By Yoona Ha
Insufficient sleep and improper sleep hygiene are often the usual suspects when a patient mentions that they are tired all the time. And for some patients, relatively simple at-home changes resolve the complaint. But for others, getting more sleep doesn’t alleviate their symptoms. And that’s where it is particularly important for clinicians to distinguish between excessive daytime sleepiness versus fatigue versus apathy.
John Winkelman, MD, PhD, professor of psychiatry at Harvard Medical School and chief of the Sleep Disorders Clinical Research Program in the Department of Psychiatry at Massachusetts General Hospital, sheds light on these issues as related to narcolepsy diagnosis in the Journal of Clinical Psychiatry.
First, it’s important to understand the definition of excessive daytime sleepiness, which can be understood as inappropriate and undesirable sleepiness during waking hours. Fatigue can be differentiated from excessive sleepiness in that it is characterized by the need to rest (not necessarily sleep) and low energy. And apathy, according to Winkelman, is distinguished by one’s lack of motivation, which often occurs when someone has depression or dementia (an example would be the feeling of not wanting to eat or do anything).
From a clinician’s perspective, it can be especially challenging to tell excessive sleepiness apart from fatigue, since the symptoms often appear hand-in-hand.
“Oftentimes, patients will come in and say, ‘I’m tired’ and that phrase can be used be people experiencing apathy, excessive sleepiness, and fatigue, to describe their symptoms, and it’s the doctor’s job to parse that—so we can go from a symptom, to a diagnosis, and then to a treatment,” Winkelman says.
But often doctors, especially primary care physicians, have about 15 minutes or less per patient to address all kinds of problems during one visit, so excessive daytime sleepiness can mistakenly be attributed to some other condition or problem.
With narcolepsy in particular, clinicians know it to be rare. UpToDate estimates that narcolepsy type 1 affects 25 to 50 per 100,000 people, and type 2 (not marked by cataplexy and therefore more difficult to detect) affects 20 to 34 per 100,000 people.
Delayed Diagnosis Harms Patients
For one reason or another, two-thirds of narcolepsy patients are officially diagnosed 5 or more years after onset of symptoms, and nearly half of patients experience a delay of more than a decade.
The debilitating effects of untreated narcolepsy have been widely reported by Sleep Review, such as the story of a comedian who decided to create a superhero webcomic series informed by her own trials and tribulations with the condition.
In the review, Winkelman also described a family’s perspective of caring for a child with narcolepsy: “The judgment that was put on him for falling asleep…[was] really rough when you look back on it now…I was trying to work with the school because he was having such a hard time keeping up in class. We’d even try to give him coffee…That was in fourth grade…We were just grasping at straws basically.”
Digging to the Root Cause
As Winkelman outlined in his paper, there are multiple ways to investigate and uncover the root cause of a patient’s excessive sleepiness. Starting with a patient’s detailed clinical history, identifying signs of REM sleep dysregulation through tests like polysomnograms and multiple sleep latency tests, and supplementary assessments like orexin testing and genetic testing can guide the provider’s investigative journey to identifying the culprit of a patient’s condition.
“As they say in medicine: When you hear hoofbeats in the distance, it’s probably a horse but possibly a zebra. In this case narcolepsy as the cause of daytime sleepiness is a little bit like the zebra,” he says. “Raising awareness and improving knowledge about narcolepsy can help patients and doctors think of the diagnosis.”
Yoona Ha is a freelance writer and healthcare public relations professional.