Epileptic seizure and electroencephalographic characteristics of adult COVID-19 inpatients during the Omicron outbreak in China: a single center retrospective study

Abstract Background This retrospective analysis assessed the characteristics of epileptic seizure and continuous electroencephalogram (CEEG) data in hospitalized patients diagnosed with COVID-19 during the Omicron outbreak. Methods CEEG was performed in 28 patients, with 17 showing unexplained altered mental status and 11 suspected of having seizures. Demographic and clinical variables, imaging results, outcomes, and comorbidities were collected. Results In total, 1,405 patients with COVID-19 infection were admitted during the study period. The proportion of patients who required intensive care unit (ICU) care and the in-hospital mortality was 16.3% and 7.8%, respectively. Among patients who underwent CEEG monitoring, 11 were in ICU, and 17 were in regular wards. Of these, 8 patients (28.5%) had severe COVID-19, whereas 6 had acute neuroimaging findings. EEG findings were not specific, with 7 patients (25%) having normal EEG results. Furthermore, 11 (39.3%) had benign EEG alterations, 6 (21.4%) had malignant, and 4 (14.3%) had highly malignant. Six patients exhibited epileptiform abnormalities, including 1 with a prior epilepsy history. Moreover, 4 patients experienced electrographic seizures, with 2 manifesting as epilepsia partialis continua and 2 as nonconvulsive status epilepticus. Periodic and rhythmic patterns were observed in 2 patients, spike-and-wave in 1 patient and generalized rhythmic delta activity in another patient. EEG attenuation without reactivity was seen in 4 patients. Conclusions Seizures can manifest as early symptoms in individuals infected with the Omicron variant of COVID-19. Despite the increased contagiousness associated with Omicron, we observed a higher prevalence of normal EEG results. This suggested that the Omicron variant may be associated with a lower likelihood of causing encephalitis or encephalopathy compared to other variants.