Generalized nonconvulsive status epilepticus with reactive alpha rhythm.

CASE REPORT A 48-year-old man with mild mental retardation was brought to the emergency department having had a seizure. He was taking lamotrigine, carbamazepine and phenytoin for generalized tonic-clonic seizures and absence-like spells since childhood. Previous EEG showed normal background (FigureA) with widespread photoparoxysmal activity, which suggested the diagnosis of probable generalized photosensitive epilepsy. Over the past decade, he had been assessed many times in the emergency room for episodes of confusion and bradyphrenia. No formal diagnosis had been made and the patient was then discharged once back to his baseline. The day of admission, he had a generalized tonic-clonic seizure. In hospital, he was confused and disoriented. He could obey simple commands, but his reactions were slow. The neurological exam was otherwise within normal limits. A cerebral computed tomography scan and blood work were normal. As there was no improvement of the confusion three hours after his arrival, an EEG was performed. It showed bisynchronous, 2 Hz generalized spike-waves and polyspikewaves, maximal in the frontal regions. A remarkable feature was an alpha rhythm in bilateral posterior regions, which was reactive to eye opening and closure. This reactive alpha rhythm was seen concomitantly with the generalized epileptiform activity, for the whole duration of the 20 minute recording. (Figure B and C) Following the recording, the patient had a two minute generalized tonic-clonic seizure treated with 2 mg of intravenous lorazepam. Afterward, he was drowsy, was not obeying commands and his verbal answers were incomprehensible. When stimulated, the patient became transiently agitated but there was no clinical sign of ongoing seizure. His level of consciousness gradually improved. A second EEG done 90 minutes after the seizure showed diffuse delta and theta activity prominent in the anterior regions, without epileptiform activity, and with partially reactive alpha activity in the posterior regions. (Figure D)