Detection of peripheral sensory nerve dysfunction: A preliminary comparison of nerve conduction and mechanoreceptor-specific vibrotactile thresholds

Abstract

Using the method described previously, mechanoreceptor-specific vibrotactile perception thresholds have been determined at the fingertips (digits 3 and 5) of a series of 24 chain saw operators, 83% of whom reported symptoms of intermittent or persistent numbness, and/or episodic white fingers. Motor and sensory nerve conduction velocities were then recorded from the median and ulnar nerves in each hand and arm, as well as motor distal latencies, following conventional procedures. If the results are compared with normative values from nonvibration exposed, symptom-free, manual workers (and the limit of normality is taken to be two standard deviations from the mean value), 71% and 29% of sawyers reported symptoms are found to possess abnormal vibrotactile thresholds and sensory nerve conduction velocities, respectively. Of the workers at present not reporting symptoms, 50% and 89% are found to possess normal vibrotactile thresholds and sensory velocities, respectively. Performance measures of the two objective tests will be discussed that attempt to account for the subjective nature of symptom reporting.