Abstracts

Rationale: Vigabatrin is effective for treating infantile spasms from tuberous sclerosis (TS). We hypothesized that it would be safe and effective in a prospective study of complex partial seizures (CPS) in patients with TS. Methods: We conducted an open-label prospective safety and tolerability study. Inclusion criteria: age 18+, possible to definite TS, >1 complex partial seizures per month, on 1+ AEDs, patient's physician agrees. Exclusion criteria: previously tried vigabatrin. Later, to augment enrollment, we revised it to include retrospective accrual. Results: 126 patients with TS and seizures were screened, but only two enrolled. One of these subjects withdrew from the study to pursue epilepsy surgery. The most common reasons for refusal were: 1) low seizure frequency 2) Doctor/patient/family refused 3) no CPS. Ultimately, three patients with TS were identified. Follow up ranged from 2-17 years. Patient 1: 30 yo woman with TS and epilepsy started vigabatrin in the prospective trial. She had seizures since age 2, and had undergone right anterior temporal lobectomy and VNS. Vigabatrin was trialed for 4 months. The patient experienced reduction in CPS but more generalized tonic-clonic seizures, and had a seizure- induced fall resulting in a vertebral spinous process fracture. Vigabatrin was weaned off. Importantly, the patient's mother was quite reluctant to stop vigabatrin because of the patient's cognitive improvement. Patient 2 (retrospective): 28 yo man with TS and epilepsy had super-refractory complex partial status epilepticus. After failure of conventional therapy, vigabatrin was tried and it stopped the seizures. He has been seizure-free since then. Patient 3 (chart review): 22 yo man with TS who developed infantile spams at age 3 months. Later he developed atonic seizures and CPS. He started vigabatrin at age 5 and has had near total seizure control since then. None of the pateints had visual changes. Conclusions: The prospective study proved impossible to enroll because of the following factors: patients with too few seizures, the doctor/patient/family turning down the study, and seizure types did not include CPS. A prospective study may still be possible, but would require a multicenter trial, and include a concerted educational campaign for prescribers. The 3 patients in this case series all had significant clinical impact from vigabatrin. There was reduction in seizure frequency in all patients. There was family-reported improvement in cognition in one. However, there was worsening of one seizure type in one patient resulting in a vertebral spinous process fracture. Our experience was similar to retrospective studies in TS patients which found improvement in seizure frequency in ~25% [1] and 34% [2] of patients. Vigabatrin may be a safe and effective treatment for complex partial-onset seizures caused by TS. This research was funded as an investigator-initiated study by Lundbeck LLC (Deerfield, IL). 1. Friedman D, Bogner M, et al. Epilepsy Behav. 2013 7:118-20 2. Camposano SE, Major P, et al. Epilepsia 2008 49:1186-91