Cryptogenic infantile spasms are associated with significantly better developmental and neurologic outcomes compared to symptomatic cases.
We reviewed the outcome (developmental, neurologic, and seizure) and prognostic factors of 57 cases of infantile spasms (17 cryptogenic, 40 symptomatic). The mean developmental score of the cryptogenic group (71.2 +/- 24.2) was significantly higher than that of the symptomatic group (48.4 +/- 24.5), as assessed by the Griffith Mental Developmental Scale. A resultant neurologic deficit was present in 23.5% of the cryptogenic group and 75.0% of the symptomatic group. Coexistence of other forms of seizures was observed in 35.3% of the cryptogenic group and 57.5% of the symptomatic group. Outcome was affected by the coexistence of other seizures, presence of neurologic deficit, time lag in initiation of treatment (cognitive outcome only), poor response to ACTH treatment, and persistent EEG abnormality. Character of spasms and time lag in initiation of treatment (seizure outcome only) did not have any significant effect on outcome.
Koo et al. (1993) studied this question.