Controlling Spasticity in MS 1 of 4
I. INTRODUCTION
Spasticity is one of the most mysterious of all MS symptoms. It comes and goes. It feels different to different people—and even to the same person at different times. There are even occasions when a physician finds spasticity, but the person affected has no symptoms. There's also an inherent paradox. Spasticity is not all negative. The stiffness it may give the legs can be a real help in moving about or transferring from bed to chairs, to car seats, on and off a toilet, and more.
What is spasticity?
The word spasticity refers to involuntary muscle stiffness or spasms (sudden muscle contractions).
In any coordinated movement, some muscles relax while others contract. Spasticity occurs when this coordination is impaired and too many muscles contract at the same time. MS-related spasticity can cause a leg to lock up and refuse to bend.
Spasticity is not completely understood. Doctors believe the problem is caused by increased sensitivity in the parts of muscles responsible for tightening, relaxing, and stretching. This likely occurs as a result of demyelination of the nerves connected to these muscles. This may lead to excessive firing of the nerves that control muscles.
In mild cases, the condition is noticeable only as a feeling of tight or stiff muscles. When the condition is severe, the person can experience painful spasms or twisted limbs, which can impede mobility and other physical functions.
There are two types of MS-related spasms: flexor and extensor. Flexor spasticity is defined as an involuntary bending of the hips or knees (mostly involving the hamstring muscles on the back of the upper leg). The hips and knees bend up toward the chest. Extensor spasticity is an involuntary straightening of the legs. Extensor spasticity involves the quadriceps (muscles on the front of the upper leg) and the adductors (inner thigh muscles). The hips and knees remain straight with the legs very close together or crossed over at the ankles.
How common is spasticity?
Spasticity is one of the more common symptoms of MS. If all degrees of spasticity are taken together, it occurs in an estimated 80 percent of people with the disease. The question of degree is important. For one person, spasticity may cause a stiff leg, while in another, it makes walking impossible. For many people, the extra effort needed to move around when muscles are spastic contributes significantly to fatigue. On the other hand, spasticity can also compensate for muscle weakness, making it easier to stand, walk, and move. Spasticity may also occur in the arms. Although this is less common in MS, it can significantly interfere with use of the hands in important activities such as bathing and eating.