Nocturnal epilepsy is a condition in which patients experience seizures at night, usually while sleeping. Often, people with the condition are unaware that they’re having night seizures, especially since patients can sometimes go into a deep sleep immediately after having a night seizure. Even if someone else sees the seizure, he or she may not know a seizure is happening since the involuntary movements made during seizures may not look much different than normal sleep movements. Some symptoms of night seizures include waking up sore and very tired even after a long night’s sleep and waking with headaches or lightheadedness. People suffering from nocturnal seizures may also wake to find that they’ve wet the bed or bitten their tongues while sleeping.
Doctors can administer tests to determine whether individuals are experiencing nocturnal epilepsy. One of the most common tests used is an electroencephalogram (EEG) that measures brain activity. A doctor can use the results of an EEG test to determine whether a patient is experiencing epilepsy or some other sleep disorder.
Nocturnal epilepsy is similar to normal epilepsy. Night seizures, however, are in some ways less dangerous than daytime seizures. Since patients are usually already lying down when night seizures strike, they are less likely to be injured by such things as falling or losing control while driving. Nocturnal epilepsy does carry some risk of concussion, as someone having a night seizure can hit his or her head on a headboard or wall behind the bed.
The seizures experienced with nocturnal epilepsy are often tonic-clonic, or gran 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 air being quickly expelled from the lungs. This phase usually lasts only a few seconds. During the clonic phase, the muscles rapidly contract and relax, causing convulsions that can range in force from light muscle twitches to violent shaking.
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 short, violent seizures during sleep. The symptoms of this disorder are often initially misdiagnosed as nightmares or night terrors. ADNFLE is believed to be caused by a malfunction in fibers between the thalamus and cerebral cortex called thalamocortical loops.
Nocturnal epilepsy is typically treated with anti-epileptic drugs. In cases where the epilepsy is resistant to drug treatment, surgery may be a treatment option. Seizures can sometimes be reduced with diet modifications and trigger avoidance.