These disorders, including narcolepsy type 1 and 2 (NT1 and NT2), idiopathic hypersomnia (IH), and Kleine-Levin syndrome, go beyond just being sleepy. The most commonly encountered disorder in this group, however, is insufficient sleep syndrome. The symptoms of these disorders invade all aspects of life and can completely hijack any feeling of control of your own life and contribute to significant disability, deeply affecting function, focus, and any enjoyment of daily life. Understanding your lived experience, or at least being able to characterize what you’re going through, is the first step toward finding relief. In this section, we’ll walk you through what these conditions are, how they’re diagnosed, and most importantly, how they can be managed. We want to be a part of your journey to living life awake, alert, and in control of your day— Trust us! We make a great co-pilot!

CDoH are, in other words, “sleepy disorders,” meaning the primary issue is excessive daytime sleepiness (EDS). The American Academy of Sleep Medicine (AASM) defines EDS as “the inability to stay awake and alert during the major waking episodes of the day, resulting in periods of irrepressible need for sleep or unintended lapses into drowsiness or sleep.”¹ Sleep specialists typically diagnose CDoH using overnight polysomnography and the Multiple Sleep Latency Test (MSLT). However, there are times when clinical history alone, actigraphy, or even sometimes cerebrospinal fluid (CSF) is used to make the diagnosis. However, a critical point to know as a person who may be “living sleepy” is that your ability to clearly define your lived experience and to advocate for yourself may be even more critical than some other sleep or circadian disorders because these conditions are more prone to being missed, dismissed, or misdiagnosed. Therefore, our goal is the same as yours: the right diagnosis, right now, to get you on the right path forward!

Insufficient Sleep

Insufficient sleep is the most common sleep problem globally, affecting millions upon millions of people.² There are many reasons you may not be getting the appropriate number of hours of sleep for your age: you are hustling to achieve your goals trying to get ahead; you’re acting as a caregiver prioritizing the needs of others over your own; or maybe you just really enjoy playing video games with your friends after a long day of school or family responsibilities. Whatever the situation, a diagnosis of insufficient sleep is based upon identifying when and for how long a person sleeps and whether they feel better if allowed to sleep longer. 

Insufficient Sleep Diagnostic Criteria¹

Criteria A-F must be met

1. The patient has daily periods of irrepressible need to sleep or daytime lapses into sleep or, in the case of prepubertal children, there is a complaint of behavioral abnormalities attributable to sleepiness.
2. The patient’s sleep time, established by personal or collateral history, sleep logs, or actigraphy, is usually shorter than expected for age.
3. The curtailed sleep pattern is present on most days for at least three months.
4. The patient curtails sleep time by such measures as an alarm clock or being awakened by another person and generally sleeps longer when measures are not used, such as on weekends or vacations.
5. Extension of total sleep time results in resolution of the symptoms of sleepiness.
6. The symptoms are not better explained by another untreated sleep disorder, the effects of medications or drugs, or other medical, neurologic, or mental disorder.

Treatment of Insufficient Sleep

The treatment of insufficient sleep seems straightforward: get more sleep, embrace sleep hygiene, and stick to consistent sleep and wake times 7 days a week. Easy right? Not always! But we are here to support you.  

Narcolepsy 

In narcolepsy, the boundaries between sleep and wake are evasive. It is living in a world where sleep intrudes into wakefulness, and wakefulness fragments nighttime sleep. One of the key features of narcolepsy is the occurrence of sleep-onset rapid eye movement (REM) periods (SOREMPs) or going into REM sleep within the first 15 minutes of falling asleep. (See the section on sleep stages for more information.)

Narcolepsy Type 1

NT1 is a condition characterized by the pentad, or five, main symptoms that represent the instability experienced between sleep and wake, especially REM sleep. As we go through these symptoms, you will find that there is a pattern of sleep-wake instability, with REM sleep features, like dreaming or muscle paralysis, frequently emerging in wakefulness or vice versa. The symptoms that may be present include the following, but not all people with narcolepsy experience all of these symptoms: 

• EDS: Present in every person with narcolepsy; however, the symptoms of sleepiness can vary by person and manifest differently over time.
• Sleep-related hallucinations: Visual, auditory, or tactile hallucinations that can occur when falling asleep (hypnagogic) or waking up (hypnopompic). 
• Disturbed nighttime sleep (DNS): Fragmented broken sleep that at times can be characterized by frequent sleep-stage shifts.  
• Sleep paralysis: Muscle paralysis or atonia that can occur while falling asleep or waking up.
• Cataplexy: Transient episodes of generalized or focal changes in tone that can occur in response to a strong emotion, but have also been described in the context of fighting a sleep attack or spontaneously. Traditionally thought to be only a loss of tone or weakness, such as knee buckling or falling to the ground, but can also be seen as muscle activation, such as tongue thrusting or eyebrow raising.  

The features of EDS can be seen as inappropriate lapses into sleep, also called sleep attacks. However, EDS symptoms can vary over time. In the very young, the symptoms can look like attention-deficit/hyperactivity disorder (ADHD)-hyperactive type, with an on-the-go, never-stop-moving compensation to prevent falling asleep. In the teenager, it can look like ADHD-inattentive type, moodiness, and even depression.

Cataplexy is typically defined as a temporary loss of muscle tone that occurs in response to a strong stimulus, such as laughter or fear. However, it’s actually incorrect. Children with narcolepsy and some people with an abrupt onset of narcolepsy can have an active motor cataplexy type. This can include features that can be mistaken for tics or movement disorders. In addition, it can occur spontaneously or independently of emotion, as a part of a wide range of emotions and also when fighting a sleep attack. The person experiencing cataplexy remains alert and aware, even when a full cataplexy attack occurs that affects the whole body, and they collapse to the ground. The range of symptoms of cataplexy may be as subtle as a simple drop of the chin or droopy eyelid and as profound as a collapse to the floor.³ 

Sometimes, the symptoms can be difficult to disentangle or identify because of possible misdiagnosis or treatments masking symptoms or confusing the description. An additional confounding factor that can occur for narcolepsy is that other central nervous system disorders can make it more likely that a person will develop a CDoH. When another disorder, such as a craniopharyngioma or a stroke, for example, causes the features of narcolepsy or IH, this is called “secondary narcolepsy.”

NT1 Diagnostic Criteria¹

Criteria A-C must be met

1. The patient has daily periods of irrepressible need to sleep or daytime lapses into sleep occurring for at least three months.
2. The presence of one or both of the following:

1. Cataplexy and either

a. Mean sleep latency of ≤ 8 minutes and two or more SOREMPs on an MSLT performed in accordance with current recommended protocols

b. SOREMP (within 15 minutes of sleep onset) on nocturnal polysomnogram

2. CSF orexin A (or hypocretin-1) concentration, measured by radioimmunoassay, is ≤ 110 pg/mL (using a Stanford reference sample) or less than one-third of mean values obtained in normal subjects with the same standardized assay by assessing CSF obtained via a spinal tap (also called a lumbar puncture).

3. The symptoms and signs are not better explained by chronic insufficient sleep, a circadian rhythm sleep-wake disorder, or other current sleep disorder, mental disorder, or medication/substance use or withdrawal.

Although CSF orexin A can be used to diagnose NT1, orexin is not necessarily absent or deficient in all people with NT1. Low or absent orexin levels have been proposed as being to a possible immune-mediated injury to the neurons, resulting in the loss of signaling of the neuropeptide orexin or hypocretin.¹ Orexin is a pivotal neurotransmitter not only in sleep-wake control, but also across multiple organ systems. To learn more about orexin, check out the sleep and circadian basics page. 

Narcolepsy Type 2

The symptoms of NT2 are similar to those of NT1, except that people with NT2 do not have cataplexy. People with NT2 have normal levels of orexin or hypocretin in their CSF.

NT2 Diagnostic Criteria¹

Criteria A-E must be met

1. The patient has daily periods of irrepressible need to sleep or daytime lapses into sleep occurring for at least three months.
2. A mean sleep latency of ≤ 8 minutes or two or more SOREMPs on an MSLT performed in accordance with current recommended protocols. A SOREMP (within 15 minutes of sleep onset) on the preceding nocturnal polysomnogram may replace one of the SOREMPS on the MSLT.
3. Cataplexy is absent.
4. If CSF hypocretin-1 concentration is measured by radioimmunoassay, it is either > 11 pg/mL (when using a Stanford reference sample) or more than one-third of mean values obtained in normal subjects with the same standardized assay.
5. The symptoms and signs are not better explained by chronic insufficient sleep, a circadian rhythm sleep-wake disorder, or other current sleep disorder, mental disorder, or medication/substance use or withdrawal.

Idiopathic Hypersomnia

IH is characterized by EDS that occurs in the face of adequate or even extended nighttime sleep (11 hours or longer). In addition to the diagnostic criteria, key features of IH include profound difficulty in awakening (called sleep inertia), unrefreshing sleep, and an increasingly recognized attribute of “brain fog.” Some people can experience an extreme form of sleep inertia called “sleep drunkenness,” during which they may experience discoordination, combativeness, and a lack of recall of waking, which can be prolonged.¹ 

The diagnosis of IH has actually undergone almost a dozen proposed or actual name changes since its initial description in 1956 by Dr. Bedrich Roth.⁴ The International Classification of Sleep Disorders (ICSD)-2 separated IH into two forms: with and without long sleep time.⁶ In the ICSD-3, the two types were combined into a single diagnosis of IH, reverting back to the previously established naming; this name persists into the latest version, ICSD-3-TR.¹ People with IH are less likely to experience REM dissociative symptoms such as sleep paralysis and hypnagogic hallucinations, but up to one-third of people with IH may experience these symptoms. Many people with IH also report having symptoms of autonomic nervous system dysfunction.⁷ 

IH Diagnostic Criteria¹

Criteria A-F must be met

1. The patient has daily periods of irrepressible need to sleep or daytime lapses into sleep occurring for at least three months.
2. Cataplexy is absent.
3. Polysomnography and MSLT findings are not consistent with a diagnosis of narcolepsy type 1 or 2.
4. The presence of at least one of the following

1. The MSLT, performed in accordance with current recommended protocols, shows a mean sleep latency of ≤ 8 minutes.
2. Total 24-hour sleep time is ≥ 660 minutes (typically 12-14 hours) on 24-hour polysomnographic monitoring (performed after correction of chronic sleep deprivation), or by wrist actigraphy in association with a sleep log (averaged over at least seven days with unrestricted sleep).

5. Insufficient sleep is ruled out (if deemed necessary, by lack of improvement of sleepiness after an adequate trial of increased nocturnal time in bed, preferably confirmed by at least a week of wrist actigraphy).
6. The symptoms and signs are not better explained by a circadian rhythm sleep-wake disorder or other current sleep disorder, medical disorder, mental disorder, or medication/substance use or withdrawal.

The Treatment of CDoH

The approach to treating the CDoH, including NT1, NT2, and IH, very frequently utilizes overlapping classes of medications such as oxybates, stimulants, and wake-promoting medications. However, there are intentional differences in what is approved for use in each of these indications. In all people with CDoH, it is imperative to evaluate and optimize lifestyle and behavior strategies. And most importantly, incorporating psychology and social support to optimize coping and adjustment strategies, which also reduces social isolation and encourages connection with others on a similar journey.⁸ Every journey is different, and many people may have not only narcolepsy, but also other medical, psychiatric, and even sleep-wake or circadian rhythm disorders as well. This is part of our core mission at WSCN, to not only learn from one another individually but also to inform and evolve our whole community. 

The Treatment of Narcolepsy

The approach to treating narcolepsy may vary internationally based on the medications that are available. This also contributes to differences in care guidelines throughout the world. As a solid first step, characterizing and understanding your personal lived experience is critical. For your healthcare partner to help determine the best treatment options, you both need to know what is holding you back. It is important to consider not only the pentad of symptoms as being absent or present, but also the frequency and impact of those symptoms. Don’t forget non-pentad symptoms, too, such as nightmare disorder or REM-sleep behavior disorder, and any other medical conditions you may have. After you have a better understanding of what your treatment goals are, you can start planning a strategy and shaping an idea of what progress will look like. Every person should have behavioral and lifestyle strategies as part of their treatment plan. This can include dietary strategies, scheduled or strategic naps, and even accommodations for work or school. 

There is no cure for narcolepsy. However, current medications that are used for treating EDS (but have varying international availability) include the oxybates (twice-nightly sodium, twice-nightly mixed-salts (low-sodium), and once-nightly sodium), alerting agents (modafinil, armodafinil, solriamfetol, and pitolisant), and traditional stimulants (methylphenidate and amphetamines). Oxybate medications and pitolisant have been shown to treat both EDS and cataplexy symptoms.⁸ 

Other medications that may be used for symptom management include antidepressant medications, baclofen, and atomoxetine. The medication reboxetine has completed phase 3 clinical trials with favorable results and is expected to be a treatment that will be available soon. In addition, multiple clinical trials are being completed with orexin as the target. At this point, these medications are represented by multiple selective orexin 2 receptor agonists. The currently available data demonstrate significant improvements in the clinical symptoms in NT1 and evidence of benefit in NT2 and IH with differing dosing regimens. 

The Treatment of IH 

Like in narcolepsy, starting off with characterizing and understanding your personal lived experience is critical for you and your healthcare partner to best determine what treatment options may help treat what is holding you back. Although the same medications may be used in IH as in narcolepsy, it is critical to distinguish that the distribution and pattern of symptoms may be very different from narcolepsy; therefore, lifestyle, behavioral, and medication strategies may differ. The only medication with US Food and Drug Administration approval for IH is mixed salts or low-sodium oxybate. A recently completed trial of pitolisant for IH demonstrated directionally favorable findings, but these were not considered statistically significant. A phase 3 clinical trial with once-nightly sodium oxybate is being conducted IH, as are earlier-stage studies with orexin 2 receptor agonists, as mentioned above.⁹

References

1. American Academy of Sleep Medicine. International Classification of Sleep Disorders, 3rd ed, Text Revision. American Academy of Sleep Medicine; 2023.
2. Chattu VK, Manzar MD, Kumary S, Burman D, Spence DW, Pandi-Perumal SR. The global problem of insufficient sleep and its serious public health implications. Healthcare (Basel). 2018;7(1).
3. Barateau L, Morse AM, Gill SK, Pizza F, Ruoff C. Connecting clinicians and patients: the language of narcolepsy. Sleep Med. 2024;124:510-521.
4. Roth B. Sleep drunkenness and sleep paralysis. Cesk Neurol. 1956:19(1):48-58.
5. American Academy of Sleep Medicine. International Classification of Sleep Disorders-2. American Academy of Sleep Medicine; 2005.
6. American Academy of Sleep Medicine. International Classification of Sleep Disorders-3. American Academy of Sleep Medicine; 2014.
7. Miglis MG, Schneider L, Kim P, Cheung J, Trotti LM. Frequency and severity of autonomic symptoms in idiopathic hypersomnia. J Clin Sleep Med. 2020;16(5):749-756.
8. Maski K, Trotti LM, Kotagal S, et al. Treatment of central disorders of hypersomnolence: an American Academy of Sleep Medicine clinical practice guideline. J Clin Sleep Med. 2021;17(9):1881-1893.
9. Morse AM, Naik S. Idiopathic hypersomnia: neurobiology, diagnosis, and management. CNS Drugs. 2023;37(4):305-322.