[Leg pain under spinal anesthesia in leprosy patients].

We studied leg pain experienced under spinal anesthesia in leprosy patients. Seven of twenty patients complained of the leg pain a few minutes after spinal block. The pain was localized in the parts of deafferentation or phantom limb, and was relatively mild and controllable. We consider that the inhibitory system is inactivated when the somatic impulse is blocked by spinal anesthesia, and as a result the abnormal burst activity of dorsal horn produced by peripheral nerve damage of leprosy causes phantom pain.