Overview
- West syndrome is characterized by the onset of epileptic spasms, typically in the first year of life.
- Global developmental impairment (with or without regression) is typically seen.
Clinical Context
- Onset of epileptic spasms occurs between 3 and 12 months of age, although later onset may occur.
- Infants may have had no antecedent history, or the antecedent history may reflect the underlying cause (e.g., acquired structural brain abnormality).
- In some cases, infants with Ohtahara syndrome or other early-onset epilepsies (typically with focal seizures) may evolve to have clinical and EEG features of West syndrome after 3-4 months of age.
- Both sexes are affected, with a higher incidence in males.
- Head size and neurological examination may be normal or findings may reflect underlying structural brain abnormalities.
- Global developmental impairment (with or without regression) is typically seen at the onset of epileptic spasms.
- Occasionally, development may be normal, and the developmental trajectory continues as expected.
