Improvement of Sensibility in the Sole of the Foot in Diabetic Patients, Induced by EMLA-application to the Lower Leg - a Double Blind Study

Sensory input from the foot as well as all other body parts results in activation of sensory cortex.

It is well known that the cortical body map is experienced-dependant and can rapidly change in response to changes in activity and sensory input from the periphery [10-12]. Increased activity and sensory input from the hand results in expansion of the cortical hand representation [13-15], while decreased sensory input, for instance by anaesthesia, amputation or nerve injury, results in shrinkage of the cortical hand representation [16-21]. Due to the constant ongoing "cortical competition" between body parts the adjacent cortical areas expand and take over the silent area, deprived of sensory input.

The investigators have recently described striking examples of such rapid cortical re-organisations induced by selective cutaneous anaesthesia of the forearm: application of EMLA cream to the volar aspect of the forearm results in improved sensory functions of the hand [18] linked to expansion of the hand representational area in sensory cortex . In analogy, EMLA application to the lower leg in healthy controls results in improved sensory functions in the sole of the foot linked to expansion of the foot representational area in sensory cortex.

To test the hypothesis that EMLA application to the lower leg of diabetic patients will result in improved sensory functions in the sole of the foot as well as expansion of the foot representation in sensory cortex. The investigators hypothesize that repeated applications of EMLA will result in a long lasting sensibility improvement.