Note: This column is for information purposes only and is not intended as a substitute for professional medical advice.

Q: I don't know what happened. I was sound asleep and the next thing I know my wife is yelling and blood was running out of her nose. She was screaming, "You hit me!" But I was asleep, I swear. She said my arm flew out sideways and smacked her in the face. I know I snore. And she's been telling me for years that I stop breathing and that my muscles twitch in my sleep. But why would I hit her? Please tell me it's a polio thing.

A: Yes, it is a polio thing. We have done three studies of sleep problems in polio survivors. In the 1985 National Post-Polio Survey, 63 percent of polio survivors reported that their muscles twitch and jump during sleep and half of those said that their sleep was disturbed by twitching.

In 1995 a group of our post-polio patients underwent sleep studies. Forty percent of the patients had periodic leg movements in sleep (PLMS), the common form of twitching where only leg muscles move. Almost 30 percent had what we dubbed generalized random myoclonus (GRM), where not just the legs but muscles all over the body, including toes, arms, hands--even face and chest muscles--contract randomly throughout the body during the night. Nearly 30 percent had PLMS plus restless legs syndrome. RLS is not twitching, but a feeling that you must make your legs move, a sensation that increases during the evening and often prevents sleep. And we found one patient who also had nighttime shadow boxing, called a "sleep start." Her arms forcefully flew outward from her body as she began to fall asleep.Had her husband been in the bed and his nose in range at the time she was falling asleep, there could have been bloodshed.

Sleep starts are obvious, since they can wake polio survivors and their bed partners. And restless leg syndrome is also no secret, since it prevents polio survivors from falling asleep. But PLMS and GRM are sneaky. Sixty percent of the patients who had sleep studies didn't know that their muscles were twitching and jumping. This is the sneaky part, since patients also didn't know that twitching was responsible for them getting too little deep sleep or dream sleep and that their brains woke up repeatedly during the night, even thoughthey thought they were sleeping soundly.

In 2001 we reviewed all the sleep studies ever performed on Post-Polio Institute patients. One third were found to have abnormal muscle movements that disturbed their sleep. Nearly half had breathing abnormalities: Ten percent had central sleep apnea, where the diaphragm stops moving; 15 percent had obstructive sleep apnea, where muscles in the back of the throat become relaxed during sleep, closing off the throat and physically preventing air from entering the lungs; and a whopping 60 percent had hypopneas, where air enters the lungs, but oxygen in your blood decreases anyway because the diaphragm is not able to move enough air in and out.

Hypopneas are the sneakiest of all sleep disorders because even if someone were looking, they couldn't tell that you weren't moving enough air in and out of your lungs, nor could they see that your blood oxygen was dropping and that your brain was being awakened hundreds of times during the night. Overall, the combination of twitching and breathing problems resulted in our patients losing 60 percent of their deep sleep and 20 percent of dream sleep. Is it any wonder that these folks felt fatigued during the day?

We have found that a very low dose of Xanax (alprazolam) taken 30 minutes before sleep stops twitching and jumping, even in patients with flailing arms. But breathing problems have to be treated before taking Xanax, since any muscle relaxant can impair breathing. The most effective treatment for apneas and hypopneas is positive airway pressure, where a breadbox-sized machine blows air into the nose, mouth, or both during the night to prevent floppy throat muscles from closing off the air passage, and to keep the lungs fully inflated. Any polio survivor who has muscle twitching while falling asleep or during the night, who snores, wakes in the middle of the night with anxiety, racing heart, choking, or shortness of breath, has headaches, isn't rested in the morning and has severe daytime fatigue should have a sleep study. Don't wait until you've hit your spouse to have your sleep evaluated.