A very generalised picture of a classical chain with 3 ganglionated masses named as superior cervical ganglion, middle cervical ganglion and inferior cervical ganglion or cervicothoracic ganglion is obtained from the previous studies, while little is mentioned about the existence of a fourth cervical ganglion or vertebral ganglion.
Many authors observed two ganglia in the middle of the cervical sympathetic chain and followed the terms "middle cervical ganglion" for the one that was related to inferior thyroid artery  and "vertebral ganglion" for the one that was related to vertebral artery.
This was said to be the vertebral ganglion. Also, VG (50%) was found more often as the sole central mass than MCG (22%).
While MCG was seen in relation to the ITA, this fourth ganglion was closely associated with the root of vertebral artery in 100% cases and to be concluded as the vertebral ganglion. Vertebral nerve was seen arising from VG in 5.6% cases.