Upper limb rehabilitation strategies for stroke recovery

Recovering Motor Function After Stroke

Stroke and Motor Learning

Strategies for Recovering Motor Function after Stroke

Strategies for Recovering Motor Function after Stroke

On an annual basis, close to a million U.S. citizens are hospitalized for stroke and their length of stay averages 5.3 days (NHLBI, 2013). Close to 60% of these are first time stroke patients. In terms of morbidity, stroke is responsible or 1.7 million Americans currently suffering from chronic physical and/or cognitive impairment. With nearly 80% of all stroke survivors suffering from limb impairment (reviewed by Thieme et al., 2012), there is a great need for remedial strategies that minimize the level of disability these patients suffer from. This report will review recent research in the area of upper limb rehabilitation strategies to better understand progress being made in this area of research.

Retraining the Mind-Body Connection

A number of different strategies have been utilized to improve limb motor control following a stroke (reviewed by Thieme et al., 2012). These strategies include robotic training, biofeedback, electrical stimulation, and motor imagery. However, Thiele and colleagues (2012) argue that while these techniques have improved arm function, improvements in daily living task performance have been lacking. One technique that has shown promise for improving the ability of patients to perform daily tasks is mirror therapy, which involves positioning a mirror in between the legs of the patient. From the patient's perspective, watching the movements of the good arm in the mirror creates the feeling of improved mobility of the impaired arm. The goal of mirror therapy is therefore to reduce the level of visuospatial neglect the patient may be experiencing towards the impaired arm.

To test the efficacy of mirror therapy for patients who are already well into their rehabilitation program, patients were randomized to receive either individual mirror therapy (N = 18), group (N = 21; 2 to 6 patients) mirror therapy, or mock mirror therapy (N = 21) (Thieme et al., 2012). Time since stroke was an average of 45 days. Average age of the 49 patients included in the study was 67 years and about two thirds were males. Improvements in arm function were measured using the Fugl-Meyer Test -- arm section, Action Research Arm test, Barthel Index for daily living, Stroke Impact Scale, modified Ashworth Scale, and the Star Cancellation Test.

All instruments, except the modified Ashworth Scale and Star Cancellation Test, revealed all treatment groups experienced significant improvement after 20 therapy sessions over the course of 5-week intervention (p < 0.002) (Thieme et al., 2012). In contrast to this finding, the Ashworth Scale and Star Cancellation Test revealed between group differences. The Ashworth scale, which is used to assess changes in passive finger and wrist movement resistance, revealed that individual mirror therapy patients experienced significant improvement in finger flexors (p < 0.001), but not for wrist flexors (p = 0.08) and that intergroup difference were significant for finger flexors only (p < 0.05). The Star Cancellation Test, which is designed to measure visuospatial neglect, revealed individual therapy patients improved significantly more compared to the control group (p < 0.01). Importantly, the five-week intervention reduced the level of visuospatial neglect experienced by individual and group patients, but the mock therapy group had increased visuospatial neglect. These findings suggest that individual mirror therapy can significantly reduce the magnitude of visuospatial neglect for the affected arm of a stroke patient.

A similar approach for improving a patient's mind-body connection is constraint-induced movement therapy (reviewed by Brunner, Skouen, and Strand, 2012). This is done by restricting the good arm during tasks requiring the use of an arm, thereby forcing the patient to rely more heavily on the impaired arm. In contrast, bilateral arm training is believed to be superior to constraint-induced therapy by some researchers based on the theory that both sides of the brain are required for proper retraining of the impaired arm.

To try and resolve this controversy, Brunner and colleagues (2012) conducted a randomized controlled study to directly compare the efficacy of both strategies. They found no statistically-significant difference between the two strategies for a number of tasks after 4 hours of training for 4 weeks. The outcomes were measured using the Action Research Arm Test, Nine-Hole Peg Test, and the Motor Activity Log and both treatment groups improved significantly by the post-treatment and 3-month follow-up assessments (p < 0.010-0.001). These findings suggest that either the constraint-induced movement or bilateral arm training therapy approaches are equally effective in improving the use of the impaired arm