Persistence of ictal activity after functional hemispherectomy in Rasmussen syndrome.

A 15-year-old girl with a 3-year history of Rasmussen syndrome (RS) underwent left functional hemispherectomy by central disconnection. Clinical seizures then ceased. Five months postoperatively, ictal EEG discharges were associated with focal hyperperfusion on SPECT within the disconnected hypoperfused left hemisphere, suggesting that the basic mechanisms of RS may continue, only to remit later. EEG and SPECT may complement studies of these in seizure-free surgically treated patients in whom clinical follow-up may be unrevealing.