Intensive motor rehab most effective 2 to 3 months post-stroke

Patients with stroke may benefit from more intensive motor rehabilitation at 60 to 90 days after stroke onset, according to results of a phase 2 clinical trial published in Proceedings of the National Academy of Sciences.

“Within days after a neuronal injury, rats show time-sensitive increases in dendritic branching peaking 2 to 3 weeks postinjury, followed by a behavior-dependent pruning of newly formed dendritic arbors,” Alexander W. Dromerick, MD, of the research division at MedStar National Rehabilitation Hospital in Washington, D.C., and colleagues wrote. “Intensive motor training provided to rodents within such periods has been shown to restore full motor function. However, there has previously been no direct evidence of similar time-limited responsiveness to intensive motor training in human adults.”

To address this research gap, the investigators conducted the current randomized controlled trial that applied the key components of rodent motor training paradigms to humans to assess whether these findings extended to adult humans with stroke.

They adaptively randomly assigned patients with stroke to initiate 20 extra hours of self-selected, task-specific motor therapy for 30 or fewer days (acute; n = 16), 2 to 3 months (subacute; n = 17) or 6 months or longer (chronic; n = 20) after stroke, and they compared outcomes with those of controls (n = 19), who received standard motor rehabilitation.

Dromerick and colleagues assessed upper extremity impairment via the Action Research Arm Test (ARAT) at up to five time points. ARAT recovery over 1 year after stroke served as the primary outcome measure.

Results showed upper extremity motor function significantly increased by 1 year among the subacute group vs. controls (ARAT difference = +6.87 ± 2.63; P = .009). Compared with controls, the acute group had smaller but significant improvement (ARAT difference = +5.25 ± 2.59 points; P = .043). The chronic group exhibited no significant improvement vs. controls (ARAT = +2.41 ± 2.25; P = 0.29).

These findings suggested task-specific motor intervention had the greatest effectiveness within the first 2 to 3 months after stroke.

“In the future, a further understanding of the mechanisms underlying these timing effects can allow us to extend and enhance the treatment timeline, with the ultimate aim of producing full motor recovery in human patients,” Dromerick and colleagues wrote.