Vibration perception thresholds in entrapment and toxic neuropathies.
J Occup Med 1986 Oct; 28(10):991-994
Use of the modified Optacon tactile stimulator for measurement of perception thresholds as an index of subclinical disease in entrapment and toxic neuropathies is reviewed. It is noted that these frequent problems encountered in occupational neurology are difficult to objectively quantify. Use of nerve conduction velocity for documenting the severity of an impairment in the peripheral nervous system is described. However, nerve conduction studies may be insensitive early in the disease process. Design of the Optacon tactile stimulator and its use are described. Studies of vibration perception threshold are cited which demonstrate an increase in these thresholds with age. Increased thresholds are also reported to correlate with peripheral neuropathy in 38 percent of subjects examined. Studies suggest that routine neurological examination and electrodiagnostic studies are more sensitive indicators of idiopathic peripheral neuropathy than vibration perception thresholds. A Study of 56 alcoholic outpatients revealed diminished sensation in a glove distribution in 62 percent of the patients and diminished sensation in a stocking distribution in 96 percent. Identification of carpal tunnel syndrome in workers exposed to neurotoxic substances or cumulative repetitive trauma of the upper extremities is discussed. Vibration perception thresholds in the compromised index finger can be compared with the ipsilateral uninvolved ulnar innervated fifth finger. As an objective measure of nerve dysfunction in carpal tunnel syndrome, the Optacon is reported to have a sensitivity of 79 percent and a specificity of 100 percent. Use of the Optacon to distinguish toxic polyneuropathy from entrapment neuropathy is discussed. The author concludes that this tool allows detection and serial quantification of sensory abnormalities in the workplace, allowing for measurement of deterioration or improvement, and recommends that studies of possible confounding factors be performed.
NIOSH-Publication; NIOSH-Grant; Occupational-health; Occupational-health-programs; Peripheral-nervous-system; Nervous-system-disorders; Vibration-effects; Medical-monitoring; Medical-examinations; Medical-screening;
Environmental Health Sciences, Johns Hopkins University, 615 North Wolfe Street, Baltimore, MD 21205
Journal of Occupational Medicine
Johns Hopkins University, Baltimore, Maryland