Lennox-Gastaut Syndrome Health Article

Diagnosis

LGS is diagnosed by some or all of the following symptoms, including:

• presence of a mixed seizure pattern
• some degree of developmental delay or intellectual disability
• distinct, slow, spike-and-wave pattern shown during electroencephalogram (EEG)

Magnetic resonance imaging (MRI) is an important part of the search for an underlying cause in a child with LGS. Abnormalities revealed by MRI associated with LGS include tuberous sclerosis, brain malformations, or evidence of previous brain injury.

Treatment team

Treatment for LGS involves a multidisciplinary team that may include a neurologist, a neuropsychologist, and a neurosurgeon. A dietitian may help with specialized diet regimens.

Treatment

The drug treatment for LGS is based on the use of anti-epileptic drugs that are effective in reducing the number of seizures. However, the improvement often only lasts for a period of months or, rarely, a year or more. Carbamazepine, sodium valproate, vigabatrin, lamotrigine, and the benzodiazepines (clobazam, in particular) are often prescribed.

One alternative treatment involves a ketogenic diet in which 87% of calories come from fat, 6% from carbohydrates, and 7% from protein. The diet is restrictive, difficult to follow, but has shown results in reducing seizures in some affected children. Other less conventional therapies such as intravenous immunoglobulin therapy have also been attempted.

For children with repeated drop attacks, a procedure to cut the corpus collosum (the large group of nerve fibers connecting the two halves of the brain) may be very helpful. However, this procedure involves significant surgery and is not always effective, and seizures may return after several months or years.

An implanted vagus nerve stimulator is effective in reducing seizures in many children with Lennox-Gastaut syndrome. It is a device, similar in size to a heart pacemaker, that is implanted in the chest with a lead wrapped around the vagus nerve in the neck. It is able to stimulate the vagus nerve automatically at adjustable intervals. The device may take months to show maximum benefit, and requires a surgical procedure for insertion as well as for removal. The batteries require replacement approximately every eight to ten years, which entails further surgery.

Recovery and rehabilitation

A very small percentage of children with LGS experience a spontaneous improvement in seizures, usually during adolescence. In these cases, mental function also shows some improvement. In the overwhelming majority of cases, however, emphasis is placed on maximizing quality of life rather than recovery.

Protective devices such as helmets and pads may be necessary during periods of high seizure activity, but many children and parents consider them too burdensome and restrictive for continuous daily use.

Clinical trials

Although as of early 2004 there were no ongoing clinical trials for LGS, the National Institutes of Health (NIH) sponsors research related to many seizure disorders. Information on the numerous current clinical trials for the study and treatment of seizure disorders can be found at the NIH Web site: <http://clinicaltrials.gov/search/term=Seizure+Disorder>.

Prognosis

The prognosis for individuals with LGS is unfavorable, but variable. Long-term studies of children with LGS found that a majority of patients continue to have typical LGS characteristics (mental retardation, treatment-resistant seizures) many years after onset. Children with an early onset of seizures, prior history of West syndrome, higher frequency of seizures, or constant slow EEG background activity have a worse prognosis than those with seizures beginning later in childhood. Tonic seizures may persist and be more difficult to control over time, while myoclonic and atypical absences become easier to control.

Special concerns

It is recognized that the frequency of seizures may be associated with the child's level of alertness. The child who is overexcited or lacks sufficient stimulation may experience more seizures. Therefore, a stable but stimulating environment may be important in reducing the number of daily seizures. This may include a strict routine of regular meals, sleep, and medication.

Providing for the safety of a child with Lennox-Gastaut syndrome is a 24-hour concern for parents. Coupled with safety concerns, children with LGS are often dependent for personal care such as toileting, management of behavioral impulses, and interpretation of attempts at communication. Often, respite care can provide parents with a chance to reenergize. As the child matures into adulthood, an assisted living center or group home may help provide maximum independence and social integration, along with continued medical supervision.

BOOKS

The Official Parent's Sourcebook on Lennox-Gastaut Syndrome: A Revised and Updated Directory for the Internet Age. San Diego: Icon Group International, 2002.

PERIODICALS

Frost, M., et al. "Vagus Nerve Stimulation in Children with Refractory Seizures Associated with Lennox-Gastaut Syndrome." Epilepsia 42 (2001): 1148–1152.

OTHER

NINDS Lennox-Gastaut Syndrome Information Page. National Institute of Neurological Disorders and Stroke. March 10, 2004 (May 23, 2004). <http://www.ninds.nih.gov/health_and_medical/disorders/lennoxgastautsyndrome_doc.htm>.