Abstracts

Rationale: The objectives of this study were to determine the yield of adult inpatient EEGs, factors predicting abnormalities on EEG and the association of EEG findings with patient management and outcome.Methods: The authors reviewed the reports of 207 consecutive adult, inpatient EEGs at an academic medical center. Results: 83% of the EEGs were abnormal, including 17% which captured epileptiform discharges, 1.5 % captured seizures and 1.9% status epilepticus. EEGs performed in an ICU were more likely to be abnormal (odds ratio [OR] =4.6). 71% of EEG results were referenced in the daily progress notes. Antiepileptic medications started or increased 34% of the time after an EEG captured epileptiform discharges and 11% after an EEG that did not capture epileptiform discharges (OR=4.4). Length of stay was 8.6 days longer for patients with abnormal EEGs than those with normal EEGs.Conclusions: Inpatient EEGs have a high yield for capturing abnormalities, particularly when performed in an ICU setting. EEGs performed in patients with documented infection are more likely to capture slowing. EEG results are often documented in medical decision making, and EEGs capturing epileptiform discharges are more likely to lead to changes in anti-epileptic medications. Patients with abnormal EEGs have a longer length of hospital stay. These findings demonstrate the utility of inpatient EEGs.