Characterized by high levels of electrical activity in the brain, epilepsy syndromes clinically present with several different kinds of seizures predominantly in children, but also in adults. Because the seizures happen during sensitive times in brain development, when they occur in children, they often result in severe learning disabilities, neurodegeneration and other longstanding neurological problems. Epilepsy syndromes do not respond well to standard treatment with anticonvulsant medication (in general), but sometimes respond to invasive surgical procedures that interfere with the ability of seizures to travel through the brain.
Lennox-Gastaut Syndrome
Lennox-Gastaut syndrome involves both tonic seizures in which the limbs of the body stiffen, and atonic or "drop" seizures where the body loses general muscle tone and abruptly falls to the floor. According to epilepsy.com, most people with the condition (i.e., about 75 percent) show a specific pattern of brain activity near the scalp that differentiates them from having other forms of epilepsy. Intellectual impairment usually accompanies the presentation of seizures. Anticonvulsants such as clonazepam (Klonopin), lamotrigine (Lamictal), topiramate (Topamax) and valproic acid (Depakene) can provide minor relief for some of the seizure- and cognitive-related symptoms of Lennox-Gastaut syndrome. However, at times, any improvement might require intrusive medical interventions like implantation of a pacemaker in the chest and upper neck to normalize brain activity, or a surgical procedure to split the two hemispheres of the brain called a corpus callosotomy.
Rasmussen's Syndrome
Rasmussen's syndrome designates an inflammatory condition in young children that leads to progressive brain damage. It involves simple partial motor seizures, but can also present with tonic-clonic status epilepticus, a life-threatening condition in which the trunk and limbs of the body undergo recurrent episodes of stiffening followed by violent convulsions. Children with Rasmussen's syndrome will usually exhibit severe learning disabilities, and problems with language and speech. Anticonvulsant medication cannot control any of the symptoms. An experimental study by Dr. James McNamara, Professor of Neurobiology at Duke University, suggests that Rasmussen's might signify an underlying autoimmune disease whereby the immune system attacks a protein expressed on the surface of brain cells. Drugs that suppress the immune system have shown some limited success treating the condition.
Landau-Kleffner Syndrome
Landau-Kleffner syndrome involves generalized tonic-clonic seizures and atypical absence seizures that look like daydreaming. Children with the condition lose language abilities (sometimes even becoming mute), although the relationship between the language problems and the seizure activity remains imprecise. Unlike in Lennox-Gastaut and Rasmussen's syndrome, epilepsy associated with Landau-Kleffner can respond to medication. Boys develop the condition more than girls by a 2:1 ratio.
Temporal Lobe Epilepsy
Seizures stemming from temporal lobe epilepsy (TLE) can begin at any age, emerging in an area of the brain that ordinarily processes memory. Not surprisingly, people suffering from TLE will re-experience old memories during their seizures. They might also enter a strange or pleasurable dream-like state, whereby they become entranced by abstract thoughts, or find that their family and surroundings suddenly feel foreign. Many cases of TLE go unexplained, although the syndrome can develop after head injury or brain meningitis.
References
- Epilepsy.com: All About Epilepsy & Seizures
- Epilepsy.com: Lennox-Gastaut Syndrome
- NINDS, Rasmussen's Encephalitis Information Page
- Science Magazine; Autoantibodies to Glutamate Receptor GluR3 in Rasmussen's Encephalitis; S.W. Rogers et al.; July 1994.
- Epilepsy Currents; The Landau-Kleffner Syndrome; P.L. Pearl et al.; November 2001.
