SCREENING FOR PERIPHERAL NEUROPATHY IN PA TIENTS WITH LEPROSY

In leprosy, the early detection of peripheral nerve damage is essentia l for the prevention of disability. To date, there is no consensus on what is the best clinical test to reveal such abnormalities. In this p rospective study, we examined the effectiveness of five clinical tests to assess radial cutaneous nerve (RCN) damage (the most frequently in volved). Light touch was assessed by two nylon threads (based on the S emmes-Weinstein monofilaments testing technique) bent on the skin at a pressure of 0,5 (N degrees 4 nylon) and 0,2 gram (N degrees 5 nylon). Pinprick and cooling sensations were examined by a needle and a drop of ether. The nerve thickness was assessed by palpation. Sensory findi ngs were then compared to sensory nerve conduction values of the RCN a nd a sensitivity analysis was performed. The patient group consisted o f 108 consecutive new leprosy sufferers (138 RCN) who attended the Ins titut de Leprologie Appliguee de Dakar during one year. Diagnosis and classification,were based on Ridley and Jopling's criteria (clinical e xamination, skin smears and biopsy). Normal values were determined amo ng 22 healthy subjects (44 RCN). The best rests in term of sensitivity were palpation (.60), N degrees 5 nylon (.65) and N degrees 5 + palpa tion (.79). Their positive predictive values were .84 (palpation), .94 (N degrees 5 nylon) and .83 (N degrees 5 + palpation). The best tests in term of area under the curve were palpation (.66), N degrees 5 nyl on (.71) and N degrees 5 + palpation (.78). The results remain the sam e for the lepromatous or tuberculoid leprosy patients. Ulnar and media n nerves, and different normal sensory nerve conduction values were te sted in a sensitivity analysis; the 2 most sensitive tests remained th e same. Appreciation of nerve thickening and/or abnormal perception of the N degrees 5 nylon thread are the most appropriate diagnostic tool s to detect early peripheral nerve damage.