Computerized Cognition Testing and Cognitive Motor Interference in MS

Walking and cognitive impairments are common in persons with multiple sclerosis (MS). Approximately 85% of persons with MS report walking as a major limitation, whereas 65% experience cognitive dysfunction. Traditionally, walking and cognition have been viewed as unrelated, but there is evidence of cognitive-motor interference (CMI). CMI is believed to stem from damage to common neural substances responsible for cognitive and motor functions. Recent evidence supports cognitive-motor interference in persons with MS. For example, there is evidence that walking performance declines when performed in conjunction with a simultaneous cognitive task (i.e., dual task cost [DTC] of walking). This decline in walking performance is greater in persons with MS compared to healthy control and is associated with walking impairment. The degree of CMI during walking is associated with walking performance and cognitive function in people with MS. For instance, CMI has been found to be related to general cognitive function and self-reported everyday cognitive errors in people with MS with minimal disability.

Cognitive-motor interference during mobility tasks is of practical and clinical importance because it has been linked to decreased community mobility and a greater risk of falls in other clinical populations such as stoke, Parkinson's disease and the elderly. We have recently demonstrated that the degree of CMI during walking was associated with physiological fall risk in MS, whereas gait velocity in and of itself was not.

Evidence gathered from other special populations suggests that CMI can be minimized with interventions. However, there is no research on rehabilitation strategies on CMI in people with MS. One possible approach for improving cognitive function and reducing CMI involves computerized cognitive testing. This approach capitalizes on neural plasticity and has been found to improve cognitive function, walking and balance in healthy older adults. Although there is limited preliminary data suggesting this type of training may improve cognitive function in people with MS, there is no extant data indicating computerized cognitive training will impact mobility. Based on association between cognitive and motor function in people with MS, it is possible that cognitive training may lead to improvements in walking performance as seen in other clinical populations. One major advantage of computerized cognitive training is that it can be completed without direct supervision and in one's home to minimize various barriers to clinic-based rehabilitation.