Harnessing the uninjured hemisphere for treatment of the stroke or brain-injured patient - evolution of the contralateral C7 transfer.

This article presents a comprehensive review of contralateral C7 (cC7) transfer surgery, tracing its evolution from treating brachial plexus injuries to its transfer to ipsilateral C7 transfer surgery in treating upper motor neurone injuries. The cC7 was initially postulated to restore function by replacing injured nerves at the peripheral level, but dynamic cortical reorganization has since been demonstrated post-surgery, which potentially allows harnessing of the cC7 procedure to expand the span of control of the uninjured hemisphere in conditions like hemiplegic stroke. By integrating principles of nerve regeneration and brain plasticity through phased rehabilitation programmes, published clinical results have demonstrated significant improvements in upper limb function, confirming the procedure's safety and efficacy, with donor site morbidity that is typically mild and transient. The cC7 procedure may play a major role in the future of restoring upper limb function in patients who have suffered upper motor neurone lesions.