Diagnostic performance of MRI and MR myelography in infants with a brachial plexus birth injury.
BACKGROUND
Detailed evaluation of a brachial plexus birth injury is important for treatment planning.


OBJECTIVE
To determine the diagnostic performance of MRI and MR myelography in infants with a brachial plexus birth injury.


METHODS
Included in the study were 31 children with perinatal brachial plexus injury who underwent surgical intervention. All patients had cervical and brachial plexus MRI. The standard of reference was the combination of intraoperative (1) surgical evaluation and (2) electrophysiological studies (motor evoked potentials, MEP, and somatosensory evoked potentials, SSEP), and (3) the evaluation of histopathological neuronal loss. MRI findings of cord lesion, pseudomeningocele, and post-traumatic neuroma were correlated with the standard of reference. Diagnostic performance characteristics including sensitivity and specificity were determined.


RESULTS
From June 2001 to March 2004, 31 children (mean age 7.3 months, standard deviation 1.6 months, range 4.8-12.1 months; 19 male, 12 female) with a brachial plexus birth injury who underwent surgical intervention were enrolled. Sensitivity and specificity of an MRI finding of post-traumatic neuroma were 97% (30/31) and 100% (31/31), respectively, using the contralateral normal brachial plexus as the control. However, MRI could not determine the exact anatomic area (i.e. trunk or division) of the post-traumatic brachial plexus neuroma injury. Sensitivity and specificity for an MRI finding of pseudomeningocele in determining exiting nerve injury were 50% and 100%, respectively, using MEP, and 44% and 80%, respectively, using SSEP as the standard of reference. MRI in infants could not image well the exiting nerve roots to determine consistently the presence or absence of definite avulsion.


CONCLUSIONS
In children younger than 18 months with brachial plexus injury, the MRI finding of pseudomeningocele has a low sensitivity and a high specificity for nerve root avulsion. MRI and MR myelography cannot image well the exiting nerve roots to determine consistently the presence or absence of avulsion of nerve roots. The MRI finding of post-traumatic neuroma has a high sensitivity and specificity in determining the side of the brachial plexus injury but cannot reveal the exact anatomic area (i.e. trunk or division) involved. The information obtained is, however, useful to the surgeon during intraoperative evaluation of spinal nerve integrity for reconstruction.
Medina
L Santiago
LS
Division of Neuroradiology, Department of Radiology, Brain Institute, Health Outcomes, Policy, and Economics (HOPE) Center, Miami Children's Hospital, Miami, FL, USA. Santiago.medina@mch.com
Yaylali
Ilker
I
Zurakowski
David
D
Ruiz
Jennifer
J
Altman
Nolan R
NR
Grossman
John A I
JA
D001720:Birth Injuries / Q000175:diagnosis* / Q000601:surgery; D001917:Brachial Plexus / Q000293:injuries* / Q000473:pathology / Q000601:surgery; D020516:Brachial Plexus Neuropathies / Q000175:diagnosis* / Q000601:surgery; D004594:Electrophysiology / Q000379:methods; D019054:Evoked Potentials, Motor; D005073:Evoked Potentials, Somatosensory; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009463:Neuroma / Q000175:diagnosis* / Q000209:etiology / Q000601:surgery; D010524:Peripheral Nervous System Neoplasms / Q000175:diagnosis* / Q000209:etiology / Q000601:surgery; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012015:Reference Standards; D012680:Sensitivity and Specificity