Reduced sensory nerve conduction velocity of the distal part of the radial nerve among patients with vibration syndrome.

The present study was aimed at clarifying the effects of vibration syndrome (VS) on the distal part of the radial nerve, which is rarely affected by chronic entrapment. Thirty-one patients with VS due to previous exposure to vibration and 18 age-matched controls were examined for sensory nerve conduction velocities in the distal part of the radial nerve (SCV-DR) in the dorsal side of the hand. The patient group was divided into two subgroups, one of those with vibration-induced white finger (VWF) in the thumb or index finger where sensory nerves are innervated by the radial nerve (N = 21) and the other without VWF (N = 10). SCV-DR among the patients was significantly slower than in the controls (t = 3.55, p = 0.00138). The ANOVA of SCV-DR for the three groups showed F2, 46 = 5.25 (p = 0.0088). A significant difference was found between the controls and the VWF (+) group (p = 0.0233), but not between the controls and the VWF (-) group (p = 0.478) by multiple comparison using Scheffe's method. These findings suggest that VS affects the radial nerve with a direct vibration effect and/or a co-operative effect with direct circulatory disturbance manifested by VWF.