The intermediate nerve, nervus intermedius, nerve of Wrisberg or glossopalatine nerve[1][2][3] is the part of the facial nerve (cranial nerve VII) located between the motor component of the facial nerve and the vestibulocochlear nerve (cranial nerve VIII). It contains the sensory and parasympathetic fibers of the facial nerve. Upon reaching the facial canal, it joins with the motor root of the facial nerve at the geniculate ganglion. Alex Alfieri postulates that the intermediate nerve should be considered as a separate cranial nerve and not a part of the facial nerve.[4]
Parasympathetic fibers
The superior salivatory nucleus contains the cell bodies of parasympathetic axons within the intermediate nerve. These fibers reach the geniculate ganglion but do not synapse. Some of these preganglionic parasympathetic fibers persist within the greater petrosal nerve as they exit the geniculate ganglion and subsequently synapse with neurons in the pterygopalatine ganglion. These postganglionic neurons send axons that provide parasympathetic innervation to the lacrimal gland via a communicating branch from the zygomatic nerve to the lacrimal nerve of cranial nerve V.
The sensory component of the intermediate nerve carries input about sensation from the skin of the external auditory meatus, from the mucous membranes of the nasopharynx and nose, and taste from the anterior two-thirds of the tongue, floor of the mouth, and the soft palate. The sensory information from the mucous membranes of the nasopharynx and palate is carried along the greater petrosal nerve, while the chorda tympani nerve (and lingual nerve) carries taste input from the anterior two-thirds of the tongue, floor of mouth, and soft palate.
The geniculate ganglion contains the cell bodies of the sensory component of the nervus intermedius.
Nervus intermedius neuralgia is a pain syndrome associated with the nervus intermedius.
