The greater occipital nerve runs very close to the vertebral artery. The artery should be identified with color Doppler.

The greater occipital nerve curls around the lower border of the obliquus capitis inferior muscle. It is attached to the bifid spine of the axis (C2) and to the transverse process of the atlas (C1).

Diagnostic and therapeutic block for migraine and cluster headache.

Finlayson RJ, Gupta G, Alhujairi M, Dugani S, Tran de QH: Cervical medial branch block: A novel technique using ultrasound guidance. Reg Anesth Pain Med 37(2): 219-23 (2012)

Shim JK, Moon JC, Yoon KB, Kim WO, Yoon DM: Ultrasound-guided lumbar medial-branch block: A clinical study with fluoroscopy control. Reg Anesth Pain Med 31: 451-54 (2006)

For the lumbar medial branch block the local anaesthetic is injected in the groove between the superior margin of the transverse process and the adjacent superior articular process.

The greater occipital nerve (GON) is the medial branch of the dorsal primary ramus of the second cervical nerve.

The GON innervates the muscles of the posterior neck: The semispinalis capitis and the multifidus cervicis. It also supplies cutaneous branches to the posterior scalp and meningeal branches to the posterior cranial fossa. And it supplies pain and proprioceptive branches for the first cervical nerve for innervation of the suboccipital muscles.

The cervical medial branches from the dorsal spinal rami follow the deepest concavity of the articular pillars of the cervical vertebrae.

The medial branches of the lumbar dorsal spinal rami cross the cranial margin of the transverse processes and the groove where the cranial margin of the transverse process is adjacent to the superior articular process.

Place the patient in the lateral decubitus position.

Place a curved array probe in the parasagittal plane and identify the superior margin of the sacrum and the transverse process of vertebra L5. Move the probe cranially while counting the transverse processes. At the target level, the probe is rotated to the axial plane and the spinous process, the articular process and the transverse process are identified.

The needle is inserted from the lateral end of the probe aiming at the groove between the superior margin of the transverse process and the superior articular proces until bony contact.

Inject 1 mL of local anaesthetic.

The flattest and most echogenic part of the articular pillar is identified in the axial plane.