Sensory Recovery in Median Nerve Repair Following Sensory Reduction

Abstract

Prangyan Singh, India Sensory reeducation programs are based on the assumption that the regenerating peripheral nerve begins to demonstrate less recovery than patient’s potential. The reason for this underachievement is the patient’s inability to interpret the altered impulses. This alteration in perception of precise touch occurs along the entire sensory pathway. At the periphery there is degeneration of receptors, reduction in nerve fibers, erroneous reinnervation, establishment of erroneous receptive fields, cross innervations, reduced conduction velocity, and changes in sizes of receptive fields. Centrally, there are abnormal receptive fields, abnormal topographical organization. Clinically, the patient demonstrates partial tactile sensitivity, poor ability to localize, and impaired ability to identify textures, forms and objects. The purpose of sensory reeducation is to correctly interpret pattern of abnormal sensory input. The goal is to increase cortical map representation for involved skin surfaces to improve spatial discrimination. The most common sensory reeducation programs utilized in hand rehabilitation following a nerve injury are 1) correction of faulty localization: the goals are to reeducate specific perception and relearn how to identify the difference between moving touch and constant touch, and pressure, and correction of false localization, 2) recognition of materials and objects: the goal is the recovery of functional tactile gnosis. Purpose of study: To find out the effect of Discriminative Sensory reeducation on sensory recovery in median nerve following repair in the Indian population. Study design: Pretest posttest experimental study design. Methodology: 20 Patients with traumatic median nerve injury at the wrist level with sensory involvement were included. The patients were equally divided in two groups (experimental and control). 10 patients (experimental group) received sensory re-education programme for 6 wks & the other group (control group) did not receive any sensory re-education. The sensory reeducation program was started after 6 wks following neural repair. All the patients were followed up after six weeks. Sensory re-education protocol: The reeducation was done by having the patient attempt to differentiate the degree of roughness of sand paper and shapes of wooden blocks. The patient performed the activities of reeducation program for 30 minutes everyday. When the patient was capable of recognizing a difference of roughness on more than 7 out of 10 trials, the patient was advanced to the second phase where the patient was trained to identify 12 different small metal objects.