Narcolepsy and Epilepsy

Narcolepsy is a sleep disorder whereby a person can not control the onset and offset of sleep, particularly REM sleep. Much like epilepsy, narcolepsy is a disorder that’s caused by changes in the brain and can result in several symptoms, including: 

• Drowsiness – A person with narcolepsy may present with excessive daytime sleepiness, 
• Cataplexy – An abrupt decrease in muscle tone with no loss of consciousness that can result in a fall or varied weakness. 
• Sleep paralysis – The inability to move during the transition into or out of sleep. 
• Hypnagogic hallucinations – Also known as ‘waking dreams’, these hallucinations present as a person is drifting off to sleep. 

Narcolepsy and epilepsy are related in two distinct ways. Firstly, each can present with similar symptoms. Secondly, there is a possibility for narcolepsy and epilepsy to co-occur, which creates unique challenges… 

Similar symptoms and misdiagnosis

Some of the symptoms of narcolepsy, particularly cataplexy, can look very similar to a seizure. During cataplexy, a person can collapse, lose control of their muscles and experience weakness in the arms and legs. In addition, there is commonly an involuntary twitching of the muscles, which is easily mistaken for convulsions associated with a tonic-clonic seizure. Cataplexy usually occurs in response to a strong emotion so can occur when a person is laughing or is really upset. 

For this reason, narcolepsy is sometimes misdiagnosed as epilepsy with cataplexy believed to be a seizure. There is a key difference that can be used to tell the difference between cataplexy and a seizure, which is that people with narcolepsy will usually remember having a cataplexy episode, whereas people with epilepsy typically won’t remember a seizure. This is not a fool proof way to distinguish between the two though and further tests will likely be required. 

When narcolepsy and epilepsy co-occur

It’s also possible for a person with epilepsy to also have narcolepsy. This can be an issue as narcolepsy can exacerbate the symptoms of epilepsy, and vice versa. Both epilepsy and narcolepsy are known to cause sleep disturbances, which can be a major trigger for seizures, and also leave a person open to cataplexy as their sleep cycle has been disturbed. Some of the medications prescribed for epilepsy may also cause further disturbances to sleep. 

When treating a person for co-occurring epilepsy and narcolepsy, it’s important that each is diagnosed and treated independently, whilst taking into account the requirements of both collectively. Quite often, finding effective treatment for either can help to lessen the symptoms of the other and result in a better quality of life for the person with both narcolepsy and epilepsy. 

Diagnosis and Treatment 

Narcolepsy will be diagnosed using a medical history, physical examination and sleep latency test. Much like epilepsy, there is no ‘cure’ for narcolepsy and instead the goal is to control the symptoms as much as possible. For narcolepsy, this means lifestyle changes to promote good sleeping habits, which could include regular naps, avoiding caffeine, alcohol and nicotine, and having a strict nighttime routine. 

In terms of medications, there are a few that may be prescribed for narcolepsy but the evidence of their effectiveness isn’t the most robust. Stimulants, such as modafinil or dexamphetamine, may be prescribed to help a person stay awake during the day. Sodium oxybate is another medication that can improve the sudden loss of muscle control and aid sleep, but it is not yet funded by the NHS in many areas. Finally, antidepressants have been used in some cases to treat symptoms such as loss of muscle control, hallucinations and sleep paralysis, although there’s uncertainty about how effective this is.   

For epilepsy, diagnosis is carried out in many ways depending on the symptoms. Witnessed accounts, medical histories, Electroencephalogram (EEG) and magnetic resonance imaging (MRI) scans are common tests for diagnosing epilepsy. However, these tests can only point towards epilepsy and on their own cannot confirm or rule it out. 
Epilepsy medications are more varied and understood than for narcolepsy. Anti-seizure medications (AEDs) can be used to control seizures. In addition, there are other treatments, such as vagus nerve stimulation (VNS) and in rare cases epilepsy surgery.