Acute improvement of contralateral hand function after deafferentation.

To study cortical reorganisation after acute hand deafferentation, we investigated 10 experimental subjects and 10 controls for function in the left hand, before, during and after tourniquet induced anaesthesia of the right hand. fMRI was performed in three experimental subjects. Right hand anaesthesia resulted in rapid significant improvement in grip strength, tactile discrimination and sensibility in the left hand. Tactile discrimination and grip strength improvements lasted at least 15 mins after anaesthesia. fMRI showed increased activation in the right primary motor cortex after anaesthesia. We conclude that tourniquet induced anaesthesia is an easy way to induce rapid and significant improvement in contralateral hand function. This finding may have a potential clinical application for evolving sensory relearning strategies after nerve repair.