SYMPATHETIC VASOMOTOR DYSFUNCTION IN LEPROSY PATIENTS - COMPARISON WITH ELECTROPHYSIOLOGICAL MEASUREMENT AND QUALITATIVE SENSATION TESTING

Testing of skin vasomotor reflexes (VRs) by laser Doppler flowmetry (L DF) is now a recognised method of measuring peripheral dysautonomia. T o assess its specificity as an indicator of impairment to unmyelinated autonomic fibres, VR testing at the fingerpulp was compared with stan dard qualitative sensation (QST) and with sensory electrophysiological (SNVC) measurements in 39 Iranian leprosy patients. There was a signi ficant relationship between VR and SNCV values (but not QST): these we re jointly measurable in 38.5% of fingers, and jointly absent in 35.3% of fingers which also showed significantly reduced LDF perfusion and skin temperatures. However, in 10.3% of fingers, predominantly index a nd otherwise apparently healthy, VRs were absent but SNCV present, sug gesting early sub-clinical autonomic impairment. In a further 16% of f ingers, predominantly ulnar and with poor microcirculation, intact (th ough impaired) VRs could be recorded despite the absence of SNCV respo nses, suggesting sparing or regeneration of these fibres. This evidenc e suggests that where there is heterogeneity of nerve damage a combina tion of VR and electrophysiological testing can indicate the functiona l status of distinct fibre types.