West syndrome is diagnosed when IS are present in clusters and in great numbers (up to 100 spasms in a cluster and sometimes many clusters a day), in infants usually with developmental delay, approximately 3 to 6 months of age (up to one year), and accompanied by hysarrhthymia (a high amplitude chaotic abnormal pattern) on EEG. Other seizure types are also seen in 30 to 50% of infants with this syndrome. Spasms usually stop as the child gets older, but other seizure types often take their place; 20 to 50% go on to have Lennox Gastaut syndrome. 75% of children with West syndrome have or will develop developmental delay/intellectual disability. 50% of children with West syndrome have some degree of cerebral palsy. [Mackay: 2004]
In the idiopathic category (10-15%), children with IS have normal development and neurological exams at the onset of the spasms and a good prognosis for growing out of them. In this group, IS are associated with poor developmental outcome mainly if the IS don't respond to medication. Therefore, early diagnosis and treatment may affect the outcome in this group of children. Some neurologists also identify a third group, cryptogenic, in which children are either abnormal in development or in their neurologic exam at the onset of the spasms, but no specific cause can be identified. These infants generally have a prognosis similar to those in the symptomatic group.
In the idiopathic group (10-15% of all children with infantile spasms), development and neurological exam are normal at onset. With ACTH treatment, 40-65% will have a complete or near-complete recovery.
In symptomatic or cryptogenic IS (85-90% of all children with infantile spasms) neurological or developmental abnormalities are present before the first seizure. In this group, complete or near-complete recovery is achieved by only 5-15%.
Epilepsy Association of Utah
For individuals with epilepsy, families, and friends, this site offers newsletters, events, links, local and youth support groups, activities for kids, first aid for seizures, and more.
A national organization that provides information about epilepsy; programs to improve epilepsy treatment; materials to assist in helping people with epilepsy find jobs; activities in schools to educate the public; activities to educate policymakers; funds for research; and news about conferences and other items of interest.
Infantile Spasms (Epilepsy.com)
Several frequently asked questions and answers about infantile spasms.
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