Definition: what is west disease?
West syndrome, or West’s disease, is a severe form ofepilepsy newborn which occurs during the first months of life, most often between 3 and 8 months. With a rather low birth prevalence – between 1/1,650 and 1/20,000 – it nevertheless remains the most common cause of epilepsy in infants, although it remains poorly known to the general public. It affects boys more than girls, the boy/girl ratio being 1.5.
Dr. Agnès Guet, neuropediatrician: This West syndrome is characterized by the typical triad: spasms in flexion, psychomotor regression, and typical tracing on the electroencephalogram called hypsarrhythmia.
West syndrome is manifested by spasms can be quite impressive : “the baby brings his arms forward rhythmically, sometimes crying, for a few tens of seconds or even minutes” describes the neuro-pediatrician. We are talking about sudden contractions of the body in flexion.
These spasms can occur at any time of the day, but they seem to be more frequent upon waking. It happens that the child’s eyes be revolted at the time of the crisis.
The description of the crises made by the parents coupled with the age of their occurrence, may suggest that it is a gastroesophageal reflux disease. “If in doubt, parents are advised to film their baby during a crisis to show the video to a pediatrician” insists the specialist.
These spasms are associated with a stagnation or even regression of psychomotor development of the baby: “the child loses recent acquisitions, he doesn’t want to play anymoreits contact deteriorates, he no longer smiles“adds the neuro-pediatrician.
Causes: what is this syndrome due to?
In 60 to 90% of cases, a cerebral lesion – brain-damage can be highlighted, one then speaks of syndrome of West symptomatic.
“The most frequent causes are then a neurological disease like the Bourneville tuberous sclerosis which is the main cause of West syndrome, a cerebral malformation or even a genetic abnormality“ indicates the neuro-pediatrician.
A perinatal ischemiaan infant tumor or a herpes encephalitis can also be implicated.
In 20% of cases remaining approximately, no cause is identified, one then speaks of syndrome of Idiopathic West.
Diagnosis of West’s disease begins with clinical examination of the child by a pediatric neurologistand observation of spasms.
A electroencephalogram (EEG) of wakefulness and sleep helps to highlight hypsarrhythmia during wakefulness. During periods of sleep, there is a fragmentation of activity hypsarrhythmic. The child’s brain is therefore permanently malfunctioning, which is responsible for the impairment of the child’s psychomotor development.
“Brain MRI (Magnetic Resonance Imaging) is then prescribed, to look for possible brain lesions which could reveal a cause of the disease” indicates Dr Guet.
Blood tests are usually ordered, in order to detect possible underlying diseases.
Finally, thelamp examination of wood is essential for diagnosing tuberous sclerosis, which is the most common cause of West syndrome.
What are Dravet, Lennox-Gastaut and Rett syndromes, and what is the difference with West syndrome?
There are a number of rare forms of epilepsy in infants, the symptomatology of which is relatively close to that of West syndrome.
the Dravet syndrome or severe myoclonic epilepsy, is rarer than West syndrome. It generally manifests itself the first time following a feverish episode caused by an ENT disease or a vaccine, and is characterized by the repetition of long or very long seizures with or without feverrequiring the administration of an anticonvulsant.
the Lennox-Gastaut syndrome is a rare, severe and early epileptic encephalopathy, which affects 3 to 6% of children with epilepsy. Seizures most often occur around 4 years, is later than West syndrome. Most children affected by this syndrome have a growth retardation prior to the onset of the first seizures.
the Rett syndrome is a rare neurodevelopmental encephalopathy of genetic origin which mainly affects girls between 6 and 18 months of life. He provokes a disability significant mental and severe motor impairments. Rett syndrome is the first cause of polyhandicap of genetic origin in girls. Epileptic seizures are part of the very varied symptomatic picture of this syndrome with severe loss of motor and mental abilities.
Very rapid initiation of treatment is essential to improve the child’s prognosishence the importance of recognizing the symptoms and being attentive to them.
Dr. Guet: Management is hospital-based and drug treatment must be put in place urgently.
The medication prescribed is Vigabatrin, an antiepileptic approved for use in the treatment of refractory epilepsy. “High dose corticosteroids may be added to it” specifies Dr. Guet.
The surgery is very rarely offeredand only if West syndrome is related to localized brain damage.
What is the prognosis for this syndrome?
The prognosis is all the more favorable the earlier the treatment. “Depending on the cause of the syndrome and the speed of treatment, children may recover fully or subsequently present a delay in acquisitions” indicates the specialist. Support in early rehabilitation may also be necessary.
Generally, the prognosis is better for idiopathic forms than for the symptomatic forms, with a greater probability of full recovery. But the majority of children will remain developmentally delayedregardless of the outcome of the crises.