Subtle Symptoms of Narcolepsy
Narcoleptics often suffer for a decade or more before getting a proper diagnosis. Learn the commonly missed signs, and your patients won’t have to wait any longer.
By Peter Blais, RPSGT
Approximately 1 in 2,000 people in the United States suffer from narcolepsy,1 the chronic, life-disrupting neurological disorder in which the brain is not able to regulate sleep-wake cycles normally.2
Yet, according to the 2012 Awareness and Knowledge of Narcolepsy (AWAKEN) survey, less than two-thirds (62%) of sleep specialists and fewer than a quarter (24%) of primary care physicians (PCPs) considered themselves “very” or “extremely” knowledgeable about narcolepsy. In fact, just 42% of sleep physicians and 9% of PCPs felt “very” or “extremely” comfortable diagnosing the disorder.3
AWAKEN survey co-author Russell Rosenberg, PhD, director of research at NeuroTrials Research Inc, in Atlanta, says: “The main point is that gaps in understanding about narcolepsy exist, even in some board certified sleep specialists. Most sleep specialists have the skills to assess patients for the primary symptoms of narcolepsy. However, some sleep specialists, and most primary care physicians, do not know how to elicit reports of other symptoms such as hypnagogic hallucinations and subtle forms of cataplexy.”
And though PCPs are generally good at recognizing sleep apnea, says Thomas Scammell, MD, professor of neurology at Beth Israel Deaconess Medical Center’s Sleep Disorders Center in Boston, many have a limited understanding of narcolepsy. “In part, this is because sleep disorders get little attention in most medical school curricula and doctors lack first-hand experience with the relatively rare disorder of narcolepsy,” Scammell says.
The AWAKEN Survey numbers were even more surprising when it came to identifying all key narcolepsy symptoms, four of which are sometimes called the “tetrad.” The tetrad is:
- hypnagogic hallucination (HH)
- excessive daytime sleepiness (EDS)
- sleep paralysis.
A fifth key symptom—sleep disruption—is also sometimes included. (Physicians can help remember the five with the acronym C.H.E.S.S.4)
While most sleep physicians and almost 40% of PCPs in the AWAKEN Survey knew the two primary symptoms—EDS and cataplexy—only 22% of sleep specialists and 7% of PCPs identified all five.
And even EDS presents some subtle symptoms and often needs additional questions put to patients by healthcare providers to be properly diagnosed. Instead of specifically mentioning EDS, patients may report feeling tired, fatigued, irritable, or subject to other mood changes. They may also note being unable to carry out usual daily activities without substantial effort, poor attention, concentration lapses, and memory difficulties.5
Narcolepsy experts say asking patients to explain what is happening to them, rather than leading the patient with specific questions, is often the best way to get helpful information.
“Patients rarely present in ‘textbook’ fashion,” says University of Washington professor of neurology Nathaniel Watson. “Keeping an awareness that narcolepsy does not necessarily have to include every element of the classic tetrad is helpful. Automatic behavior is pretty consistently present in my patients. So when I am not hearing a patient describe cataplexy, hypnagogic or hypnapompic hallucinations (HH), or sleep paralysis, but I think they may have narcolepsy, I often ask about behaviors such as putting dishes in the freezer or getting in their car and forgetting where they were intending to go.”
Most sleep physicians would have little difficulty recognizing full-blown cataplexy, especially if there are clear emotional triggers, Scammell says. “However, cataplexy is often more subtle and may involve mild weakness of the face, neck, or voice. Thus, it is helpful to ask specifically about mild, transient weakness affecting just [certain] parts of the body.”
Patients sometimes have difficulty describing everything leading up to their cataplexy events. Physicians can elicit helpful information by asking specific questions such as whether patients experience weakness when feeling a strong emotion such as when laughing at or telling a joke, Scammell says. “If cataplexy is suspected, it is important to inquire about other triggers with open-ended questions since it is essential to determine whether it is true muscle weakness with a functional impact (eg, can’t hold head up or speech is slurred) rather than feelings of fatigue. Sometimes cataplexy begins with intermittent weakness resembling asterixis,” he says.
And regarding the three lesser known symptoms (per the AWAKEN survey) of hypnagogic hallucination, sleep paralysis, and sleep disruption:
- Hypnagogic hallucination presents as vivid, dream-like experiences occurring during transitions between wake and sleep. They may be misdiagnosed as a psychotic disorder, Scammell says. “But the HH can be clearly identified when one establishes that they occur only around the beginning or end of sleep or when drowsy,” he says.
- Sleep paralysis is the temporary inability to move voluntary muscles while falling asleep or waking up. The experience may be extremely distressing.6 These episodes typically end spontaneously within 1 to 10 minutes, or disappear when another person touches the patient.5 These symptoms often occur together.
- Sleep disruption is the interruption of sleep by frequent arousals and awakenings5 and may be present in about half of narcolepsy patients. While sleep onset is rarely a problem, an inability to maintain continuous sleep is very common.6 To identify sleep disruption, healthcare professionals should ask patients to rate sleep quality overall during the past month. Additional items to ask about may include: how long it usually takes to fall asleep at night; how much total time the patient spends in bed each night; how many hours of sleep the patient usually gets each night; how many times the patient wakes up during the night; whether poor sleep ever interferes with the patient’s activities the next day.7
Narcolepsy often first appears between the ages of 10 and 25.6 The median time frame between symptom onset and diagnosis is 10.5 years, but better awareness of the symptoms—both the subtle and the more obvious—can decrease the amount of suffering patients endure.8
Peter Blais, RPSGT, is a registered sleep technologist with the Center for Sleep Disorders at St. Mary’s Regional Health System in Auburn, Me. He estimates about 1% of patients at the center are tested for narcolepsy. CONTACT email@example.com
1. Ahmed I, Thorpy M. Clinical features, diagnosis and treatment of narcolepsy. Clin Chest Med. 2010;31(2):371-381.
2. NINDS Narcolepsy Information Page. National Institute of Neurological Disorders and Stroke website. http://www.ninds.nih.gov/disorders/narcolepsy/narcolepsy.htm. Accessed September 16, 2014.
3. Rosenberg R, Kim AY. The AWAKEN survey: Knowledge of Narcolepsy Among Physicians and the General Population. Postgrad Med. 2014;126(1):78-86.
4. Pelayo R, Lopes MC. Narcolepsy. In: Lee-Chiong TL. Sleep. Hoboken, NY: Wiley and Sons Inc; 2006:145-149
5. Ahmed IM, Thorpy MJ. Clinical evaluation of the patient with excessive sleepiness. In: Thorpy MJ, Billiard M, eds. Sleepiness: Causes, Consequences and Treatment. Cambridge, United Kingdom: Cambridge University Press; 2011:36-49.
6. American Academy of Sleep Medicine. The International Classification of Sleep Disorders. 3rd ed. Darien, Ill: American Academy of Sleep Medicine; 2014.
7. Symptom Recognition Guide. Narcolepsy Link. http://www.narcolepsylink.com/hcp/symptom-recognition-guide-print.html. Accessed September 16, 2014.
8. Morrish E, King MA, Smith IE, Shneerson JM. Factors associated with a delay in the diagnosis of narcolepsy. Sleep Med. 2004;5(1):37-41.