His jerking legs ae shaking our bed

Dear Dr. Roach: My husband will be 82 in July. About three years ago, I became aware of his sudden movements during the night. We were renting in Florida, and the bed was smaller than our bed at home. His body would jerk, sometimes strongly. These movements would not wake him; he just seemed asleep. He does not remember anything about it in the morning.

We went to see his doctor at home, who said that he is in very good shape. He did not know what caused the movements.

We are once again staying in Florida, and his body movements are the same, sometimes strong enough to shake the bed. I find it hard to believe that this is normal. Do you have any advice? — B.N.S.s

This is a classic description of a condition called periodic limb movements of sleep. These usually involve the legs, and typically involve pointing the toe while flexing the ankle, knee and sometimes the hip. Each movement lasts a few seconds and repeats every 30 seconds or so. Your story that he doesn’t remember them is very typical: It’s usually the sleeping partner who notices them. PLMS is more common in older adults.

PLMS by itself is not a disease and does not need treatment; however, it is often associated with other conditions, especially restless leg syndrome (Willis-Ekbom disease), rapid eye movement sleep behavior disorder (which includes sometimes violent movements) and narcolepsy.

Since your husband apparently has no symptoms, he does not need treatment. However, he should be specifically asked about symptoms like an urge to move the legs while awake, abnormal feelings in the legs, difficulty falling asleep and sleepiness during the day. These would be likely to indicate RLS or its close relative, periodic limb movement disorder. Write to Dr. Roach at ToYourGoodHealth @med.cornell.edu.