Abstracts

Rationale: : Although seizures occur less frequently than smell dysfunction, headaches, cognitive impairments, and myopathy in COVID-19 patients, there may be some correlation between incidence of seizures with COVID-19 infected patients with or without prior history of epilepsy. Additionally, seizures may be difficult to identify in COVID-19 patients when they present with encephalopathy. Early detection of seizures may improve overall cognitive outcome of COVID-19 patients. We evaluated the EEG findings of patients who had EEGs ordered for seizures or encephalopathies. Differences between the two groups were analyzed to better understand the EEG patterns and possibly identify risk factors for seizures.

Methods: This study was conducted at the Banner University Medical Center in Phoenix, which had the highest COVID-19 cases per capita in the world from March 2020 and February 2021. We retrospectively reviewed EEG data among hospitalized patients who tested positive for COVID-19 RNA and had inpatient EEGs. We divided them into two groups: Group A had EEGs ordered for potential seizures, and Group B with encephalopathy only. Information was collected after obtaining IRB approval, which included the patient's age, indication for EEG, history of prior seizures, and EEG findings in respect to the background, epileptiform discharges, and seizures.

Results: During the study period, 99 cases were identified who had EEGs studies ordered and had been infected with COVID-19. 33 EEGs were ordered to evaluate potential seizures (Group A), 63 EEGs for encephalopathy (Group B) and remaining 3 cases for other reasons. In Group A, the most common EEG background findings were diffuse background slowing (51.5%, n=17/33), followed by normal EEG patterns (42.4%, n=14/33), burst-suppression pattern (3.0%, n=1/33), and severe suppression (3.0%, n=1/33). In Group B, the most common background EEG findings were diffuse background slowing (88.9%, n=56/63), followed by normal EEG (6.4%, n=4/63), burst-suppression pattern (3.2%, n=2/63), and suppression (1.6%, n=1/63). Among patients with diffuse background slowing, severe degree of slowing was most common with 41.2% in Group A and 41.1% in Group B. Four cases of ictal pattern EEGs were noted in Group A (12.1%), while only one seizure was noted in Group B (1.6%, p=0.087).

Conclusions: The data suggest that the incidence of detected seizures was more frequently observed in EEG reports when clinical suspicion was raised for seizures, opposed to other reasons such as encephalopathies, among COVID-19 patients. However, the incidence of overall seizures among COVID-19 patients appears to be higher than the incidences in previously reported studies. Despite the fact that the most commonly found EEG pattern was diffuse background slowing, the possibility of seizure should be considered in patients with COVID-19 and altered mental status.

Funding: Please list any funding that was received in support of this abstract.: none.