Medical Edge Newspaper Column

Specialists Can Help Determine Cause of Sleep Disorders

April 3, 2008
Dear Mayo Clinic:
My husband and I have nearly conquered his snoring habit (so that I can get some sleep) only to have a new problem crop up. Around 4 to 5 a.m. every morning, his whole body begins to jerk, which does not wake him up, but sends me into a panic! Any ideas why this happens, and more importantly, how we can get it to stop?

Answer:
There are several sleep disorders that could be causing the symptoms you describe.

First, some people have a condition associated with snoring called obstructive sleep apnea. A person's throat closes off and blocks the flow of air. Lack of air causes the person to wake briefly. Obstructive sleep apnea may happen at various times during the night, but it often occurs in a stage of sleep called rapid eye movement (REM) sleep, which commonly occurs in the early morning hours. So, it's possible your husband is experiencing obstructive sleep apnea during that stage of sleep and at that time of night. His struggle to breathe and overcome the air blockage in his throat may be leading to the jerking movements you're noticing.

The second possibility is a less common condition called REM sleep behavior disorder (RBD). Normally when you dream, your body is paralyzed. Your eyes can move — hence the rapid eye movements of this stage of sleep — as can your diaphragm, the main muscle for breathing, but the rest of your body can't. The benefits of this are clear. You don't want to dream about something and be able to act on it, because you can't control those actions when you're sleeping.

People who have REM sleep behavior disorder lose their sleep paralysis, and they start to act out their dreams. It can be as subtle as shaking or twitching. Or, it could be much more dramatic. Some people actually act out what's happening in the dream, such as a punch, a swing or a kick. At times, these actions may cause them to fall out of bed. Older men seem to be more susceptible to this disorder. In some cases, this sleep behavior disorder may appear before or along with a neurodegenerative disease, particularly parkinsonism.

Third, your husband's movements could be associated with a condition known as periodic limb movement disorder. It's the nighttime equivalent of restless legs syndrome. About 80 percent of people who have restlessness in their legs while they're awake also twitch at night. Usually, those leg twitches are more common early in the night, but theoretically this condition is another possibility.

A fourth possible explanation for your husband's movements during sleep is a seizure disorder. Sleep may facilitate seizure activity in some people.

To sort it all out, I recommend that you and your husband meet with a sleep specialist. This specialist could evaluate the situation, ask some specific questions to get a better sense of what's happening and perform a careful physical exam. For instance, the possibility of sleep apnea could be explored through your answers to the following questions: What is your husband's breathing like when he has the symptoms? Are his body shakes associated with a struggle to breathe, a pause in his breathing or an increase in snoring? REM sleep behavior disorder could be addressed by asking your husband if he's aware of any dreams he's had that might be consistent with the movements you're seeing.

Your husband should also undergo a sleep study. The study will involve sensors to monitor his brain activity and breathing, as well as video observation. Results of the sleep specialist evaluation and the sleep study findings should provide a diagnosis and point you in the right direction regarding appropriate treatment.

— Eric Olson, M.D., Center for Sleep Medicine, Mayo Clinic, Rochester, Minn.