In the deep groove on the upper surface of the posterior arch of the atlas are the vertebral artery and the first cervical or suboccipital nerve.
It forms the lower boundary of the suboccipital triangle of the neck.
The electrodes are implanted in the bilateral suboccipital region.
It ascends after emerging from below the suboccipital triangle beneath the obliquus capitis inferior muscle.
It lies within the suboccipital triangle along with the vertebral artery, where the artery enters the foramen magnum.
Through the condylar canal, the occipital emissary vein connects to the venous system including the suboccipital venous plexus, occipital sinus and sigmoid sinus.
It supplies muscles of the suboccipital triangle, the rectus capitis posterior major, obliquus capitis superior, and obliquus capitis inferior.
The suboccipital nerve also passes through this defect.
