Electroencephalographic evolution of hypsarrhythmia: toward an early treatment option.

Purpose: A retrospective study for a classification of prehypsarrhythmic elecroencephalographies (EEGs) was carried out to enable an early treatment option for West syndrome.

Methods: Out of 39 infants with symptomatic West syndrome, 18 infants (age 3-14 months) with 61 serial non-REM sleep EEG records of the prehypsarrhythmic phase were identified. The prehypsarrhythmic phase encompassed 2 to 13 months (mean 4.