Raynaud's phenomenon of occupational origin

The association between vibration and vascular injury in rheumatic diseases: a review of the literature

Vascular manifestations can be seen early in the pathogenesis of inflammatory rheumatic diseases. Animal experiments, laboratory and clinical findings indicated that acute or long-term vibration exposure can induce vascular abnormalities. Recent years, in addition to Raynaud's phenomenon (RP), vibration as a risk factor for other rheumatic diseases has also received corresponding considered. This review is concentrated upon the role of vibration in the disease of systemic sclerosis (SSc). In this review, we are going to discuss the main mechanisms which are thought to be important in pathophysiology of vascular injury under the three broad headings of "vascular", "neural" and "intravascular". Aspects on the vibration and vascular inflammation are briefly discussed. And the epidemiological studies related to vibration studies in SSc and other rheumatic diseases are taken into account.

Assessing the Influence of Antivibration Glove on Digital Vascular Responses to Acute Hand‐arm Vibration

This study was designed to assess the influence of an antivibration glove on digital vascular responses in healthy subjects exposed to short-term grasping of a vibrating handle. To measure finger blood flow (FBF) and finger skin temperature (FST) once at the end of every min, a blood flowmeter sensor was attached to the dorsum and a thermistor sensor was attached to the medial surface of the subject's middle phalanx of the third finger of the right hand. After 5 min of baseline measurements without or with an antivibration glove meeting ISO standard 10819, worn on the right hand, subjects gripped a vibrating handle with the same hand for a period of 5 min. Vibration was generated at two frequencies of 31.5 Hz and 250 Hz with a frequency weighted rms acceleration of 5.5 m/s(2). FBF and FST continued to be recorded for a further 5 min after release of the vibrating handle. Statistical analysis showed no significant change after vibration exposure in either FST or FBF at 250 Hz, compared to baseline (control) measurements while using the antivibration glove. At 31.5 Hz, FBF data exhibited a significant difference between before and after grasping of vibrating handle, which was less under the condition of wearing the antivibration glove than under the condition of bare hand. The results provide evidence that the antivibration glove considerably influenced finger vascular changes in healthy subjects induced by vibration exposure, especially against high frequency vibration. Further studies are required to assess finger vascular responses to hand-transmitted vibration with antivibration gloves of different manufacturers.

Evidence for frequency-dependent arterial damage in vibrated rat tails

The effects of single 4-hr bouts of continuous 30, 60, 120, and 800 Hz tail vibration (49 m/sec2, root mean squared) were compared to assess frequency-amplitude-related structural damage of the ventral caudal artery. Amplitudes were 3.9, 0.98, 0.24, and 0.0055 mm, respectively. Vibrated, sham-vibrated, and normal arteries were processed for light and electron microscopy. The Curry rat tail model of hand-arm vibration (Curry et al. Muscle Nerve 2002;25:527-534) proved well-suited for testing multiple frequencies. NFATc3 immunostaining, an early marker of cell damage, increased in smooth muscle and endothelial cells after 30, 60, and 120 Hz but not 800 Hz. Increased vacuolization, which is indicative of smooth muscle contraction, occurred for all frequencies except 800 Hz. Vacuoles increased in both endothelial and smooth muscle cells after 60 and 120 Hz. Only 30 Hz showed pronounced smooth muscle cell vacuolization along the internal and external elastic membranes, suggesting stretch-mediated contraction from the large amplitude shear stress. Discontinuities in toluidine blue staining of the internal elastic membrane (IEM) increased for all frequencies, indicating vibration-induced structural weakening of this structure. Patches of missing IEM and overlying endothelium occurred in approximately 5% of arteries after 60, 120, and 800 Hz. The pattern of damage after 800 Hz suggests that the IEM is disrupted because it resonates at this frequency. Vibration acceleration stress and smooth muscle contraction appear to be the major contributors to arterial damage. The pattern of vibration-induced arterial damage of smooth muscle and endothelial cells is frequency-amplitude-dependent.

Prognosis of vibration induced white finger: a follow up study

OBJECTIVES--To follow up 102 patients with vibration induced white finger (VWF). METHODS--102 subjects with VWF were reexamined one to 13 years after the condition had first been diagnosed. Information about symptoms, occupation, vibration exposure, smoking habits, age, and the prevalence of other diseases was present in the medical records from the first examination and was collected by a questionnaire and an interview at the second examination. The decrease in systolic blood pressure in a finger during cold provocation (FSP%) was measured in the same finger at both examinations. RESULTS--At the second examination, 22% stated that the frequency of attacks had decreased. The improvement was most frequent in subjects with little or no exposure to vibration during the previous two years, in non-smokers, and in subjects without other circulatory diseases than VWF. 32% stated that the frequency of attacks had increased. The aggravation was most notable in smokers and subjects who also had circulatory diseases other than VWF. The number of finger phalanges that blanched on cooling averaged 15.8 at the first examination and 14.4 at the second examination. Working with high vibration hand held tools during the previous two years was related to an aggravation, with more finger phalanges affected at the second examination. Presence of other circulatory diseases had the same effect. In non-smokers the number of affected finger phalanges had decreased at the second examination. The FSP% had increased (improvement) in 43%, decreased (aggravation) in 12%, and was unchanged in 45%. The increase in FSP% was more pronounced in the older than in the younger subjects. The decrease of FSP% was more frequent among the younger subjects and subjects with a short follow up. CONCLUSION--As the FSP% in nearly half of the subjects had improved, it is concluded that VWF has a good prognosis in patients with mainly moderate to severe VWF after one to 13 years of observation. The improvement in FSP%, however, was not reflected in the subjective experience of the development of attacks of VWF. Continued work with high vibration hand held tools, smoking, other circulatory diseases, and low age at the time of diagnosis had an unfavourable influence on the prognosis.