Epilepsy Syndromes Juvenile Absence

Juvenile absence seizures are very similar to childhood absence seizures, so it is often difficult to distinguish the two syndromes. Juvenile absence seizures generally develop later than childhood absence seizures (usually between 7 and 17 years of age, with peak development being between 10 and 12 years of age). Juvenile absence epilepsy is an idiopathic generalized epilepsy syndrome, meaning that the seizures affect the entire brain (generalized) and the cause of the syndrome is unknown (idiopathic).

Absence seizures are non-convulsive staring spells. Juvenile absence seizures in children may often be misinterpreted as inattentiveness, which means that this condition often goes undiagnosed, and it may actually be more common than the current data suggests. At present, researchers at Toronto’s Hospital for Sick Children estimate that approximately 20 percent of absence seizures in children begin after 10 years of age, and most of these cases are classified as juvenile absence seizures.

What Causes Juvenile Absence Seizures?

The causes of juvenile absence seizures are not well understood, but like childhood absence epilepsy, the disorder is probably inherited. Neurological and developmental disorders don’t appear to be a factor, and the majority of youths with absence seizures experience normal development in both of these areas.

What Do Juvenile Absence Seizures Look Like?

Juvenile absence seizures tend to be longer but less frequent than absence seizures in children. A youth may only experience a few seizures per day. These may or may not occur in clusters.

Absence seizures are often so subtle that they may remain undetected until a generalized tonic-clonic (convulsive) seizure occurs; according to Epilepsy Action, approximately 80 percent of youths with absence seizures will experience an occasional tonic-clonic seizure.

In children with juvenile absence epilepsy, absence status epilepticus (a serious condition in which numerous, successive seizures take place) is also common. Myoclonic (muscle contraction) seizures can also occur, but are much less common in youths with juvenile absence epilepsy.

What’s the Prognosis for Juvenile Absence Seizures?

Most young people with juvenile absence seizures don’t outgrow their seizures and must continue to take medication throughout their lives. Anti-epileptic medication successfully controls seizures in the vast majority of cases. The effectiveness of the medication may depend, in part, on the individual. Some common teenage lifestyle choices—such as drinking and staying up late—can actually trigger seizures and reduce the effectiveness of the medication.

Resources

Donner, E. J et al. (2006). Childhood and juvenile absence epilepsy. Retrieved March 22, 2010, from http://www.aboutkidshealth.ca/Epilepsy/Childhood-Juvenile-Absence-Epilepsy.aspx?articleID=6983