Researchers from the Department of Physical Medicine & Rehabilitation at the University of Cincinnati’s Academic Medical Center looked at the impact of “mental practice” (the imaginal rehearsal of physical movements) on affected arm movements in stroke patients, as well as changes in cortical mapping in the brain.

Mental practice (MP) is a noninvasive, inexpensive method of enabling repetitive, task-specific practice (RTP) which has been shown in past studies to increase affected arm use and function significantly more than just RTP alone. 

As a next step, this 10-subject case series examined the possibility that cortical plasticity is a mechanism underlying the positive treatment effect from mental practice (MP) when combined with RTP (repetitive task-specific practice). Ten chronic stroke patients (mean = 36.7 months) exhibiting stable, moderate motor deficits, received 30-minute therapy sessions for their affected arms 3 days/week for 10 weeks, emphasizing valued activities of daily living (ADLs).

Directly after therapy, subjects received 30-minute mental practice imagery sessions, where subjects imagined performing the same valued tasks of daily living that they were working on during the physical therapy.

Behavioral outcomes were blindly measured using the Action Research Arm Test (ARAT) and the Fugl-Meyer Assessment (FM).  Functional magnetic resonance imaging (fMRI) was administered before and after the intervention period, to assess cortical changes.

Before the intervention, subjects exhibited stable motor deficits.  After the intervention, subjects exhibited ARAT and FM score increases (+5.3 and +4.2, respectively) and clinically significant gains in tasks of daily living.

The post-intervention fMRI revealed significant increases in activation to wrist flexion and extension of the affected hand in the pre-motor area and primary motor cortex, on both the same side and the opposite side of the affected hand, as well as in the superior parietal cortex on the same side as the affected hand. Also, decreased activation was noted in the parietal cortex of the same hemisphere as the affected hand. These changes correlated with anatomical regions in which behavioral changes were observed in the ARAT and FM measures.

The investigators conclude that mental practice is an easy to use, cost-effective strategy that was once again shown to improve affected arm outcomes after a stroke. Additionally, this is the first study to demonstrate measurable changes in the cortical map as a response to the mental practice training.

Citation: Page SJ, Szaflarski JP, Eliassen JC, Pan H, Cramer SC.  Cortical plasticity following motor skill learning during mental practice in stroke. Neurorehabil Neural Repair. 2009 May; 23 (4): pages 382-8. Epub 2009 Jan 20. [email protected]