A long winter's nap.

Welcome to midwinter. Long nights punctuated by short days--and brutal cold in some parts of the country. Smart animals hibernate.

Perhaps you feel like hibernating, too. But don't run off with the ground squirrels and terrapins: A constant feeling of exhaustion isn't seasonal in humans. It may be MS fatigue--or a sign that you aren't getting quality sleep.

MS fatigue or poor sleep?

It's hard to tell the difference. They feel similar and they can be interrelated. But there are signs to look for.

If you're getting up day after day feeling unrested--even before using the bathroom or taking a shower--that could be a sign that you aren't getting enough sleep, or that your sleep quality is being disturbed.

MS fatigue is usually less of a problem shortly after waking. MS fatigue is generally better when you're cooler. If keeping cool and fatigue management aren't working, try some of the sleep strategies in the box on page 64 and talk with your doctor about the possibility of a sleep disorder.

Quality sleep, and the disorders that can prevent it

No two people need the same amount of sleep. What's most important is getting a restful, undisturbed sleep, including delta, or deep sleep, as well as REM, or rapid eye movement, which is commonly associated with dreaming. Sleep disorders that interfere with a good night's rest are numerous; many may be related to MS.

The study of sleep is a relatively new field. But enough is known to diagnose many of the problems that can rob you of your ZZZs.

Muscle problems

These include parasomnias, or abnormal movements or behavior during sleep.

* REM disorder (talking or walking in your sleep).

* Restless leg syndrome (an irresistible urge to move your leg).

* Involuntary kicking or twitching, known as periodic limb movements in sleep, or PLMS. PLMS often involves bending at the hips or knees, which can awaken you with a start. But some PLMS are tiny. Your foot or toe involuntarily pulls up and then relaxes again. This might happen every 15 to 90 seconds over the course of a half hour or so. The movement may not wake you, but it can keep you from deep sleep.

Nocturia

Having to go the bathroom frequently during the night--called nocturia--has many causes, some of them surprising. Obviously drinking a lot of liquids right before bedtime--especially diuretics like tea or coffee--is tempting fate. But decreased mobility during the day can cause fluid retention.

Urinating before going to bed is always a good idea. If nocturia persists, your doctor may prescribe DDAVP (desmopressin), which blocks the kidney's production of urine for brief periods. It is frequently used to treat nocturia in people with MS.

Anxiety and depression

Emotions may easily keep you from falling asleep. Drinking alcohol might put you out, but won't guarantee a good night's rest for it can prevent deep (or delta) sleep and increase the need to awaken to urinate. A better fix is to seek psychological expertise to get at the root of your anxiety.

If you constantly wake up earlier than you want to--and not because you need to urinate--you might be clinically depressed.

See a mental health professional for diagnosis and treatment, if necessary.

Sleep apnea 

Sleep apnea--temporary pauses in breathing, often accompanied by gasping, choking, or violent snoring--tends to be a problem in older people or in people who are overweight. But it can occur in people with MS--especially those who experience weakness in their throat or chest muscles. Sleep apnea needs to be diagnosed with a sleep study (polysomnogram).

A polysomnogram involves spending a night or two in a sleep laboratory. Electrodes and monitoring devices are attached to you--they're painless. As you sleep, your brainwaves, eye movements, muscle tone, and air movement through your nose and mouth are all measured. Infrared cameras record your body's movements. If you're experiencing PLMS, it will be picked up on tape.

Medication side effects 

Some people using an MS disease-modifying drug (Rebif, Avonex, Copaxone, Betaseron) are told to take it before bedtime so as to sleep through the side effects. This can be a bad idea if you're a light sleeper--the side effects may wake you and keep you up all night.

Other medications, including some for depression, may also keep you up. Bring a list of all the medications and dietary supplements you take to your doctor and ask which ones might disturb sleep. Your doctor may modify your dosage or change the time of day you take it.

Rest for the weary

Don't take sleep disturbance lightly. If problems persist after talking with your doctor, ask for a referral to a professional certified by the American Board of Sleep Medicine.

Resources

Read the National MS Society's Sleep Disorders and MS: The Basic Facts. Go to nationalmssociety.org/BrochuresSleepDisorders.asp or call your chapter at 1-800-FIGHT-MS and ask for a copy in the mail.

The National Sleep Foundation publishes brochures on sleep and sleep disorders. Write: 1522 K Street, NW, Suite 500, Washington, DC 20005. Tel: [phone]. Web site: www.sleepfoundation.org.

Sleep strategies

* Unwind before bed. Make a cup of chamomile tea or warm milk. Meditate or listen to calming music.

* Count sheep. Simple, repetitive mental exercises, such as repeating a mantra, can focus your attention away from things that may be keeping you awake.

* Imagine yourself in a relaxing setting. This works best if you mentally conjure up a specific environment, such as a beach, with dappled sunlight on the waves, palm trees swaying in the wind ...

* Progressively relax. Focus on one area of your body, such as your left hand, tensing and then relaxing the muscles, and moving up through your arms, shoulders, and so on until you've drifted off. People with spasticity might want to avoid this exercise, as tensing could trigger muscle spasms.

* Don't languish in bed. If you don't drift off within 10 minutes, get up and perform some quiet, simple activity, such as doing a puzzle or writing a letter. (But stay off the Internet. No chatrooms, poker, or porn!)

Rock Heyman, MD, is director of the MS Center at the University of Pittsburgh Medical Center. He also serves on the National MS Society's National Council of Clinical Advisory Committee Chairs and the National Medical Advisory Board. He is board certified in neurology and sleep disorders medicine.