Retention of the spacing effect with mental practice in hemiparetic stroke.

Mental practice (MP) is a promising adjuvant to physical practice that involves many of the same mechanisms and takes on many of the same properties as physical practice. This study compared efficacy of a "massed" MP regimen versus a "distributed" MP regimen on upper extremity (UE) motor impairment and functional limitation. Twenty-seven chronic stroke survivors were administered the UE section of the Fugl-Meyer (FM) and Action Research Arm Test (ARAT), followed by standardized physical practice and MP regimens. One group was administered "massed" MP (60 min of MP during a single daily session) and a second group administered distributed MP (20 min of MP occurring three times/day). After intervention, changes in FM and ARAT scores of subjects in the distributed condition were significantly higher than those of subjects in the massed condition (FM 3.65, 95 % CI 0.82-6.49, p value = 0.01; ARAT 3.95, 95 % CI 1.24-6.67, p value = 0.006). Likewise, at POST 3, subjects in the distributed group showed significantly higher change in ARAT scores (ARAT 4.90, 95 % CI 0.57-9.22, p value = 0.03); the change in FM scores at POST 3 was 3.18 points higher among subjects in the distributed condition, but only approached significance (95 % CI -1.27 to 7.63, p value = 0.15). Results suggest that a distributed MP schedule is more efficacious in bringing about paretic UE changes than a massed practice schedule, especially in terms of reducing UE functional limitation.