A pilot study of topiramate in the treatment of infantile spasms

Purpose: West syndrome is a rare epileptic syndrome associated with infanti le spasms, a specific abnormal electroencephalographic pattern (termed hyps arrhythmia), and mental retardation. Management of this disorder is difficu lt because current treatment regimens, including many anticonvulsants and h ormones, are often ineffective. Topiramate (TPM) is a new antiepileptic dru g that may be effective in pediatric epilepsies. We conducted a pilot study to test the effects of rapid TPM dosing in patients with refractory infant ile spasms. Methods: Eleven children with refractory infantile spasms were given an ini tial dose of 25 mg TPM per day in addition to their current therapy. Dosage was increased by 25 mg every 2-3 days until spasms were controlled, the ma ximal tolerated dose was reached, or the maximal dose of 24 mg/kg/day was a chieved. Efficacy was primarily assessed by video EEG and secondarily by pa rental count of spasm frequency. Results: Five (45%) subjects became spasm free during the study, with absen ce of infantile spasms and hypsarrhythmia (either classic or modified) prov en by video EEG. Nine subjects, including the five spasm free, thieved a sp asm reduction of greater than or equal to 50%. Spasm frequency decreased fr om 25.6 +/- 19.3 to 6.9 +/- 5.9 spasms/day. Sixty-four percent of the subje cts were able to achieve TPM monotherapy. Conclusions: Results in this cohort of 11 patients with refractory disease show TPM to be a promising new agent for the treatment of infantile spasms.