Definition of an Effective Site for Greater and Third Occipital Nerve Block in the Nuchal Region: A Fetal Cadaver Study.

Abstract

The suboccipital region is an important area due to having intensive anatomical content. For different clinical applications, it is important to know the course of the nerves in this region and the relationship with the muscles. The aim of this study was to determine the localization of the greater occipital nerve and the third occipital nerve according to palpable bone landmarks and their relationship with muscles in the suboccipital region and to define an effective zone for clinical approaches. This study was conducted on 15 fetal cadavers. Bone landmarks to be used as reference were determined by palpation, and measurements were taken before dissection. The location, relationship and variation of these nerves and muscles (trapezius, semispinalis capitis, obliquus capitis inferior) were noted. It was detected that the nape triangular area formed between the reference points was scalene in males and isosceles in females. It was found that greater occipital nerve pierced aponeurosis of trapezius and passed under obliquus capitis inferior in all fetal cadavers and 96,7% of them had pierced semispinalis capitis. It was determined that the greater and third occipital nerve pierced the trapezius aponeurosis approximately 2 cm below the reference line and 0.5-1 cm lateral to the midline. One of the important factors for the high success rate in suboccipital invasive procedures in the pediatric population is to know the location of the nerves in the region correctly. We believe that the results of this study will contribute to the literature.