People living with multiple sclerosis are at increased risk of sleep disturbances, which can lead to daytime sleepiness and fatigue. The most common sleep problems associated with MS include insomnia, obstructive sleep apnea (OSA), and restless legs syndrome (RLS). Other sleep problems may include periodic limb movement disorder (PLMD), rapid eye movement (REM) sleep behavior disorder (RBD) and narcolepsy.
Fatigue vs. sleepiness
Fatigue and sleepiness are similar, but may have different causes. If you start the day energized, but lose physical or mental energy over time, it’s probably MS-related fatigue. If symptoms are worse during sedentary, monotonous activities, rather than during extended physical or cognitive activity, the excessive sleepiness (hypersomnolence) is more likely caused by sleep disturbances and needs to be assessed with an overnight sleep study.
Insomnia occurs when you have trouble falling asleep or staying asleep. It can contribute to symptoms of fatigue, impaired concentration or memory, mood disturbances, excessive daytime sleepiness, behavioral problems, reduced motivation or energy, impaired social, family, academic, or occupational performance, proneness to errors, and concerns or dissatisfaction with sleep.
Common symptoms of MS, such as chronic pain, neurogenic bladder, spasticity, anxiety and depression — as well as the use of certain medications, such as selective serotonin reuptake inhibitors, stimulants and wake-promoting agents, or antihistamines — have the potential to interfere with sleep and cause insomnia. Strategies to reduce insomnia include improved sleep hygiene, cognitive behavioral therapy, adjustment of prescription medication, and melatonin.
Obstructive sleep apnea (OSA) occurs when the upper airway collapses or becomes blocked. Changes in the function of cranial nerves might contribute to OSA by affecting muscles of the tongue or palate. Obstructive sleep apnea is more common in people with MS than it is in the general population and studies suggest that those with brainstem involvement have more severe OSA. Signs of OSA include loud snoring, choking, or gasping for air during sleep. Standard treatment is positive airway pressure (PAP) therapy to keep the airway open. In some cases, oral appliances that reposition the jaw bone might be used, instead.
Central sleep apnea (CSA) is a less common neurological problem where the brain momentarily fails to tell the respiratory system to breathe during sleep. Diagnosis requires a sleep study that shows a reduction in airflow in the absence of respiratory effort. It is possible to have both OSA and CSA. Drugs that depress the central nervous system, such as opiates or antispasmodics, may worsen CSA. Treatment for CSA may include supplemental oxygen, bi-level PAP, or adaptive servo-ventilation (ASV).
Restless Leg Syndrome (RLS) and Periodic Limb Movement Disorder (PLMD)
Restless leg syndrome (RLS) is a neurologic movement disorder of the limbs often associated with a sleep complaint. Patients with RLS may report unusual sensations, such as an almost irresistible urge to move the legs. It’s not painful, but definitely bothersome. Restless leg syndrome is three times more common in people with MS than in the general population and can lead to significant physical and emotional disability.
Periodic limb movements of sleep (PLMS) consist of rhythmic movements of the lower extremities during sleep. About 80 percent of people with RLS have PLMD. Treatment may include medication, discontinuation of medication that worsens the condition, exercise, improved sleep hygiene, avoidance of caffeine and alcohol in patients who are sensitive to these substances, and cognitive behavioral therapy.
REM sleep behavior disorder (RBD)
REM sleep behavior disorder (RBD) is characterized by abnormal behavior during sleep, such as people acting out their dreams. This might include sleep talking, shouting, screaming, hitting, or punching. REM sleep behavior disorder is rare and affects less than 1 percent of the general population. RBD can be associated with neurological diseases such as MS and patients with new symptoms should be evaluated by MRI for signs of disease progression. Management of RBD begins with implementing safety measures to avoid injury of the patient or the bed partner. Common drug therapies include clonazepam and melatonin.
Narcolepsy is characterized by an abnormal and irrepressible need to sleep during normal waking hours. It is often accompanied by cataplexy (sudden loss of muscle tone), sleep paralysis, and hallucinations during that hazy stage just before you fall asleep. A nighttime sleep study combined with a daytime nap test is needed for diagnosis. The prevalence of narcolepsy among people with MS is currently unknown.
If you experience excessive sleepiness or unexplained fatigue, talk to your neurologist about a sleep study. In the meantime, begin to identify and eliminate potential triggers of your sleep disturbances and work to improve your sleep hygiene.
See more helpful articles:
Multiple Sclerosis and Sleep Disorders: Fatigue and Daytime Sleepiness
Restless Leg Syndrome: Causes, Treatments
6 Ways to Improve Sleep With MS
Braley TJ, Chervin RD. A practical approach to the diagnosis and management of sleep disorders in patients with multiple sclerosis. Therapeutic Advances in Neurological Disorders. 2015;8(6):294-310. doi:10.1177/1756285615605698.