Other Names for this Disease
- Infantile spasm
- Tonic spasms with clustering, arrest of psychomotor development and hypsarrhythmia on EEG
- West's syndrome
- X-linked infantile spasm syndrome
What is West syndrome?
West syndrome is characterized by a specific type of seizure (infantile spasms) seen in infancy and childhood. This syndrome leads to developmental regression and causes a specific pattern, known as hypsarrhythmia (chaotic brain waves), on electroencephalography (EEG) testing. The infantile spasms usually begin in the first year of life, typically between 4-8 months. The seizures primarily consist of a sudden bending forward of the body with stiffening of the arms and legs; some children arch their backs as they extend their arms and legs. Spasms tend to occur upon awakening or after feeding, and often occur in clusters of up to 100 spasms at a time. Infants may have dozens of clusters and several hundred spasms per day. Infantile spasms usually stop by age five, but may be replaced by other types of seizures. Many underlying disorders, such as birth injury, metabolic disorders, and genetic disorders can lead to these spasms, making it important to identify the underlying cause. In some children, no cause can be found.
Last updated: 3/28/2011
- National Institutes of Health. Infantile Spasms Information Page. National Institute of Neurological Disorders and Stroke. February 22, 2011; http://www.ninds.nih.gov/disorders/infantilespasms/infantilespasms.htm. Accessed 3/21/2011.