Subacute neurological sequelae in mild COVID-19 outpatients.

Introduction: Neurological aspect of COVID-19 is less understood compared to its respiratory and systemic effects. We aimed to define subacute neurological sequelae in patients who recovered from mild COVID-19.

Materials And Methods: This study enrolled long COVID patients who had mild infection, were non-hospitalized, and admitted to our hospital with neurological complaints occurring after COVID-19. The evaluation included detailed history of the symptoms, neurological examination, blood tests and necessary investigations relevant to their personal medical situation, and also a retrospective inquiry about their respiratory and neurological status during the acute phase of infection. Descriptive statistical measures, Chi-square and Student's t-test were utilized.

Result: We identified 50 patients (29F/21M) with a mean age of 36.9 ± 1.6 (mean ± SEM). The average time from COVID-19 to admission was 99 days(min-max= 15-247). Most frequent neurological complaints were headache (42%) and cognitive dysfunction (42%). Sleep disturbance (36%), prolonged anosmia (30%), prolonged ageusia (22%), fatigue (22%), and dizziness (8%) followed. Most patients with headache experienced headache also as an acute manifestation of COVID-19 (p= 0.02). Acute-stage sleep disorders were found to be more associated with subacute cognitive symptoms than other central symptoms (p= 0.008). The most common neurological symptom in the acute phase was headache (74%). Six patients, despite the absence of any acute-stage neurological symptoms, presented with emergence of subacute neurological sequela. There were only five patients with pulmonary involvement during the acute stage, who were not different from the rest of the cohort in terms of neurological sequelae. There was no increase of inflammatory markers in the blood tests at the subacute stage, or no association of the symptoms to biochemical parameters.

Conclusions: This study gives a description of neurological sequelae of mild COVID-19 at the subacute stage, in a relatively young group, and reveals that cognitive disturbances, as well as headache, are quite frequent.