Predisposing factors and causes of West Syndrome

Research indicates that approximately 60-75%% of infants diagnosed with West Syndrome will have had either a brain trauma or some form of brain disease prior to the commencement of the seizures. However, this is not necessarily the case and in approximately 25-40%, no history of abnormal growth and development nor impairment of, or injury to brain function in any way is present.

Malformations of the brain at birth, asphyxia during birth and congenital infection can all be contributing factors to the development of West Syndrome. It’s impossible to list all those conditions which may play a role in a predisposition to this type of infantile spasm, but any metabolic, chromosomal or rare genetic disorder may increase the risk. Example of conditions which can lead to the development of West Syndrome include (but are not limited to):

  1. cortical dysplasia, hemimegalencephaly or other malformations
  2. Down syndrome
  3. neurocutaneous disorders
  4. incontinentia pigmenti
  5. Sturge Weber syndrome
  6. pyridoxine deficiency
  7. non-ketotic hyperglycemia
  8. Otahara’s syndrome
  9. biotinidase deficiency
  10. maple syrup urine disorder
  11. mitochondrial encephalopathies
  12. ARX or CDKL5 gene mutations


Tuberous sclerosis, an autosomal genetic condition where benign tumours grow in multiple sites, is one of the most common causes of West Syndrome.

When an underlying cause can be identified, it is known as symptomatic West Syndrome. Idiopathic cases are referred to as cryptogenic West Syndrome.

The gender of the infant (other than in X-linked West Syndrome - see below) or a family history of the condition is not believed to influence the incidence nor is there is any evidence to link West Syndrome to immunisations.

Prenatal tests to detect West Syndrome are not available although it may be possible to test for some of the genetic conditions which lead to an increased risk of infantile spasms.

Introduction to West Syndrome

Causes of West Syndrome

Diagnosis of West Syndrome

Treatment & prognosis of West Syndrome