Objective
This study aims at evaluating the usefulness of the electrodiagnostic study (EDx) and the magnetic resonance imaging (MRI), which are performed before surgical operation of brachial plexus injury. Method: We reviewed 57 cases of brachial plexopathy diagnosed with surgical findings. EDx and MRI were performed to the patients before surgery. Based upon intraoperative findings, we evaluated the occurrence of preganglionic root injury and subsequently each injured spinal root level. Results: EDx and MRI for preganglionic root injuries showed 92.1% and 78.9% of diagnostic sensitivity and 63.2% and 42.9% of diagnostic specificity, respectively. The followings were about each injured spinal root level. EDx showed that the sensitivities of C5, C6, C7, C8, T1 were 91.4%, 91.4%, 92.6%, 96%, 95.8%, and their specificities were 59.1%, 59.1%, 56.7%, 68.8%, 66.7%. MRI showed that the sensitivities were 47.4%, 57.9%, 58.3%, 75%, 66.7%, and their specificities were 57.1%, 71.4%, 78.6%, 85.7%, 85.7%. Conclusion: As for preganglionic brachial plexopathy, EDx was more useful than MRI to diagnose preganglionic root injury and determine the level of injured spinal root. (J Korean Acad Rehab Med 2005; 29: 608-613)