Improved sensory relearning after nerve repair induced by selective temporary anaesthesia – a new concept in hand rehabilitation

The outcome after nerve repair in adults is generally poor. We hypothesized that forearm deafferentation would enhance the sensory outcome by increasing the cortical hand representation. A prospective, randomized, double-blind study was designed to investigate the effects of cutaneous forearm anaesthesia combined with sensory re-education on the outcome after ulnar or median nerve repair. During a 2 week period, a local anaesthetic cream (EMLA®) (n=7)(n=7) or placebo (n=6)(n=6) was applied repeatedly onto the flexor aspect of the forearm of the injured arm and combined with sensory re-education. Evaluation of sensory function was carried out at regular intervals and at 4 weeks after the last EMLA®/placebo session. The EMLA® group showed significant improvement compared to placebo in perception of touch/pressure, tactile gnosis and in the summarized outcome after 6 weeks. These results suggest that cutaneous forearm anaesthesia of the injured limb, in combination with sensory re-education, can enhance sensory recovery after nerve repair.