World Federation of Neurology proposes international registries to report neurological manifestations of COVID-19
A comprehensive review of neurological disorders reported during the current coronavirus disease 2019 (COVID-19) pandemic demonstrates that infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) affects the central nervous system (CNS), the peripheral nervous system (PNS) and muscles, leading the Environmental Neurology Specialty Group of the World Federation of Neurology to propose implementation of international neurological registries.
“Although the a priori impression is that CNS injury occurs predominantly as a result of metabolic and inflammatory responses in elderly patients admitted to intensive care units [ICUs], a direct viral attack might be a more likely explanation for the extremely high mortality,” postulated the authors of the recent literature review. [J Neurol Sci 2020;414:116884]
The authors hypothesized that SARS-CoV-2, like other human coronaviruses, has neurogenic properties. According to the results of a multicentre European study, SARS-CoV-2 infection resulted in olfactory and gustatory dysfunctions in over 80 percent of mild-to-moderate cases, which must occur shortly after the virus reaches ACE2 receptors in the nasal epithelium. [Eur Arch Otorhinolaryngol 2020;6:1-11] “Given the relative absence of nasal congestion and rhinorrhea, anosmia likely results from viral presence in the olfactory bulbs,” wrote the authors. [Int J Infect Dis 2020;94:91-95; Lancet 2020;395:507-513; ACS Chem Neurosci 2020, doi: 10.1021/acschemneuro.0c00122]
Other symptoms indicative of CNS involvement include headache (6 percent of all patients vs 13 percent of patients who go on to suffer a stroke) and impaired consciousness (1 percent of non-fatal cases vs 22 percent of fatal cases. [J Inf Secur 2020;80:401-406; BMJ 2020;368:m1091] “In some patients, the viral neurotropism of SARS-CoV-2 probably invades the brain via axonal transport and transneuronal spread from the olfactory nerves to the rhinencephalon, finally reaching the brainstem, causing the irreversible respiratory failure in severe COVID-19,” hypothethized the authors.
Compared with reports of CNS involvement in COVID-19, the bibliography describing PNS and muscle pathology is more limited. However, cases of Guillain-Barré syndrome, Miller Fisher syndrome, polyneuritis cranialis, and rare instances of viral myopathy with rhabdomyolysis have been reported. [Lancet 2020, doi: 10.1016/S1474-4422(20)30109-5; Am J Otolaryngol 2020, doi: 10.1016/j.amjoto.2020.102473; Emerg Infect Dis 2020, doi: 10.3201/eid2607.200445]
“The main conclusion of this review is the pressing need to define the neurology of COVID-19, its frequency, manifestations, neuropathology and pathogenesis. On behalf of the World Federation of Neurology, we invite national and regional neurological associations to create local databases to report cases with neurological manifestations observed during the ongoing pandemic ... [and] help to define the natural history of this worldwide problem,” wrote the authors.