Neurology of COVID-19 in Singapore

Koh, Jasmine Shimin; De Silva, Deidre Anne; Quek, Amy May Lin; Chiew, Hui Jin; Tu, Tian Ming; Seet, Christopher Ying Hao; Hoe, Rebecca Hui Min; Saini, Monica; Hui, Andrew Che-Fai; Angon, Jasmyn; Ker, Justin Ruixin; Yong, Ming Hui; Goh, Yihui; Lim, Tchoyoson Choie Cheio; Tan, Benjamin Yong Qiang; Ng, Kay Wei Ping; Yeo, Leonard Leong Litt; Pang, Yu Zhi; Prakash, Kumar M.; Ahmad, Aftab; Thomas, Terrence; Lye, David Chien Boon; Tan, Kevin; Umapathi, Thirugnanam

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 early in relatively mild infection. 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 Singapore healthcare system.