West syndrome consists of triad of symptoms which include infantile spasm, learning disability and peculiar hypsarrythmia pattern on EEG. It is a disorder that usually begins in infancy and childhood. Infantile spasm is a form of epileptic seizures. It begins in first year normally between 4th to 8th months after birth. Dr West was the first person to identify and describe this disorder in his 4 month old son in the year 1841. The disorder is hence named after him.
This form of epilepsy is rare and may occur in 1 out of 4000 children.The infantile spasms are numerous and occur after feeding or as the child awakes. Spasms occur in cluster sometimes even more than100 of spasm at a given time. Such types of seizures stop after the age of five, but unfortunately it is replaced by some other form of seizure.
Infantile spasm is caused due to reasons such as brain injury during birth, abnormality in brain, metabolic disorder etc. In many children the cause remains unknown. Treatment aim is to stop seizures. Various medicines are used for the purpose. If spasm is due to a lesion in brain, surgical removal of the lesion will bring overall improvement in the child.
What Are The Causes Of West Syndrome?
The exact etiopathogenesis is not very well understood. However, researchers have put forth few hypotheses. One of them is irregular secretion and distribution of GABA, a type of neurotransmitter in brain. Increased level of corticotrophin releasing hormone is also suggested as the cause. The hypotheses gains its support taking this view into consideration that medicines used in treatment of West syndrome is found to be effective.
Nearly in 40 percent of cases, no clear cause is found. However, a broad range of potential causes suspected are caused due to some type of injury or insult in the brain either during prenatal, perinatal or postnatal period. Following can be the potential reasons:
- Hydrocephalus (enlarged head due to accumulation of fluid).
- Down’s syndrome
- Hypoxic ischemic injury (reduced oxygen supple to brain).
- Infections such as meningitis and encephalitis.
- Hemorrhage in brain due to birth injury.
- Metabolic disorders
Signs And Symptoms Of West Syndrome
West syndrome is characterized by triad that includes infantile spasm (seizures), deterioration in development, and a typical abnormal pattern on EEG. Following clinical features are remarkable of West syndrome:
- Infantile spasm a type of seizure occurring in first year of life of the infant. It usually starts between the age of 4 to 8 months.
- In its beginning stage, the seizures are not frequent or typical that may hint towards West syndrome. Initially the pattern of seizure and crying of infant is suggestive of intestinal colic and thus even the physician gets misguided.
- During the seizure the body and arms become stiff.
- The legs and knee bend towards stomach. Both the legs and knee bend together. The body bends like a bow.
- Each episode of seizure is short and lasts only for few seconds. There is a pause for few seconds before another spasm occurs. Infantile spasm in West syndrome occurs in cluster or in a row.
- There can be several clusters of spasms in a day, particularly while awakening or after feeding.
- Baby is irritable.
- Decreased developmental growth.
Diagnosis And Treatment Of West Syndrome
For diagnosis of West syndrome, patient will need to undergo several tests. A diagnosis of infantile spasm is made only after the reading of EEG is abnormal. The EEG in this case shows disorganized pattern of waves. These are called hypsarrythmia. Often the abnormal electrical brain activity is noted only when the infant is sleeping. The child will also require other tests such as CT scan or MRI of brain, blood tests, urine test etc.
The main aim of treatment is to control and eliminate epileptic spasms in the child. Several medicines have been found to be useful in controlling and reducing the frequency. Anti epileptics, steroids are found to be efficacious.
In most cases ketogenic diet is helpful to the child. A ketogenic diet includes high fat, low carbohydrate and optimum amount of protein. Ketogenic diet is used to control seizures in children that are difficult to treat.
If there is growth in brain, surgical removal is another treatment measure that may be used to reduce and control seizures of West syndrome.
Prognosis: Some children respond well to the treatment. In others curtailing seizures remains a difficult task. In majority of children there is deterioration or plateauing of developmental trajectory. Seizures regresses after the age of 5, but unfortunately most the epilepsy takes another form as the child grows. Long term prognosis of the disease mainly depends on the underlying cause.