The West syndrome is a type of epilepsy that in 90% of cases occur by the age of 1 year, usually between 4 and 6 months of age, while a very small percentage can occur up to 4 years of age.

The West syndrome was first described by Dr. West in 1841, in a letter published in the medical journal “The Lancet” in England. Dr. West described the attacks of the infantile spasm that he noticed on his son. Although doctors were already aware of this type of attack, 8 years later, the spasms were associated with psychomotor retardation. The third symptom characteristic of The West syndrome doctors has described in 1952 when a large number of children with infantile spasms had a unique form of EEG findings, hypsarrhythmia.

The Eponym West syndrome was created by Drs. Gastaut, Poirier, and Pampiglione.

The incidence of The West syndrome is from 1:20 000 to 1:60 000 live births and is more common in boys.


The West syndrome is characterized by three symptoms:

1. Infantile spasms

The first infantile spasms in most cases occur between the 4 and 6 months of age, often before sleeping and after waking up (Image 1), and rarely can occur during sleep. Tactile stimulation and strong, sudden sounds or noise can improve the appearance of spasms. Infantile spasms can be flexor, extensor and mixed.

 2. Abnormal EEG

The main characteristic EEG findings are hipsarrythmia or change and disruption of the electrical activity of the neurons of the cortex.

3. Mental retardation

With two-thirds of children in which is not determined the cause of infantile spasms appears certain degree of neuropsychological differences. Severe mental retardation is present in 70% of children and is often accompanied by features of autism spectrum disorders and hyperactivity.

Image 1. Infantile spasms usually occur before sleeping and after waking up

Two types of The West syndrome:

  1. Idiopathic West syndrome – occurs in one-third of children with West syndrome, characterized by normal psychomotor development before occurring off the first attack.
  2. Symptomatic West syndrome  – there is a certain degree of neuropsychological differences before the occurring of the first spasms.


The West syndrome therapy includes the treatment for infantile spasms, corticotropin, and steroids.