Abstracts

Epilepsy surgery is generally accepted for tuberous sclerosis (TS) patients with stable and stereotyped partial seizures, a well-localized and single seizure focus, and a corresponding underlying tuber. TS patients with seemingly multifocal or generalized seizures are usually excluded from epilepsy surgery. We report six children with TS, refractory partial seizures, multiple cortical tubers, global developmental delay and evidence from seizure semiology, scalp EEG monitoring and ictal SPECT of seizures arising from or involving multiple tubers. One patient had subdural EEG monitoring. All patients underwent multiple tuberectomy at age 2-17 years. Seizure onset ranged from birth to 7 years (median 4 months) and all had evidence of partial seizures. Three patients had electroclinically-discrete seizures arising independently from 3-4 regions in opposite hemispheres. Three patients had evidence for involvement of several tubers in what appeared to be a single electroclinical seizure type. The evidence implicating multiple tubers in these six patients came from seizure semiology in 5, ictal EEG onset in 3, ictal EEG propagation in 6 and ictal SPECT in 4. Bifrontotemporal subdural EEG monitoring in one patient confirmed independent focal origin of clinically-distinct seizures from separate tubers in four different regions.
Stereotactically-guided resection of 2-5 tubers was performed. Resection was staged in the three cases involving opposite hemispheres, with continued seizures between operations. Two patients with unilobar resection of 2-3 tubers are seizure free with improved alertness, behaviour and interictal EEG (follow-up 9 and 20 months). Four patients with resection of 3-5 tubers in one or more lobes have had [gt]75% seizure reduction, including abolition of tonic and tonic-clonic seizures (follow-up 2-11 months). TS patients with intractable epilepsy and partial seizures, either arising independently from different lobes or hemispheres, or seemingly involving several tubers in the one lobe, may benefit from multiple tuberectomy. (Supported by Neurological Foundation of New Zealand)