Neurological diagnosis: aspects of bedside and electrodiagnostic examinations in relation to hand-arm vibration syndrome.

Objectives: The objective of this paper, was to direct attention to the diagnostic strategy and clinical approach necessary in the diagnosis of neuropathy in workers exposed to vibration. The purpose encompassed evaluation of selected aspects of bedside and electrodiagnostic examinations with respect to biological validity and the ability to distinguish between subjects with and without neuropathy.
Methods: The neurological examinations viewed were restricted to those applicable to the upper extremity and neck system. A MEDLINE search was performed through the clinical queries service of PubMed searching for the following terms: nerve-conduction, Tinel's test, Phalen's test, tendon reflex, two-point discrimination test, abduction external rotation test, and Spurling test. Retrieved articles were discussed both in relation to the test accuracy and the validity aspects of the tests.
Results: The evidence in support of the view that neurological tests can accurately distinguish between subjects with and without neuropathy specifically addressing hand-arm vibration syndrome was sparse. The initial number of diagnostic hypotheses could be reduced by progressively ruling out diseases based on negative results of highly sensitive tests. As the possible diagnostic alternatives become fewer, the use of positive results from highly specific tests are more effective. The information value of the various diagnostic tests is determined by the change in pre-test to post-test probability of target disorder, which depends on the prevalence of the disorder and the likelihood ratios of the tests. The review showed that target disease characteristics influence the test outcome as well as the choice of "gold standard" and the population domain of the studies.
Conclusions: The selection of various bedside examinations and diagnostic electrophysiological tests should be dependent on the clinical context, the history and results from the successive diagnostic tests.