The trigeminal nerve (TGN) is the largest cranial nerve and can be involved in multiple inflammatory, compressive, ischemic, or other pathologies.
see Trigeminal neuralgia.
Postherpetic neuralgia in 20% of cases involves the trigeminal nerve (with a predilection for the ophthalmic division, called herpes zoster ophthalmicus).
Lesions in the cavernous sinus involve cranial nerves III, IV, VI, and V1 & V2 (ophthalmic and maxillary divisions of the trigeminal nerve), and spare II and V3.
Superior orbital fissure syndrome: dysfunction of nerves III, IV, VI and V1.
Orbital apex syndrome: involves II, III, IV, VI and partial V1.
In Sturge-Weber syndrome: Ipsilateral port-wine facial nevus (nevus flammeus) usually in the distribution of 1st division of trigeminal nerve (forehead and/or eyelid) (rarely bilateral): not always present, alternatively sometimes in V2 or V3 regions 1).
Postoperative trigeminal nerve symptoms occur transiently in 22% and permanently in 11% following microsurgery, similar to the results of SRS 2).
Basilar impression: trigeminal nerve anesthesia.
In vestibular schwannoma or cerebellopontine angle meningioma, trigeminal nerve involvement may occur with tumors > 3 cm (check corneal reflex), with tic douloureux-like symptoms being unusual.