Applied Force Alters Sensorineural and Peripheral Vascular Function in a Rat Model of Hand-Arm Vibration Syndrome

OBJECTIVE

This study described the effects of applied force (grip) on vascular and sensorineural function in an animal model of hand-arm vibration syndrome (HAVS).

METHODS

Rat tails were exposed to 0, 2, or 4 N of applied force 4 hr/d for 10 days. Blood flow and sensitivity to transcutaneous electrical stimulation and pressure were measured.

RESULTS

Applied force increased blood flow but reduced measures of arterial plasticity. Animals exposed to force tended to be more sensitive to 250-Hz electrical stimulation and pressure applied to the tail.

CONCLUSIONS

Effects of applied force on blood flow and sensation are different than those of vibration. Studies examining co-exposures to force and vibration will provide data that can be used to determine how these factors affect risk of workers developing vascular and sensorineural dysfunction (ie, HAVS).

Arterial abnormalities in the hands of workers with vibration white fingers - a magnetic resonance angiography case series

Vibration white finger (VWF) is a complication from exposure to hand-arm vibrations. Poor knowledge of the pathophysiology of VWF means that making an accurate prognosis is difficult. Thus, a better understanding of VWF's pathophysiology is of importance.The purpose of this study was to investigate whether there were arterial abnormalities in the hands in patients with VWF and a positive Allen's test, using ultrasound and MRA imaging.This was a case series where arterial abnormalities in the hands were investigated in ten participants with VWF and using prolonged Allen's test (> 5 s). The participants had an average vibration exposure of 22 years and underwent Doppler ultrasound and Magnetic Resonance Angiography (MRA) to check for arterial abnormalities.The participants had VWF classified as 1-3 on the Stockholm workshop scale. Ultrasound and MRA identified vascular abnormalities in all participants, the predominant finding was missing or incomplete superficial arch. Also, stenosis was identified in four participants.This study reveals a high proportion of arterial stenosis and abnormalities in patients with VWF and a prolonged Allen's test.

Prevalence, risk factors, and clinical correlates of ulnar artery occlusion in the general population

BACKGROUND

Occlusion of the ulnar artery is found in a substantial proportion of elderly patients. The aim of this study was to estimate the prevalence of ulnar artery occlusion in a sample of the general population of France, look for its risk factors, and evaluate its clinical correlates.

METHODS

This study was an offshoot of a cross-sectional epidemiologic study in the general population of four locations in France (Tarentaise, Grenoble, Nyons, and Toulon). In phase I, random samples of 2000 individuals per location aged >or=18 years old were interviewed by phone for screening of Raynaud phenomenon. In phase II, subsamples of individuals were invited to a medical interview and physical examination where the presence of Raynaud phenomenon and occupational risk factors were recorded and a bilateral clinical Allen test was performed for the detection of ulnar artery occlusion. Phase II comprised 688 women and 335 men.

RESULTS

In 36 men and seven women, at least one occluded ulnar artery was found. The estimated prevalence was 9.6% in men and 1.0% in women (P < .001). The occluded artery was more often in the dominant hand of both men (8.1% vs 2.4%; P < .001) and women (0.9% vs 0.4%; P = .34). Ulnar artery occlusion was found more often in men aged >50 years (16.4%) than in younger men (1.4%; P < .001). Besides age, male sex, and dominant side, the only independent risk factor was an occupational exposure in men to repeated palmar trauma, with a significant quantitative relationship in the frequency of the impacts (P < .001) and the duration of the exposure (P < .001). Exposures to hand-held vibrating tools and cigarette smoking did not show a significant relationship in the multivariate analysis. Most individuals with ulnar artery occlusion did not have associated complaints; however, the diagnostic criteria for Raynaud phenomenon was validated in 13 of the 36 affected men. The association remained significant after adjusting for occupational exposure to vibrating tools. One individual reported a previous episode consistent with an attack of permanent digital ischemia.

CONCLUSION

This study confirms a substantial prevalence of ulnar artery occlusions in the general population, mostly in middle-aged and elderly men, which appears to be principally related to an occupational exposure to repeated occupational palmar trauma. Although there is a significant association with Raynaud phenomenon, most often the consequences of this occlusion remain subclinical.