Neurologic features in hospitalized patients with COVID-19 : a prospective cohort in a catalan hospital

Objectives: To study the prevalence and timing of neurological manifestations, including cognitive involvement, in patients hospitalized for Coronavirus disease 2019 (COVID-19). To analyze the pathogenic mechanisms and any association they have with disease severity. Methods: Longitudinal cohort study with prospective follow-up of patients who required hospitalization. Patients under 65 who had no pre-existing cognitive impairment and did not require an ICU stay were evaluated 3 and 12 months after discharge using a battery of neuropsychological tests. Results: Of 205 patients hospitalized for COVID-19, 153 (74.6%) presented with neurological manifestations. The most frequent were myalgia (32.7%), headache (31.7%), dysgeusia (29.2%), and anosmia (24.9%). Patients with more severe illness at the time of hospitalization presented fewer neurological manifestations. Of the 62 patients who underwent neuropsychological examination 3 months after discharge, 22.6% had impaired attention, 19.4% impaired working memory, 16.1% impaired learning and retrieval, 9.7% impaired executive functions, and 8.2% impaired processing speed. Patients with anosmia also presented with more headache (OR 5.45; p < 0.001) and greater risk of working memory impairment (OR 5.87; p 0.03). At follow-up 12 months after hospital discharge, 14.3% of patients still showed impaired attention, 2.4% impaired working memory, 2.5% impaired executive functions, and 2.5% impaired processing speed. Discussion: Neurological manifestations are common in patients hospitalized for COVID-19 regardless of severity. The high prevalence of anosmia and its association with headache and working memory impairment at 3 months, suggest potential direct or indirect damage to the prefrontal cortex via invasion of the olfactory bulb by COVID-19.