My experience with restless legs syndrome was a very different sensation from what I feel pretty much constantly now - a constant humming numbness in my feet, which can often feel like burning. Moving my feet around doesn’t really help and it doesn’t get worse at night, although when I am trying to go to sleep I notice it more. This feeling is just my old friend, parasthesia, which came to stay shortly before my diagnosis with MS.
Curious to learn more about restless legs syndrome and its association with multiple sclerosis, I looked it up on UpToDate -- an electronic reference used by many physicians who encounter patients with MS and patients looking for in-depth medical information.
See what UpToDate has to say, then read on for answers to questions you may have about what all of this means for you.
Restless legs syndrome and multiple sclerosis: Information from UpToDate
”Restless legs syndrome (RLS) refers to symptoms of spontaneous, continuous leg movements associated with unpleasant paresthesias. These sensations occur only at rest and are relieved by movement. Sleep disturbance and a frequent association with involuntary, jerking movements of the legs during sleep, known as periodic leg movements of sleep (PLMS), are common.
Mounting evidence suggests that RLS is associated with multiple sclerosis (MS), but data are conflicting. In the largest study, a prospective multicenter epidemiologic survey of 861 patients with MS and 649 control subjects, the prevalence of RLS was significantly higher in patients with MS than in controls (19 versus 4 percent, relative risk 5.4, 95% CI 3.56-8.26).”
Your Questions: AnsweredFully understanding all of this will not only give you a better grasp of what is going on, but it will help you be better able to discuss your situation with your doctor.
I Sometimes Experience Pretty Violent Jerks of My Legs at Night. Is This Restless Legs Syndrome or MS-Related Spasticity?Restless legs syndrome is diagnosed when the following criteria are met:
- There is an urge to move the legs (usually caused by or accompanied by uncomfortable or unpleasant sensations in the legs)
- This urge to move gets worse when you are still, usually lying down, but can also occur when sitting
- Moving around relieves (at least partially) the urge to move or unpleasant sensation, while the movement continues
- The urge is much worse at night than during the day
People with MS may be experiencing extensor spasms, which happen when a limb stiffens and the person is unable to bend the joint. These cause the limb, usually a leg, to jerk away from the body. It usually affects the quadriceps (the large muscles on the front of the thigh), causing the lower leg to straighten. Some extensor spasms can be so sudden and strong that the person can fall out of a chair or bed. These are very different from the experience of RLS. Extensor spasms are involuntary movements, rather than an “urge.” They are not relieved by movement, but can actually be the result of trying to move, such as turning over in bed or trying to move to a wheelchair.
“Unpleasant sensations,” known as parasthesias, are a very common symptom of MS, and primarily occur in the lower legs and feet. They feel like numbness or tingling, or a pins-and-needles combination of both. These feelings are also very distinct from the unpleasant sensations of RLS, as there is no relief from them when the person is moving (movement can actually cause these sensations to intensify). They are also usually present in the day, and not only at night.
Could Restless Legs Syndrome Be the Reason for My MS-Related Fatigue?If you have RLS, it is probably contributing to your MS-related fatigue by causing you to lose sleep. This is called secondary fatigue and is the result of tiredness as a result of symptoms or insomnia.
The primary cause of fatigue for people with MS, however, is the demyelination of the disease process of MS itself. Much of what those of us living with MS are feeling is called “lassitude,” which is an overwhelming tiredness that is not directly related to increased activity. This is the terrible, impossible-to-explain, crushing exhaustion that is one of the most common symptoms of MS.
In addition to RLS, other secondary causes of fatigue in people with MS include: sleep disturbances due to other causes, like spasms; depression or anxiety; pain; the frequent need to urinate at night (nocturia); medication side effects; physical exertion to make up for loss of function caused by symptoms; infections, such as colds, flu or urinary tract infections; or lack of physical fitness.