FUNCTIONAL SENSIBILITY OF THE HAND IN LEPROSY PATIENTS

The aims of this cross-sectional comparative study was to compare the results of Semmes-Weinstein monofilament testing (SWM) and moving 2-po int discrimination (M2PD) with four tests of functional sensibility: r ecognition of objects, discrimination of size and texture and detectio n of dots. Ninety-eight leprosy in- and outpatients at Green Pastures Hospital in Pokhara, Nepal were tested with each of the above tests an d the results were compared to see how well they agreed. Using the tes ts of functional sensibility as reference points, we examined the vali dity of the SWM and M2PD as predictors of functional sensibility. Ther e was definite, but only moderate correlation between thresholds of mo nofilaments and M2PD and functional sensibility of the hand. A normal result with the SWM and/or M2PD had a good predictive value for normal functional sensibility. Sensitivity was reasonable against recognitio n of objects and discrimination of textures as reference tests (80-90% and 88-93%), but poor against discrimination of size and detection of dots (50-75% and 43-65%). Specificity was high for most combinations of SWM or M2PD with any of the tests of functional sensibility (85-99% ). Above a monofilament threshold of 2g, the predictive value of an ab normal test was 100% for dot detection and 83-92% for textural discrim ination. This indicates that impairment of touch sensibility at this l evel correlates well with loss of dot detection and textural discrimin ation in patients with leprous neuropathy. For M2PD the pattern was ve ry similar. Above a threshold of 5 mm, 95-100% of affected hands had l oss of dot detection and 73-80% had loss of textural discrimination. M onofilament testing and M2PD did not seem suitable as proxy measures o f functional sensibility of the hand in leprosy patients. However, a n ormal threshold with monofilaments and/or M2PD had a good predictive v alue for normal functional sensibility. Above a monofilament threshold of 2g and/or a M2PD threshold of 5 mm, textural discrimination was ab normal in most hands.