By ACCORDANT HEALTH SERVICES
Until about 25 years ago doctors thought that multiple sclerosis (MS) produced only physical symptoms. Since 1980, however, research findings, supported by diagnostic advances like magnetic resonance imaging (MRI), have shown conclusively that MS also produces cognitive changes.
Cognitive symptoms may be present at the onset of the disease, or, more often, they may appear after a person has had MS for some time. Cognitive symptoms do not necessarily correlate with the severity of physical symptoms. A person with severe physical disability may have no cognitive problems, while a person with no physical symptoms could have severe cognitive problems.
Types of Cognitive Problems
Cognitive problems may include difficulty with:
Some people have problems with word retrieval or slurred speech. People generally have no problems drawing conclusions or discerning the differences in the meanings of words. The ability to concentrate on simple tasks, known as "simple attention span," is not likely to be affected either.
To varying degrees, thinking problems can affect a person vocationally and socially. On a personal level, they may interfere with driving, family responsibilities like cooking, or even personal hygiene. Of those with cognitive difficulties, about 80% have mild symptoms. The remaining 20% have symptoms serious enough to interfere with employment and routine activities of daily life. The cognitive symptoms of MS can cause four main types of thinking problems:
It may be difficult to recall information. Memory difficulties can complicate the educational process. Learning new material can be challenging because it is harder to consolidate new information rapidly, and harder to recall it later. Aricept® (donepezil) has been used to improve memory performance.
It may be difficult to stay focused or to concentrate. It may be hard to keep one's train of thought. Background noise may be distracting, and it may be hard to shift one's attention appropriately or to pay attention.
Planning and Prioritizing
The "executive functions" of problem solving, making plans, setting priorities, expressing emotions and controlling one's behavior may be affected. The person may be disorganized and find it difficult to come to the point during conversation, changing from topic to topic.
It may be difficult to make sense of what is seen. For example it may be hard to comprehend the contents of a messy drawer. (This is not as common as the other problems.)
A recent study showed that patients with MS experience cognitive fatigue. Study participants were given tests that measured memory, conceptual planning, attention span and verbal communication. They were given the same tests repeatedly. With repetition, healthy participants' performance improved while the performance of patients with MS declined. The patients felt more mentally fatigued and depressed than the others in the study. The researchers are not sure why cognitive fatigue occurs.
Why Cognitive Changes Occur
It is important to remember that none of the MS-related thinking problems is a reflection of an individual's intelligence, motivation or character. Cognitive symptoms, like physical symptoms, are biological in origin. They are caused by demyelination of the nerves in the areas of the brain responsible for information processing.
The total number of brain lesions and the exact location of the lesions probably determine which cognitive functions are affected. For example, it is thought that people whose lesions are in the frontal lobes of the brain have more difficulty with problem solving and decision-making.
Cognitive problems in patients may not always be related to MS. Other illnesses, depression or fatigue can cause similar problems. Certain medications, such as antidepressants, can mimic or aggravate cognitive dysfunction. A neuropsychological evaluation can determine the cause of cognitive dysfunction.
Detecting Cognitive Changes
Neuropsychology is the study of how the brain changes because of trauma or disease. To determine the nature of a person's cognitive changes, a neuropsychologist can administer a battery of tests. The tests examine memory, attention, reasoning and the ability to process information and can take several hours to administer. These kinds of tests are optional and are not routinely done. Patients should discuss this type of testing with their doctor.
Most of the time, the symptoms of cognitive change are so mild that they are overlooked, especially by the patient. Family members or friends may be the first to notice a change. Patients can usually learn techniques to compensate for cognitive problems.
Coping with Cognitive Changes
There are many creative strategies for coping with the cognitive problems that may accompany MS. Here are 10 tips.
Presently, there is no treatment that can prevent or cure MS-related cognitive problems. However, doctors know that patients with many brain lesions are more likely to have cognitive impairment. For this reason, it is believed that the disease-modifying drugs, which slow the progression of some forms of MS, also reduce the chances for cognitive problems.
Last Modified Date: March 01, 2009 © Accordant Health Services, a CVS/Caremark company. All rights reserved.
This article has been reviewed for accuracy by a member of the Accordant Health Services Medical Advisory Team.
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