Anomalous exit of the C-6 nerve root via the C-6, C-7 foramen.

We report a case of the anomalous exit of the C-6 nerve root at the C-6, C-7 foramen. This caused intense radicular and cervical pain in a 25-year-old woman. At myelography, the 5th and 6th cervical roots appeared conjoined, and at operation the C-6 root and ganglion were found to turn acutely downward, lateral to the pedicle of C-6, and then to exit with the C-7 nerve root through the C-6, C-7 foramen. The ganglion of C-6 was placed nearly parallel to the dural sac and tethered at its origin on the dural sac and at the exit foramen with the C-7 root. The pedicle of C-6 was interposed between the dural sac and the ganglion of C-6. Cervical hemilaminectomy and resection of the pedicle of C-6 defined the anatomy and resulted in a clinical cure. The radiological features are described and contrasted with those of other anomalies. To our knowledge, this is the first report of such an anomalous course of exit of a cervical root.