Indeterminate EMU admissions: does repeating the admission help?

Epilepsy monitoring unit (EMU) admissions during 2007-2009 at Mayo Clinic Hospital Arizona were reviewed. Of the 106 indeterminate admissions, 13 (12%) went on to have a second admission. During the second admission, 8 (62%) were diagnosed. Five patients went on to have a third or fourth admission, with none of them receiving a diagnosis. Nineteen (18%) patients had ambulatory EEG monitoring after an indeterminate admission, with only one (5%) receiving a diagnosis after ambulatory EEG monitoring. Even in patients who were initially indeterminate, medication management changed 37% of the time. Admission to the EMU was helpful for spell classification, with 80% of the patients receiving a diagnosis after the first admission. Based on this study, a second admission should be considered if no diagnosis is reached after the first admission. If no diagnosis is made after the second EMU admission, subsequent admissions are unlikely to produce a definitive diagnosis.