Long-lasting brain fog is related with severity clusters of symptoms in COVID-19 patients.

Background: COVID-19 patients may experience Long-lasting symptoms from weeks to even months.

Aim: To evaluate long-term cognitive impairment based on the severity of symptoms of COVID-19 infection in a primary health system setting.

Material and methods: From a database of 363 patients, 83 cases aged 47 ± 15 years, (58% females) were selected from June to August 2020. In patients who survived the virus, 24 infection-related symptoms were collected to create three severity clusters (mild, moderate, and severe). The follow-up time was at least seven months. Comparing the first two clusters with the severe cluster, the existence of brain fog and risk factors (obesity, hypertension, diabetes, chronic lung disease, and hypothyroidism) were analyzed.

Results: Thirty-one patients (37%) had persistent symptoms lasting up to 240 days. Fifty-one patients (61%) experienced brain fog. Concentration was affected by symptom severity (odds ratio [OR] 3.63, 95% confidence interval [CI] 1.26-10.46, p = 0.02). Short- or long-term memory loss was not affected. Moreover, symptom severity was related to brain fog (OR 3.16, 95% CI 1.05-9.51, p = 0.04). Patients with persistent symptoms had a concentration impairment associated with severity patterns (OR 24.3, 95% CI 1.73-340.11, p = 0.03).

Conclusions: Brain fog is associated with symptom severity in COVID-19 survivors and lasts for more than eight months.