What is the prognosis of infantile spasm (West syndrome)?

Updated: Jan 11, 2019
  • Author: Tracy A Glauser, MD; Chief Editor: Stephen L Nelson, Jr, MD, PhD, FAACPDM, FAAN, FAAP  more...
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The long-term overall prognosis for patients with infantile spasm is poor and is related directly to the condition’s etiology. [7, 8] Infants with idiopathic infantile spasms have a better prognosis than do infants with symptomatic infantile spasms. Only 14% of infants with symptomatic West syndrome have normal or borderline-normal cognitive development, compared with 28-50% of infants with idiopathic infantile spasms. Mental retardation is severe in 70% of patients, often with psychiatric problems such as autistic features or hyperactivity.

Infrequently, spasms may persist in adulthood. It has been found that 50-70% of patients develop other seizure types and that 18-50% of patients will develop Lennox-Gastaut syndrome or some other form of symptomatic generalized epilepsy. [6, 9]

Subsets of patients among the symptomatic infantile spasms group seem to have a better prognosis. A retrospective study of 17 children with trisomy 21 and infantile spasms found that 13 of 16 survivors were seizure free for more than 1 year and that 10 patients were no longer taking anticonvulsants.

A study of 15 children with neurofibromatosis type 1 and infantile spasms also reported a relatively benign seizure and cognitive outcome.

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