What is Petit Mal Epilepsy?

Petit mal epilepsy is a form of epilepsy that causes seizures known as absence seizures or petit mal seizures. Someone who has these seizures experiences a brief lapse in conscious thought and activity. During an absence seizure, he or she might suddenly stop moving and stare into space for several seconds or longer before resuming activity. In most cases, seizures caused by petit mal epilepsy can be managed with medication.

The absence seizures caused by petit mal epilepsy often seem to be mild and even harmless to observers. This is especially so when absence seizures are compared to the jerky, sometimes violent muscle contractions caused by myoclonic seizures or the sudden loss of consciousness and fainting caused by atonic seizures. Even so, absence seizures can be dangerous. For example, children who have absence seizures cannot swim or even bathe alone, because of the risk of drowning caused by seizure. Teens and adults might be unable to drive or carry out other tasks that most people take for granted, because of the seizure risk.

Absence seizures, and other types of seizures, are caused by abnormal neuron activity. Neurons are cells in the brain that transmit electrical energy in the form of chemical signals. These chemical signals are transmitted via synapses, or junctions, which connect adjacent neurons. When neurons transmit these chemical signals in an abnormal fashion, the normal pattern of electrical activity in the brain is altered.

The type of seizure that occurs depends on the specific pattern of abnormal electrical energy that is occurring. In petit mal epilepsy seizures, the pattern is a three-second sequence of electrical signals. This is repeated for as long as the seizure continues.

Petit mal seizures are more common in children than in adults. This is because the brains of young children still are growing and contain more synapses than an adult brain. The majority of children with petit mal epilepsy stop having seizures as they grow up. In a small proportion of cases, the child might continue having absence seizures or might begin having the type of full-body movement seizures associated with grand mal epilepsy.

The various types of epilepsy generally are diagnosed on the basis of tests such as electroencephalography (EEG) and a brain scan such as a magnetic resonance imaging (MRI) test. An EEG is carried out to examine the electrical activity in the brain. During this test, the patient will be exposed to stimuli to provoke a seizure so that abnormal brain activity can be evaluated. An MRI scan is carried out to examine the brain itself to determine whether a tumor or structural abnormality is causing the seizures.

Petit mal epilepsy generally can be controlled effectively with medication, but it is not always easy for the right medication and the right dose to be determined quickly. Finding the most effective medication and dose is often a matter of trial and error, and it can take several months or longer. Anti-seizure medications also tend to have a large number of potential side effects, such as headaches, insomnia, nervousness, hyperactivity, gastrointestinal upset and immune system suppression.