Reference values for touch sensibility thresholds in healthy Nepalese volunteers

A hundred and thirty-six apparently healthy volunteers between the ages of 16 and 67 were used to determine normative thresholds of tactile sensibility in the Nepali adult population. Tactile sensibility thresholds on standardized sites on hands and feet were assessed for two sensory tests: Semmes-Weinstein monofilaments (SWM) and moving-point discrimination (M2PD). Results are reported as the proportion of subjects able to feel a given threshold. The effect of age, sex, side, occupation, smoking habit and alcohol consumption on the results was examined with quantile regression. On the hand 200 mg seemed an appropriate threshold for 'normal' touch sensibility measured with monofilaments. About 99% (95% confidence interval 97-100) of individuals could detect this filament at all sites. A similar proportion could discriminate two points 4 mm apart which were moved from proximal to distal on the volar pad of the distal phalanx of the index and little finger. For the sole of the foot the thresholds were 2 g and 8 mm. Variability of results was greatest at the heel. Normal thresholds for tactile sensibility were higher than those published for the North American population. Monofilament thresholds suitable for screening were 200 mg (log number 3 center dot 61) and 2 g (log number 4 center dot 31) for hand and foot, respectively. For moving 2-point discrimination on the hand this threshold was 4 mm.