MICROSCOPIC CHARACTERISTICS OF EXTRADURAL NERVE ROOTS ANOMALIES

Abstract

Full Text

Background. Raising number of unsuccessful disc hernia operations highlighted the importance of knowledge of different types of nerve roots anomalies. Various anatomical studies aimed on elucidating them were peformed worldwide. Aim. Our cadaverous study has focused on microscopic features of found extradural nerve root anomalies. Material and Methods. Study was performed on 43 cadavers within 24 hours after death (32 males, 11 females). Bodies were dissected in a prone position, with wide and long laminectomy revealing full spinal canal for bilateral examinations of each spinal nerve root from origin to its exit through intervertebral foramen or sacral hiatus. Uncommon extradural features in all spinal regions were followed and documented. Extradural roots anomalies were excised, proccessed with light microscopy method, stained with hematoxyllin-eosin, luxol blue and Holmes silver methods. Results and Discussion.Totally 20 extradural root anomalies were observed (46.5%): including atypical spacings, 2 roots exiting 1 neuroforamen, extradural anastomoses, extradural missing a nerve root or aberrant root. Especially in cases of multiplied roots in 1 neuroforamen, root anastomoses and aberrant roots the tissue samples were compared with samples of apparently normal roots. In case of cervical and thoracic connecting branches (anastomoses) we failed to prove nervous tissue presence within the samples. Conclusions. Not all the extradural communicating branches are real nervous connections, despite this any iatrogenic injury by various less invasive spinal surgical procedures must be avoided. Further histological and electrophysiologic investigations are probably need for elucidating their impact on classic image of segmental dermatome and myotome organization of human body.