Bilateral Priming Accelerates Recovery of Upper Limb Function After Stroke A Randomized Controlled Trial

Background and Purpose The ability to live independently after stroke depends on the recovery of upper limb function. We hypothesized that bilateral priming with active-passive movements before upper limb physiotherapy would promote rebalancing of corticomotor excitability and would accelerate upper limb recovery at the subacute stage. Methods A single-center randomized controlled trial of bilateral priming was conducted with 57 patients randomized at the subacute stage after first-ever ischemic stroke. The PRIMED group made device-assisted mirror symmetrical bimanual movements before upper limb physiotherapy, every weekday for 4 weeks. The CONTROL group was given intermittent cutaneous electric stimulation of the paretic forearm before physiotherapy. Assessments were made at baseline, 6, 12, and 26 weeks. The primary end point was the proportion of patients who reached their plateau for upper limb function at 12 weeks, measured with the Action Research Arm Test. Results Odds ratios indicated that PRIMED participants were 3x more likely than controls to reach their recovery plateau by 12 weeks. Intention-to-treat and per-protocol analyses showed a greater proportion of PRIMED participants achieved their plateau by 12 weeks (intention to treat, (2)=4.25; P=0.039 and per protocol, (2)=3.99; P=0.046). ANOVA of per-protocol data showed PRIMED participants had greater rebalancing of corticomotor excitability than controls at 12 and 26 weeks and interhemispheric inhibition at 26 weeks (all P<0.05). Conclusions Bilateral priming accelerated recovery of upper limb function in the initial weeks after stroke. Clinical Trial Registration URL: http://www.anzctr.org.au. Unique identifier: ANZCTR1260900046822.