Vibratory thresholds in the hands: comparison of patients with suprathalamic lesions with normal subjects.

Absolute thresholds for sensation of a 100-Hz mechanical sine-wave stimulus applied with an electromagnetic vibrator were measured on eight stimulus points in the glabrous skin of the human hand in normal subjects and in patients with verified, circumscribed unilateral suprathalamic lesions of the hemispheres. In both groups, the threshold on the hypothenar eminence was lower than the threshold on the third digit, which in turn had a lower threshold than the fifth digit. For each locus of stimulation, there was a rectilinear regression of threshold with age. Women had lower thresholds than men. The spatial distribution of the thresholds might suggest that Pacinian corpuscles are the receptors activated by threshold stimulation. Unilateral suprathalamic lesions of the hemisphere did not cause any elevation of vibratory thresholds.