Professeur docteur oussama chaalane

Dr Usama F Shaalan MD;PhD

Infantile Spasms
Infantile spasms were originally described in 1841. They begin when a child is six months old, on average. The seizures often follow a very distinctive pattern; the child bobs his head slightly, then “jackknifes,” folding at the waist with his head almost meeting his knees. He then relaxes into an upright position. In other cases, the spasms are more subtle. These spasms often occur 10 or 20 times per attack and a child may have several attacks per day. Children with infantile spasms also have a characteristic EEG pattern between and during seizures.
In many cases, children with infantile spasms have existing neurological or developmental problems.
What are other terms for infantile spasms?
Other terms for infantile spasms that you may come across include:
• flexion spasms
• hypsarrhythmia
• infantile epileptic encephalopathy with hypsarrhythmia
• jackknife convulsions
• jackknife seizures
• salaam attacks
• salaam seizures
• West syndrome
What causes infantile spasms?
About 80% of infantile spasms are symptomatic. Over 200 disorders are associated with infantile spasms, including:
• brain malformations
• brain atrophy (shrinking)
• brain tumours
• trauma
• infections
• lack of oxygen
• strokes or blood clots
• tuberous sclerosis
The proportion of infantile spasms that are classed as symptomatic has risen in recent years as neuroimaging techniques (MRI and CT scans) have improved.
Some researchers believe that a small number of children have idiopathic infantile spasms. If so, the number is probably fewer than 10%. These children have normal IQs, no behavioural disorders, and normal development before the seizures began; their seizures usually do not cause problems over the long term.
A significant proportion of infantile spasms are cryptogenic. These children developed normally until the seizures began. There are no known factors causing the seizures, and no problems can be seen with neuroimaging. However, because these children have developmental delay and some neurological abnormalities, doctors suspect that there is an underlying cause for the seizures.
There is little information on the genetics of infantile spasms. Large studies have shown that between 7% and 17% of children with infantile spasms have family histories of epilepsy or febrile seizures. A few families (approximately 3% to 6% of cases) have a history of infantile spasms, and some underlying causes of infantile spasms have a genetic basis. One study found that a family history of epilepsy was more common in cryptogenic than in symptomatic infantile spasms.
What are the features of infantile spasms?
Infantile Spasms
Infantile spasms usually begin within the first year of life, typically between the ages of three and seven months.
The classic pattern of infantile spasms features slight head bobbing. Eventually, the child begins to have flexor, extensor, or mixed spasms:
• Flexor spasms are the most common. The child’s neck, arms, and legs draw towards his chest. The child often bends at the waist in a “jackknife” motion.
• Extensor spasms are the least common. The child’s neck, arms, and legs stretch out.
• Mixed spasms, in which the child’s arms and body contract and his legs stretch out, are also very common.
The spasms are usually symmetrical, although they may be stronger on one side in some cases. Their intensity varies from child to child and from spasm to spasm; they can be very subtle.
In most cases, the spasms occur in clusters. They repeat every five to 30 seconds, sometimes 10 to 40 times in a single attack; the attack usually continues for two to three minutes. The spasms become less intense and farther apart as the cluster progresses.
A child may have several such attacks per day. The seizures rarely occur while a child is asleep, and often happen just after he wakes up. He may be quiet before and during the attack, or he may cry between spasms. After a cluster of spasms, he may be exhausted or more alert.
The seizures are usually not triggered by any obvious stimulus. In some cases, the child may have other seizure types (either partial or generalized) before or with the spasms.
To diagnose infantile spasms, the doctor will look for a typical EEG pattern called hypsarrhythmia.
Between 33% and 89% of children with infantile spasms, depending on the study, have neurological problems. These may be due to an underlying brain abnormality that is also causing the spasms, and may include an abnormally small head, movement difficulties, blindness, or deafness.
After they develop infantile spasms, some children may also have psychomotor or developmental regression. This means that they lose abilities they have already acquired, such as sitting, controlling their head, reaching for objects, smiling, or following objects with their eyes. They may show less interest in people and events around them than they did before the spasms began. It may be difficult to identify this deterioration, since most children with infantile spasms have existing neurological or psychomotor problems.
How many other children have infantile spasms?
It is estimated that one child in every 2,200 to 4,500 children born will develop infantile spasms. Some studies have reported that more boys than girls develop infantile spasms, but the figures vary.
How do you know that a child has infantile spasms?
Doctors usually determine whether a child has infantile spasms by looking at the type of seizures and the EEG pattern between seizures. Many children with infantile spasms have a characteristic EEG pattern between seizures, known as hypsarrhythmia. The EEG shows random, high-voltage slow waves and spikes that are almost continuous. Other patterns may occur. No relationship has been identified so far between the EEG pattern and the underlying cause of the spasms.
How are infantile spasms treated?
There are two common approaches to treating infantile spasms: vigabatrin and steroids. In some cases, the doctor may use other medications to control seizures as well.
For children with tuberous sclerosis, vigabatrin has been demonstrated to be quite effective at controlling infantile spasms.
Adrenocorticotropic hormone (ACTH) is a steroid medication which is injected intramuscularly. ACTH controls infantile spasms in many cases, but it may have severe side effects.
Different studies show different success rates for drug treatment. The child will usually respond to medications within a week or two after starting the treatment. In most studies of infantile spasms, between one-quarter and one-third of children that were successfully treated with drug therapy later relapsed.
If the seizures are caused by a focal brain abnormality such as a tumour or a cyst, your child’s doctor may decide to perform surgery to remove the abnormality. Although there have not been many studies of how many children’s infantile spasms go away after surgery, this does happen in some cases.
Infantile spasm syndrome, X-linked
*Gene map locus Xp22.13
ISSX
Infantile spasms, X-linked
West syndrome, X-linked
[Clinical features: early-onset generalized seizures; hypsarrhythmia; mental retardation]
[Inheritance: X-linked vs. multifactorial (polygenic plus environmental)]
American Journal of Human Genetic : http://www.cell.com/AJHG/

Disruption of the Serine/Threonine Kinase 9 Gene Causes Severe X-Linked Infantile Spasms and Mental Retardation

Mutations in the X-Linked Cyclin-Dependent Kinase-Like 5 (CDKL5/STK9) Gene Are Associated with Severe Neurodevelopmental Retardation

Mutations in the X-Linked Cyclin-Dependent Kinase-Like 5 (CDKL5/STK9) Gene Are Associated with Severe Neurodevelopmental Retardation

CDKL5 mutations cause infantile spasms, early onset seizures, and severe mental retardation in female patients

أضف تعليقاً

Please log in using one of these methods to post your comment:

WordPress.com Logo

أنت تعلق بإستخدام حساب WordPress.com. تسجيل خروج   / تغيير )

صورة تويتر

أنت تعلق بإستخدام حساب Twitter. تسجيل خروج   / تغيير )

Facebook photo

أنت تعلق بإستخدام حساب Facebook. تسجيل خروج   / تغيير )

Google+ photo

أنت تعلق بإستخدام حساب Google+. تسجيل خروج   / تغيير )

Connecting to %s

معرض الوسوم

%d مدونون معجبون بهذه: