Disability fingerprints: patterns of disability in spinal cord injury and multiple sclerosis differ

Models for causation of functional disability differ as to whether different diseases lead to common expressions of disability versus producing unique "disability fingerprints." Multiple sclerosis (MS) and Spinal Cord Injury (SCI) both affect the spinal cord; however, their pathophysiologies differ (progressive vs. nonprogressive; multifocal vs. unifocal).

Patterns of disability were compared among veterans who reported in a national survey that they had MS (n = 1789) or SCI (n = 6361) as the sole cause of their spinal cord dysfunction. The study used self-reported information on disease duration, physical impairments, and self-care skills to compare the two samples for differences in disability overall and after stratification according to (a) disease duration, and (b) specific physical impairments.

Patterns of disability differed significantly among persons with MS compared to SCI (p = .001). Differences in level of disability between the two samples remained statistically significant after stratification on disease duration. There were substantial, statistically significant differences between the two samples in the amount and kinds of physical impairment. However, differences in level of disability between the two conditions remained highly significant after stratifying on number of affected limbs (p = .003), amount of useful movement (p = .001), overall motor impairment (p = .003), amount of sensation (p = .001), impairment in memory and thinking (p = .001), and visual impairment (p = .001).

This study shows differing diseases indeed have unique disability fingerprints, which remain unique after controlling for disease duration and for population-specific differences in physical impairment. These findings point out the need to explain the disablement process more fully.