In multiple sclerosis, damage to the myelin in the central nervous system (CNS), and to the nerve fibers themselves, interferes with the transmission of nerve signals between the brain and spinal cord and other parts of the body. This disruption of nerve signals produces the primary symptoms of MS, which vary depending on where the damage has occurred.
Over the course of the disease, some symptoms will come and go, while others may be more lasting.
Fatigue is one of the most common symptoms of MS, occurring in about 80% of people. Fatigue can significantly interfere with a person’s ability to function at home and at work, and may be the most prominent symptom in a person who otherwise has minimal activity limitations.
Numbness of the face, body, or extremities (arms and legs) is one of the most common symptoms of MS, and is often the first symptom experienced by those eventually diagnosed as having MS.
GAIT & WALKING
Problems with gait (difficulty in walking) are among the most common mobility limitations in MS. Gait problems are related to several factors.
Bladder dysfunction, which occurs in at least 80% of people with MS, usually can be managed quite successfully.
Constipation is a particular concern among people living with MS, as is loss of control of the bowels. Diarrhea and other problems of the stomach and bowels also can occur.
A vision problem is the first symptom of MS for many people. The sudden onset of double vision, poor contrast, eye pain, or heavy blurring is frankly terrifying-and the knowledge that vision may be compromised can make people with MS anxious about the future.
Dizziness is a common symptom of MS. People with MS may feel off balance or lightheaded. Much less often, they have the sensation that they or their surroundings are spinning, a condition known as vertigo.
Sexual problems are often experienced by people with MS, but they are very common in the general population as well. Sexual arousal begins in the central nervous system, as the brain sends messages to the sexual organs along nerves running through the spinal cord. If MS damages these nerve pathways, sexual response—including arousal and orgasm—can be directly affected. Sexual problems also stem from MS symptoms such as fatigue or spasticity, as well as from psychological factors relating to self-esteem and mood changes.
Pain syndromes are common in MS. In one study, 55% of people with MS had “clinically significant pain” at some time. Almost half were troubled by chronic pain.
Cognition refers to a range of high-level brain functions, including the ability to learn and remember information: organize, plan, and problem-solve; focus, maintain, and shift attention as necessary; understand and use language; accurately perceive the environment, and perform calculations. Cognitive changes are common in people with MS—approximately 50% of people with MS will develop problems with cognition.
Emotional changes are very common in MS—as a reaction to the stresses of living with a chronic, unpredictable illness and because of neurologic and immune changes caused by the disease. Bouts of severe depression (which is different from the healthy grieving that needs to occur in the face of losses and changes caused by MS), mood swings, irritability, and episodes of uncontrollable laughing and crying (called pseudobulbar affect) pose significant challenges for people with MS and their family members.
Depression is common during the course of multiple sclerosis. In fact, studies have suggested that clinical depression, the severest form of depression, is more frequent among people with MS than it is in the general population or in persons with other chronic, disabling conditions.
Spasticity refers to feelings of stiffness and a wide range of involuntary muscle spasms (sustained muscle contractions or sudden movements). It is one of the more common symptoms of MS. Spasticity may be as mild as the feeling of tightness of muscles or may be so severe as to produce painful, uncontrollable spasms of extremities, usually of the legs. Spasticity may also produce feelings of pain or tightness in and around joints, and can cause low back pain. Although spasticity can occur in any limb, it is much more common in the legs.