Bonzano et al. Quantitative assessment of finger motor impairment in multiple sclerosis. PLoS One. 2013 May 31;8(5):e65225.
METHODS: 40 MSers (Expanded Disability Status Scale (EDSS): 0-7) and 80 healthy controls (HC) performed a repetitive finger-to-thumb opposition sequence with their dominant hand at spontaneous and maximal velocity, and uni- and bi-manually metronome-paced. A sensor-engineered glove was used to measure finger motor performance. Twenty-seven HC were tested twice, one month apart, to assess test-retest reliability.
RESULTS: The motor parameters showed a good reproducibility in HC and demonstrated significantly worse performance in MSers with respect to HC. A multivariate model revealed that rate of movement in the spontaneous velocity condition and inter-hand interval (IHI), indicating bimanual coordination, contributed independently to differentiate the two groups. A finger motor impairment score based on these two parameters was able to discriminate HC from MSers with very low EDSS scores (p<0.001): a significant difference was already evident for MSers with EDSS = 0. Further, in the MS group, some motor performance parameters correlated with the clinical scores. In particular, significant correlations were found between IHI and EDSS (r = 0.56; p<0.0001), MS Functional Composite (r = -0.40; p = 0.01), Paced Auditory Serial Addition (r = -0.38; p = 0.02). No motor performance parameter correlated with Timed 25-Foot Walk.
CONCLUSIONS: A simple, quantitative, objective method measuring finger motor performance could be used to define a score discriminating healthy controls and MSers, even with very low disability. This sensitivity might be of crucial importance for monitoring the disease course and the treatment effects in early MS patients, when changes in the EDSS are small or absent.