Corticobulbar tract

Last revised by Craig Hacking on 19 Aug 2024

The corticobulbar (or corticonuclear) tract originates primarily in Brodmann area 4 and exits at the brainstem to synapse on the lower motor neurons of the cranial nerves bilaterally. The exception to this bilateral connection is the facial nerve and hypoglossal nerve. Innervation to the lower half of the face (via the facial nerve) and the tongue (via the hypoglossal nerve) is only contralateral.

The corticobulbar fibers pass through the corona radiata and run through the genu of the internal capsule into the brainstem 1

It is involved in the movement of the face, head and neck 2.