Thermotactile threshold testing for the evaluation of sensory nerve function in vibration-exposed patients and workers

Abstract

Objectives: The aim of the present study was to ascertain the usefulness of thermotactile testing under the measuring conditions clari®ed by our previous study in the evaluation of vibration-induced neuropathy. Method: Thermal (warm and cold) thresholds were examined on the index ®ngers of both hands of ten patients with hand-arm vibration syndrome, 36 workers exposed to hand-transmitted vibration, and ten healthy controls, using an aesthesiometer under the following measuring conditions: change rate of the applicator temperature was ®xed at a rate of 1°C/s; ®nger contact force on the applicator was kept at 0.5 N; and forearm was positioned on a support. Vibrotactile thresholds at 125 Hz and pain thresholds were also measured on the index ®ngers. Results: Both warm and cold thresholds had more severely deteriorated in the patients than in the controls. Vibrotactile and pain thresholds were also increased in the patients. In the vibration-exposed workers, the neutral zone between the warm and cold threshold diered from in the controls. Thermotactile thresholds were likely to have deteriorated with advanced nerve impairment. Likelihood ratios of thermotactile testing were signi®cantly high between the patients and the controls. For vibration-exposed work-ers with elevated vibrotactile and pain thresholds, the ratios were also signi®cantly high, particularly in the neutral zone, though the accuracy tended to be lower than in the patients. Thermotactile thresholds appeared to be more closely correlated with pain thresholds than vibrotactile thresholds. Conclusions: Thermotactile threshold testing under the present measuring conditions can be useful for evaluating small sensory nerve ®bre dysfunction in vibration-exposed subjects, and the neutral zone may be a sensitive indicator in vibrationexposed workers who may have slight or mild nerve impairments.

Thermal perception thresholds among workers in a cold climate

“…Reports on normative values differ considerably (Bakkers et al 2013 ), which makes possible comparisons with previous studies of magnitude, abnormality and normative values uncertain. However, for comparison, the results of studies in different geographic regions (Bovenzi et al 2011 ; Carlsson et al 2016 ; Miscio et al 2005 ; Sakakibara et al 2002 ; Seah and Griffin 2008 ) have been summarized in Fig. 1 together with the results from the subarctic region obtained in our study.…”

“…1 Comparison of the measured mean difference in degrees Celsius (°C) from baseline temperature to detection temperature in different geographic areas with standard deviation bars . The annual ambient temperature for each region and the number of participants in each study are 1 (Bovenzi et al 2011 ) n = 63, 14 °C, 2 (Miscio et al 2005 ) n = 51, 12 °C, 3 (Sakakibara et al 2002 ) n = 56, 11 °C, 4 (Seah and Griffin 2008 ) n = 80, 10 °C, 5 (Carlsson et al 2016 ) n = 81, 0 °C …”

Influence of vibration exposure on tactile and thermal perception thresholds

“…Today, it is known that exposure to hand-transmitted vibration could increase the occurrence of symptoms and signs of vascular, neurological and musculoskeletal disorders of the upper extremities among vibration-exposed workers [1]. The neurological symptoms could be manifested by deterioration of finger tactile perception [2][3][4] and/or impaired thermal perception [3,[5][6][7].…”

Quantitative sensory testing: effect of site and pressure on vibration thresholds

“…Toibana et al showed that thermal thresholds were significantly correlated with pain thresholds, and the sensitivity of the thermal threshold testing tended to be greater than that of the pain threshold testing in vibration-induced neuropathy [321]. Sakakibara et al found thermal threshold testing useful in vibration-exposed subjects, and that it might be a sensitive indicator in vibration-exposed subject who may have slight or mild nerve impairments [322]. QST of thermal and vibration thresholds are, thus, useful in the evaluation of local vibration induced nervous lesions in the hands.…”

“…Sensory nerves are more vulnerable to vibration induced neuropathy than motor nerves[305,321,322]. HAVS probably starts as a sensory neuropathy, but may later include motor symptoms.…”