Pectoral nerve conduction studies: technique in healthy subjects and evaluation of brachial plexopathy.
OBJECTIVE
To define the optimal nerve conduction study (NCS) technique of the pectoral nerves and evaluate its clinical utility.


METHODS
Prospective electrophysiologic study with healthy controls.


METHODS
Electrophysiologic laboratory in a large general hospital.


METHODS
Thirty healthy controls and 10 patients with cervical root or brachial plexus pathologies.


METHODS
Not applicable.


METHODS
Correlation of pectoral NCS with electromyography and magnetic resonance imaging.


RESULTS
For pectoral NCS, the mean values +/- standard deviation of onset latency, amplitude, and interside amplitude ratio (ratio of smaller over larger amplitude) were 2.01+/-0.22 ms, 11.75+/-2.21 mV, and .95+/-.04 mV, respectively. Subject age correlated significantly with both onset latency (r=.46, P<.001) and amplitude (r=-.34, P<.008). All 5 patients with brachial plexopathy had amplitude ratios below the normal limit of controls (.87). However, this was not seen for all 5 patients with cervical spondylotic radiculopathy.


CONCLUSIONS
The pectoral NCS technique is feasible in healthy subjects. It is useful when differentiating brachial plexopathy from cervical root lesions.
Lo
Yew-Long
YL
Department of Neurology, National Neuroscience Institute, Singapore General Hospital, Singapore. gnrlyl@sgh.com.sg
Prakash
Kumar M
KM
Leoh
Teng-Hee
TH
Tan
Yam-Eng
YE
Dan
Yan-Fang
YF
Ratnagopal
Pavanni
P
D000328:Adult; D020516:Brachial Plexus Neuropathies / Q000175:diagnosis / Q000503:physiopathology*; D004576:Electromyography; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology*; D011446:Prospective Studies; D013900:Thoracic Nerves