Periodic limb movement disorder (PLMD) causes repetitive limb movements that disrupt sleep. The movements usually involve the legs, particularly the big toe, ankle, and knee, but can also include movements of the hip and sometimes the arms. This often occurs during light sleep and at regular intervals of five to 90 seconds, but the frequency can vary from night to night. Most people with symptoms of PLMD aren't aware that their limbs are moving, but bed partners are. Affected individuals are often tired or sleepy during the day as a result of frequent waking during the night and poor quality of sleep.
Diagnosis is made on the basis of overnight monitoring with a device that records body movements during sleep. Respiration is also monitored to make sure the cause of disrupted sleep is not a breathing problem (such as sleep apnea).
PMLD hasn't been widely studied, and we don't know how prevalent it is. It occurs among both men and women and seems more common with advancing age. PLMD has also been linked to uremia, diabetes, iron deficiency, and spinal cord injury.
I haven't had any experience treating PLMD, so I checked with Rubin Naiman, Ph.D., clinical assistant professor of medicine at the Arizona Center for Integrative Medicine and an expert on sleep and dreaming. Dr. Naiman noted that PLMD can be exacerbated by caffeine, alcohol, nicotine, and heavy evening meals and advised avoiding all of these potential triggers. The use of tricyclic and SSRI antidepressants such as Prozac also seems to worsen PLMD; if your husband is taking any of those medications, talk to his physician about alternatives.
Dr. Naiman said that iron and vitamin C supplements can help many individuals with PLMD and suggested consulting a qualified physician or nutritionist for a personalized treatment plan (do not take supplemental iron except on the advice of a physician who has looked at your blood counts).
Drugs used to treat PLMD include medications for Parkinson's disease (such as the dopamine you mentioned) anticonvulsants, benzodiazepines, and narcotics. The first line of treatment is usually with the anti-Parkinson's drugs. While there is no cure for the disorder, drug treatment can reduce or eliminate the symptoms.
Andrew Weil, M.D.