Painful leg cramps during the day or at night can be very disturbing — both to daily activities and to sleep. And many aging adults complain of this problem, so it has caught the interest of doctors and scientists around the world.
So far, scientists still don’t know exactly what causes leg cramps to start. They have identified various other health conditions that may be linked with leg cramps but don’t know the mechanism that leads to this symptom. It may be a problem at the motor unit of the muscle. There are some studies showing that older adults start to lose motor groups with age.
But this wouldn’t necessarily explain what happens in other cases such as women who are pregnant, people with diabetes, or anyone taking certain medications that seem to be linked with leg cramps. Some of those medications include diuretics (water pills), statins to lower cholesterol, beta-blockers for heart disease, steroids and antidepressants.
In this study from Japan, researchers from Keio University School of Medicine in Tokyo report on leg cramps in patients with lumbar spinal stenosis compared to older adults without spinal stenosis. Stenosis is a narrowing of the spinal canal around the spinal cord This type of narrowing can also affect the foraminal spaces (holes) where the spinal nerves pass through the vertebral bone in order to travel down to the legs.
Stenosis is a common finding in older adults. And leg cramps are common in both stenosis and older adults. But as mentioned, leg cramps also occur in pregnant women, people with diabetes, as a result of taking some medications, and may be a hereditary disorder in some people.
So the question is: if stenosis causes leg cramps, would decompressive surgery relieve those symptoms? Decompression surgery removes bone from around the spinal nerve roots. When the spinal nerve roots are being compressed, back and leg pain with leg cramps can occur. Removing bone from around the nerves gives them more space and removes the pressure. The hoped for result is reduced pain (or in this case, leg cramps).
They sent a survey of questions about leg cramps to two groups of people. The first group had decompression surgery at one or two lumbar levels for back and leg pain associated with lumbar spinal stenosis. The second (control) group was from the general population. They didn’t have any back pain or back surgery. They came to the clinic for a general health checkup and agreed to participate in the study.
The survey asked questions to identify who had leg cramps, how often they occurred, if they affected both legs and where the symptoms were located (foot, calf, shin, thigh). The participants also answered questions about time of day/night the symptoms came on, if they could walk (and how far), and if there were other symptoms present such as numbness, cold sensation, or a restless sensation.
For the patients who had surgery, they asked if the leg cramps had changed from before to after surgery and if they were satisfied with the results. They also answered questions about any treatment they may have had for leg cramps (e.g., medications, massage, acupuncture, physical therapy). The presence of any sciatica (shooting pain or numbness down the leg) was reported by the surgical group. Both groups were asked if (and how) the leg cramps affected their daily activities.
Here’s what they found:
For the surgical group, they found about two-thirds of patients still had leg pain, numbness in the legs, and leg cramps after surgery — enough to disturb daily activities. Only 18 per cent reported being better after surgery. The rest were either worse or unchanged.
Despite continued symptoms, more than half of the patients expressed satisfaction with the results of surgery. The reason for this was unclear. The authors thought perhaps they had enough improvement in their symptoms or walking ability to make it worth having the surgery.
The authors concluded that lumbar spinal stenosis is definitely one reason why people develop leg cramps. Decompressive surgery did not help. If the leg cramps was coming from pressure on the spinal nerve roots, then surgery should have made a difference. Since it didn’t, why not?
Two possible explanations were offered. First, it’s possible those lumbar nerve roots were damaged beyond repair. Removing the pressure from around them was too little too late. Second, maybe once the nerves were unimpaired, the motor units fired up too much, causing hyperexcitability. This hyperexcitability of the motor units then resulted in leg cramps. And third, since most of the surgical patients could walk farther after surgery, perhaps muscle fatigue and a build-up of cell byproducts in the legs led to leg cramps.
It’s clear that leg cramps disturbs peoples’ quality of life. Further study is needed to really get down to the bottom of leg cramps — both in the general population and in patients with lumbar spinal stenosis. Besides finding out what causes this problem, there’s a need to find treatment that works well. Decompressive surgery may help some walk further but doesn’t really improve the symptoms for most patients.