Longitudinal assessment of hand function in individuals with multiple sclerosis

Abstract Objective Little is known about the frequency and severity of hand dysfunction in individuals with multiple sclerosis (MS). Hence, we sought to determine the extent that quantitative tests of hand function detect changes over time, evaluate their relationship to global disability measures, and identify predictors of hand function. Methods One-hundred and forty-seven individuals with MS were included (96 women, 84 relapsing-remitting MS [RRMS]) along with 35 age-and-sex matched controls. Quantitative tests of hand function (grip strength, pinch strength, 9 hole peg test [9HPT], finger tapping) and leg strength were acquired and normalized to age and sex. Expanded Disability Status Scale (EDSS) and timed 25 foot walk were also obtained. Spearman correlations, multivariate regression models and mixed effects linear regression were used for analysis. Results Our cohort had an EDSS of 3.6 ± 2.2 (median ± SD) and age 44.6 ± 11.9 years. Follow up time was up to 5 years. At baseline, 14/63 individuals with progressive MS (PMS) required more than twice as much time to complete the 9HPT using their dominant hand, compared to controls. Similarly, 11 individuals with PMS had less than 50% of grip strength and 6 had less than 50% of pinch strength, compared to controls. Additionally, 7 individuals with PMS were found to be at least 50% slower than controls in finger tapping. Over two years, 27/85 individuals with MS had more than 20% worsening in their 9HPT results from baseline (17 RRMS, 10 PMS) and 37/74 (20 RRMS, 17 PMS) had more than 20% worsening in their grip strength compared to baseline. Conclusions Hand function is commonly impaired in individuals with MS. Assessing hand dysfunction with dynamometry and the 9HPT could help improve the precision of detecting changes in hand function over time in MS, and may be more sensitive in detecting changes in PMS. These quantitative tests may be useful as outcome measures in clinical trials using neuroprotective or reparative therapies and rehabilitative interventions.