The successful management of 21 children with infantile spasms and hypsarrhythmia using vigabatrin monotherapy is reported from the Alder Hey Children’s Hospital, Liverpool, UK. Age at onset of spasms was 3 to 16 months. A symptomatic cause was identified in 17(81%). Spasms were completely controlled in 17(81%) with an initial dose of vigabatrin 25-50 mg/kg/day, increasing to a maximum of 80-120 mg/kg/d in 3-5 days. At a mean 2 year follow-up, 14(67%) remained seizure-free, and vigabatrin was withdrawn in 4 without relapse. Only one patient failed to respond; this child had meningitis at 4 months and spasms were refractory to all AEDs, including ACTH. Transient drowsiness in 2 patients was the only side-effect noted. [1]
COMMENT. Vigabatrin has replaced ACTH and prednisone as the first-line treatment for West syndrome in the Liverpool Children’s Hospital. Dr Verity and colleagues in the UK have been very successful in their organization of a multicenter, comparative trial of sodium valproate and carbamazepine. A similar controlled trial of vigabatrin and ACTH based in Liverpool might be necessary to convince other centers to initiate a change in treatment of infantile spasms.
Of interest, only 4 children (10%) were seizure free following vigabatrin monotherapy for intractable epilepsy in a previous report from the Royal Liverpool Children’s Hospital. Complex partial seizures responded partially but myoclonic seizures were not benefited.(Gibbs et al. 1992; see Progress in Pediatric Neurology II, 1994, pp 104-5).
An open, add-on trial of vigabatrin in 20 children with Lennox-Gastaut syndrome, reported from Wien, Austria, showed 85% with a 50-100% reduction in seizure frequency, even after valproate dosage was reduced. Dyskinesia in 1 child was the only side-effect [2]. Serious mood disorders, depression and/or aggression, were the main reason for withdrawing vigabatrin in 9 (12%) of 73 adults with refractory epilepsy treated at the Meer & Bosch Epilepsy Centre, Heemstede, The Netherlands [3]. Vigabatrin results in a significant increase in brain GABA concentration by inhibiting GABA transaminase.