What are Infantile Spasms (West syndrome)

Infantile spasms (IS) also known as West syndrome, is a rare and serious seizure disorder that usually begins during the first year of life. A spasm is a type of seizure that involves involuntary muscle tightening (contraction).

This condition is associated with intellectual disability and delays in brain development.

Infantile spasms usually end by age 4. However, most babies with IS will have developmental disabilities later in life.

Many babies with IS will eventually develop other types of seizures. In some cases, early treatment of seizures can help the brain to develop and function normally.

What are the causes?

The cause of this condition is not always known. There are many possible causes, including:

• Lack of oxygen at birth.
• Brain injury (trauma).
• Infections in the brain or spinal cord.
• Abnormal brain development or brain tumors.
• Disorders of the nerves or skin (neurocutaneous disorders).
• Genetic disorders, such as tuberous sclerosis.
• Metabolic disorders. This is rare.
• Lack (deficiency) of vitamin B6.

What are the signs or symptoms?

Spasms are the main symptom of this condition. Spasms are sudden contractions of one or more muscle groups that last 1–2 seconds. The appearance, frequency, and severity of spasms can vary. The spasms usually happen in clusters of 5–10 muscle jerks within 1–2 minutes. Clusters of spasms may happen several times a day. They happen most often when the baby is awake, but they can also happen when the baby is asleep.

Spasms may cause the baby to:

• Hunch forward.
• Arch backward (salaam attacks).
• Bend or extend the limbs.

After the spasms, the baby’s body may get very stiff. This stiffening phase usually lasts less than 10 seconds.

How is this diagnosed?

This condition is diagnosed based on your baby’s age and medical history. Your baby’s health care provider will observe the spasms and perform a physical exam. Your baby may have tests, including:

• Blood tests.
• MRI.
• Electroencephalogram (EEG). This records patterns in the brain’s electrical activity. A disorganized, chaotic pattern (hypsarrhythmia) is a sign of IS.

Your baby may have more tests to diagnose any underlying conditions that may be causing IS. Your baby may be referred to a specialist.

How is this treated?

Treatment for this condition depends on the cause. The goals of treatment are to control spasms and to treat any underlying condition that may be causing IS.

Treatment may include:

• Medicines to reduce inflammation in the brain. These may be given by injection or by mouth.
• Medicines to control seizures (anticonvulsants).
• Vitamin B supplements.
• A special diet that is high in fat and low in carbohydrates (ketogenic diet).
• Surgery. This may be necessary for infants who have a brain injury or abnormality.

Follow these instructions at home:

• Pay attention to your baby’s symptoms. Tell your baby’s health care provider if symptoms change or if new symptoms develop.
• Give your baby over-the-counter and prescription medicines only as told by your baby’s health care provider.
• Keep all follow-up visits as told by your baby’s health care provider. This is important.

Contact a health care provider if:

• Your baby has side effects from medicines.
• Your baby has a fever.

Get help right away if:

• Your baby has difficulty breathing or your baby’s airway is blocked.
• You think that your baby has numbness in one or more limbs.