West Syndrome (Infantile Spasms)

What is West syndrome (infantile spasms)?

West syndrome is a group of symptoms characterized by epileptic/infantile spasms and abnormal brain wave patterns called hypsarrhythmia and intellectual disability.

West syndrome spasms usually begin in the early months after birth but in rare occasions can also occur in older patients (epileptic spasms).

What are the symptoms of West syndrome (infantile spasms)?

Epileptic spasms is the principal symptom of West syndrome. Spasms typically begin suddenly and last for a few seconds in recurring clusters that can last 10-20 minutes. Such episodes are characterized by sudden, involuntary contractions of the head, neck, and trunk, and/or uncontrolled extension of the legs and/or arms. The duration, intensity, and muscle groups affected by seizures vary.

Infants with West syndrome also have severe electroencephalogram (EEG) high amplitude, chaotic spike wave patterns (hypsarrhythmia), and delays in acquiring skills that require coordination of muscles and voluntary movements (psychomotor retardation).  Those with West syndrome often develop Lennox-Gastaut syndrome with mixed types of seizures that are difficult to control and are associated with intellectual disability.

What causes West syndrome (infantile spasms)?

Any disorder that can lead to brain damage can be an underlying cause of West syndrome including trauma, brain malformations, infections, chromosomal abnormalities, etc. This cause can be identified in 75% of all cases. The most common disorder responsible for West syndrome is tuberous sclerosis complex (TSC).

X-linked West syndrome can also be caused by a mutation in the CDKL5gene or the ARX gene in the X chromosome.

How is West syndrome (infantile spasms) diagnosed?

• A physical and neurological exam
• An EEG to look at the electrical activity of the brain, as an EEG in a baby with infantile spasms usually shows a pattern called hypsarrhythmia when the seizures are not occurring
• Most infants diagnosed with infantile spasms will need other tests like an MRI of the brain, as well as blood and urine tests.

What are the available treatments for West syndrome (infantile spasms)?

It is possible to help reduce or control various types of seizure activity associated with West syndrome with drugs such as adrenocorticotropic hormone (ACTH), prednisone, vigabatrin and pyridoxine.

Other possible medications include:

• Benzodiazepines
• Valproic acid
• Topiramate
• Rufinamide
• Zonisamide

Where can I find out more about West syndrome (infantile spasms)?

• National Organization of Rare Disorders (NORD)
• Epilepsy Foundation
• Medscape