title: Assessment of conduction from C8 nerve root exit to supraclavicular fossa--its value in the diagnosis of thoracic outlet syndrome.
abstract: Conduction across the thoracic outlet in the components of the lower trunk of the brachial plexus was studied. With the recording electrode over the abductor digiti quinti latencies of stimulation in the supraclavicular fossa and of the C8 nerve root were ascertained. The difference between these 2 values reflected conduction time between C8 and the supraclavicular fossa. Four normal volunteers, 150 patients without Thoracic Outlet Syndrome and 50 patients with clinical thoracic outlet syndrome were studied. Using this method, conduction time from C8 to supraclavicular fossa ranged from 0.4 to 1.2 msec (mean = 0.6570, S.D. = 0.2097) in patients without thoracic outlet syndrome, and from 1.0 to 2.6 msec (mean = 1.7836, S.D. = 0.1984) in patients with thoracic outlet syndrome. These values show a significant difference between the 2 groups at the 0.05 level of confidence (T-Test). In thoracic outlet syndrome, conduction time has a tendency to be prolonged and the value above 1.3 msec is strongly suggestive of thoracic outlet syndrome. The values are consistent and reproducible. This method is easy to carry out and is a useful addition to the diagnostic assessment of thoracic outlet syndrome.
authors.forename: A P
authors.initials: AP
authors.lastname: Pavot
authors.forename: D R
authors.initials: DR
authors.lastname: Ignacio
authors.forename: G W
authors.initials: GW
authors.lastname: Gargour
mesh_terms: D000328:Adult; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology*; D013126:Spinal Nerve Roots / Q000502:physiology*; D013901:Thoracic Outlet Syndrome / Q000175:diagnosis* / Q000503:physiopathology