Diagnostic test using monofilament compared to electroneuromyography (ENMG) for detection of peripheral neuropathy in leprosy at Sanglah General Hospital, Bali-Indonesia

Introduction: Leprosy is a chronic granulomatous infection caused by M. leprae with high affinity to Schwann cell. Primary concern of leprosy is disability due to progressive nerve damage so that patients and their families are sometimes faced with social stigma and discrimination. This can be caused by late detection and treatment of nerve damage. Electroneuromyography (ENMG) as the gold standard for nerve damage detection has limitations in terms of cost and operational procedures, so there is a need for simpler and cheaper method such as monofilament test. This study aims to determine the validity of monofilament test compared to ENMG for the detection of peripheral neuropathy in leprosy. Method: Study design using analytic method with cross-sectional approach, a total 40 patients including paucibacillary and multibacillary type of leprosy who met inclusion and exclusion criteria were recruited by consecutive-sampling. All subjects undergo monofilament test at Dermato-Venereology Clinic of Sanglah General Hospital Denpasar and electroneuromyography test at Neurology Clinic of Sanglah General Hospital Denpasar from December 2018 to February 2019. The data was analyzed to determine sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Result: The result of this study revealed that monofilament test had an overall sensitivity of 67.2% and specificity of 77.5%. High sensitivity and specificity were found in the sural nerve (85.7% and 75%) and radial nerve (82.7% and 80%) Conclusion: monofilament test can be considered for early detection of peripheral neuropathy, especially for sural and radial nerve.