Neurodevelopmental evolution of West syndrome: a 2-year prospective study.

OBJECTIVE The aim of this study was to evaluate the epileptic and developmental evolution in infants with West syndrome. METHODS A prospective study of 21 infants was performed, with a follow-up at 2 years. Serial assessment included long-term EEG monitoring, visual and auditory evaluation and assessment of neurodevelopment. RESULTS Neurosensory and developmental impairments at the spasm onset were transitory in seven cases, including four cryptogenic forms. In all other cases, there was a progressive worsening in neurosensory and developmental impairments. The epileptic evolution was generally better: in 11 of the 16 infants without seizures at outcome, spasms had already disappeared by 2 months after disease onset. Statistic analysis of results showed a correlation between neurosensory impairment and development throughout the whole follow-up. In addition, visual function at T1 resulted significant predictor of developmental outcome. Among the epileptic features, disorganization of slow sleep was an unfavorable prognostic factor. CONCLUSION Some forms of West syndrome are confirmed to have a benign evolution: among them there are not only cryptogenic cases but also symptomatic ones without significant neurodevelopmental impairment. Abnormalities of sleep organization, expression of the pervasive epileptic disorder, seem to play a role in determining a developmental deterioration. Neurosensory impairment since the onset of the disease could be a relevant cause of the developmental disorder.