Using Dynamometry to Assess Grip Strength over Five Years in Individuals with Multiple Sclerosis

Thursday, June 2, 2016
Exhibit Hall
Cindy Darius, MS, RN , Neurology, Johns Hopkins School of Medicine, Balitmore, MD
Scott D Newsome, D.O. , Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD
Kathryn Fitzgerald, ScD , Neurology, Johns Hopkins Hospital, Baltimore, MD
Moira Baynes, RN , Neurology, Johns Hopkins University, Baltimore, MD
Peter A Calabresi, MD , Neurology, Johns Hopkins University, Baltimore, MD
Kathleen M Zackowski, PhD, OT , Neurology, Johns Hopkins University, Baltimore, MD

Background: Assessment tools such as the Expanded Disability Status Scale (EDSS) focus heavily on gait and ambulation but little attention has been placed on the importance of hand function. Hand function is known to impact quality of life for individuals with multiple sclerosis (MS).

Objectives: In this study we explore the extent that quantitative tests of hand strength are able to detect change over time.  We hypothesize that a decline in hand strength will be quantified using a hand-held dynamometer and that individuals with MS progressive disease will show greater decline than those with relapsing disease.

Methods: A longitudinal two year hand function study on 147 individuals with MS was previously conducted. From this original cohort we followed a sub group of fifty-five individuals (40 women; 35 relapsing-remitting MS) with EDSS ranging from 0-8.5 over five years (mean follow-up 4.82 years). Annual hand grip strength was quantitatively measured bilaterally using dynamometry. Symptom duration and EDSS were also collected. Multivariate mixed-effects regression models using a patient-specific random intercepts were used for analysis.

Results: Following adjustment for age, disease subtype, symptom duration and sex, we observed a statistically significant annual decline of -0.91 pounds (95% CI: -1.43 to -0.36; P=0.001) in dominant-hand grip function and of -0.75 pounds (95% CI: -1.30 to -0.18; P=0.01) in weaker hand function. When accounting for MS subtype we observed a marginally stronger rate of decline in weaker and dominant hand function among progressive patients (for changes in dominant hand function: P=0.08; for changes in weaker hand function: P=0.18).

Conclusions: The data presented here show that hand strength is frequently impaired in individuals with MS.  Assessing hand strength with a dynamometer is a quantitative way to accurately monitor change over time. It is therefore important to assess hand function when following individuals with MS both in a clinical setting as well as in trials.