First detected in December 2019, COVID-19 has spread to pandemic proportions. Neurological complications include stroke, hyposmia/parosmia, and encephalopathy. Studying the EEG findings in COVID-19 encephalopathy can provide mechanistic insights into its neurotropism. Some authors have noted diffuse slow activity in patients with COVID-19 encephalopathy, while others have observed frontal sharp waves. EEG is prognostic tool for mortality and cognitive morbidity in patients in the ICU with delirium. As more patients develop COVID-19 encephalopathy, identifying characteristic EEG patterns could become useful for prognostication of neurological function.  

Sixteen patients with COVID-19, hospitalized at an academic medical center between June and September of 2020, who underwent EEG monitoring, were reviewed. 30-minute samples of EEG with limited artifact were identified for spectral analysis.

The most common indication for EEG monitoring was altered mental status (15/16 patients). Mean age was 59.5, and all patients had non-neurologic medical comorbidities. 7/16 patients were deceased. All EEGs demonstrated continuous generalized slow activity, consistent with encephalopathy, and EEG findings did not appear to relate to mortality outcome. Focal non-epileptiform abnormalities (slow activity or attenuation of faster frequencies) were present in 6/16 patients. Definitive sharp waves were seen in 2/16 patients, both of whom had a history of epilepsy. Whole-brain basic spectral composition (delta, theta, alpha, beta and average band power) did not demonstrate a difference between survivors and non-survivors in this cohort. A history of seizures or epilepsy was more common in deceased patients (42.8% vs 22.2%).