Autosomal dominant nocturnal frontal lobe epilepsy

Autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) is an uncommon, inherited form of epilepsy. People with ADNFLE have seizures that usually occur at night during sleep. Some people with ADNFLE also have seizures during the day. These seizures can last from a few seconds to a few minutes, and can vary from causing simple arousal from sleep, to dramatic muscle spasms and movements. The onset of ADNFLE ranges from infancy to adulthood, but most cases begin in childhood. Episodes tend to become milder and less frequent with age.^[1][2] It is diagnosed based on symptoms and the results of tests such as an EEG. ADNFLE is inherited in an autosomal dominant manner and may be caused by a mutation in any of several genes. In most cases however, the genetic cause is not found. Seizures can usually be controlled with anti-seizure medications.^[2]

The main symptom in people with autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) is seizures that generally occur at night. Seizures may begin anywhere from early childhood to adulthood, but most often begin in childhood.^[3][4] Seizures may last from a few seconds to a few minutes.^[1] The frequency of seizures varies from several per year to several per night.^[3] Seizures may become less frequent or more mild as a person gets older.^[1] Some people with ADNFLE occasionally have seizures while they are awake.^[4] 

When a person with ADNFLE is having a seizure, they may experience a variety of movement-related symptoms ranging from mild to severe. Examples include:^[1][3][4]

• Short bursts of random, repetitive movements of the limbs, trunk, or head, lasting 2 to 4 seconds.
• Brief, sudden arousal (waking), sometimes with repetitive movements, making sounds, crying, or feelings of fear.
• Major attacks lasting 20 to 30 seconds, characterized by extreme stiffening of muscles, or movements such as pelvic thrusting, pedaling, twisting and writhing, or fast, forceful motions of the limbs.

Recurring episodes of exertion during the night may lead to sleepiness during the day.^[4]

Most people with ADNFLE have normal intellect (thinking abilities), but in some cases, intellect is reduced. Some people with ADNFLE also have psychiatric disorders or behavior problems, but it is unclear if these are directly related to ADNFLE.^[1][3]

A diagnosis of autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) is made based on signs and symptoms. In addition to the doctor taking a detailed medical and family history from the person with symptoms, obtaining information from others who see episodes occur is very helpful. In some cases, video-EEG monitoring during sleep is needed.

The features that suggest a diagnosis of ADNFLE include:

• Clusters of seizures that occur mainly during sleep.
• A normal neurologic exam and normal findings on brain imaging tests.
• A normal EEG recorded during a seizure (ictal EEG), or one that is obscured by movement of the cables or electrodes.
• An EEG recorded between seizures (interictal EEG) that shows few or no instances of patterns seen in people with epilepsy.
• The presence of the same disorder in other family members, with evidence of autosomal dominant inheritance.

If ADNFLE is suspected, genetic testing may be ordered. However, genetic testing can confirm the diagnosis in only 20% of people with a family history of ADNFLE, and in fewer than 5% of people with no family history.^[2]