The effects of repetitive proprioceptive stimulation on corticomotor representation in intact and hemiplegic individuals.

OBJECTIVE

To determine the effects of a passive wrist movement intervention on cortical representation of forearm musculature.

METHODS

Transcranial magnetic stimulation was used to map cortical representation of a forearm flexor muscle in healthy individuals and in individuals following stroke before and immediately after a 30 min session of passive wrist movement.

RESULTS

In the healthy individuals, no changes in map area or map centre of gravity were noted after the intervention; however, map volume increased significantly across all subjects. In the stroke patient group there were no significant changes in any parameters following the intervention.

CONCLUSIONS

It is speculated that the enlargement in map volume following the passive movement intervention arose through a heightened synaptic efficacy of the corticospinal pathway in response to the increase in afferent information. Short-term proprioceptive stimulation can induce alterations in corticomotor excitability in the target musculature.

SIGNIFICANCE: These findings provide a potential neural substrate to account for alterations in motor and sensory function in stroke patients in response to long-term passive movement interventions.