Generalised cognitive motor interference in multiple sclerosis

- Cognitive motor interference (CMI) occurs in the upper and lower limb of those with MS and controls.
- CMI is generalised and present across the disease spectrum in MS.
- MS interventions must address CMI in the upper and lower limb of persons with MS.

Researchers have examined cognitive motor interference (CMI) for lower extremity function in MS, but have not examined this in the upper extremity. This study examined CMI for both lower and upper extremity motor tasks in persons with MS and without MS. Eighty-two persons walked on a GAITRite electronic walkway (velocity) and performed the nine-hole peg test (NHPT, seconds) without (single task) and with a cognitive challenge (dual task). The data were analysed with mixed-factor ANOVA and Pearson correlations. When comparing MS and controls, there were statistical significant and exceptionally large Task main effects on gait velocity (ηp2 = .41; F1,60 = 55.78; p < .005) and NHPT performance (ηp2 = .62; F1,60 = 127.8; p < .005). When considering disability status among those with MS, there were statistically significant and large Task main effects on velocity (ηp2 = .38; F1,60 = 37.3; p < .005) and NHPT test (ηp2 = .62; F1,60 = 95.7; p < .005). The dual task cost of walking and performing the NHPT were significantly correlated in the entire sample, those with MS and controls, and in those with MS who had mild, moderate, and severe disability (all |r| > .450). CMI occurs in both the lower and upper extremities, and is comparable between persons with and without MS and across MS disability level.