Narcolepsy can be a debilitating sleep disorder caused by the dysregulation of neurophysiological pathways that control the stability of sleep and wake states in patients. Narcolepsy has a worldwide prevalence of about 26 to 50 per 100,000 individuals. However, the disease is associated with high healthcare resource use, substantial functional limitations, and reduced employment and work productivity. Studies also show that patients with narcolepsy have a higher medical and psychiatric comorbidity burden. The chronicity of narcolepsy mandates that patients receive life-long treatment, regardless of their age of onset.

Narcolepsy Symptom Onset

The onset of narcolepsy generally occurs during a person’s second decade of life, but it’s commonly reported that there are delays between symptom onset and a narcolepsy diagnosis, sometimes for as long as 5 to 10 years. Narcolepsy tends to be clinically defined by a symptom tetrad of:

1. Excessive daytime sleepiness.
2. Cataplexy.
3. Hypnagogic or hypnopompic hallucinations.
4. Sleep paralysis.

Disturbed and fragmented nocturnal sleep often reported by patients suggests that narcolepsy actually comprises a symptom pentad. However, patients typically do not show all five symptoms.

Research suggests that there is an autoimmune explanation for narcolepsy. It has been associated with seasonal streptococcus infections and H1N1 influenza and vaccination. Narcolepsy has also been linked to a specific genotype of the human leukocyte antigen, HLA-DQB1*06. This genotype may underlie the observed loss of the hypocretin-producing neurons that are associated with narcolepsy.

Proactive-Disgnosis-Narcolepsy-Callout

Understanding & Perceptions of Narcolepsy

My colleagues and I recently published a survey—the Awareness and Knowledge of Narcolepsy—to assess the understanding and perceptions of narcolepsy. Participants included 1,000 adults, 300 primary care physicians (PCPs), and 100 sleep medicine specialists, 36% of whom were board certified. The survey showed that 70% of the general public had heard of narcolepsy, but the condition ranked lowest in awareness when compared with other chronic diseases that require long-term treatment. About two-thirds (62%) of sleep specialists and one-quarter (24%) of PCPs believed they were “very” or “extremely” knowledgeable about narcolepsy, but only 42% and 9% of sleep specialists and PCPs, respectively, felt “very” or “extremely” comfortable diagnosing the disorder. Just 7% of PCPs identified all five key narcolepsy symptoms, and no participant in the general population could identify all these symptoms. About two-thirds (63%) of sleep specialists and 39% of PCPs knew that excessive daytime sleepiness and cataplexy were the most prominent narcolepsy symptoms.

Considering the gaps in understanding of narcolepsy, there is a need for educational initiatives for physicians to improve recognition of symptoms in their patients. Patients who complain of excessive sleepiness and/or any of the tetrad of narcolepsy symptoms should be referred to local sleep specialists to get the care they need.

References

Andlauer O, Moore H, Jouhier L, et al. Nocturnal rapid eye movement sleep latency for identifying patients with narcolepsy/hypocretin deficiency. JAMA Neurol. 2013;70:891-902.

Black J, Reaven NL, Funk S, et al. High rates of medical comorbidity in narcolepsy: findings from the burden of narcolepsy disease (BOND) study of 9,312 patients in the United States [APSS abstract 0723]. Sleep. 2013;36(suppl):A249.

Jennum P, Ibsen R, Petersen ER, Knudsen S, Kjellberg J. Health, social, and economic consequences of narcolepsy: a controlled national study evaluating the societal effect on patients and their partners. Sleep Med. 2012;13:1086-1093.

Morrish E, King MA, Smith IE, Shneerson JM. Factors associated with a delay in the diagnosis of narcolepsy. Sleep Med. 2004;5:37-41.

Rosenberg R, Kim AY. The AWAKEN survey: knowledge of narcolepsy among physicians and the general population. Postgrad Med. 2014;126:78-86.

Roth T, Dauvilliers Y, Mignot E, et al. Disrupted nighttime sleep in narcolepsy. J Clin Sleep Med. 2013;9:955-965.

Singh AK, Mahlios J, Mignot E. Genetic association, seasonal infections and autoimmune basis of narcolepsy. J Autoimmun. 2013;43:26-31.