Letter to the Editor regarding “Cranial neuropathy during severe acute respiratory syndrome coronavirus 2 infection: a case report”

I read with interest the case report by Yazdani et al. describing cranial neuropathies occurring in association with acute severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, with detection of viral RNA in cerebrospinal fluid 1.The authors present a case that contributes to the expanding spectrum of neurological manifestations temporally associated with coronavirus disease 2019 .The authors suggest that direct viral involvement of the cranial nerves may represent a potential mechanism.While this is reasonable, interpretation of cerebrospinal fluid polymerase chain reaction findings remains challenging.Detection of SARS-CoV-2 RNA in cerebrospinal fluid is uncommon and does not consistently correlate with definitive evidence of central or peripheral nervous system infection 2,3.The patient's history of poorly controlled diabetes mellitus is important.Microvascular ischemic cranial neuropathies-particularly involving the oculomotor nerve-are well recognized in these populations and may occur with normal neuroimaging and gradual spontaneous improvement 4.The favorable clinical course described in this case is compatible with diabetic microischemia and may coexist with, or be independent of, acute SARS-CoV-2 infection.The mildly elevated cerebrospinal fluid protein level further adds to the difficulty of interpretation.Although Guillain-Barr spectrum disorders were considered unlikely, focal or early immune-mediated neuropathies associated with COVID-19 have been reported and may not always present with classic clinical or laboratory features 5.Distinguishing among direct viral, immunemediated, and microvascular mechanisms therefore remains difficult.Finally, while the patient had improvement following antiviral and corticosteroid therapy, it is difficult to determine the extent to which treatment influenced outcome, given the self-limited course observed in many COVID-19-associated neurological syndromes 2,3.Overall, this report is valuable in highlighting diagnostic uncertainty when cranial neuropathies arise during acute SARS-CoV-2 infection.Emphasizing this uncertainty is important and may help future investigations.