Epilepsy is a neurological disorder that disrupts normal brain activity, causing a person to experience seizures — sudden, uncontrolled electrical disturbance in the brain. On rare occasions, epilepsy occurs alongside narcolepsy type 1, another condition that affects the brain. A person with narcolepsy type 1 may have either generalized epilepsy or focal epilepsy. In addition to being potential comorbidities — conditions that occur at the same time — narcolepsy and epilepsy share similar symptoms. Those symptoms can be worse for people who have both disorders.

The comorbidity of narcolepsy and epilepsy can significantly impact a person’s diagnostic journey and treatment plan. Here, we will explore the connection between the two disorders, including how they may be managed. If your doctor suspects that you may have epilepsy, they will work with you to find the right course of treatment.

What Is Epilepsy?

Epilepsy is a neurological disorder, meaning it affects the central nervous system. In people with epilepsy, the brain’s electrical activity suddenly spikes, disrupting normal brain functioning. This sudden surge in electrical activity leads to recurring, unpredictable seizures. Various factors can cause epilepsy and seizures, including having a family history of the disorder. In about half of people with epilepsy, the disorder has no known cause.

Seizures are generally classified into two types: focal or generalized. Focal seizures (also known as partial seizures) occur when abnormal electrical activity is limited to one area of the brain. Generalized seizures are believed to involve abnormal electrical activity in multiple areas of the brain. There are six types of generalized seizures:

• Absence seizures
• Atonic seizures
• Clonic seizures
• Myoclonic seizures
• Tonic-clonic seizures

Seizures themselves can cause a wide range of sensations, behaviors, and neurological phenomena, depending on which part of a person’s brain is affected and the extent of their seizure activity.

The Relationship Between Narcolepsy and Epilepsy

Research has found that both generalized and focal epilepsy may be comorbid with (occur alongside) narcolepsy, though it is a rare occurrence. Researchers do not know the exact prevalence of epilepsy and narcolepsy comorbidity.

Experts are also uncertain why some people develop narcolepsy and epilepsy simultaneously. Some research suggests there may be a common genetic factor at play. However, researchers have not yet established what it may be.

Similarities in Symptoms

Characteristic symptoms of narcolepsy type 1 may all be mistaken for epileptic seizures. These include:

• Cataplexy — Sudden loss of muscle power
• Hypersomnolence — Excessive daytime sleepiness
• Hypnagogic hallucinations — Hallucinations just before falling asleep
• Sleep paralysis — Being unable to move or speak while falling asleep or upon waking

Cataplexy, for instance, may cause a person to fall to the ground. This symptom may resemble an atonic seizure or “drop seizure.” The opposite is also true: Epileptic seizures may be mistaken for sudden sleep attacks, cataplexy, or sleep paralysis.

What’s more, hypersomnolence is a common symptom of epilepsy. Those with the disorder may become excessively sleepy as a side effect of their anti-seizure medication. Nighttime (nocturnal) seizures may also disrupt a person’s sleep, causing them to feel drowsy during the daytime.

Distinguishing Epilepsy and Narcolepsy

Due to the similarities between the two conditions, some people are misdiagnosed with epilepsy when they actually have narcolepsy. Moreover, a doctor may overlook one of the disorders in people who have both. For example, a doctor may mistake a person’s narcolepsy symptoms for those of epilepsy if they already have a history of seizures.

To differentiate between narcolepsy and epilepsy, your doctor will likely begin by conducting a physical examination and reviewing your personal and family medical history. They will also likely recommend several clinical tests used to diagnose the two disorders in a differential diagnosis. Differential diagnosis refers to the process of ruling out other potential causes of your signs and symptoms.

Performing a differential diagnosis is an important part of the diagnostic process because it rules out other factors that may contribute to a person’s symptoms, which can include:

• Other sleep disorders
• Medical and mental health conditions
• Medications or other substances

Along with tests used to diagnose narcolepsy, experts recommend the following tests to help differentiate between and diagnose narcolepsy and epilepsy.

Epworth Sleepiness Scale Questionnaire

A thorough medical history is often the first step to arriving at a narcolepsy diagnosis. A neurologist or sleep specialist will ask about symptoms of narcolepsy. Information gathered in your medical history can also help your provider determine if conditions other than narcolepsy could be responsible for your symptoms. They also may ask you to fill out the Epworth Sleepiness Scale questionnaire. This questionnaire asks how likely you are to fall asleep during several specific activities, including sitting and reading, sitting in a briefly stopped vehicle, or talking with someone.

Hypocretin Tests

To diagnose the type of narcolepsy you have, your doctor will determine whether or not you experience cataplexy. Experiencing cataplexy indicates narcolepsy type 1; not experiencing it indicates narcolepsy type 2.

If your diagnosis is in question, your doctor may also want to determine the level of hypocretin in your cerebrospinal fluid. Also called orexin, hypocretin is a brain chemical that helps to regulate sleep, among other functions. Low hypocretin levels are found in about 90 percent of cases of narcolepsy type 1. They are less common in cases of narcolepsy type 2, found in about 10 percent to 24 percent of cases.

Video Electroencephalogram

A video electroencephalogram is a specialized form of an electroencephalogram. For this test, a person is video-monitored while electrodes applied to their scalp monitor their brain’s electrical activity. By marrying these two components, doctors can observe abnormalities in a person’s brain waves while they are experiencing a seizure in real time.

Multiple Sleep Latency Test

The multiple sleep latency test (MSLT) is the standard test used to measure and diagnose narcolepsy and daytime sleepiness. It’s generally the most important test used to diagnose narcolepsy.

Also known as the daytime nap study, the MSLT measures the time it takes for a person to fall asleep (known as sleep latency) in a quiet environment during the day. The MSLT is a full-day test, made up of four or five scheduled daytime naps. Each nap, which lasts for 20 minutes or more, is separated by a two-hour break. During these naps, the sleep specialist conducting the MSLT will measure how long it takes for a person to fall asleep. They will also monitor how quickly the person enters rapid eye movement sleep after sleep onset.

Treating Epilepsy and Narcolepsy

Your health care team may recommend a combination of medication and lifestyle changes to help manage the symptoms of epilepsy and narcolepsy.

Medication for Epilepsy and Narcolepsy

Researchers have determined that a combination of two medications — lamotrigine (used to treat seizures) and Provigil (modafinil) (prescribed to treat narcolepsy) — can help manage the excessive daytime sleepiness and automatic behaviors sometimes seen in people with the disorders.

Furthermore, combining antiepileptic medications with Xyrem (sodium oxybate) — another drug used to treat excessive daytime sleepiness and cataplexy — has been found to be safe and effective for people with epilepsy and narcolepsy type 1.

Other Therapies for Epilepsy

Alongside medication, the following therapies may help treat or manage the symptoms of epilepsy.

Vagus Nerve Stimulation

Vagus nerve stimulation is often used when a person doesn’t respond to anti-seizure medications (which occurs in about one-third of cases of epilepsy). In this therapy, a battery-powered device called a vagus nerve stimulator is implanted in the chest, just below the skin. This device transmits electrical impulses through the vagus nerve in the neck to the brain.

Most people with epilepsy will need to continue taking antiepileptic drugs while undergoing vagus nerve stimulation. Although researchers are not certain how vagus nerve stimulation works to prevent seizures, the therapy typically prevents 20 percent to 40 percent of seizures.

Deep Brain Stimulation

Deep brain stimulation involves implanting electrodes into the thalamus or other areas of the brain. Powered by a generator implanted in the skull or chest, these electrodes transmit electrical signals to the brain, potentially reducing the number of seizures a person experiences.

Ketogenic Diet

Doctors may recommend that children with epilepsy follow the ketogenic diet — a diet low in carbohydrates and high in fats — for several years until they stop experiencing seizures.

Epilepsy Surgery

If medications and other therapies are unsuccessful in treating a person’s epilepsy, doctors may recommend surgery to remove the area of the brain responsible for the seizures.

Other Therapies for Narcolepsy

Doctors may recommend that a person with narcolepsy tries the following to help manage their symptoms.

Sleep Hygiene

Most neurology specialists recommend a combination of medications to treat narcolepsy and lifestyle changes to support good sleep hygiene. The National Institute of Neurological Disorders and Stroke recommends that people with narcolepsy practice the following as much as possible:

• Stick to a regular sleep schedule, even on weekends.
• Take short naps when you feel sleepiest during the day.
• Exercise daily for at least 20 minutes.
• Avoid caffeine, alcohol, or heavy meals before bedtime.
• Don’t smoke, especially in the evening.
• Keep your sleeping space comfortable and maintain a cool temperature.
• Take time to relax before bed.

Cognitive Behavioral Therapy

Psychotherapy can be effective in helping to treat narcolepsy, in addition to medications. Specifically, cognitive behavioral therapy (CBT) has been found to help people with narcolepsy manage behaviors related to sleep patterns, manage anxiety, and control stimuli that trigger cataplexy.

People with narcolepsy are also at a higher risk of experiencing depression and anxiety. CBT can help people manage these disorders and their accompanying symptoms.

Meet Your Team

Navigating life with narcolepsy can be a challenge — but you don’t have to go it alone. MyNarcolepsyTeam is the social network dedicated to people with narcolepsy and their loved ones. Here, members from across the globe come together to ask questions, offer support and advice, and meet others who understand life with narcolepsy.

Are you living with narcolepsy and epilepsy? Share your thoughts in the comments below or by posting on MyNarcolepsyTeam.