Extradural and intradural characteristics of the cervical nerve root anomalies.

The anomalous anatomical arrangement of the cervical spinal nerve roots within the spinal canal can complicate the surgical treatment of several pathologies. This work aimed to reveal intraspinal anatomical anomalies of the extradural and also intradural cervical spinal nerve roots courses. The anatomical study was realised in 43 cadavers with a mean age of 53.7 (32 men and 11 women). After opening the spinal canal and also the dural sac the intradural and extradural anomalies of the cervical spinal nerve roots (bilaterally) were explored and documented. We found completely 49 cases (56.98%) of intraspinal cervical nerve root anomalies. Extradural anomalies were found in 11 cases (12.79%) including atypical spacing, two roots exiting through one neuroforamen, extradural communications, aberrant root. Intradural anomalies observed in 28 cases (32.56%) comprised: communications between the dorsal roots and ventral roots separately or together and the multiple communications. Other anomalies (10 cases, 11.63%) included various types of atypical spacing of the roots and their asymmetry. All the results are differentiated according to the plexus type (pre-, postfixed, normotyped). This study describes intraspinal (extradural and intradural) anatomical anomalies of the cervical spinal nerve root courses. Knowledge of these variabilities should help to prevent the failure of several medical procedures.