NEW ORLEANS—Contrary to researchers’ hypothesis, fatigue did not result in worsening of spasticity in patients with multiple sclerosis (MS), resulting instead in a nonsignificant decrease. “Clinically, this suggests that the worsening of gait seen over time in persons with MS may be due to reasons other than spasticity,” reported Herbert Karpatkin, PT, DSc, NCS, MSCS, an Assistant Professor at Hunter College in New York, NY, and colleagues at the ACTRIMS 2016 Forum.
Herbert Karpatkin, PT, DSc, NCS, MSCS
Disturbance of gait is known to occur in approximately 80% of patients with MS. Fatigue and spasticity are among the most common and debilitating symptoms in this patient population and both have been known to worsen with physical performance. Anecdotal reports claim that spasticity is associated with worsening fatigue, but the literature provides little information regarding this relationship.
Dr. Karpatkin and colleagues sought to determine whether, as they hypothecized, increases in fatigue in patients with MS result in increases in lower extremity spasticity. If correct, this would mean that physical therapists who perform gait-training activities in patients with MS would need to take the interaction between fatigue and spasticity into account as a factor that may impact outcomes and help determine an appropriate course of treatment.
A convenience sample of 16 ambulatory subjects with MS was recruited from New York City physical therapy practices that specialize in MS. Demographic and subject characteristics including MS type, years since diagnosis, age, gender, Expanded Disability Status Scale (EDSS) score, medications, and use of assistive devices were recorded and analyzed. The Fatigue Severity Scale (FSS), the MS Impact Scale–29 (MSIS–29), and the MS Severity Scale–88 (MSSS–88) were completed for baseline analysis.
Subjects were randomized into walking and resting groups. All subjects received spasticity testing using the Modified Ashworth Scale (MAS). Subjects in the walking group then underwent a six-minute walk to induce fatigue, while subjects in the resting group lay supine for six minutes to minimize fatigue. Immediately following either six-minute condition, MAS testing was repeated. This was performed on three separate trials during a five-day period, followed by a two-week detraining period. Subjects then crossed over to the opposite condition. Fatigue was measured using the Visual Analog Scale of Fatigue (VAS–F) before and after each six-minute condition.
Sixteen subjects (mean EDSS, 3.59) completed the study. Mean MAS scores decreased nonsignificantly following the six-minute walk from 1.054 to 0.827. MAS scores also decreased nonsignificantly in the nonfatigued condition from 0.841 to 0.839. Mean VAS–F scores increased 29.5 mm following the six-minute walk, indicating that MAS testing was performed in a fatigued condition.