[Recent topics of vibration syndrome in Japan--changes of finger systolic blood pressure due to segmental local cooling].

Exposure to hand-arm vibration can lead to a complex condition with vascular, sensorineural and musculo skeletal disorders. The vascular disorder has been known as vibration induced white finger (VWF). From the clinical and medico-legal points, objective diagnostic tests for VWF are needed. Measurement of finger systolic blood pressure after finger cooling (FSBP test) is considered to be the most accurate diagnostic laboratory method for an objective confirmation of VWF. In 2005, the FSBP test was standardized internationally. Rosai-hospital group performed a multi-centre study on the FSBP test for diagnosis of VWF and confirmed the diagnostic validity of the FSBP test.

Current perception threshold for assessment of the neurological components of hand-arm vibration syndrome: a review.

Current perception threshold (CPT) has been proposed as a quantitative method for assessment of peripheral sensory nerve function. The aim of this review of selected reports is to provide an overview of CPT measurement for the assessment of the neurological component of hand-arm vibration syndrome (HAVS). The CPT values at 2000 Hz significantly increased for patients with HAVS. This result supports the previous histological findings that demyelination is found predominantly in the peripheral nerves in the hands of men exposed to hand-arm vibration. Diagnostic sensitivity and specificity were high for severe cases of Stockholm sensorineural (SSN) stage 3 compared with non-exposed controls, but not high for mild cases of SSN stage 1 or 2 and for carpal tunnel syndrome associated with HAVS. However, there are only a few studies on the diagnostic validity of the CPT test for the neurological components of HAVS. Further research is needed and should include diagnostic validity and standardizing of measurement conditions such as skin temperature.

Multicenter study on finger systolic blood pressure test for diagnosis of vibration-induced white finger.

OBJECTIVE: A multicenter study (six Rosai hospitals around Japan) was performed to investigate the diagnostic value of changes in finger systolic blood pressure (FSBP) after segmental local cooling for vibration-induced white finger (VWF). METHODS: Subjects were 154 men without exposure to vibration and 135 men with occupational vibration exposure. They were classified into four groups: Group A, 154 unexposed control cases; Group B, 21 exposed cases without VWF; Group C, 31 cases with a history of VWF but without any signs of VWF within the last year; and Group D, 83 cases with active VWF within the last year. FSBP% measurements were taken at room temperatures of 23 +/- 1 and 21 +/- 1 degrees C, using a strain-gauge Digimatic 2000 plethysmograph (Medimatic). RESULTS: At a room temperature of 23 +/- 1 degrees C, there was a significant difference between Groups A and D, and B and D. At a room temperature of 21 +/- 1 degrees C, there was a significant difference between Groups A and C, A and D, and B and D. The values in Group D were the lowest at both room temperatures. Assuming a cut-off value of 75% at 23 +/- 1 degrees C, the sensitivity and specificity were 65.2 and 87.5%, respectively. Assuming the same cut-off value at 21 +/- 1 degrees C, the sensitivity and specificity were 73.9 and 82.5%, respectively. These values were not too high. Most of the subjects with WVF in this study were retired and had not used vibratory tools for many years. The situation of the subjects may affect the results of the FSBP test. Our data did not confirm a difference in diagnostic accuracy between room temperatures of 23 +/- 1 and 21 +/- 1 degrees C. CONCLUSIONS: Our study showed that the sensitivity and specificity of the FSBP test with a cut-off value of 75% at 23 +/- 1 degrees C, were 65.2 and 87.5%, respectively, and at 21 +/- 1 degrees C, they were 73.9 and 82.5%, respectively.

Factors influencing finger systolic blood pressure test for diagnosis of vibration-induced white finger.

Finger systolic blood pressure (FSBP) measurement during finger cooling is a feasible method for the diagnosis of vibration-induced white finger (VWF). The standardization of the FSBP test is required. The final draft of an international standard for the measurement and evaluation of FSBP (ISO/DIS 14835-2) has been proposed in 2004. The aim of this review is to overview factors influencing the FSBP test and discuss some issues in the final draft. The FSBP test is a method of diagnosing VWF with reasonable sensitivity and specificity, although the sensitivity was relatively low in studies of mild VWF. The test results depend on cold provocation procedures including finger cooling, body cooling, room temperature and other factors such clothing and smoking. There are some versions of procedures for cold provocation and the tested fingers in the final draft. These may cause a low sensitivity of the FSBP test. To determine how the methodological difference influence the results of the FSBP test, further studies are needed. Although there are issues in the draft, the international standard of the FSBP test is extremely useful for the diagnosis, treatment and compensation of VWF.

Long-term follow-up study on patients with vibration-induced white finger (VWF).

The prognosis of vibration-induced white finger was investigated with a long follow-up period. From 1975 to 1994, 99 men with hand-arm vibration syndrome who received the annual compulsory examination at San-in Rosai Hospital were followed up for 15 years or longer. Based on the extent of finger-blanching attacks described in the medical records, they were classified according to the vascular stage of the Stockholm workshop scale. In our laboratory, finger systolic blood pressure (FSBP) measurement after finger cooling has been performed since 1989. We compared the stage classification with the results of FSBP measurement after finger cooling in the period 1989-1994. The stage 2 and stage 3 groups showed a significant decrease in FSBP% compared with the stage 0 group. The vascular stage classification based on subjective symptoms in this study was to a certain extent reliable. Although vibration-induced white finger symptoms tended to improve to some extent, 43.2% and 70.4% of patients with stage 2 and stage 3 at first examination, respectively, still suffered from finger blanching attacks after 15 years of observation. Blanching of fingers in advanced stages, especially stage 3, was found to be persistent many years after cessation of vibration exposure.