Additional Studies Specifically Aimed at Defining the Relationship Between COVID-19, Seizures, and Epilepsy
Lu et al20 specifically collected data about new-onset acute symptomatic seizures between January and February 2020 at 42 hospitals in the Hubei province, the epicenter of COVID-19 in China. They enrolled 304 patients, none with a prior history of epilepsy, 108 of whom had severe disease. Patients presented with acute cerebrovascular disease and systemic disorders which could provoke seizures, but without seizures, febrile seizures, or episodes of status epilepticus. Two patients had seizure-like events, diagnosed as seizure mimics due to acute stress reaction and hypocalcemia. The authors concluded that COVID-19 poses minimal risk for acute symptomatic seizures, though a significant portion of severely ill patients had increased potentially provocative risk factors. A limitation of this study was lack of routine or long-term EEG recordings to investigate these seizure-like episodes or to assess for subclinical seizures.
There are studies describing EEG findings for COVID-19 positive patients. Helms et al21 reported neurologic features in severe COVID-19 with acute respiratory distress syndrome in 58 patients. Eight patients underwent EEG, all of whom had nonspecific findings with no epileptiform discharges or seizures. Galanopoulou et al22 reported a study of 28 patients under investigation for COVID-19 who underwent hospitalization and EEG studies (either routine or continuous EEG). Of the initial 28 patients, subsequent testing defined COVID-19 positive (n = 22) and negative (n = 6) groups, with respective comparisons of the groups showing indications for EEG testing as new-onset encephalopathy (68.2% vs 33.3%) and seizure-like events (14/22, 63.6%; 2/6, 33.3%). “Seizure-like” events were reported in patients without a prior history of seizures (11/17, 64.7%; 2/6, 33.3%). Intermittent epileptiform discharges, most typically as frontal sharp waves, were present in 40.9% of COVID-19-positive and 16.7% of COVID-19-negative patients. There were no electrographic seizures in either group.
There are now numerous case reports describing seizures and other paroxysmal events in association with COVID-19.23 Individual reports include a new-onset generalized tonic clonic seizure during likely COVID-19 presentation,24 focal status epilepticus,25 seizures in critically ill patients,26 and COVID-19 presenting with paroxysmal events (possibly seizures) in a 6-week-old male.27
As compared to population-based studies of the initial clinical presentation of COVID-19, studies in patients with seizures and epilepsy are lacking. However, available studies are consistent with the general concept that seizures and epilepsy are infrequently worsened by COVID-19. Case studies, despite their inherent drawbacks in accounting for the multifactorial causes of seizures and epilepsy, highlight that some patients will present with seizures early in the course of COVID-19 infection.