A preliminary study of locognosia in people affected by leprosy

Locognosia is the ability to localize a sensory stimulus on the body's surface and can be tested by graded filaments (Semmes-Weinstein monofilaments). This point localization of sensation (locognosia) wastested by SW filaments over four quadrants of the pulp of the fingers in ulnar/median and ulnar paralysis in 38 new patients affected by leprosy. The results were compared with standard testing of sensation at selected sites by Semmes Weinstein monofilament. Both pulp quadrant testing and standard site testing were done in leprosy patients and also in a group of controls. Sensation was tested in 73 hands in leprosy patients and 34 hands in controls. Results indicate a positive correlation between locognosia and standard SW filament testing. When locognosia and standard SW filament tests were compared, there was significant difference between the two tests to pick up abnormal sensation in leprosy patients both over the entire hand and over individual fingers. This preliminary study suggests that locognosia may be a useful tool to diagnose sensory impairment in leprosy. Further studies are required to corroborate this.