Hypersomnia, or hypersomnolence, is excessive daytime sleepiness. While many daytime sleep disorders result from a lack of nighttime sleep, people with hypersomnia may sleep 10 or more hours each night. The condition is rare in children.
Types of hypersomnia
- Secondary hypersomnia is the result of another cause, such as lack of sleep or medical problems, including sleep apnea.
- Primary hypersomnia has no identifiable cause. This type of disorder is also known as idiopathic hypersomnia.
Secondary hypersomnia in children can be caused by infections, kidney problems or disorders such as myotonic dystrophy. Research is ongoing, but idiopathic hypersomnia may be the result of problems with the brain's sleep-wake cycle. It may also be caused by atypical depression.
The main symptom of hypersomnia in children is excessive drowsiness, often after sleeping for 10 or more hours at night. Other symptoms of hypersomnia include
- Need for daytime naps (that don't relieve the sleepiness)
- Trouble waking from long sleeps
- Awaking confused or disoriented
- Need for naps at inconvenient times (such as during school)
Less common symptoms may include
- Anxiety or irritation
- Loss of appetite
- Slow speech, or trouble thinking
Tests & Diagnosis
While excessive daytime sleepiness is common in adolescents and adults, it is rare in children. Idiopathic hypersomnia is more unusual still—affecting less than one percent of the population.
How can I tell if my child has hypersomnia?
Kids with hypersomnia will often sleep more than 10 hours at night and nap another 4 to 8 hours during the day (if possible). They may also be extremely difficult to wake. Your child may nap in inconvenient or unacceptable places (such as school). Other symptoms of hypersomnia may include anxiety, irritation, loss of appetite and slow thinking or speech.
If your child has had symptoms for more than three uninterrupted months without an identifiable cause, see a doctor.
Tests and diagnoses
Your child's doctor will perform a physical exam to rule out medical conditions that may be behind her excessive sleepiness. The physician may want older kids to keep a sleep diary for a week or more before recommending a sleep test. The following sleep tests can help diagnose hypersomnia in children:
- Multiple Sleep Latency Test (MSLT): An MSLT measures the speed at which your child enters a deep sleep over several two-hour periods. Kids with hypersomnia usually fall asleep quickly (in less than 10 minutes). A multiple sleep latency test is one of the best ways to detect hypersomnia in children.
- Sleep Study (Polysomnography): A sleep study can rule out other sleep disorders that may be behind the excessive daytime sleepiness. If the first test is normal, your child may need to come back for a second polysomnogram. If the sleep specialist still can't find another cause, he may diagnose hypersomnia.
If your child is having trouble staying awake during the day despite getting plenty of sleep the night before, he may have hypersomnia. A secondary hypersomnia may result from interrupted sleep or medical conditions such as sleep apnea. A primary hypersomnia (idiopathic) may be a biological disruption in the brain's circadian sleep-wake cycle.
If your child has a medical condition causing her excessive daytime sleepiness, she will need to be treated for that first. It is important to note there are currently no approved treatments for idiopathic hypersomnia. The following medications are most often used to treat a secondary hypersomnia:
- Stimulants: Stimulants are amphetamine derivatives that can prevent your child from napping during the day. Stimulants usually prescribed include dextroamphetamine and methylphenidate (Ritalin). Stimulants may have harmful side effects, such as aggressiveness, dependence and heart problems.
- Wake-inducing medications: Medications such as modafinil and armodafinil may influence brain chemistry and stimulate wakefulness. They are not stimulants. Side effects of modafinil and armodafinil include headache and a potentially life-threatening rash.
- Sodium oxybate: Sodium oxybate is a drug that your child takes at bedtime (and again during the night). It promotes deep sleep, which can reduce excessive daytime sleepiness in some patients.
Currently, behavioral changes are the only effective way to treat idiopathic hypersomnia. Your child should have a regular sleep schedule and a comfortable bed and pillows in a quiet room. The following behavioral changes can help kids with both secondary and primary hypersomnia:
- Avoiding caffeinated beverages before bedtime
- Using blackout shades
- Avoiding naps during the day or, alternately, encouraging scheduled naps to regulate sleep patterns
For more information about excessive daytime sleepiness (hypersomnia), please visit the following sites:
- This page offers a quick overview of idiopathic hypersomnia, and links to descriptions of other disorders that can cause daytime sleepiness.
- A definition of hypersomnia and an introduction to different types of it:
- This site has information about the effects of hypersomnia and what you should do about it.
- An overview with information about the diagnosis and treatment of hypersomnia: