Acute radiological features facilitate diagnosis and prognosis of anti-N-methyl-d-aspartate receptor (NMDAR) and anti-voltage-gated potassium channel (VGKC) encephalitis in adults.

BACKGROUND: Anti-N-methyl-d-aspartate receptor (NMDAR) and anti-voltage-gated potassium channel (VGKC) encephalitis are the commonest antibody-associated autoimmune encephalitides (AIE). Acute clinical features have been well-described, but data on the role of radiological findings in diagnosis and prognosis of AIE are limited. METHODS: Anti-NMDAR and anti-VGKC encephalitis patients from the National Neuroscience Institute were identified. We compared clinical and paraclinical features, at acute presentation and on follow-up between and within groups. RESULTS: Twenty-six anti-NMDAR and 11 anti-VGKC encephalitis patients were reviewed. At acute presentation, dysautonomia (57.7%) and impairment of consciousness (84.6%) occurred exclusively in anti-NMDAR encephalitis. Cerebrospinal fluid pleocytosis was more common in anti-NMDAR encephalitis (88.5% vs 20.0%, p = 0.003), while ictal electroencephalography abnormalities were more frequent in anti-VGKC encephalitis (11.5% vs 45.5%, p = 0.022). On acute imaging, leptomeningeal enhancement was seen only in anti-NMDAR encephalitis (37.5%), while hippocampal T2 hyperintensities supported the diagnosis of anti-VGKC encephalitis (63.6% vs 12.5%, p = 0.002). At follow-up (median 53.0 months, range 13.0-119.0), anti-NMDAR encephalitis patients had better modified Rankin scale scores (median 0.0 vs 3.0, p = 0.023). Relapses occurred equally in both groups. Anti-VGKC encephalitis patients with abnormal acute MRI were more likely to have poor outcomes compared to those with normal imaging (100% vs 25%, p = 0.008), whereas acute imaging features in anti-NMDAR encephalitis did not predict long-term outcomes. CONCLUSIONS: Acute MRI findings can aid in early diagnosis and prognostication in suspected AIE. Leptomeningeal enhancement in anti-NMDAR encephalitis and hippocampal lesions in anti-VGKC encephalitis, together with typical clinical features, may allow distinction between these antibody subtypes, and specific abnormal imaging features in anti-VGKC encephalitis may be used as a prognostic marker.

Neurology of COVID-19 in Singapore.

PURPOSE: To describe the spectrum of COVID-19 neurology in Singapore. METHOD: We prospectively studied all microbiologically-confirmed COVID-19 patients in Singapore, who were referred for any neurological complaint within three months of COVID-19 onset. Neurological diagnoses and relationship to COVID-19 was made by consensus guided by contemporaneous literature, refined using recent case definitions. RESULTS: 47,572 patients (median age 34 years, 98% males) were diagnosed with COVID-19 in Singapore between 19 March to 19 July 2020. We identified 90 patients (median age 38, 98.9% males) with neurological disorders; 39 with varying certainty of relationship to COVID-19 categorised as: i) Central nervous system syndromes-4 acute disseminated encephalomyelitis (ADEM) and encephalitis, ii) Cerebrovascular disorders-19 acute ischaemic stroke and transient ischaemic attack (AIS/TIA), 4 cerebral venous thrombosis (CVT), 2 intracerebral haemorrhage, iii) Peripheral nervous system-7 mono/polyneuropathies, and a novel group, iv) Autonomic nervous system-4 limited dysautonomic syndromes. Fifty-one other patients had pre/co-existent neurological conditions unrelated to COVID-19. Encephalitis/ADEM is delayed, occurring in critical COVID-19, while CVT and dysautonomia occurred relatively early, and largely in mild infections. AIS/TIA was variable in onset, occurring in patients with differing COVID-19 severity; remarkably 63.2% were asymptomatic. CVT was more frequent than expected and occurred in mild/asymptomatic patients. There were no neurological complications in all 81 paediatric COVID-19 cases. CONCLUSION: COVID-19 neurology has a wide spectrum of dysimmune-thrombotic disorders. We encountered relatively few neurological complications, probably because our outbreak involved largely young men with mild/asymptomatic COVID-19. It is also widely perceived that the pandemic did not unduly affect the Singapore healthcare system.

Serial outcomes in acute necrotising encephalopathy of childhood: A medium and long term study.

OBJECTIVE: Acute necrotising encephalopathy (ANEC) is a severe, debilitating childhood disorder. We used the ANEC scoring system (ANE-ss) and standardised neurodevelopmental scores to objectively characterise medium and long term outcomes. METHODS: Retrospective review of children with ANEC at KK Women's and Children's Hospital, Singapore, from 2005 to 2012. ANE-ss was determined from clinical features and neuroimaging, and neurodevelopmental scores (Pediatric Glasgow Outcome Scale Extended, Pediatric Cerebral Performance Category scale and Pediatric Overall Performance Category scale) were applied at 1, 6, 12 and 24months post diagnosis. RESULTS: Seven patients with ANEC were studied. All had a viral prodrome with fever, and encephalopathy at presentation, and received immunotherapy (steroids or immunoglobulin). ANE-ss scores were medium risk in 4 patients and high risk in 3 patients. One died (high risk ANE-ss) and outcome was determined in the 6 survivors. At 1month post diagnosis, 3 patients (50%) were mildly affected and 3 (50%) were severely affected. Morbidity rates improved by 12months, with 67% and 33.3% scoring in the mildly affected and severely affected ranges, respectively. Medium risk patients did well with majority having little or no neurological deficits and good outcome scores. CONCLUSION: Mortality and severe morbidity correlated well with high risk ANE-ss. However, our patients with medium risk ANE-ss had good neurodevelopmental sequelae. Serial disability scoring is useful in evaluating the progress of ANEC patients on follow up. Assessment at 1month post diagnosis can aid prognostication of long term outcome.

Clinics in diagnostic imaging (153). Severe hypoxic ischaemic brain injury.

A 58-year-old Indian woman presented with asystole after an episode of haemetemesis, with a patient downtime of 20 mins. After initial resuscitation efforts, computed tomography of the brain, obtained to evaluate neurological injury, demonstrated evidence of severe hypoxic ischaemic brain injury. The imaging features of hypoxic ischaemic brain injury and the potential pitfalls with regard to image interpretation are herein discussed.