Current concepts in plasticity and nerve transfers: relationship between surgical techniques and outcomes.

OBJECTIVE Neuroplasticity is analyzed in this article as the capacity of the CNS to adapt to external and internal stimuli. It is being increasingly recognized as an important factor for the successful outcome of nerve transfers. Better-known factors are the number of axons that cross the coaptation site, the time interval between trauma and repair, and age. Neuroplasticity is mediated initially by synaptic and neurotransmitter changes. Over time, the activation of previously existing but lowly active connections in the brain cortex contributes further. Dendritic sprouting and axonal elongation might also take place but are less likely to be prominent. METHODS The authors reviewed different factors that play roles in neuroplasticity and functional regeneration after specific nerve transfers. RESULTS The authors found that these different factors include, among others, the distance between cortical areas of the donor and receptor neurons, the presence versus absence of preexisting lowly active interneuronal connections, gross versus fine movement restoration, rehabilitation, brain trauma, and age. CONCLUSIONS The potential for plasticity should be taken into consideration by surgeons when planning surgical strategy and postoperative rehabilitation, because its influence on results cannot be denied.