Influence of combined afferent stimulation and task-specific training following stroke: a pilot randomized controlled trial.

BACKGROUND Reorganization of the human motor cortex can be induced by specific patterns of peripheral afferent stimulation. The potential for afferent stimulation to facilitate the functional recovery associated with conventional rehabilitative techniques has not previously been investigated. OBJECTIVE The authors sought to determine whether combining appropriate afferent stimulation with task-specific training resulted in greater improvements than training alone in patients with impaired upper limb function in the subacute phase following stroke. METHOD Twenty patients with hemiparesis due to stroke were allocated randomly to either a stimulation or control group. All received 9 sessions of task-specific physiotherapy training over 3 weeks. Prior to each training session, associative electrical stimulation of the motor point of 2 hand muscles was given in the stimulation group, whereas the control group received sham stimulation. Changes in dexterity were assessed using a grip-lift task, and standard measures of upper-limb function were made before and following the intervention. Corticospinal excitability was examined using transcranial magnetic stimulation. RESULTS Both groups showed comparable improvements in functional measures of upper-limb function. Of the 20 patients, only 14 could perform the grip-lift task, which is an objective measure of dexterity. Patients in the stimulation group exhibited significantly greater improvements in this task than the control group. There was no significant change in corticospinal excitability in either group. CONCLUSION This pilot study provides preliminary data suggesting that targeted afferent stimulation may facilitate the response to conventional rehabilitation in patients with hemiparesis due to stroke, but these results need to be confirmed in a larger scale study.