Thursday, May 7, 2009

LENNOX GASTAUT SYNDROME

The Lennox-Gastaut syndrome is very serious but uncommon.

Three basic features define it:

Generalized seizures of more than one type, which are difficult to control .Slowness of intellectual growth and associated personality difficulties .A specific EEG abnormality called a slow spike-and-wave pattern, found when the child is awake, and generalized fast rhythms during sleep

Who gets it?

The seizures usually begin in children between 2 and 6 years of age, but they can start a little earlier or later. Many of the children who develop Lennox-Gastaut syndrome have a pre-existing brain disorder or injury. About one-third previously had infantile spasms with an underlying brain disorder (also known as symptomatic West syndrome).

More About L.G.Syndrome:-

Three kinds of seizures that usually occur in Lennox-Gastaut syndrome are tonic, atonic (also known as akinetic), and atypical absence seizures. Tonic seizures tend to be the most common seizure type and are especially frequent when the child sleeps. Some children also have other types, such as myoclonic, partial or tonic-clonic seizures. Because "drop attacks" (atonic or tonic seizures) in which the child falls suddenly are common, many of these children need a helmet and facemask to prevent injury.

A few children do well, but most (75-95%) with the Lennox-Gastaut syndrome have intellectual impairment that ranges from mild to severe.

Behavioral problems are also common. They probably have several causes:

the brain injury
frequent seizures
lack of normal social stimulation
side effects from seizure medicines

Status epilepticus (a state of continuous seizure activity) affects about 90% of those with Lennox-Gastaut syndrome. It is very important to recognize and treat it. A long convulsive seizure is usually easy to recognize. But children with Lennox-Gastaut syndrome most often have non-convulsive status epilepticus, which can be very difficult to recognize. The child may be described as confused, irritable, tired, or apathetic. Parents and teachers often think that the child is ill, experiencing side effects from medicine, or just lonely and bored.

How is it treated?

Medications that are useful for controlling the seizures of patients with Lennox-Gastaut syndrome include:

Depakote (valproate)
Frisium (clobazam, not available in the US)
Topamax (topiramate)
Lamictal (lamotrigine)
Felbatol (felbamate) is also effective and often can improve behavior and quality of life, but it has a high risk of life-threatening blood or liver disorders and must be used carefully.

Sabril (vigabatrin) also has been used, but it can cause significant visual defects. It is not approved in the United States but is available in many other countries, including Canada, the UK, and Australia.

If high doses of seizure medicines are used to try to control frequent seizures, behavioral, social, and intellectual problems may worsen. This effect is especially likely if more than one medicine is used at the same time. Sometimes it's better to accept slightly more frequent seizures if it allows the child to be more alert and attentive, with a much better quality of life.

The ketogenic diet, vagus nerve stimulation (VNS), or a type of surgery called a corpus callosotomy can be helpful treatments for some patients. The ketogenic diet and the VNS have much lower risks, so patients generally try these approaches before considering callosotomy.

What's the outlook?

The course of the seizures varies greatly. Some children have fairly good seizure control later in life. Others grow up to have severe tonic seizures or drop attacks, and some develop partial and tonic-clonic seizures.

Children whose seizures come under fair to good control may have intellectual and behavioral development that approaches normal, but those with frequent seizures who are given high doses of more than one drug may be severely delayed. Both the child and the family often need support from a multidisciplinary medical and psychosocial team.

This syndrome usually continues through adulthood. Many affected people need to live in a residential (adult foster care) group home when their parents are no longer able to care for them.

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