Infantile spasms in Down syndrome -: effects of delayed anticonvulsive treatment

To investigate the impact of treatment lag in infantile spasms (IS) on treatment response, occurrence of later epilepsy, and long-term cognition and behavior in patients with one single etiological entity, we examined 18 patients with Down syndrome (DS) and earlier IS retrospectively (follow-up period of 32-180 months with a mean of 85.1 months), and determined their history and present condition, in terms of previously mentioned items. There was a statistically significant correlation between treatment lag and lag to cessation of spasms (R = 0.55, P = 0.02), developmental quotient (DQ) (R = -0.75, P = 0.003), and score of autistic features (AF) (R = 0.57, P = 0.04). Moreover we found that the later the response to treatment of IS, the lower was the DQ (R = -0.86, P = 0.001) and the higher was the score of autistic features (R = 0.5, P = 0.06). A long duration of spasms also determined a low DQ (R = -0.93, P < 0.0001) and a high score of autistic features (R = 0.66, P < 0.01). All patients with persistent epilepsy (n = 5) had had a treatment lag of over 2 months. Conversely, for all children treated within 2 months (n = 8) spasms ceased within 3 months of treatment and none of them had later epilepsy. This group of patients with a treatment lag of less than 2 months had earlier treatment response (P = 0.002), higher DQ (P = 0.004) and lower score of autistic features (P = 0.006). The data stress the importance of a short treatment lag in view of mental development and prevention of later epilepsy and autistic features, and raise the question of antiepileptogenic effect in this specific condition. (C) 2003 Elsevier B.V. All rights reserved.