Startle epilepsy associated with infantile hemiplegia (SEIH): video-polygraphic features and long-term outcome.

Objective: The aim of this study was to inves- tigate the video-polygraphic features and the long-term outcome of epilepsy in two patients with startle epilepsy associated with infantile hemiplegia (SEIH). Material and Methods: Two patients (patient 1: a 14-year-old girl; patient 2: a 17 year-and- half-year-old girl), with hemiparesis and moder- ate mental retardation, underwent a full clinical and neurophysiological examination with video- polygraphic monitoring and recording of startle- evoked seizures. The follow-up was 9 years from epilepsy onset in patient 1, and 8 years from epi- lepsy onset in patient 2. Results: Firstly, video-polygraphic recordings of startle-evoked seizures, triggered by unex- pected auditory stimuli, showed tonic asymmet- rical postures with ictal EEG characterized by an abrupt and diff use electrodecremental pattern or a seizure discharge predominant over the vertex and anterior regions controlateral to the postur- ing limbs. Electromyogram recording showed a prevalent involvement of proximal muscles with a concomitant tachycardia and apnoea. In partic- ular, in patient 1 ictal heart rate was high, with persisting tachycardia for 60 - 120 s after the end of seizures. Secondly, a high seizure frequency persisted throughout the course of the disease, as seizures were medically refractory to all cur- rently available anti-epileptic drugs. Conclusions: The long-term outcome of epi- lepsy in SEIH, with constantly high seizure fre- quency, suggests an early surgical intervention, avoiding years with unsuccessful drug treat- ments and poor quality of life.