How does cross-education affects muscles of paretic upper extremity in subacute stroke survivors?

Evaluation of Contralateral Limb Cross Education and High-Frequency Repetitive Transcranial Magnetic Stimulation on Functional Indices of the Affected Upper Limb in Subacute Phase of Stroke

Background

Stroke is one of the causes of long-term morbidity. Despite rehabilitation strategies, most survivors live with motor deficits in the upper limbs.

Objectives

The aim of the study was to compare the effect of contralateral cross education (CE) and high-frequency repetitive magnetic stimulation (HF-rTMS) on the function of upper extremity in subacute phase of stroke.

Methods

Forty patients were randomly assigned into 4 groups. Group "A" received physical therapy (PT) for 10 sessions, 3 times per week. Group "B" received PT and HF-rTMS as follows: stimulation of 20 Hz for 5 s, intertrain interval for 50 s, 20 trains, 2000 pulses at 90% resting motor threshold, and conventional PT. Group "C" was treated with CE and PT. In group "D," HF-rTMS, CE, and PT were administered.

Results

Significant differences were found in the Fugl-Meyer scale between "A" and "C" (P = 0.01), "A" and "D" (P = 0.02), and "B" and "C" groups (P = 0.01). In the box-block test, there were significant differences between "A" and "B" (P = 0.01), "A" and "C" (P < 0.001), "B" and "D" (P = 0.001), and "B" and "C" groups (P = 0.01). Statistical differences were observed in grip strength between "A" and "B" (P = 0.01) and "A" and "C" groups (P = 0.02).

Conclusions

It is suggested that clinicians select the therapeutic methods in line with their expected goal. When the goal is to improve upper extremity function, CE+PT could be more effective than HF-rTMS+PT. Also, CE+PT and HF-rTMS+PT were more effective than CE+HF-rTMS+PT at improving grip strength. Therefore, combining several methods would not always lead to better results.

Strength Training of the Nonhemiplegic Side Promotes Motor Function Recovery in Patients With Stroke: A Randomized Controlled Trial

OBJECTIVE

To observe the effect of strength training of the nonhemiplegic side (NHS) on balance function, mobility, and muscle strength of patients with stroke.

DESIGN

A single-blinded (evaluator) randomized controlled trial.

SETTING

A tertiary hospital rehabilitation center.

PARTICIPANTS

139 patients with first stroke (N=139) were recruited and randomly separated into a trial (n=69) or control group (n=70).

INTERVENTIONS

The control group underwent usual rehabilitation training, including step training and trunk control training in standing position. The trial group underwent strength training of NHS on the basis of usual rehabilitation training. The strength training of NHS included lower limb stepping training with resisting elastic belt and upper limb pulling elastic belt training in standing position. The training for both groups was 45 min, once a day, 5 days a week for 6 weeks.

MAIN OUTCOME MEASURES

Balance evaluation was done with the Berg Balance Scale (BBS); mobility assessment with the 6-minute walk test (6-MWT); activities of daily life was examined via the modified Barthel Index (MBI); muscle strengths of the biceps brachii, iliopsoas, and quadriceps were measured via the isokinetic muscle strength testing system. All assessments were performed at baseline (T0) and after intervention (T1).

RESULTS

The trial group performed better than control group in BBS scores (adjusted mean difference: 6.83; 95% confidence interval [CI]: 4.71-8.94) and 6-MWT (adjusted mean difference: 50.32; 95% CI: 40.58-60.05) after intervention. In terms of muscle strength of the hemiplegic side, the trial group displayed greater gains in biceps brachii, iliopsoas, and quadriceps than control group after intervention.

CONCLUSION

Strength training of the NHS can promote recovery of balance, mobility, and muscle strength of the paretic side of patients with stroke.

A scoping review of the contralateral effects of unilateral peripheral stimulation on neuromuscular function

It is known that resistance exercise using one limb can affect motor function of both the exercised limb and the unexercised contralateral limb, a phenomenon termed cross-education. It has been suggested that cross-education has clinical implications, e.g. in rehabilitation for orthopaedic conditions or post-stroke paresis. Much of the research on the contralateral effect of unilateral intervention on motor output is based on voluntary exercise. This scoping review aimed to map the characteristics of current literature on the cross-education caused by three most frequently utilised peripheral neuromuscular stimulation modalities in this context: electrical stimulation, mechanical vibration and percutaneous needling, that may direct future research and translate to clinical practice. A systematic search of relevant databases (Ebsco, ProQuest, PubMed, Scopus, Web of Science) through to the end of 2020 was conducted following the PRISMA Extension for Scoping Review. Empirical studies on human participants that applied a unilateral peripheral neuromuscular stimulation and assessed neuromuscular function of the stimulated and/or the unstimulated side were selected. By reading the full text, the demographic characteristics, context, design, methods and major findings of the studies were synthesised. The results found that 83 studies were eligible for the review, with the majority (53) utilised electrical stimulation whilst those applied vibration (18) or needling (12) were emerging. Although the contralateral effects appeared to be robust, only 31 studies claimed to be in the context of cross-education, and 25 investigated on clinical patients. The underlying mechanism for the contralateral effects induced by unilateral peripheral stimulation remains unclear. The findings suggest a need to enhance the awareness of cross-education caused by peripheral stimulation, to help improve the translation of theoretical concepts to clinical practice, and aid in developing well-designed clinical trials to determine the efficacy of cross-education therapies.