Altered Sensorimotor Neuroplasticity in the Subacute Period Following Burn Injury.

PurposeBurn injuries affect the central nervous system, and evidence suggests they induce changes in cortical excitability related to motor dysfunction. The current study investigated markers of neuroplasticity in the motor cortex and motor performance in the subacute period following burn injury. MethodsThirty-four patients with a minor burn injury (total body surface area: 1.0 {+/-} 2.0%; 16 females; age: 46.0 {+/-} 14.0 years) participated in a longitudinal study with assessments ranging from [~]1 to [~]17 weeks post-injury. Transcranial magnetic stimulation (TMS) was used to evaluate motor cortex excitability and short- and long-intracortical inhibition (SICI; LICI) before and after application of paired associative stimulation (PAS) to induce neuroplasticity. Motor performance was assessed using the Purdue Pegboard. ResultsPatients showed improvements in bilateral motor performance from [~]3 to [~]6 weeks post-injury. PAS did not induce any change in net motor cortex excitability or SICI but increased LICI, which was greatest [~]6 weeks post-injury. Adjusted modelling showed that greater PAS-induced increase in LICI was associated with better bilateral motor performance, suggesting an association between PAS-induced neuroplasticity of GABAB-mediated inhibition and motor function following burn injury. ConclusionsThese findings highlight a potential role for neuroplasticity of inhibitory circuits in the motor cortex in recovery of motor function following burn injury. The data provide a neurophysiological basis to test whether targeting inhibitory networks in the subacute period after burn injury can enhance or expedite functional recovery.