Recognizing the Symptom Spectrum of Narcolepsy to Improve Timely Diagnosis: A Narrative Review

Abstract

Narcolepsy is a chronic sleep disorder with a strong negative impact on quality of life, especially when untreated. Diagnostic delay is a persistent problem, with obvious detrimental effects on patients. A diagnosis of narcolepsy may be delayed because of its broad symptom presentation which is much more encompassing than the classical "tetrad" of sleepiness, cataplexy, hallucinations, and sleep paralysis. Furthermore, symptoms can vary over time. Presentation of symptoms can also be markedly different between children and adults. Finally, common sleep-related comorbidities increase the risk of narcolepsy being masked by overlapping symptoms or treatment. In this review, we provide a detailed description of the broad and dynamic symptom spectrum of narcolepsy, with specific attention to the different manifestations in both adults and children. The overarching goal is to help not only sleep specialists, but general practitioners, pediatricians, and other caregivers with early recognition and prompt diagnosis of this severe but treatable disorder.

Idling for Decades: A European Study on Risk Factors Associated with the Delay Before a Narcolepsy Diagnosis

“…44–48 EDS can also be easily mislabeled as laziness and inattention, leading to a misdiagnosis of behavioral conditions, and also to attention deficit hyperactivity disorder (ADHD) in children. 48 , 49 These results are in line with our result that pediatric patients have longer diagnostic delays than patients with EDS onset during adulthood, which has been recently reported in a US narcolepsy cohort. 18 , 20 It is not surprising that the severity of symptoms (eg, the frequency of cataplexy, duration of episodes of irresistible daytime sleep) negatively contributes to the diagnostic delay, because frequent cataplexy attacks and irresistible daytime sleep can interrupt patients’ daytime functioning and lead to accidents.…”

“… 18 , 20 It is not surprising that the severity of symptoms (eg, the frequency of cataplexy, duration of episodes of irresistible daytime sleep) negatively contributes to the diagnostic delay, because frequent cataplexy attacks and irresistible daytime sleep can interrupt patients’ daytime functioning and lead to accidents. 48 Thus, those patients are likely to seek clinical help earlier or be correctly diagnosed more quickly. The narcolepsy severity scales (NSS) for adults 50 and children 51 have been recently developed.…”

Sleep Disorders in Childhood

“…Excessive daytime sleepiness can also present as an increase in irritability, social withdrawal, and shyness 103 . Excessive daytime sleepiness in adolescents may be perceived as laziness; more than one-half of their day is spent in a classroom setting, and excessive daytime sleepiness during a passive activity like sitting can be interpreted as misbehavior by teachers 104 …”

“…REM sleep intrusions can also present differently in children. The bizarre nature of sleep-related hallucinations and sleep paralysis may confuse children, and they may be embarrassed to discuss the nocturnal phenomena 104 …”

“…Precocious puberty occurs in 17% of pediatric patients with narcolepsy compared to 1.9% in children with obesity who do not have narcolepsy 107 . Recognition of excessive daytime sleepiness in association with precocious puberty or rapid weight gain as part of pediatric narcolepsy type 1 may help in early detection 104 …”