Hypersomnia is a term used to define a condition and class of sleeping disorders characterized by hypersomnolence: excessive daytime sleepiness (EDS) and extensive nighttime sleeping periods. It is common for people with a hypersomnia disorder to sleep 10 or more hours per 24 hour period and wake up exhausted despite extensive time asleep. Excessive sleepiness can lead to potential problems with work, driving abilities, and social engagements. Approximately 15 - 30% of the population are affected by hypersomnolence and 4 - 6% of the population is affected by a hypersomnia condition.
What is Excessive Daytime Sleepiness?
Excessive daytime sleepiness (EDS) is much more than being fatigued or tired. There is actually a difference between the terms sleepiness and fatigue, though oftentimes they are used interchangeably, which can easily blur the lines between what each of them means.
Fatigue is most commonly known as a sense of exhaustion. Feeling “foggy” or “sluggish” are words frequently used when describing fatigue. EDS, however, is more severe in that it is extreme, abnormal sleepiness that causes people to have difficulty maintaining wakefulness at times when they should be alert. Unplanned or unintended periods of drowsiness or sleep are common with those experiencing excessive daytime sleepiness. Due to the ongoing threat of sleep or drowsiness, excessive daytime sleepiness can be extremely dangerous not only to those experiencing its effects, but also to those in the immediate vicinity — especially if driving or handling of machinery are part of one’s daily routine.
EDS is a prevalent symptom for a variety of conditions and disorders. Physicians use a questionnaire called the Epworth Sleepiness Scale to help determine the severity of someone’s daytime sleepiness. The Epworth Sleepiness Scale consists of 8 potential situations ranging from watching television to sitting and talking with someone and has patients assign a value ranging from 0 (would never doze) to 3 (high chance of dozing) to each situation. The values are then added to reveal an overall “score” of sleepiness. A score greater than or equal to 10 demonstrates excessive daytime sleepiness and the potential for further testing to determine cause and possible treatment.
Hypersomnia is classified under a category called the central disorders of hypersomnolence, referring to disorders of the central nervous system and brain. All of the disorders in this category include excessive daytime sleepiness. Currently there are 8 disorders classified as a central disorder of hypersomnolence and they include:
- Idiopathic hypersomnia
- Kleine-Levin syndrome
- Narcolepsy (both type 1 and type 2),
- Hypersomnia due to a medical disorder
- Hypersomnia due to a medication or substance
- Insufficient sleep syndrome
- Hypersomnia associated with a psychiatric disorder
Hypersomnia can be further categorized as primary or secondary for the purpose of understanding the origin of the different disorders. Primary hypersomnia does not have other conditions associated with it; excessive fatigue occurs independent of other medical conditions. Primary hypersomnias include:
- Both type 1 and type 2 narcolepsy
- Kleine-Levin syndrome
- Idiopathic hypersomnia
Primary hypersomnia is less common than secondary hypersomnia.
Secondary hypersomnia is related to other conditions. Secondary hypersomnias include:
- Hypersomnia due to a medical disorder (neuromuscular disorders such as muscular dystrophy, ALS, or myasthenia gravis; neurodegenerative conditions such as Alzheimer’s or Parkinson’s disease; or obstructive sleep apnea)
- Hypersomnia due to a medication or substance (sleepiness as a result of prescription or over the counter medications or drugs)
- Hypersomnia associated with a psychiatric disorder (the relationship is not cause and effect, but rather one is related to the other)
- Insufficient sleep syndrome (sleeping less than the recommended 7-9 hours with variability within that shortened range of sleep)
The most common tools utilized for testing hypersomnia and to differentiate between narcolepsy and idiopathic hypersomnia is an overnight polysomnogram followed by a multiple sleep latency test (MSLT). The overnight polysomnogram includes a multitude of electrodes monitoring brain waves, heart rate, oximetry, breathing patterns and muscle activity in the legs. If the overnight polysomnogram is negative, meaning there was no diagnosable sleep related breathing disorder or existance of primary snoring, an MSLT commonly follows.
During an MSLT, only the brain waves and heart rate are monitored and the test is typically performed by a sleep technologist trained at reading the various stages of sleep. The patient is given 5 opportunities to sleep throughout the day at 2 hour intervals, starting 2 hours following light on from the overnight polysomnogram. Each sleep opportunity is 20 minutes in length, less than 20 minutes if quantifiable sleep is observed. The sleep technologist monitoring the patient will note the start time of the test, document sleep onset, and whether or not the patient entered REM sleep. Periods of REM sleep during an MSLT provide sleep physicians with a solid foundation for making proper diagnoses. In addition, physicians may require comprehensive sleep journals and a full medical history.
Treatment for hypersomnia depends on the type of hypersomnia disorder. For some primary hypersomnias, such as narcolepsy, there are three classes of medications typically used for treatment. The three classes include stimulants, non-stimulants, and sodium oxybate. Stimulants may include medications like Adderall or Ritalin. Non-stimulant medications include modafinil (Provigil) and armodafinil. They are considered non-stimulant because though they do act as a stimulant and assist in maintaining wakefulness, they do not have same chemical structures as that of traditional stimulants. Sodium oxybate works to foster deep sleep while also improving sleepiness experienced during the daytime.
Other prescribed medications can include antidepressants or monoamine oxidase inhibitors (MAOIs). MAOIs work by impeding the breaking down of serotonin, a neurotransmitter pivotal for wakefulness. Medications for specific diseases related to hypersomnia disorders like Parkinson’s disease or muscular dystrophy may also be employed as a means to combat the symptoms associated with hypersomnia. For those diagnosed with obstructive sleep apnea, use of continuous positive airway pressure (CPAP), bilevel positive airway pressure (BiPAP) or adaptive servo ventilation (ASV) may be beneficial in decreasing the effects of excessive daytime sleepiness.
Behavioral changes, such as maintaining proper sleep hygiene and avoiding stimulants or medications that cause wakefulness close to bedtime, may also offer some relief. Use of cognitive behavioral therapy may also serve to help mitigate symptoms for some. As with any other medical disorder, working closely with a physician to find the right combination of therapies is vital for establishing and maintaining overall health and wellbeing.