Unilateral Versus Bilateral Upper Limb Training After Stroke
The Upper Limb Training After Stroke Clinical Trial
Background and Purpose—Unilateral and bilateral training protocols for upper limb rehabilitation after stroke represent conceptually contrasting approaches with the same ultimate goal. In a randomized controlled trial, we compared the merits of modified constraint-induced movement therapy, modified bilateral arm training with rhythmic auditory cueing, and a dose-matched conventional treatment. Modified constraint-induced movement therapy and modified bilateral arm training with rhythmic auditory cueing targeted wrist and finger extensors, given their importance for functional recovery. We hypothesized that modified constraint-induced movement therapy and modified bilateral arm training with rhythmic auditory cueing are superior to dose-matched conventional treatment.
Methods—Sixty patients, between 1 to 6 months after stroke, were randomized over 3 intervention groups. The primary outcome measure was the Action Research Arm test, which was conducted before, directly after, and 6 weeks after intervention.
Results—Although all groups demonstrated significant improvement on the Action Research Arm test after intervention, which persisted at 6 weeks follow-up, no significant differences in change scores on the Action Research Arm test were found between groups postintervention and at follow-up.
Conclusions—Modified constraint-induced movement therapy and modified bilateral arm training with rhythmic auditory cueing are not superior to dose-matched conventional treatment or each other in improving upper limb motor function 1 to 6 months after stroke.
Clinical Trial Registration—URL: http://www.trialregister.nl. Unique identifier: NTR1665.
In poststroke upper limb rehabilitation, unilateral training protocols such as constraint-induced movement therapy1 stand in stark contrast to bilateral training protocols such as bilateral arm training with rhythmic auditory cueing.2 A recent meta-analysis revealed that both types of training are similarly effective in patients in the early and the chronic phase after stroke.3
The present single-blinded randomized controlled trial, called the Upper Limb Training After Stroke trial, is the first to compare the merits of both unilateral and bilateral training to each other and an equally intensive, dose-matched conventional treatment (DMCT) in patients starting the intervention between 1 and 6 months after stroke. In the unilateral and bilateral training protocols, emphasis was placed on the increase of control of wrist and finger extensors, given its importance for functional recovery.4 Patients were divided into 3 intervention groups: modified constraint-induced movement therapy (mCIMT), modified bilateral arm training with rhythmic auditory cueing (mBATRAC), and DMCT. We hypothesized that both mCIMT and mBATRAC would significantly improve upper limb function when compared with DMCT.
A detailed description of the methods (including stratification in subgroups) is presented in file I in the online-only Data Supplement and elsewhere.5
Sixty patients were recruited from the Reade rehabilitation center in Amsterdam between 1 to 6 months after a first ever stroke, an upper limb paresis, and at least minimal distal control.
After obtaining informed consent, a pretest of outcome variables was performed. Next, patients were randomized in permuted blocks and allocated to 1 of the 3 intervention groups. Concealed allocation was effectuated online using the minimization method.
After randomization, there was a 6-week intervention period. The posttests were conducted during the week after intervention. Follow-up tests were conducted 6 weeks after the posttests.
The mCIMT therapy involved repetitive task practices and shaping of the desired movements,1,6 with an emphasis on the increase of control of wrist and finger extensors. Patients were encouraged to wear a mitt on the nonparetic hand for 6 hours each weekday. The mBATRAC therapy involved a modification of the original bilateral arm training with rhythmic auditory cueing protocol2, which targeted rhythmic flexion and extension movements about the wrist rather than movements of proximal parts of the upper limb. The DMCT was an exercise therapy on the basis of existing guidelines for upper limb rehabilitation after stroke, discarding specific elements of mCIMT and mBATRAC. All patients received 60-minute therapy sessions, 3 days a week for 6 consecutive weeks. They were also instructed to practice outside of therapy hours and encouraged to perform activities of daily living according to the concept of their allocated treatment.
The Action Research Arm test served as primary outcome measure. Secondary outcome measures are described in file I in the online-only Data Supplement.
We tested for differences between the groups on baseline values, change scores from pretests to posttests, and from posttests to follow-up tests. We also tested for significant changes within groups after the intervention and at follow-up (see file I in the online-only Data Supplement).
Sixty patients were assigned to the mCIMT, mBATRAC, or DMCT groups, with 55 patients being tested after intervention and 52 patients at follow-up (Figure 1). Baseline data, patient characteristics, and therapy compliance are presented in Table 1. There were no significant differences between groups.
No significant differences in change scores were obtained on the primary and secondary outcome measures between the groups at posttest and follow-up. Tabulated change-score data are presented in files III and IV in the online-only Data Supplement.
All groups demonstrated significant improvement on the Action Research Arm test after intervention, which lasted or improved further during the 6-week follow-up period (Figure 2).
This is the first trial that emphasized training of distal extensors of the paretic limb in a direct comparison of unilateral and bilateral upper limb training after stroke. The results indicate that mCIMT and mBATRAC are not superior to DMCT or each other in improving upper limb motor function 1 to 6 months after stroke when provided with comparable intensity. Hence, the results suggest that the intensity of active exercise of the paretic upper limb may be more important than specific features that distinguish the training approaches, such as unilateral and bilateral training.3,7
A limitation of this trial is the small sample size because of the eligible criteria for applying mCIMT or mBATRAC. However, on the basis of the obtained difference of 1.6 points on the Action Research Arm test between mBATRAC or mCIMT on the one hand and DMCT on the other hand, we calculated that 265 patients are required per group to achieve a significant difference between these interventions.5 Moreover, such a small difference is deemed clinically irrelevant.8 Second, there was considerable variation in the starting moment of the intervention after stroke. Given the nature of the interventions, we recruited patients with at least minimal distal motor control (ie, the possibility to actively extend wrist, thumb, and 2 fingers for 10°). Some patients showed this ability at intake in the rehabilitation center and others some time later. Given the randomized allocation within 6 months after stroke, it may be expected that all 3 groups benefitted from certain spontaneous mechanisms of recovery, such as restored neuronal networks in reperfused cerebral tissue and alleviation of diaschisis,7 which would imply that any differences in effect are related to differences between the interventions. Furthermore, self-practice and mitt-compliance were inconsistently documented. Hence, the assumptions of equivalent self-practice between groups and mitt-compliance for the mCIMT group relied on verbal staff reports. Nonetheless, this was the first trial comparing unilateral and bilateral upper limb training with patients starting the intervention between 1 to 6 months after stroke (ie, the time-window in which most patients receive therapy).
As it stands, the relative contributions of actual (re)learning and spontaneous recovery to the improvement of upper limb function after stroke are unknown, and the same applies to the time evolution of these processes. For a better understanding of motor recovery, longitudinal studies with repeated kinematic measures in time combined with neuroimaging studies are required.
Sources of Funding
This study was funded by the Dutch Scientific College of Physiotherapy of the Royal Dutch Society for Physical Therapy.
The online-only Data Supplement is available with this article at http://stroke.ahajournals.org/lookup/suppl/doi:10.1161/STROKEAHA.113.001969/-/DC1.
- Received April 28, 2013.
- Revision received May 31, 2013.
- Accepted June 4, 2013.
- © 2013 American Heart Association, Inc.
- Whitall J,
- McCombe Waller S,
- Silver KH,
- Macko RF
- Nijland RH,
- van Wegen EE,
- Harmeling-van der Wel BC,
- Kwakkel G