Neurological manifestations of COVID-19 - an approach to categories of pathology.

BACKGROUND: Various neurological manifestations of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been reported, associated with a broad spectrum of diverse neurological symptoms and syndromes. Estimating rate and relevance of these manifestations remains difficult as there is a lack of standardised case definitions.
METHODS: We defined comprehensive categories including most reported neurological manifestations associated with SARS-CoV-2 to allow for a more standardised data collection. After a literature search of MEDLINE with ten keywords, 12 selected studies and larger case series were included. We compared the rate and relevance of neurological manifestations in hospitalized patients. We propose four main categories including 1) cerebrovascular disease, 2) inflammatory syndromes of the central nervous system (CNS), peripheral nervous system (PNS) and muscle, 3) metabolic/toxic dysfunction of CNS, PNS and muscle and 4) miscellaneous disorders.
CONCLUSION: Ageusia (702) and anosmia (805) have been reported as the most common and the first occurring neurological symptoms. Cerebrovascular disease (451) and encephalopathy (663) were associated with a more severe course and worse clinical outcome. Any neurological manifestation was associated with a longer hospital stay and a higher morbidity and mortality compared to patients without neurological manifestations. We suggest reporting future neurological manifestations of coronavirus disease-19 (COVID-19) following a pathophysiology-based approach using standardized pre-defined case definitions to yield more specific and comparable data.