Sleep Myoclonus: Waking Up with a Start. Do You Twitch or Jerk as You Drift Off to Sleep?
Sleep Myoclonus is a benign condition that causes an arm or leg to twitch when a person begins to fall asleep. That’s enough to wake up someone who is trying to fall asleep. Doctors refer to the condition as “sleep starts” or “Sleep Myoclonus.”
The Condition.
A few years ago, I noticed that at night just as I started to fall asleep, I often woke up with a start, as if there had been some sudden noise or movement in the room, though I knew that there had been neither. Once the initial stage of falling asleep passed over into deeper sleep, I wasn’t aware of those movements occurring again.
I am a Physician Assistant. During many years of family practice I can’t recall anyone complaining to me about sleep starts, or Sleep Myoclonus. Now, I, myself, have developed sleep start symptoms. Lucky me!
Sometimes my left arm and shoulder twitches at other times it is my right side that is involved. One of my legs might twitch or my entire upper torso. It is simply a single, sudden contraction of muscles of whatever part of me is involved. At first, I just called it a “fright response” because the sleep start felt like someone shook me.
The Diagnosis.
I found myself scratching my head: Is this condition serious? Is it a warning sign of some neurological disease? Hoping for some answers, I requested a referral for a sleep study from my health care provider.
A sleep study is routine for me because I have had sleep apnea for many years. I use a C-PAP machine at night which sends air under pressure into my throat to keep it open. If I don’t use the machine, then my sleep apnea causes snoring which affects my breathing and wakes me up. I wanted to see if sleep starts would occur during the study and if so, how they affected my sleep patterns.
Sure enough, the neurologist who interpreted the results of my sleep study noted sudden involuntary muscular contractions and diagnosed this condition as “Sleep Myoclonus,” not “Periodic Limb Movement” which is also a common disturber of sleep.
The Prognosis.
Sleep Myoclonus is the least serious form of myoclonus and is, for the most part, a benign condition, according to the National Institute of Health. The condition is not considered a disease or a signal of an impending health problem.
My neurologist, however, did offer to prescribe a medication often used for neurologic disorders. But, because the sleep myoclonus is not affecting me much, I thought the medication would not be necessary at this time. The neurologist agreed. The prognosis is that incidents of sleep starts are not likely to increase enough to disturb my sleep patterns.
Gerald Watt is a retired Physician Assistant and has written many articles on the practice of medicine.
Sources:
www.ninds.nih.gov/disorders/myoclonus. National Institute of Neurological Diseases and Stroke,
www.mayoclinic.com/health/myoclonus . Mayo Clinic.
“My experience of a Sleep Study and Use of a CPAP Machine.” Gerald Watt.
