sleep

What is sleep-related hypermotor epilepsy?

  • Nocturnal frontal lobe epilepsy was first described in 1981 in 5 people with peculiar movements that happen in sleep.
    • Violent movements of arms or legs and strange posturing were seen, similar to seizures seen in people having EEG (electroencephalogram) monitoring.
    • People were not sure if this was a movement disorder or an epilepsy syndrome. Yet finding seizure discharges on the EEG proved this to be an epilepsy syndrome.
  • Seizures begin between 1 and 60 years of age. Over 85% of people are diagnosed before 20 years old. It usually begins when someone is 9 years old.
  • Both males and females are affected equally.
  • People are developmentally normal before the seizures start and rarely have worsening of thinking and memory.
  • The syndrome's name was changed from autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) to sleep-related hypermotor epilepsy (SHE), because
    • Events are brought on by sleep
    • Seizures can arise from other areas of the brain
    • Motor movements are seen
  • Other names for this syndrome are

What do seizures in SHE look like?

  • Seizures in people with SHE are characterized by frequent brief hypermotor seizures in sleep. A person may average 8 seizures in one night.
  • The seizures can look like a simple arousal from sleep, at times confused as a nightmare or night terror. They can also be more involved movements like twisting, turning, pelvic thrusting, pedaling, grimacing, wandering, startling, and vocalizations like screaming, moaning or crying.
  • Sometimes a person is fully aware during a seizure while having wild movements of the arms and legs.
  • Some people have have a sensation of being unable to catch a breath during a seizure.
  • These seizures may last a few seconds to a few minutes, but are usually about 30 seconds.

Is this epilepsy syndrome inherited?

This epilepsy syndrome is typically inherited, but other causes have been reported. Genetic mutations on the following genes have been associated with this epilepsy syndrome:

  • Nicotinic receptor subunit genes (CHRNA4, CHRNB2, CHRNA2)
  • Potassium channel genes (KCNT1)
  • Other genes like DEPDC5, NPRL2, etc.

How is SHE diagnosed?

  • A complete history and examination of a child or adult with suspected sleep-related hypermotor epilepsy is the first step.
  • An EEG should be done.
    • In many cases, a prolonged EEG or video EEG is required to record the events during sleep.
    • The EEG in children and adults with this epilepsy syndrome may be normal or show rare sharp waves n the frontal region of the brain.
  • Genetic tests may be recommended to look for gene changes.
  • An MRI (magnetic resonance imaging) scan is usually normal but is required to exclude a brain abnormality like focal cortical dysplasia.
  • Diagnosing SHE can be difficult as the seizures are similar to other movement disorders or sleep problems.

How is this epilepsy treated?

If your seizures are not controlled, seek out the help of an epilepsy specialist or visit an epilepsy center to explore all treatment options.

Children and adults with SHE may have cluster seizures and need emergency medical treatment or treatment with a rescue therapy. Emergency treatments include diazepam rectal gel (Diastat) or another form of benzodiazepine given into the nose (intranasally) or under the tongue.

What is the outlook for people with SHE?

  • SHE is a lifelong condition, but it is not progressive.
  • Usually seizures can be controlled with medications or they become milder and less frequent with age.
  • Most people are intellectually normal; however, some people with SHE have experienced mood disorder, behavioral problems, or intellectual disability.

Resources

References

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Authored By: 
Charuta Joshi MBBS
Authored Date: 
11/2019
Reviewed By: 
Elaine Wirrell MD
Patty Obsorne Shafer RN, MN
on: 
Tuesday, November 19, 2019