Syndrome of West
The syndrome of West , so known under the name of infantile spasms, is the rare shape of epilepsy of the infant. Named according to the English doctor, William James West (1793-1848), which it first made of it description in an article published in the magazine " The Lancet" in 1841.
Other terms are used to describe it: " epilepsy in inflection généralisée" , " encéphalite myoclonic infantile with hypsarythmie" , " tic of salaam" (hello, in Arabic) or " spasm infantile".
The syndrome is connected to the age, starting between the third and it twelfth month of life, more generally the fifth month. Several causes are known (Polyétiologie). The syndrome is often caused by a faulty operation of the brain whose origins can be antenatal, perinatal (during the childbirth) or postnatal.
Prevalence
The Prévalence is from approximately 1/4000 to 1/6000. Statistically, the boys are more at the risks than the girls, in a ratio of 3/2. In 90% of the cases the spasms appear for the first time between 3 and 12 months of life. In rarer cases, the spasms begin during the first two months from life or during the second at the fourth year.
Syndrome of West and syndrome of Down
On average the syndrome of West appears at 1 to 5 pourcent children reached of the syndrome of Down. Where normally this form of epilepsy is relatively difficult to treat in the children who do not have the chromosomal difference found at the syndrome of Down, the syndrome of West affects those which have this difference with much less severity and the answer to medication is better. The " Deutsches Down-Syndrom InfoCenter" , or German Center of information on the syndrome of Down, noted into 2003 that what is normally regarded as a serious form of epilepsy is in these often benign cases.The statements EEG of a child with the syndrome of Down are often more symmetrical. Whereas they are not all the children who will not have any more episodes when they are under medication, those having the syndrome of Down have less chance to develop the Syndrome of Lennox-Gastaut or other forms of epilepsies that those not having an additional material on the 21st Chromosome. The reason for which it is easier to treat the syndrome of West in the children reached of trisomy 21 is not known.
The syndrome of West in the children having other syndromes
In addition to the syndrome of Down (trisomy 21), other affections are associated with a greater risk to develop the syndrome of West, including Incontinentia pigmenti, Sclérose tuberose, the Syndrome of Foix-Chavany-Marie and the Syndrome of Sturge-Weber.
Causes
The discovery of the biochemical mechanism responsible for the syndrome of West was not made yet. An assumption exists with the effect that it could be an error in the operation of the Neurotransmetteur S, or more precisely, a defect in the regulation of the processes of transmission of the Acide gamma-aminobutyrique. Another at present studied possibility is a hyperproduction of the Hormone of release of the corticotrophine. It is possible that more than one factor is concerned. The two assumptions are supported by the action of certain drugs used in the treatment of the syndrome of West.Here possible causes:
-
Environ one the third of the children reached presents a major dysfunction of the brain, including:
- cortical microcephalus
- Dysplasie
- cerebral Atrophy
- bacteriological Lissencéphalie
- Meningitis
- Phacomatoses (e.g Syndrome of Bourneville)
- Syndrome of Aicardi
- Sclerosis tuberose
- Céphalhématome and
- vascular malformation .
Moreover, other causes are in rise in the literature:
-
neurometabolic disease
- congenital infection (e.g Cytomegalovirus)
- Hypoglycemia
- cerebral lesion by Asphyxiation or Hypoxia (lack of oxygen during the birth for example), perish-ventricular Leucomalacie, Céphalhématome, Accident cérébrovasculaire or any other type of cerebral lesions, of which those caused by a premature Birth.
-
Some cases exist in which the spasms began as an side effect of a combination of vaccines against the Rougeole, the Oreillons and the Rubéole or the Tétanos, the Coqueluche, the Diphtérie, the Poliomyélite, the Hépatite B and the Haemophilus influenzae of the type B. On the other hand, it is difficult to establish a relation of cause and effect between the immunization and the syndrome of West since in the majority of the cases the immunization is done for the period when the spasms begin. The syndrome of West is not recognized as being Iatrogénique.
If an etiology arises, the syndrome is then known as as being symptomatic , since the episodes appear like a symptom of another anomaly.
Sometimes the syndrome is known as cryptogenic , when an etiology cannot be given. In 20% of the children affected by the syndrome of West, no cause can be given. The criteria of diagnostic are:
-
normal Development before the beginning of the episodes or the beginning of the therapy;
- no Pathology discovered during the Neurological or neuroradiologic examinations ;
- no sign of a release of spasms.
In 15% of the cases, the children of the same family dévoloppent the syndrome of West. In these cases it is known as idiopathic , i.e. heredity and the genetics have a role to play. Cases exist in which the syndrome appears in the successive male generations; what is due to the heridity of X chromosome.
Clinical presentation
The crises observable epileptics in the infants are classified in three categories. Normally this trio of attacks appears together, but it is possible that they are independent:
-
Flash : Severe myoclonic convulsion of all the body or several parts of this one in a fraction of a second, especially on the level of the legs which yield (convulsions of the Flexors is generally more severe than those of the Extenseurs)
- Hochement of head : Convulsion of the muscles of the head and the neck, the chin moves towards the chest or the head moves towards the interior
- Salaam : A spasm in inflection with a fast projection of the head and chest forwards, simultaneously the arms rise and yield partially, ammenant the hands more or less units. By imagining this movement with the idle, it is similar to the Eastern hello (salaam), from where it draws its name.
Therapy
Compared with other forms of epilepsy, the syndrome of West is difficult to treat. A fast diagnosis and a treatment applied as of the supplemented diagnosis increase the chances of effectiveness of traiment and decrease the risk of long-term after-effects. Despite everything, nothing guarantees the success of the therapy even when it begins under best the conditions.Research is insufficient as for the long-term influence of the treatment on the forecast. While being based on what is known today, the forecast depends largely on the cause of the episodes and the duration of the Hypsarythmie. In general the forecast worsens when the response of the patient to the treatment is not very good and that the continuous abnormal cerebral activity. The treatment differs for each case and depends on the cause (etiologic classification) and the level of development on the brain at the time on the damage.
Two drugs are présentements used as treatment of first line because of their respective side effects.
- ACTH - Used mainly in the United States
- the side effects are: Profit of weight, particularly with the chest and the face, Hypertension, anormalitiés of the metabolism, severe irritability, Osteoporosis, Septicaemia and Cardiac failure.
- Vigabatrine (Sabril) - Approval in several countries, of which the major part of Europe, Canada and Mexico.
- the side effects are: Somnolence, headaches, dizzy spell, tiredness, profit of weight, reduction in the vision or another change to the vision
Vigabatrine is well-known for its effectiveness, particularly with the children reaches Sclérose tuberose, with benign side effects. But due to recent studies showing a peripheral loss of the visual fields, it is not approved yet in the United States. Several specialists believe that a short use (6 months or less) of Vigabatrine will not affectra the vision. Also, considering the devastator effect of the crises on the life of the every day and the mental development, certain parents prefers to take the risk of a loss of visual fields.
When these two drugs are ineffective, others can be used together or individually. Topiramate (Topamax), Lamotrigine (Lamictal), Levetiracetam (Keppra) and Zonisamide (Zonegran) those are used courrement.
The ketogenetic Diète was tested and is recognized as being effective, up to 70% of the children showing a reduction of 50% or more of the crises.
Forecast
It is not really possible to emit a Pronostic on the development due to the variability of the causes, as mentioned above, the various symptoms and the etiology. Each case must be evaluated individually.The forecast of the children with a syndrome of West cryptogenic is generally more positive than those having the idiopathic or symptomatic form. The cases cryptogenic are likely less to show problems of development before the beginning of the episodes, they can be treated more easily and effectively and the rate of relapse is lower. The children with this type of syndrome are less at the risk to develop other forms of epilepsy; approximately 2 children out of 5 (40%) develop with the same rate/rhythm as the other children.
On the other hand, in other cases, the treatment of the syndrome of West is relatively difficult and the unsatisfactory result; for the children with the syndrome of West idiopathic or symptomatic the forecast is generally unfavourable, particularly when that there is not an good answer with the therapy.
Statistically, 5% of the children with the syndrome of West do not survive beyond the fifth year, in certain cases due to the etiologic cause of the syndrome, in others for reasons connected to medication. Less than half are released entirely from the attacks with the assistance of the drugs. The statistics show that the treatment produced a satisfactory result in 3 children out of 10, with 1 out of 25 whose development Cognitif and Moteur is done more or less normally.
A great proportion (up to 90%) of the children suffer from physical and cognitive deficiencies, even when the treatment succeeds. It is not usually caused by the crises epileptics itself, but rather by the subjacent causes (cerebral anomalies, their sites or the degree of severity). Moreover, severe and frequent episodes can damage even more the brain.
The permanent damage usually associated in the literature with the syndrome of West includes cognitive disability, of the difficulties of training and the disorders of behavior, the cerebral, so called driving Infirmité cerebral paralysis (up to 50% of the cases), of the psychological disorders and the Autisme (surroundings 30% of the children). Once again, the etiology of each individuals must be taken into account when the cause-effect ones are discussed.
As well as 6 children out of 10 will suffer from epilepsy into growing old. Sometimes the syndrome of West is transformed into partial or generalized epilepsy. Approximately half of all the children develop the Syndrome of Lennox-Gastaut.
History
The syndrome of West was named according to the doctor and chrurgien English William James West (1793-1848), which with lived with Tonbridge. In 1841 it observes this type of epilepsy on his own son, who was old of approximately 4 months at that time. It published its observations under a scientific point of view in stores The Lancet. It named the crises " Ticks of Salaam" at that time.
The documents according to are quoted in the German version of Wikipedia, which was translated into English. The French version is an integral translation of the english language version.
Altrup U., Elger E.C.: Epilepsy. Informationen in Texten und Bildern für Betroffene, Angehörige und Interessierte , Novartis Pharma GMBH, 2000, ISBN 3933185491 This article is a translation of
References
External bonds
| Random links: | Battle of Hastings | Porsche 356 | Magic constant | Jean-Jacques Lénient | Insane Clown Poses | Commercial bond | John_Cunliffe |