The Clinical Outcome of Non-Diagnostic Epilepsy Monitoring Unit (EMU) Studies

Objective: To identify risk factors for diagnostic EMU studies after initial nondiagnostic evaluation and evaluate the probability of confirmed diagnosis on repeat EMU admissions. Background: EMU studies can rectify incorrect diagnoses of epilepsy, saving the patient and healthcare facilities the cost of unnecessary antiepileptic therapy and redirecting patients to pursue the appropriate treatment after establishing the correct diagnosis. Design/Methods: In this retrospective study, consecutive EMU admissions were analyzed between 2011–2014 and only patients with non-diagnostic studies were included. Clinical characteristics were recorded such as age, gender, diagnosis, length of admission, time to EMU admission since presentation, number of subsequent EMU admissions, number of spell types, pretest suspicion of non-epileptic events (NEE), MRI brain and interictal EEG findings, comorbid relevant medical and psychiatric history, and anticonvulsant regimen. Descriptive and non-parametric statistical analysis was used. Results: In the four year span, 202 patients had a non-diagnostic EMU study. Of these, 52 (25.7%) had a second or third EMU admission, and of those, 31 (15.2%) had continued unconfirmed diagnosis, 12 (5.9%) had a confirmed epilepsy (CE) diagnosis, and 9 (4.5%) had a confirmed non-epileptic (C-NE) diagnosis. A median length of stay of 2 days for CE was observed vs. 3 days for either C-NE or unknown diagnosis (p=0.0042). Pretest suspicion of NEE was associated with C-NE diagnosis on re-admission (78%, vs. CE, 25%, and unknown, 29%, p=0.023). Male gender was associated with receiving either an unknown or CE diagnosis on readmission (p=0.026). Conclusions: Approximately 40% of those referred for a repeat EMU evaluation after an initial non-diagnostic study were ultimately given a confirmed diagnosis. Low clinical suspicion of epilepsy is a statistically significant predictor for confirmed NEE on re-admission. Patients who will ultimately have a confirmed diagnosis of epilepsy on re-admission are likely to be diagnosed within the first two days of study. Disclosure: Dr. Amin has nothing to disclose. Dr. Cios has nothing to disclose. Dr. Gupta has nothing to disclose. Dr. Palettas has nothing to disclose. Dr. Peng has nothing to disclose.