Characterization of electroencephalographic abnormalities and their radiographic correlates associated with COVID-19

Objective: To identify the prevalence of electroencephalographic (EEG) and neuroimaging abnormalities in patients with COVID-19 and neurologic changes. Background: Neurological complications associated with COVID-19 are increasingly being recognized, though the incidence of epileptiform abnormalities and prognosis remains uncertain. Design/Methods: Retrospective case series of 192 adult COVID-19 inpatients with EEG performed between March and June 2020 in four hospitals in the Northwell Health system in the New York City area, including 159 patients undergoing continuous EEG, 24 undergoing routine EEG, and nine with reduced montage EEG. Associated patient characteristics were analyzed including EEG indication, epilepsy history, and in-hospital mortality. Cases with epileptiform abnormalities were reviewed for acute and chronic neuroimaging abnormalities. Results: EEG indications included encephalopathy (57.3%), coma (16.7%), seizure (15.6%), abnormal movements (5.2%), and focal neurological deficit (5.2%). Eight of the 30 patients with clinical seizures had known epilepsy. Generalized slowing was seen in 88.5% of patients, while epileptiform abnormalities, including periodic patterns, occurred in 38.0%. Focal intermittent epileptiform discharges were in 24.0%, lateralized periodic discharges in 5.7%, and generalized periodic discharges in 18.8%. Seizures were recorded in 3.6%, including three patients with status epilepticus. Intracranial abnormalities were seen on neuroimaging of 68.4% of patients with epileptiform abnormalities, two-thirds of which were acute. In-hospital mortality rate was 37.5% for all patients studied: 41.1% in patients with epileptiform abnormalities on EEG and 35.8% in patients without epileptiform abnormalities on EEG. Mortality rates were highest for those with periodic patterns on EEG. Conclusions: There is a high correlation between patients with COVID-19 with neurologic symptoms, and abnormalities on EEG. Many patients with EEG abnormalities, especially epileptiform abnormalities, have associated intracranial lesions on neuroimaging, most acute Mortality rates were elevated in patients with epileptiform abnormalities on EEG, particularly those with periodic patterns. These findings may guide the prognosis and management of patients with COVID-19 and neurologic changes.