FOCAL SPASMS IN CLUSTERS, FOCAL DELAYED MYELINATION, AND HYPSARRHYTHMIA - UNUSUAL VARIANT OF WEST SYNDROME

We report a patient who began to have clusters of seizures characteriz ed by brief elevation of the right arm at 6 months of age. An interict al electroencephalogram (EEG) at 7 months revealed hypsarrhythmia with out definite asymmetry. Simultaneous EEG and video recording disclosed that these focal spasms were associated with fast wave bursts superim posed on slow waves most markedly in the left centro-midtemporal regio n. The patient became seizure-free after synthetic ACTH therapy. The p atient is developmentally normal at 3 years 5 months, but magnetic res onance imaging studies revealed findings suggestive of delayed myelina tion in the left frontal region. This patient is considered to have ha d an unusual variant of West syndrome associated with focal delayed my elination.