Use of the criteria in 11.09C is dependent upon (1) documenting a diagnosis of multiple sclerosis, (2) obtaining a description of fatigue considered to be characteristic of multiple sclerosis, and (3) obtaining evidence that the system has actually become fatigued. The evaluation of the magnitude of the impairment must consider the degree of exercise and the severity of the resulting muscle weakness.
The criteria in 11.09C deal with motor abnormalities which occur on activity. If the disorganization of motor function is present at rest, paragraph A must be used, taking into account any further increase in muscle weakness resulting from activity.
Sensory abnormalities may occur, particularly involving central visual acuity. The decrease in visual acuity may occur after brief attempts at activity involving near vision, such as reading. This decrease in visual acuity may not persist when the specific activity is terminated, as with rest, but is predictably reproduced with resumption of the activity. The impairment of central visual acuity in these cases should be evaluated under the criteria in Listing 2.02, taking into account the fact that the decrease in visual acuity will wax and wane.
Clarification of the evidence regarding central nervous system dysfunction responsible for the symptoms may require supporting technical evidence of function impairment such as evoked response tests during exercise.
11.01 Category of Impairment, Neurological
11.04 Central nervous system vascular accident. With one of the following more than 3 months post-vascular accident:
B. Significant and persistent disorganization of motor function in two extremities, resulting in sustained disturbance of gross and dexterous movements, or gait and station (see 11.00C).
11.09 Multiple Sclerosis. With:
A. Disorganization of motor function as described in 11.04B; or
B. Visual or mental impairment as described under the criteria in 2.02, 2.03, 2.04, or 12.02; or
C. Significant, reproducible fatigue of motor function with substantial muscle weakness on repetitive activity, demonstrated on physical examination, resulting from neurological dysfunction in areas or the central nervous system known to be pathologically involved by the multiple sclerosis process.
1.01 Category of Impairments, Special Senses and Speech
1.02 Impairment of Central Visual Acuity. Remaining vision in the better eye after best correction is 20/200 or less.