bound patient with urinary catheter, areflexia in the lower limbs, and a sensation level at T10. Spinal magnetic resonance imaging showed diffuse lesions with contrast-enhanced areas extending from the medullary-cervical junction to the conus medullaris and cauda equina. A review of the literature reveals that this is the first report of clinical and imaging signs of myeloradiculitis with cauda equina involvement following DF infection.