Nocturnal epilepsy is a condition in which patients experience seizures at night, usually while sleeping. People with the condition are often unaware that they are having nocturnal seizures, especially since patients can sometimes sleep soundly immediately after a nocturnal seizure. Even if someone else sees the seizure, they may not know a seizure is occurring, since the involuntary movements made during seizures may not be much different than normal sleep movements. Some symptoms of nocturnal seizures include waking up sore and very tired, even after a long night's sleep, and waking up with headaches or lightheadedness. People who experience nocturnal seizures may also wake up to find that they wet the bed or bit their tongue while sleeping.
Doctors can administer tests to determine if people are experiencing nocturnal epilepsy. One of the most common tests used is an electroencephalogram (EEG) which measures brain activity. A doctor can use the results of an EEG test to determine if a patient is experiencing epilepsy or some other sleep disorder.
Nocturnal epilepsy is similar to normal epilepsy. Nocturnal seizures, however, are somewhat less dangerous than daytime seizures. Since patients are usually already in bed when nocturnal seizures occur, they are less likely to be injured by things like falling or losing control while driving. Nocturnal epilepsy carries some risk of concussion, as a person having a nocturnal seizure may hit their head on the headboard or the wall behind the bed.
Seizures experienced with nocturnal epilepsy are often tonic-clonic or grand mal seizures. Tonic-clonic seizures occur in two phases. In the first, tonic phase, the person loses consciousness, the muscles tense, and the individual experiencing the seizure may make loud vocal sounds caused by the rapid expulsion of air from the lungs. This phase usually lasts only a few seconds. During the clonic phase, muscles rapidly contract and relax, causing seizures that can range in strength from mild muscle twitching to violent tremors.
A specific type of nocturnal epilepsy is autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE). ADNFLE is a rare disorder that often begins during childhood and causes brief, violent seizures during sleep. The symptoms of this disorder are often initially diagnosed as nightmares or night terrors. ADNFLE is thought to be caused by a malfunction in the fibers between the thalamus and the cerebral cortex called the thalamocortical loops.
Nocturnal epilepsy is usually treated with anti-epileptic drugs. In cases where epilepsy is resistant to drug treatment, surgery may be a treatment option. Seizures can sometimes be reduced with dietary modifications and trigger avoidance.