Vibrotactile sense in the hand-arm vibration syndrome

Objectives The purpose of this study was to investigate disturbances of the vibrotactile sense and their relation to clinical symptoms and findings am ong male symptomatic workers suffering from the hand-arm vibration syndrome . Methods Ninety-six such patients were interviewed and given a clinical and tactilometric examination. The symptoms were classified according to the St ockholm Workshop Scale. A sensibility index was used to quantify vibrotacti le sense in the tactilogram. Results An abnormal sensibility index (<0.8) was recorded for 57.3% of the patients (mean of 4 fingers), at least 1 finger being abnormal in 72.9% of the patients. The sensibility index did not statistically differ between th e patients suffering from sensorineural symptoms and those with vibration w hite finger. The stages of sensorineural symptoms, according to the Stockho lm Workshop Scale, corresponded with the sensibility index, whereas the sta ges of vibration white finger did not. There were significant differences i n the sensibility index between the fingers, between the right and left han ds, and between the fingers innervated by the ulnar and median nerves. Bila teral symptoms and cold intolerance were associated with considerable impai rment of the vibrotactile sense. Clinical median nerve involvement in the c arpal tunnel was not reflected by the sensibility index. Conclusions There is a considerable degree of neural involvement in all sym ptomatic vibration-exposed patients irrespective of symptoms. As symptoms p rogress, the severity of sensorineural symptoms, but not of vibration white finger, is reflected by the sensibility index. Cold intolerance is strongl y related to nervous involvement and should be noted in the patient history . Tactilometry should be performed on 1 median and 1 ulnar nerve-innervated finger of both hands, as an examination of 1 finger alone may be misleadin g.