| Cognitive Impairments in Multiple Sclerosis Approximately one-half of persons with MS
experience some degree of cognitive impairment.
Of the MS patients with cognitive dysfunction, most (80 percent) exhibit
relatively mild symptoms such as difficulties remembering lists of food items to
buy in the supermarket or performing tasks in distracting environments. Most
patients can learn ways to compensate for these nuisance symptoms. The
remaining 20 percent experience more serious cognitive problems that may
interfere with their ability to work and engage in everyday activities such as
cooking and driving.
In MS, the cause of cognitive dysfunction
is directly related to changes that occur in the brain.
MS produces changes, called lesions, in the white matter of the brain. These
lesions affect the way electrical impulses are transmitted across nerve cells.
The lesions can be visualized with magnetic resonance imaging (MRI). Almost all
patients with MS have some brain lesions on MRI scans. Research has shown that
the degree and type of cognitive impairment observed in MS patients is related
to the amount and location of the lesions in the brain. Thus patients with a
small number of lesions may not experience any cognitive dysfunction, whereas
persons with a large number of lesions are at high risk for experiencing
cognitive problems.
Cognitive impairments are typically
diagnosed as part of a neuropsychological examination.
Neuropsychology is a subspecialty field within clinical psychology that is
devoted to the diagnosis and treatment of cognitive dysfunction. A clinical
neuropsychologist will administer a battery of cognitive tests and compare the
results to a normative sample of healthy individuals of the same age and
educational level as the person being evaluated. This examination can be lengthy
(three to five hours), but it can provide information and useful recommendations
to the patient, family, and treating physician. Such an evaluation is often
requested by the patient's physician, although occasionally a patient may
contact a neuropsychologist directly.
For more Information:
National Institutes of Health Multiple Sclerosis Web Site
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