Narcolepsy and epilepsy are both disorders caused by changes in the brain. These conditions are related to each other in two important ways, including the similarity of their symptoms, and their tendency to co-occur with one another.

Similar Symptoms

Many of the symptoms of narcolepsy mimic epileptic seizures. Cataplexy, a common symptom of narcolepsy, can cause individuals to collapse after laughing or feeling a strong emotion. During episodes of cataplexy, people may lose control of muscles, exhibit broken speech, or experience complete weakness in the face, arms, legs and midsection. In many cases, cataplexy can also cause involuntary muscle twitching, which can be easily mistaken for the jerking motions common during epileptic seizures.

Because these symptoms are so similar to those associated with epileptic seizures, some individuals with narcolepsy are misdiagnosed with epilepsy. However, one key difference between narcolepsy and epilepsy is that individuals with narcolepsy typically have memories of their episodes of cataplexy, while people usually lose consciousness during epileptic seizures and have no memory of them.

Co-Occurring Narcolepsy and Epilepsy

Many people with epilepsy also have co-occurring narcolepsy. When a person has both narcolepsy and epilepsy, they can exacerbate the symptoms of both conditions. The seizures characteristic of epilepsy are known to cause sleep disturbances, which tend to increase epileptic seizures and narcolepsy symptoms simultaneously. Additionally, many of the drugs used to treat epilepsy can also disrupt sleep and further exacerbate the symptoms of narcolepsy.

Because of the adverse effect that co-occurring narcolepsy and epilepsy can have on each other, it’s crucial that both conditions are diagnosed and treated correctly. In most cases, diagnosing and addressing co-occurring narcolepsy can increase seizure control and dramatically improve the quality of life of someone with epilepsy.

Zeman, A., Douglas, N., & Aylward, R. β€œNarcolepsy mistaken for epilepsy.” BMJ (Clinical research ed.) Jan 27, 2001. Accessed February 20, 2019.