West syndrome; Infantile spasms

West syndrome is the term used to describe a type of epilepsy which most typically starts in the first year of life, between four and eight months of age. It may, however, start younger than this. The hallmark of West syndrome is the occurrence of a particular type of epileptic seizure called a spasm. Spasms typically produce a sudden jerk of the body followed by stiffening of the limbs. Different types of spasms may occur but most typically a child will suddenly bend forward with elevation of the arms or legs. These attacks usually occur in runs or clusters when one spasm occurs after another for a period of several minutes. These episodes may occur several times per day. Very commonly, when a child starts to have spasms there is change in their behaviour and they appear to switch off and lose interest in their surroundings. The diagnosis of West syndrome is based on the occurrence of infantile spasms and the presence of a very abnormal EEG (brain wave recording). The most typical EEG abnormality is called hypsarrhythmia but other abnormal patterns may occur.

West syndrome is not one condition but is a symptom of many different brain disorders. A cause can be found in most children but in a small proportion no obvious cause can be identified. Sometimes West syndrome occurs in children with severe abnormalities of the brain such as congenital infections, severe brain injury due to birth asphyxia or severe malformations of the brain. Sometimes very rare genetic or metabolic diseases cause West syndrome. One of the commonest causes of West syndrome is tuberous sclerosis. Chromosome abnormalities may also cause West syndrome. It is therefore very important when a diagnosis of West syndrome is made that an extensive search is carried out to find the underlying cause.

The most common treatments for West syndrome are Vigabatrin (an anti-epileptic drug) or steroids (Prednisolone, Hydrocortisone or ACTH). In many children the spasms will stop with appropriate treatment, however after a period of time they will often relapse and require a change of treatment.

The prognosis for West syndrome depends in part upon the underlying cause. However, overall it is one of the more severe forms of epilepsy and most children with West syndrome will have long-term problems which may include developmental delay, learning disability, epilepsy or any combination of these three. Around twelve to fifteen per cent of children with West syndrome will stop having spasms and will develop normally.

Inheritance patterns
This depends on the underlying cause and genetic advice should be sought.

Prenatal diagnosis
None.

Medical text written November 2002 by Dr J Livingston, Consultant Paediatric Neurologist, Leeds General Infirmary, Leeds, UK.

Further Online Resources
Medical texts in The Contact a Family Directory are designed to give a short, clear description of specific conditions and rare disorders. More extensive information on this condition can be found on a range of reliable, validated web sites and links to them are included in the CD-ROM version of this Directory. Further information on these resources can be found in our Medical Information on the Internet article.

The current West Syndrome Support Group was re-established in 2002, having been originally, established in 1994. It is run by parents and can offer support and a sympathetic ear to families of affected children

Group details last updated May 2007.