Detection of root avulsion in the dominant C7 obstetric brachial plexus lesion: experience with three-dimensional constructive interference in steady-state magnetic resonance imaging and electrophysiology.
OBJECTIVE
Preoperative, reliable detection by ancillary investigations of spinal nerve root avulsions in infants with severe obstetric brachial plexus lesions to avoid ineffective operative repair from deceivingly intact but actually avulsed nerve roots.


METHODS
Ten infants were selected with an infrequent, severe dominant C7 lesion, primarily because of the anatomically distinct supraclavicular course of this spinal nerve. Three-dimensional constructive interference in steady-state magnetic resonance imaging (3D CISS MRI) studies under mild sedation were performed and evaluated for detection of avulsed nerve roots by two experienced neuroradiologists. Preoperative electrodiagnostics (electromyography and somatosensory evoked potentials) as well as intraoperative somatosensory potentials and muscle contractions after electrostimulation were recorded. Preoperative and intraoperative ancillary investigations were correlated with intraoperative findings in eight patients and clinical status in two children who recovered spontaneously.


RESULTS
Despite two minor motion artifacts, the quality of the 3D CISS MRI studies was good. In 8 of 10 patients, prediction of root continuity was consistent with operative or clinical findings, and 2 remained doubtful. Preoperative and intraoperative electrodiagnostics tended not to correlate with intraoperative findings in this small, selected group.


CONCLUSIONS
3D CISS MRI provides good images of anterior and posterior spinal roots in infants with obstetric brachial plexus lesions. Images seem to allow accurate prediction of root avulsion in the majority of patients. In this study, electrodiagnostics were of limited value.
van Ouwerkerk
Willem J R
WJ
Department of Neurosurgery, Vrije Universiteit, University Medical Center, Amsterdam, The Netherlands. W.vOuwerkerk@vumc.nl
Strijers
Rob L M
RL
Barkhof
Frederik
F
Umans
Ulco
U
Vandertop
W Peter
WP
D001917:Brachial Plexus / Q000473:pathology*; D004576:Electromyography / Q000379:methods; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000379:methods; D011843:Radiculopathy / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D012189:Retrospective Studies; D013126:Spinal Nerve Roots / Q000473:pathology*; D014057:Tomography, X-Ray Computed / Q000379:methods