Idiopathic Hypersomnia

What is idiopathic hypersomnia?

Idiopathic hypersomnia is an uncommon, chronic neurologic sleep disorder that is characterized by excessive daytime sleepiness that persists and is not alleviated by an adequate night's sleep. The condition can develop over weeks to months and is distinct from other sleep disorders.

People with idiopathic hypersomnia find it difficult to wake up after sleeping, often don't feel better after sleeping, and sometimes feel worse upon waking up.

Treatment is focused on controlling symptoms with medication.

You should speak with your physician about these symptoms as it's likely a prescription stimulant is needed.

Idiopathic hypersomnia symptoms

The main and most prominent symptom of idiopathic hypersomnia is sleeping normal to long amounts of time each night, but still feeling very sleepy during the day.

Other symptoms

Additional symptoms and signs of this condition include:

• Non-restorative sleep: Meaning sleep that does not help with symptoms. People with idiopathic hypersomnia do not find relief from their sleepiness through naps or adequate sleep hygiene.
• Sleep inertia: Sleep inertia is characterized by difficulty waking up from sleep accompanied by grogginess, confusion, and disorientation upon waking.
• Sleep drunkenness: This symptom is characterized by difficulty thinking clearly and carrying out tasks upon awakening. People with this condition often feel "foggy" while they are awake and find even basic physical and mental tasks difficult to perform.

Symptoms often first appear in the mid-to-late teens or early twenties, but they can also begin in childhood or at a later age. Symptom intensity often varies (between weeks, months, or years) and can worsen just prior to menses in women.

Idiopathic hypersomnia causes

The exact cause of idiopathic hypersomnia is unknown. It is a disorder of the nervous system and studies suggest that it may be caused by excess production of a small molecule in the body that acts as a sleeping drug. The exact composition of this molecule is not known, but it interacts with GABA, which is a molecule known for promoting sleep. It may be that this sleeping molecule promotes and enhances the sleep-promoting effects of GABA.

Idiopathic hypersomnia is a diagnosis of exclusion — it cannot be caused by other medical conditions or sleep disorders. Your physician may perform specific tests in order to get to the proper diagnosis including:

• Polysomnogram: In this test, also known as a sleep study, you stay in a sleep center overnight and your brain activity, eye movements, leg movements, heart rate, breathing function, and oxygen levels are monitored as you sleep.
• Multiple sleep latency test: This test measures your sleepiness and the types and stages of sleep you go through during daytime naps. This test is generally conducted the day after a polysomnogram.

Treatment options and prevention for idiopathic hypersomnia

There is no FDA approved treatment for idiopathic hypersomnia. Your physician may use medications that are approved for other sleep disorders, such as narcolepsy, instead.

Narcolepsy is a sleep disorder also characterized by excessive sleepiness; however, narcolepsy is also associated with sleep attacks, sleep paralysis, hallucinations and sometimes sudden loss of muscle control (known as cataplexy).

Medication

A wakefulness medication called Modafinil is FDA approved for narcolepsy and is often prescribed as an "off-label" medication for idiopathic hypersomnia. Studies have shown that modafinil can help with the sleepiness people experience; however, these medications do not work well for everyone with idiopathic hypersomnia and may stop working over time.

Therapy

Your physician may also prescribe treatments such as Cognitive Behavioral Therapy (CBT) to help you learn skills and adopt behavioral changes that can help you cope with idiopathic hypersomnia.

Complications

Since the need to sleep can happen at any time, for example, while driving a car, swimming, or working, idiopathic hypersomnia can be very dangerous.

On top of that, since people with idiopathic hypersomnia often sleep more than 11 hours per day, it can be extremely difficult to maintain jobs and relationships, stay in school, and fully engage with family and friends.

Even with medications, these symptoms are chronic and persistent, and people may struggle with these activities despite treatment.

Prognosis

Idiopathic hypersomnia is a chronic condition that lasts for a lifetime in most people, but sometimes symptoms may spontaneously resolve in 10 to 15 percent of those affected.

When to seek further consultation for idiopathic hypersomnia

Once you begin noticing symptoms, make an appointment with your physician promptly — especially if symptoms are beginning to interfere with activities of daily living and relationships with family, friends, and coworkers.