Hand-arm vibration syndrome: clinical characteristics, conventional electrophysiology and quantitative sensory testing

Abstract

Objective: Workers exposed to vibrating tools may develop hand-arm vibration syndrome (HAVS). We assessed the somatosensory phenotype using quantitative sensory testing (QST) in comparison to electrophysiology to characterize (1) the most sensitive QST parameter for detecting sensory loss, (2) the correlation of QST and electrophysiology, and (3) the frequency of a carpal tunnel syndrome (CTS) in HAVS.

Methods: QST, cold provocation tests, fine motor skills, and median nerve neurography were used. QST included thermal and mechanical detection and pain thresholds.

Results: Thirty-two patients were examined (54 ± 11 years, 91% men) at the more affected hand compared to 16 matched controls. Vibration detection threshold was the most sensitive parameter to detect sensory loss that was more pronounced in the sensitivity range of Pacinian (150 Hz, x12) than Meissner's corpuscles (20 Hz, x3). QST (84% abnormal) was more sensitive to detect neural dysfunction than conventional electrophysiology (37% abnormal). Motor (34%) and sensory neurography (25%) were abnormal in HAVS. CTS frequency was not increased (9.4%).

Conclusion: Findings are consistent with a mechanically-induced, distally pronounced motor and sensory neuropathy independent of CTS.

Significance: HAVS involves a neuropathy predominantly affecting large fibers with a sensory damage related to resonance frequencies of vibrating tools.

Keywords: Autonomous nervous system; CDT; CMAP; CPT; CTS; Carpal tunnel syndrome; DFNS; DMA; DML; Deutscher Forschungsverbund Neuropathischer Schmerz=German Research Network on Neuropathic Pain; HAVS; HPT; HRV; Hand-arm vibration syndrome; MDT; MPS; MPT; Neurography; PHS; PPT; QST; Quantitative sensory testing; SNAP; SSR; TSL; VDT; VWF; Vibration-induced white fingers; WDT; WUR; cold detection threshold; cold pain threshold; compound muscle action potential; distal motor latency; dynamic mechanical allodynia; hand-arm vibration syndrome; heart rate variability; heat pain threshold; mNCV; mechanical detection threshold; mechanical pain sensitivity; mechanical pain threshold; motor nerve conduction velocity; paradoxical heat sensation; pressure pain threshold; quantitative sensory testing; sNCV; sensory nerve action potential; sensory nerve conduction velocity; sympathetic skin response; thermal sensory limen; vibration detection threshold; vibration-induced white finger disease; warm detection threshold; wind-up ratio.