Abstracts

Rationale:
There is growing evidence that acute encephalopathy can occur in hospitalized COVID-19 patients with variable EEG findings. Case series to date have relied on an 8-channel headband EEG demonstrating the need for further data collection utilizing a full array of scalp electrodes.
Method:
This study was approved by the Medstar Georgetown University Hospital Institutional Review Board. We analyzed a retrospective cohort of 10 consecutive inpatients who tested positive for COVID-19 by nasopharyngeal PCR and who underwent long term video EEG monitoring (for medically indicated reasons) between April 23rd - June 23rd of 2020. The recordings utilized scalp electrodes placed according to the international 10-20 system. Results10 patients (6 males, 61-95 years, mean 73 years±11.5) with COVID-19 underwent long term monitoring (mean 32.3 hours±13.9). 50% of patients were intubated at the time of EEG. EEGs were requested due to suspected seizure-like activity in 60% of patients; Acute encephalopathy prompted LTM in 60% of patients. 20% of patients had a prior history of epilepsy. 50% of patients were treated with anti-seizure medications with levetiracetam (LEV) being the most commonly used drug (n=5), including one patient treated with a combination of LEV, phenytoin and carbamazepine. Mortality was 30% (n=3) with mean length of stay of 13 days±13. All patients underwent head CT with pre-COVID-19 MRI brain on file for comparison in 3/10. Findings included left frontal meningioma (n=1), chronic ischemic infarcts (n=4), new embolic infarct (n=1), chronic volume loss (n=3), posterior reversible encephalopathy syndrome (PRES; n=1), and punctate hemorrhage (n=1). EEG findings included generalized periodic discharges (GPDs) with triphasic morphology in 6/10 (fig.1), all with a diffusely slow but symmetric background including one patient with generalized intermittent rhythmic delta activity (IRDA). Focal slowing in the left anterior region was seen in 1/10 patient. Focal non-convulsive seizures (fig.2) arising from the right frontocentral and left frontal region were seen in a single patient with a history of epilepsy. While clinical concern for seizure-like activity was reported in 6/10 patients, seizures were recorded in only one patient suggesting that clinical observations of seizure-like activity were confounded by encephalopathy and/or early treatment with anti-seizure medications which reduced the likelihood of recording seizures and/or epileptiform abnormalities on EEG. Clinically, acute encephalopathy upon presentation (80%) in conjunction with GPDs with triphasic morphology (60%) on EEG suggest that hospitalized COVID-19 patients are prone to multiple metabolic/electrolyte abnormalities which may partly explain the prolonged recovery/ventilatory support that has been observed in this patient population.
Conclusion:
Our data suggest that acute encephalopathy is a common clinical feature prompting EEG monitoring in hospitalized COVID-19 patients. While clinical suspicion for seizure-like activity was high, seizures were rarely recorded on EEG. 
Funding:
:This abstract received no funding.