Infantile Spasms.

Infantile spasm is a catastrophic form of epilepsy found only in infants and young toddlers. Onset is before one year of age, with a peak incidence occurring between 4 to 7 months of age. The prevalence is difficult to calculate, but previous reviews have estimated between 1 per 2000 to 6000 live births. There are many causes of infantile spasms, including tuberous sclerosis, malformations of cortical development, hypoxic-ischemic injury, congenital infectious diseases, inborn errors of metabolism, genetic syndromes such as Aicardi's syndrome, and chromosomal abnormalities. A small percentage of patients have idiopathic infantile spasms, with no identifiable cause and premorbid normal growth and development. In order to prevent an ongoing epileptic encephalopathy with its concomitant consequences of cognitive impairment and intractable seizures, treatment should be aggressive and immediate. It is not enough to control the clinical infantile spasms. The underlying "interictal" hypsarrhythmia pattern must also be abolished if the prognosis is to be improved. Otherwise, the immature brain appears to remain hyperexcitable.