Continuous Electroencephalography (cEEG) Characteristics and Acute Symptomatic Seizures in COVID-19 Patients

Abstract

Background: Neurological manifestations of COVID-19 have only recently been described, with a paucity of literature reporting the potential relationship between COVID-19 and acute symptomatic seizures. Two prior studies found no clinical or electrographic seizures in their cohorts of COVID-19 patients with altered mental status (AMS) and clinical seizure-like events (SLEs). Methods: In this retrospective cohort study, 22 critically-ill COVID-19 patients above the age of 18 years who underwent EEG (electroencephalography) monitoring between April 20th, 2020 and May 20th, 2020 were studied. 19 patients underwent continuous EEG (cEEG) for at least 24 hours, and 3 patients underwent routine EEGs (<1 hour). Demographics including age, gender, comorbid medical, and neurological conditions were collected. Clinical variables included EEG findings, anti-seizure medications, discharge disposition, and survival. Findings: 17 patients underwent EEG monitoring for unexplained altered mental status changes and 5 patients underwent monitoring for a seizure-like event. 5 patients had epileptiform abnormalities on EEG (4 patients on cEEG, 1 on routine EEG); and only 2 of 5 epileptic EEG patients had a prior history of epilepsy. 2 patients in our cohort had electrographic seizures in the absence of prior epilepsy history. No patients with epileptiform abnormalities or electrographic seizures had acutely abnormal neuroimaging on CT or MRI. Interpretation: Encephalopathic COVID-19 positive patients had a range of EEG abnormalities, and a higher proportion of patients in this series had electrographic seizures than previous literature suggests. This may be influenced by the duration of monitoring with cEEG and the use of a 21 channel electrode system. cEEG findings may help to guide antiseizure medical therapy, as well as the workup of altered mental status in the setting of unremarkable neuroimaging. Funding: No funding was used for this study.

Neurologic complications of COVID-19

“…26 This study also reported a variety of other EEG findings, including continuous slowing, generalized rhythmic activity, and generalized periodic discharges. 26 These studies support the high incidence of encephalopathy in hospitalized patients with COVID-19 and the presence of acute symptomatic seizures from an underlying metabolic or toxic process or primary CNS insult as a complication of COVID-19.…”

“…23 24 Two retrospective studies have described electroencephalogram (EEG) patterns seen in patients with acute COVID-19. 25,26 One study reported frequent sporadic interictal epileptiform discharges in 22 patients with COVID-19 using mostly continuous 8-channel EEGs; 25 however, this finding was not supported by the other study, which used standard 21-channel EEGs. 26 This study also reported a variety of other EEG findings, including continuous slowing, generalized rhythmic activity, and generalized periodic discharges.…”

“…25,26 One study reported frequent sporadic interictal epileptiform discharges in 22 patients with COVID-19 using mostly continuous 8-channel EEGs; 25 however, this finding was not supported by the other study, which used standard 21-channel EEGs. 26 This study also reported a variety of other EEG findings, including continuous slowing, generalized rhythmic activity, and generalized periodic discharges. 26 These studies support the high incidence of encephalopathy in hospitalized patients with COVID-19 and the presence of acute symptomatic seizures from an underlying metabolic or toxic process or primary CNS insult as a complication of COVID-19.…”

Response: Epileptic discharges in acutely ill patients investigated for SARS‐CoV‐2/COVID‐19 and the absence of evidence

“…Subsequent to our report, case series of COVID-19-positive patients with EEG studies (n = 13-111 each) have been published by independent groups; yet, none has incorporated COVID-19-negative patient populations exhibiting similar presentations. Among COVID-19-positive patients, the reported rates of EDs in these recently published studies varied between 0% and 38% [3][4][5][6][7][8][9][10] ; our reported 40.9% rate falls at the higher end of the spectrum. Such a spread of rates of epileptiform EEGs among small-or moderate-scale case series from different institutions exemplifies how differences in inclusion criteria, study design, patient enrollment and demographics, and clinical history may alter outcomes.…”

The Neurocritical Care Society of India (NCSI) and the Indian Society of Neuroanaesthesiology and Critical Care (ISNACC) Joint Position Statement and Advisory on the Practice of Neurocritical Care during the COVID-19 Pandemic

“…38 Epileptiform abnormalities are detected in COVID-19 patients with encephalopathy. 39 However, it is still unclear whether COVID-19 infection is directly responsible for seizures and if epileptiform activity affects outcome in these patients.…”