Other Names: Infantile spasm; IS; X-linked infantile spasm syndrome; X-linked infantile spasms; West's syndrome; Tonic spasms with clustering, arrest of psychomotor development and hypsarrhythmia on EEG
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 disorders leading to brain injury, such as birth problems, cerebral anomalies, 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.
Cause and inheritance
A rare autosomal recessive inherited neurodegenerative disorder caused by mutations in the pla2g6 gene.
It is characterized by the development of swellings called spheroids along the axons of the central nervous system. Signs and symptoms appear early in life and include movement difficulties, muscle hypotonia and spasticity, and cognitive dysfunction. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed.
80%-99% of people have these symptoms
- Developmental regression(Loss of developmental milestones)
- Infantile spasms
30%-79% of people have these symptoms
- Abnormality of skin morphology(Abnormal skin structure)
Diagnosis is based on the clinical picture and EEG pattern.
The goals of treatment are to reduce or eliminate seizures, and include several medications, such as corticoids, avigabatrin, and antiepileptic drugs.Some children have spasms as the result of brain lesions, and surgical removal of these lesions may result in improvement. The medication(s) listed below have been approved by the Food and Drug Administration (FDA) as orphan products for treatment of this condition.
- Repository corticotropin injection (Brand name: H.P. Acthar Gel)repository corticotropin injection (H.P. Acthar Gel) was approved for the treatment of infantile spasms.
NIH genetic and rare disease info
West syndrome is a rare disease.