About MS

Multiple sclerosis involves random attacks on a fatty material called myelin in the brain and spinal cord, the structures that make up the central nervous system. When myelin is attacked, the body is able to make some repairs, but eventually patchy areas of scarring develop on nerve fibers where healthy myelin once was. The nerve fiber (or axon) may also be damaged or broken. In addition, MS can also result in loss of brain tissue.

These three types of changes—loss of myelin, damage to axons, and loss of brain tissue—may occur in any part of the central nervous system and account, in part, for the wide variety of possible MS symptoms .

The most common symptoms are problems with balance, strength, vision, fatigue, muscle control, or bladder or bowel activity, and odd sensations such as numbness or tingling.

The brain and the mind

The brain holds what we call the mind. It is the home of personality, emotions, and the intellect—the attributes that make us unique.

MS has the potential to affect these brain functions, either directly or indirectly. The idea is upsetting, but the facts emerging from research are encouraging. Severe damage to these aspects of the self are not common. Mild problems are.

The first step to take in dealing successfully with cognitive problems caused by MS is to learn the basic facts. This booklet is intended as an introduction.

Physical symptoms such as numbness or vis-ual problems, which are common in MS, are usually the result of damage to specific, easily identified areas in the brain and spinal cord.

In contrast, it is not always clear what is causing problems in the mind, especially if intellectual functioning is affected. Such problems are called cognitive dysfunction.

The intellect is sensitive to many potentially disruptive factors. These include normal aging as well as disease or injury. The intellect can also be affected temporarily by tension, emotional stress, depression, sleep disturbances, menopause, or fatigue. It can, in addition, be affected by nutrition; for example, by low blood sugar (hypoglycemia). And it can be disrupted by some prescription drugs or by drug or alcohol abuse. Moreover, many of these factors can and do occur in combination.

II. Which intellectual functions might be affected by MS?

Although investigators are still in the process of answering this, some consistent information has emerged.

• Memory or recall problems are the most frequently reported. Memory loss seems to be confined largely to recent events. For example, a person may have trouble remembering an important phone number learned in the past year. In contrast, the same person will have little difficulty remembering information from the distant past, such as the meanings of words that were learned in school.

Several studies suggest that most people with MS are able to remember or store information adequately but may have difficulty recalling it quickly and effectively. However, Dr. John DeLuca of the Kessler Institute in New Jersey has found that some people with MS may take longer to learn new information. This suggests that poor recall in MS may be the result of not having adequately learned something.

• Abstract reasoning and problem-solving abilities are sometimes affected. These include the capacity to analyze a situation, identify the salient points, plan a course of action, and carry it out. Occasion-ally people with MS report that their judgment is sometimes poor. More often, family members, or employers, notice changes in problem solving or reasoning.
• Visual-spatial abilities can be affected in MS. These include the ability to recognize objects accurately and to draw or assemble things. Visual-spatial abilities are involved in many everyday tasks such as driving, finding one’s way around, or packing a
  suitcase.
• Verbal fluency is still another area affected in MS. Fluency problems are different from MS speech problems, which slow speech down or change voice quality. A fluency problem often manifests itself as the “tip-of-the-tongue” phenomenon. A person wants to say a word, it’s on the tip of the tongue, but she or he just can’t think of it.
• Speed of information processing--Both recall and fluency skills require rapid processing of information. Dr. Stephen Rao of the Medical College of Wisconsin has completed a study in which he found that people with MS performed as well as control volunteers on a specialized memory task but they did so at a significantly slower speed. Many people with MS feel that their thinking is slowed and say they are not able to think through an issue and respond as quickly as they once did.

What research shows

When intellectual problems stem from physical damage done by MS, the source is probably damage to brain tissue. Lesions (or areas of scarring) in the cerebral hemispheres —the higher areas of the brain are the ones of greatest significance.

Studies have found that areas of scarring occur with roughly equal frequency in the right and left halves of the brain, and in those areas of the brain called white matter, where myelin occurs in abundance. MS lesions are particularly common near the ventricles, or inner cavities of the brain, through which the cerebrospinal fluid flows. Moreover research has shown that it is not only the myelin that is damaged in MS. The nerve fibers themselves may also be damaged.

More recent studies using magnetic resonance imaging (MRI) have confirmed these findings and shown a definite relationship between the lesions and intellectual problems, leaving no doubt that MS is the cause. Damage to the structures that join the left and right halves of the brain are particularly serious.

Dr. Rao and others have found that about half of all people with MS show no evidence at all of intellectual problems. About 40% have mild dysfunction, while about 5-10% have moderate to severe impairments.

In other words, research shows that nine out of ten people with MS are free of severe intellectual or cognitive problems.

But what do mild or moderate problems mean in people’s lives? This question is hard to answer because people’s circumstances vary so much. For one person, mild intellectual impairment could require a major life shift—the end of a career or professional practice. But another with the same degree of impairment might need no change in lifestyle at all, because he or she is able to cope using self-help measures or through reasonable accommodations on the job.

From:  US National MS Society