Motor skill changes and neurophysiologic adaptation to recovery-oriented virtual rehabilitation of hand function in a person with subacute stroke: a case study

Abstract

Purpose: The complexity of upper extremity (UE) behavior requires recovery of near normal neuromuscular function to minimize residual disability following a stroke. This requirement places a premium on spontaneous recovery and neuroplastic adaptation to rehabilitation by the lesioned hemisphere. Motor skill learning is frequently cited as a requirement for neuroplasticity. Studies examining the links between training, motor learning, neuroplasticity, and improvements in hand motor function are indicated.

Methods: This case study describes a patient with slow recovering hand and finger movement (Total Upper Extremity Fugl-Meyer examination score = 25/66, Wrist and Hand items = 2/24 on poststroke day 37) following a stroke. The patient received an intensive eight-session intervention utilizing simulated activities that focused on the recovery of finger extension, finger individuation, and pinch-grasp force modulation.

Results: Over the eight sessions, the patient demonstrated improvements on untrained transfer tasks, which suggest that motor learning had occurred, as well a dramatic increase in hand function and corresponding expansion of the cortical motor map area representing several key muscles of the paretic hand. Recovery of hand function and motor map expansion continued after discharge through the three-month retention testing.

Conclusion: This case study describes a neuroplasticity based intervention for UE hemiparesis and a model for examining the relationship between training, motor skill acquisition, neuroplasticity, and motor function changes. Implications for rehabilitation Intensive hand and finger rehabilitation activities can be added to an in-patient rehabilitation program for persons with subacute stroke. Targeted training of the thumb may have an impact on activity level function in persons with upper extremity hemiparesis. Untrained transfer tasks can be utilized to confirm that training tasks have elicited motor learning. Changes in cortical motor maps can be used to document changes in brain function which can be used to evaluate changes in motor behavior persons with subacute stroke.

Keywords: Stroke; hand; rehabilitation; robotics; upper extremity; virtual reality.

Conflict of interest statement

Disclosure statement

The authors state that they have no conflicts of interest.

Figures

Figure 1. Training performance

(a) Average time to attain a target (top) versus peak force (bottom) recorded on seven consecutive training days during performance of the Monkey Business. (b) Average time to perform a keystroke (squares, top), the difference between flexion angles of cued and non-cued fingers (middle) and the number of correct keys pressed divided by the total number of keys pressed (traingles, bottom) recorded on eight consecutive training days during performance of the Piano Trainer simulation.

Figure 2. Untrained transfer task kinematics

(a) Changes in max pinch force and active finger extension range of motion. (b) Attempts to trace red sine wave controlling cursor by pinching force sensor. Measured preintervention (top), postintervention (middle) and at 3 month retention (bottom). (c) Attempts to trace red sine wave controlling cursor by extending (up) and flexing (down) fingers as measured with a strain-gauge glove. Measured preintervention (top), postintervention (middle) and at 3 month retention (bottom).

Figure 3. Clinical assessment

(a) AD’s performance on the WMFT, UEFMA and BBT. Performances were measured 1 day before intervention, 1 day after intervention and 3 months after intervention. (b) Average time to complete each of the 15 items of the Wolf motor function test. Unimpaired UE performance (blue boxes) and impaired UE performance (red circles) measured on same days as (a).

Figure 4. Motor maps

(a) Non-lesioned hemisphere motor map area for the first dorsal interosseous muscle (blue columns), the adductor pollicis brevis (red columns) and extensor digitorum communis (green columns). Data collection occurred on the same day as the clinical and kinematic measures from Figures 2 and 3. (b) Lesioned hemisphere motor map area for the same muscles collected on same days.