ID 301 – Corticospinal reserve predicts walking ability in progressive multiple sclerosis Academic Article uri icon

abstract

  • Objective Walking impairment affect multiple sclerosis (MS) patients, impacting their quality of life. Despite a known relationship between objective and subjective walking measures, gait and neurophysiological motor parameters relationships remains to be explored. Methods 50 progressive MS people underwent following assessments: 10-meters-walking-test (10 mWT), 2 and 6 min-walking-test (2 mWT, 6 mWT), Modified-Ashworth-Scale (MAS), Spasticity and pain Numerical-Rating-Scale (NRS), Fatigue-Severity-Scale (FSS), expanded-disability-status-scale (EDSS), 12-items-MS-walking-scale (MSWS-12). A Walking-Fatigability-Index (WFi, performance decay from 2 to 6 min during 6 mWT) was calculated according to the formula:[(2 mWT ∗ 3–6 mWT)/2 mWT ∗ 3]. Resting-motor-threshold (RMT, the lowest intensity for evoking an electromyographic or visually-evident muscle activation) was obtained using a H-Coil. Correlations were explored using the Spearman-rho coefficient (significance set at p = 0.05). Results RMT correlated positively with the 10 mtWT ( p = 0.012) and with MSWS-12 ( p = 0.005), and negatively with the 2 mWT ( p = 0.016), but not with 6 mWT, nor with fatigue (FSS) or fatigability (WFi). WFi was significantly correlated with disability (EDSS; p p = 0.007). Conclusions Resting motor threshold, as measure of pyramidal reserve, is correlated with subjective impact of MS on walking, predicting walking speed rather than endurance or fatigability, the latter being associated with disability and spasticity. The lack of association between subjective fatigue and objective fatigability suggests different mechanisms underling the two phenomena.

publication date

  • January 1, 2016