Abstracts

Rationale: Increasing evidence demonstrates neurologic sequelae associated with coronavirus (COVID-19) infection. However, the incidence of encephalopathy, seizures, and other epileptiform abnormalities in COVID-19 patients remains poorly understood. Furthermore, the relationship between EEG changes and patient’s clinical severity markers is unknown.

Methods: We identified all the COVID-19 patients who underwent EEG studies at UC Irvine Medical Center between March 2020 and January 2021. Their EEG tracings were retrospectively reviewed to determine the incidence of 1) seizures, 2) epileptiform discharges, 3) level of encephalopathy, 4) focal dysfunction, and 5) presence of sleep architecture. Clinical factors such as indication for order EEG, reasons for admission, history of seizures and other medical problems, home anti-seizure medications, and changes in anti-seizure medications during hospitalization were also obtained. Clinical severity markers (sodium, BUN, creatinine, WBC, % and absolute lymphocyte count, albumin, ammonia, ESR, CRP, procalcitonin, and ferritin levels) were compared to EEG findings to identify potential predictors of EEG abnormalities.

Results: Demographics
Between March 2020 and January 2021, 44 patients with confirmed COVID-19 infection underwent continuous EEG monitoring. Of these, 65.9% were men and 79.5% did not have a history of seizure. Mean age was 62 + 17 years. The most common indication for ordering an EEG study was to evaluate for encephalopathy (56.8%), followed by seizure-like activity (22.7%) and post-cardiac arrest (20.5%). Mean duration of EEG study was 41.6 hours.

EEG findings
The most common finding was diffuse slowing which was present in 93% of the patients. Posterior dominant rhythm was only present in 22.7% of the patients while Stage II marker of sleep was present in 60%. Lateralized dysfunction and epileptiform discharges were both present in 20.5% of patients, but they were not mutually inclusive. Seizure was only detected in 3 patients, but interestingly none of these patients had a history of epilepsy.

Clinical findings
Patients with more severe encephalopathy trended towards having lower % and absolute lymphocyte count and albumin, while having higher WBC, ammonia, procalcitonin, and ferritin level. Patients who had posterior dominant rhythm had lower WBC, CRP, procalcitonin, and Ferritin while having higher lymphocyte % and albumin level. Patients who had stage II markers of sleep trended towards having lower BUN, CRP, and procalcitonin but this relationship was not statistically significant.

Conclusions: Our study further demonstrates possible neurologic complications of COVID-19. The most common EEG finding in COVID-19 patients was diffuse cerebral dysfunction, which was more severe in patients with worse clinical severity markers. The incidence of seizure was low in our study, and interestingly only occurred in patients who did not have a history of seizure. Elucidating these relationships will improve patient care as well as resource utilization.

Funding: Please list any funding that was received in support of this abstract.: N/A.