Intraspinal (Extradural and Intradural) Spinal Nerve Variations

For this aim of the study, 43 human cadavers were examined after performing a wide laminectomy and following each spinal nerve root from its origin till its exit through the intervertebral foramen and sacral hiatus. All the found intradural and extradural anastomoses were examined for the presence of nerve tissue and are presented in the tables, images, and schemes. The prefixed or postfixed plexus type was identified according to the C2 root origin. Extradural variations were observed in 60.5% of cases, an atypical spacing of nerve roots in 20.9% of cases, and extradural anastomoses between nerve roots in nine cases. Intradural variations were present in all cases, especially in the lumbosacral region. Such multisegmental participation of the spinal segments proves that the skin and muscles receive axons from several neurotomes.