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