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- Location Dublin, Ohio
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Narcolepsy & Idiopathic Hypersomnia
Narcolepsy and idiopathic hypersomnia are chronic sleep disorders that cause excessive daytime sleepiness, but they differ in their underlying mechanisms. Narcolepsy is a neurological disorder characterized by sudden sleep attacks, overwhelming daytime drowsiness, and, in some cases, symptoms like cataplexy (sudden muscle weakness), sleep paralysis, and disrupted nighttime sleep. Idiopathic hypersomnia, on the other hand, involves persistent excessive sleepiness despite adequate or prolonged nighttime sleep, often without the sudden sleep-onset symptoms seen in narcolepsy. Both conditions significantly impact daily functioning and quality of life but can be managed with proper diagnosis and treatment.
You may have narcolepsy if you experience some of the following symptoms:
Excessive daytime sleepiness is usually the first symptom to appear and is often the most disabling. Excessive sleepiness may include irresistible urges to sleep throughout the day. Individuals with narcolepsy tend to easily nod off when inactive and have a higher risk of motor vehicle accidents. Excessive sleepiness may also adversely affect a patient’s short-term memory and performance. It can be partially relieved by short “therapeutic” naps lasting from a few minutes to an hour.
Cataplexy is a sudden loss of muscle tone specifically triggered by strong emotions such as laughter, startle or fear, and is a symptom that is only found in narcolepsy. The loss of muscle tone may range from slight weakness (head drop, arm weakness, slurred speech, or buckling knees) to total body collapse, during which time the individual may appear unconscious, even though awake and alert. Cataplectic events can last from a few seconds to several minutes. Although patients with narcolepsy may experience cataplexy, many will never experience cataplexy.
Some individuals with narcolepsy experience vivid, dream-like hallucinations called hypnagogic (from wake to sleep) or hypnopompic (from sleep to wake) hallucinations, which occur during the transitions between wakefulness and sleep. These hallucinations can vary from simple images to nightmare-like events.
Sleep paralysis at sleep onset or upon awakening may occur. The individual is unable to move or talk for a few seconds to several minutes even though awake and aware of the surroundings. Sleep paralysis can be very frightening, especially when combined with vivid hallucinations.
Individuals with narcolepsy often experience frequent awakenings at night and difficulty maintaining sleep but tend to have little problem initiating sleep. Disturbed sleep at night may be so prominent in some patients that they may have a primary complaint of sleep maintenance insomnia.
If you answer yes to the following questions, you may suspect narcolepsy or idiopathic hypersomnia and should consult one of our providers. You may or may not experience all symptoms listed above, however it is important to seek help.
1. Are you often overwhelmed by a feeling of sleepiness or falling asleep during the day?
2. Do you struggle throughout the day, never feeling fully alert even though you had a full night of sleep?
you wake up frequently during the night?
3. Do you feel still sleepy even though you recently had a long nap?
Causes
Narcolepsy and idiopathic hypersomnia are two different disorders that have excessive daytime sleepiness as a major symptom, and, in some cases, these disorders may be difficult to differentiate clinically. The cause of narcolepsy has been discovered, whereas the cause of idiopathic hypersomnia remains unknown. Indeed, the term “idiopathic hypersomnia” actually means “sleepiness of unknown cause.”
Narcolepsy is a neurological disorder. Narcolepsy is caused by a loss of the neuropeptide hypocretin (orexin) in the brain. The loss of hypocretin (orexin) containing neurons is believed to be due, in most cases, to an autoimmune cause.
Learn More About What Causes Narcolepsy
Usually, hypocretin (orexin) neurons in the hypothalamus (region of the brain) help keep the brain awake. For reasons that are not yet clear, neurons containing hypocretin (orexin) degenerate and die in narcoleptics. No other neurons in the brain, however, appear to be affected. As a result of the loss of these “waking neurons”, the level of alertness is decreased, and individuals with narcolepsy develop excessive daytime sleepiness. Once narcolepsy is present, the degree of sleepiness tends to be stable throughout the remainder of the lifetime. If an individual with narcolepsy develops worsening sleepiness later in life, it is generally caused by an independent problem or disorder, such as chronic sleep deprivation (lifestyle) or the onset of a different sleep disorder such as obstructive sleep apnea.
Idiopathic hypersomnia also is believed to be caused by pathology within the brain, but its cause has remained a mystery. Although the degree of pathologic sleepiness may be prominent, daytime sleepiness in patients with idiopathic hypersomnia is generally not as severe as in patients with narcolepsy.
It is believed that both genetic and non-genetic predisposing factors contribute to the development of narcolepsy. Narcolepsy equally affects both men and women. It usually starts during adolescence, but the onset can start as early as five years of age or even after the age of 60. It affects roughly 130,000 Americans or about one out of every 2,000 people. Although narcolepsy is perceived as a relatively rare disorder, its prevalence is the same as multiple sclerosis.
Consequences
The chronic course of the disease and the potentially devastating socioeconomic impact (diminished self-esteem, strained relationships, accidents, lost jobs, etc.) make narcolepsy a significant problem. Nodding off when relatively inactive can happen anytime or anywhere, while you read or talk, eat, or even drive, and can put your life and others in danger. Patients with narcolepsy should not drive a motor vehicle if untreated. Individuals with narcolepsy have minimal restrictions as long as they seek and adhere to medical therapy. If events of everyday life such as joking, playing sports or even making love become intimidating because of excessive sleepiness or a potential of developing cataplexy, you should seek help and no longer feel the need to avoid such situations out of fear or embarrassment.
Diagnosis
As a symptom, sleepiness is often confused with fatigue in the medical community. Fatigue is usually described as a feeling of low energy or malaise, whereas sleepiness is the actual propensity to fall asleep when inactive. Many medical conditions may cause fatigue, as in patients with thyroid disorders, depression or heart disease, but these other conditions are generally not associated with excessive sleepiness. That is, although patients with congestive heart failure may feel “fatigued,” they typically will not nod off when sitting inactive (unless they also have a sleep disorder).
Learn More About the Diagnosis of Narcolepsy
Because fatigue and sleepiness are terms that are often erroneously used interchangeably by the medical community, patients with narcolepsy often go through many years of experiencing symptoms before being properly diagnosed with a sleep disorder. Moreover, most physicians outside of sleep medicine have never seen a patient with cataplexy, and patients with cataplexy are often misdiagnosed with other disorders (such as epilepsy, depression, schizophrenia, or syncope) before being properly diagnosed with narcolepsy. Therefore, it is critical for you to be evaluated by our sleep provider who will conduct a clinical evaluation based on your symptoms and health history.
If narcolepsy is suspected, you will be asked to undergo an overnight polysomnogram (PSG) or sleep study and a Multiple Sleep Latency Test (MSLT) the following day to confirm the diagnosis or rule out other sleep disorders with similar symptoms. We will monitor your brain activity, heart, muscles, eye movements, airflow and blood oxygen levels during sleep. The MSLT measures how fast you fall asleep during the day and the type of sleep you experience during naps.