West syndrome also known as West's Syndrome is a rare epileptic disorder seen in infants. This syndrome was named after William James West who was an English doctor and a surgeon. He had observed this form of epilepsy in his son, James E. West, when he was around four months old. He named the seizures experienced by his son at that time as "Salaam Tics." West's Syndrome is also known as Infantile Epileptic Encephalopathy, Generalized Flexion Epilepsy, Infantile Myoclonic Encephalopathy, Massive Myoclonia, Jackknife Convulsions and Salaam Spasms.
West syndrome consists of a triad of infantile spasms, mental retardation and a pathognomonic EEG pattern known as hypsarrhythmia. However, the international definition of this condition needs only two of these three elements.
West's syndrome is age-related and commonly occurs when the child is aged between three and twelve months. It most commonly manifests around the fifth month. There are different causes for this condition ("polyetiology"); the common cause being an organic brain dysfunction, which can be prenatal, perinatal or postnatal.
According to statistics, boys are more prone to be affected by this condition than girls. Commonly the spasms develop for the first time when the child is between three and twelve months of age. Rarely, spasms can occur in the first two months of the child's life or when the child is between two to four years old.
Causes of West's Syndrome
The exact cause or the bio-chemical mechanisms, which lead to West's syndrome is not clear. It is thought to occur due to a malfunction in the function of a neurotransmitter or a malfunction in the management of the GABA transmission process. Other causes thought to be responsible include over-production of the corticotropin-releasing hormone (CRH). It is quite possible that more than one cause is behind it.
If the cause of west's syndrome is identified, then the condition is said to be ''symptomatic'' West's syndrome because the attacks occur as a symptom of some other problem. Any type of brain damage can be related and are divided into prenatal, perinatal, and post-natal. Given below is the list of conditions, which can cause West's' syndrome:
About 1/3 of the children have organic disorder of the brain, which includes the following:
- Cortical dysplasia.
- Cerebral atrophy.
- Bacterial meningitis.
- Aicardi syndrome.
- Vascular malformation.
Additional possible causes of West's' syndrome include:
- Foix-Chavany-Marie syndrome.
- Incontinentia pigmenti.
- Sturge-Weber syndrome.
- Patau syndrome (trisomy 13).
- Neurometabolic diseases.
- Congenital infections.
- Brain damage from hypoxia or asphyxiation, periventricular leukomalacia, cerebrovascular accident, cephalhematoma, or brain damage occurring from premature birth.
- There are some cases where the spasms have started after vaccination for measles, mumps, tetanus, rubella, diphtheria, pertussis, polio, haemophilus, hepatitis B and influenzae type B.
- Stress also is a trigger for the seizures.
- Cryptogenic: There are cases, where a direct cause cannot be identified; however, the child has other neurological disorders, then the syndrome is known as ''cryptogenic'' West's syndrome in which the underlying cause cannot be found. There are cases, where more than one child in the same family develops West's syndrome.
- Idiopathic: If a cause cannot be ascertained then the syndrome is also referred to as ''idiopathic'' West's syndrome. Some of the important diagnostic points are:
- The child develops regularly until the onset of the attacks or before the therapy is initiated.
- There is no evidence of what triggers the spasms.
- There are no pathological findings found.
Signs & Symptoms of West's Syndrome
"Infantile Spasms" is a group which comprises of three categories of the epileptic seizures seen in infants having West's syndrome. Commonly the child with West's syndrome experiences a triad of attack types. These three types often occur simultaneously; however, they can also occur individually.
- ''Lightning attacks'' comprise of sudden and severe myoclonic convulsions of the complete body or many parts of the body in a few seconds. Legs, especially, are bent. In these types of attacks, the flexor muscle convulsions are more severe than the extensor ones.
- ''Nodding attacks'' comprise of convulsions of the flexor muscles of the throat and neck. In these spasms, the chin is forcefully jerked down towards the breast. The head can also be flexed inward.
- ''Salaam or jackknife attacks'' comprises of a flexor spasm where there is rapid bending of the head and the torso is pushed forward along with raising and bending of the arms where the hands are partially drawn together in front of the chest. Sometimes there is flailing of the hands.
- If examination is done with a Wood's lamp, then hypopigmented skin lesions characteristic of this condition can be seen.
- Child has mild to moderate growth retardation.
- Neurological examination can reveal vague and nonspecific features of brain damage.
Investigations for West's Syndrome
- Blood tests are done, which include finding the levels of LFTs, FBC, renal function, calcium, glucose, magnesium and phosphate.
- In case infection is suspected, then urine examination, blood cultures and cerebrospinal fluid analysis is done.
- Urine organic acids, amino acids and serum biotinidase are done.
- CT or MRI scan of the brain is done before the treatment is started. In majority of the cases, abnormalities are found.
- EEG is a vital test, which is done to find out hypsarrhythmia, as this is crucial to the diagnosis.
Treatment for West's Syndrome
- The treatment of West's syndrome is difficult when compared to other types of epilepsy. It is important that the condition is diagnosed early and the treatment started as soon as possible to increase the chances of a successful treatment and to decrease the risk of longer-lasting effects. Even then, there are no guarantees that the treatment will be successful.
- Research is being carried out about the type of treatment for West's syndrome, which will have an effect on the long-term prognosis. The prognosis primarily depends on the cause of the attacks and the duration of the hypsarrhythmia.
- The prognosis for West's syndrome is bad if the patient does not respond well to treatment and the epileptic seizures continue.
- Treatment of West's syndrome depends on the cause, on each individual patient, the condition of development of brain at the time of the damage.
- The two main drugs used as the first-line treatment for West's syndrome are: ACTH and Vigabatrin.
- ACTH is mainly used in United States. The side effects of this medicine are: Weight gain, (particularly in the face and trunk), metabolic abnormalities, hypertension, severe irritability, sepsis, osteoporosis and congestive heart failure.
- Vigabatrin (Sabril) is approved in many countries, such as Canada, Europe and Mexico. Side effects of this medicine include: Headache, somnolence, dizziness, weight gain, fatigue, vision changes, such as decreased vision. Vigabatrin is an effective medicine, particularly in those children who also have tuberous sclerosis. This medicine has few side effects. According to studies there may be loss of peripheral vision with this drug.
- When the above mentioned drugs are not effective for treating West's syndrome, then other medicines can be used either alone or in combination with them. Corticosteroids (prednisone) are often used medications in this condition. Other than this, medicines which can be used in West's syndrome include pyridoxine therapy, topiramate, lamotrigine, levetiracetam and zonisamide.
- Other than medications, the ketogenic diet is also effective in treating and reducing infantile spasms or West's syndrome.
Prognosis & Life Expectancy for West's Syndrome
- The prognosis is good for children having idiopathic West's syndrome when compared to prognosis of children with cryptogenic or symptomatic type of West's syndrome. Idiopathic west's syndrome has a less tendency to display signs of developmental problems before the seizures start. The attacks usually can be treated easily and effectively with a less relapse rate. Idiopathic West's syndrome is less likely to develop into other types of epilepsy.
- In some types of West's syndrome, treatment is difficult and the result of the treatment is not satisfactory. Children suffering from symptomatic and cryptogenic West's syndrome have a poor prognosis especially if they do not respond to treatment.
- According to statistics, 5 in every 100 children having West's syndrome do not live beyond five years of age. The reason could be the cause of the syndrome and in some cases the reason is medication related.
- About less than 50% of children can be completely free from seizures after starting medications.
- Majority of the children tend to suffer from severe cognitive and physical impairments, even when the child is responding to treatment. Frequent and severe attacks damage the brain more.
- There can be permanent damage with West's syndrome including learning difficulties, cognitive disabilities, and behavioral problems, psychological disorders, cerebral palsy and autism.
- Some children having West's syndrome can also suffer from epilepsy later on in their life.
- There are cases where the West's syndrome can develop into focal or other generalized epilepsy. About 50% of children will develop Lennox-Gastaut syndrome.