Intense Arm Rehabilitation Therapy Improves the Modified Rankin Scale Score: Association Between Gains in Impairment and Function

Abstract

Objective: To evaluate the effect of intensive rehabilitation on the modified Rankin Scale (mRS), a measure of activities limitation commonly used in acute stroke studies, and to define the specific changes in body structure/function (motor impairment) most related to mRS gains.

Methods: Patients were enrolled >90 days poststroke. Each was evaluated before and 30 days after a 6-week course of daily rehabilitation targeting the arm. Activity gains, measured using the mRS, were examined and compared to body structure/function gains, measured using the Fugl-Meyer (FM) motor scale. Additional analyses examined whether activity gains were more strongly related to specific body structure/function gains.

Results: At baseline (160 ± 48 days poststroke), patients (n = 77) had median mRS score of 3 (interquartile range, 2-3), decreasing to 2 [2-3] 30 days posttherapy (p < 0.0001). Similarly, the proportion of patients with mRS score ≤2 increased from 46.8% at baseline to 66.2% at 30 days posttherapy (p = 0.015). These findings were accounted for by the mRS score decreasing in 24 (31.2%) patients. Patients with a treatment-related mRS score improvement, compared to those without, had similar overall motor gains (change in total FM score, p = 0.63). In exploratory analysis, improvement in several specific motor impairments, such as finger flexion and wrist circumduction, was significantly associated with higher likelihood of mRS decrease.

Conclusions: Intensive arm motor therapy is associated with improved mRS in a substantial fraction (31.2%) of patients. Exploratory analysis suggests specific motor impairments that might underlie this finding and may be optimal targets for rehabilitation therapies that aim to reduce activities limitations.

Clinical trial: Clinicaltrials.gov identifier: NCT02360488.

Classification of evidence: This study provides Class III evidence that for patients >90 days poststroke with persistent arm motor deficits, intensive arm motor therapy improved mRS in a substantial fraction (31.2%) of patients.

© 2021 American Academy of Neurology.

Figures

Figure 1. Intensive Arm Therapy Improves Modified Rankin Scale (mRS) Scores

The number of patients at each mRS level is shown at baseline (at study entry, 160 ± 48 days poststroke) and 30 days after end of a 6-week course of intense rehabilitation therapy (approximately 12 weeks postbaseline). Intense rehabilitation therapy targeting the arm was associated with activities gains as measured by the mRS. (A) At baseline, median mRS score was 3 (2–3), decreasing to 2 (2–3) at 30 days posttherapy (p < 0.0001). This decrease reflects 24 patients (31.2%) with an mRS score decrease, 50 patients (64.9%) with no change, and 3 (3.9%) patients with an mRS score increase. (B) The proportion of patients with mRS score ≤2 increased from 46.8% at baseline to 66.2% at 30 days posttherapy (*p = 0.015).

Figure 2. Odds Ratio for Modified Rankin Scale (mRS) Score Improvement in Relation to Gains in Specific Motor Impairments

The forest plot displays the odds ratio (95% confidence interval) for mRS decrease in relation to improvement in each of the specific motor impairments measured by the 33 FM subscores; no data are presented for the second subscore (triceps reflex) because calculation of the odds ratio was unstable due to 74 of 77 patients showing no change over time. CMC = carpometacarpal; IP = interphalangeal; MCP = metacarpophalangeal.