Sleeping Problems: Hypersomnia or Somnolence Syndrome or Nightmares

Hypersomnia

Hypersomnia, also called somnolence, excessive daytime sleepiness, or prolonged drowsiness, is a condition characterized by excessive sleeping, or the inability to maintain wakefulness when desired. Hypersomnia can include long periods of sleep (10 hours or more at a time), excessive amounts of deep sleep, and difficulty staying awake during the day. Hypersomnia can interfere with your relationships, prevent you from enjoying activities, and make it difficult to handle necessary tasks, such as attending doctors' appointments, completing household chores, and managing family or work responsibilities.

Although similar, hypersomnia and fatigue are not the same. Fatigue involves feelings of exhaustion and lack of energy, but fatigue symptoms are not relieved by sleep. Unlike hypersomnia, fatigue is not associated with excessive daytime sleeping and the inability to stay awake.

Causes

Hypersomnia can be caused by both cancer and cancer treatments. Possible causes of hypersomnia include:

Some brain cancers in adults (for example, meningioma, brain stem tumors)
Some childhood central nervous system (CNS) cancers (for example, brain stem glioma, cerebellar astrocytoma, medulloblastoma)
Some secondary brain tumors (brain metastases)
Some chemotherapy drugs (for example, teniposide [VM-26], pegaspargase [Oncaspar], thalidomide [Thalomid])
Other prescription and over-the-counter medications (for example, some antidepressants, antinausea medications, opioid pain killers, sedatives, antihistamines, sleeping pills)
Other symptoms of cancer or side effects of cancer treatments (for example, hypercalcemia [high levels of calcium], hypokalemia [low levels of potassium in the blood], hypothyroidism [a condition in which the thyroid gland is underactive and produces an insufficient amount of thyroid hormones], depression)

Management

If possible, hypersomnia is first treated by diagnosing and treating the underlying cause. In most cases, hypersomnia related to chemotherapy will improve after treatment ends. If other medications are the cause, your doctor may be able to substitute a different medication or adjust the dosage. Your doctor may also prescribe stimulant medications to help you stay awake during the day.

The following tips may help manage hypersomnia:

Sleep a few hours longer at night to avoid excessive sleepiness during the day.
If possible, exercise daily during the morning or early afternoon.
Spend time doing enjoyable activities that require your full attention, such as spending time with friends, writing letters, or playing with a pet.
Try to go to sleep and wake up at the same time every day.
Get out of bed and stay out of bed until bedtime.
Avoid foods that make you sleepy (for example, turkey, milk, alcohol, heavy meals) during the day.

Somnolence syndrome

Somnolence syndrome is a type of hypersomnia associated with cranial radiation (radiation treatment to the head) in children. Symptoms of somnolence syndrome include excessive drowsiness, prolonged periods of sleep (up to 20 hours a day), headaches, low-grade fever, nausea, vomiting, and irritability. Symptoms usually occur three to 12 weeks after the end of radiation treatment and can last from a few days to several weeks.

Nightmares

Nightmares are vivid, frightening dreams that usually cause the dreamer to wake up able to remember part or most of the nightmare. Most people have nightmares from time to time, but the frequency or vividness of nightmares can increase after a cancer diagnosis and during cancer treatment. Frequent nightmares can lead to a fear of going to sleep, restless sleep, and daytime sleepiness.

Nightmares are often associated with an increase in emotional stress and are thought to be a part of the mind's own way of working through unresolved feelings and fears. Nightmares can also be caused by certain medications (for example, some antibiotics and heart medications), withdrawal from central nervous system (CNS) depressants (for example, alcohol and some anti-anxiety medications), and uncontrolled pain.

Having cancer is frightening and extremely stressful, and it is normal to experience some nightmares during treatment and recovery. The following tips may help a person cope with nightmares.

Talk about the nightmares with a family member or friend.
Find creative ways to express the content or themes of the nightmares, such as writing in a diary or drawing a picture.
Make up alternative endings or storylines to the nightmares and visualize them.
Discuss any fears and feelings with a family member or friend earlier in the day, rather than at night, and try to express these feelings truthfully.

Nightmares are not real and do not predict the future or cause bad things to happen. If the nightmares become frequent or continue for a prolonged period of time, cause excessive anxiety, or prevent you from sleeping well, talk to your doctor or seek help from a psychologist or other mental health professional.

More Information

Cancer.Net Feature: Strategies for a Better Night's Sleep

Cancer.Net Podcast: Strategies for a Better Night's Sleep

Last Updated: February 18, 2005