Sleep-related Movement Disorders Linked to Relapsing-remitting MS
ARTICLE IN BRIEF
Fifty-four percent of relapsing-remitting MS patients with sleep disorders also had a sleep-related movement disorder, according to a new study.
SALT LAKE CITY—People with multiple sclerosis (MS) have trouble with sleep. Now, investigators have described several factors that might explain that problem in a new report described here at the annual meeting of the American Neurological Association.
In a study of MS patients treated in the Veterans Health System, those with sleep-related movement disorders were more likely have the relapsing-remitting form of the disease, said Christopher Bever, MD, a neurologist at the Multiple Sclerosis Center of Excellence at the East Baltimore Veterans Affairs Medical Center.
And patients with progressive-remitting disease were more likely to have sleep apnea breathing problems that interfered with their sleep.
Dr. Bever and colleagues reviewed MRI and clinical data on 206 randomly selected MS patients who had been treated in the VA system between 1998 and 2006 and who also had sleep disorders.
Seventy-five patients were diagnosed with a sleep-related movement disorder, in which patients' bodies twitch, jerk, and make rocking motions during the night. Most of these patients had restless leg syndrome.
The remaining 131 patients had other types of sleep disorders, including obstructive sleep apnea, in which air stops flowing through the nose and mouth, but the other breathing mechanics of the throat and abdomen continue normally; central sleep apnea, in which air flow, throat, and abdomen activities are all interrupted; and REM sleep behavioral disorder, in which patients act out their bad dreams, and narcolepsy.
Fifty-four percent of relapsing MS patients with sleep disorders also had a sleep-related movement disorder, with a statistically significant p-value of less than 0.0001. That compared to 19 percent of the secondary progressive patients, with p-value of less than 0.0001, and 28 percent of the primary progressive patients, with a p-value of 0.04.
Patients with either primary or secondary progressive MS were more likely to have either obstructive or central sleep apnea, but, with a p-value of 0.08, the link wasn't statistically significant.
Researchers also studied the 206 cases for lesions in the primary and supplementary motor cortices, periventricular white matter, thalamus, basal ganglia, brain stem, cerebellum, and spinal cord.
Sixty-five percent of patients with sleep-related movement disorders were more likely to have lesions in the primary and supplementary motor cortex areas than those with other kinds of sleep disorders (−16 percent). The p-value was less than 0.0001.
Sleep apnea was also associated with the presence of spinal cord lesions, with a p-value of 0.046.
Dr. Bever said the study underscores the need for doctors to pay attention to sleep disorders when treating MS patients.
Neurologists should recognize and discuss the frequency of sleep disorders with MS patients, Dr. Bever said. If clinicians suspect a sleep disorder, they should request a sleep study so they can characterize the problem, he added.
“Treatment for obstructive sleep apnea would be quite different from treatment for sleep-related movement disorders so you need to know what the patient's problem is to really figure out how to manage it,” he continued.
He said that researchers should take a closer look at the location of the lesions and how that is associated with different types of sleep disorders. “We've only really looked at about 200 cases,” Dr. Bever said.
Jeffrey A. Cohen, MD, director of the Clinical Neuroimmunology Fellowship at Cleveland Clinic's Mellen Center for Multiple Sclerosis Treatment and Research, said more attention to sleep disorders might help in treating other aspects of the disease as well.
“The study suggests that approximately 6 percent of patients with MS have sleep disorders,” he wrote in an e-mail to Neurology Today. “Disturbed sleep may contribute to fatigue and cognitive symptoms, both of which are common in MS. Treatment of the sleep disturbance needs to be tailored to the patient's specific problem.”