Radiological anatomical consideration of conjoined nerve root with a case review.

Nerve root anomalies are frequently underrecognized regardless of the advances in imaging studies; they are also underappreciated and underreported when encountered surgically. The classification of conjoined nerve roots is based on whether the nerve root emerges at an abnormal level or from an anastomotic branch. In the present report, we describe case with a conjoined nerve root that emerged at a more caudal level than that normally observed that was an undiagnosed on preoperative imaging studies. We also discuss the atypical imaging features obtained through preoperative imaging studies. As observed in the present case, preoperative recognition and diagnosis of such anomalies offer the best opportunity of performing a successful procedure and preventing inadvertent damage to nerve roots intraoperatively.