This document summarizes key information about the trigeminal nerve including its sensory and motor distribution, lesions, and clinical presentations. It discusses supranuclear, nuclear, and peripheral lesions and their effects. Supranuclear lesions can cause pseudobulbar palsies or unilateral jaw deviation. Nuclear lesions typically involve the trigeminal nuclei and cause ipsilateral facial sensory deficits. Peripheral lesions affect the trigeminal ganglion or branches, potentially causing numbness, pain or motor deficits in the corresponding regions of the face.

1. Adams and Victor’s Principles of Neurology, 8th edition Dr. Deepan Rajamanickam K
Paul W. Brazis Localization in Clinical Neurology, 5th edition
TRIGEMINAL NERVE Trigeminal nucleus
sensory and motor distribution
LESIONS
Supranuclear lesions
B/L UMN (pseudobulbar) Exaggerated jaw jerk, motor paresis
Unilateral Deviation of jaw away from the lesion
Thalamic lesions Anesthesia in contra lateral face
Parietal lesions Depression of corneal reflex alone
Nuclear lesions
(identified by the company they
keep)
Primary or metastatic tumors, AV malformations, demyelinating lesions, infarction , hemorrhage,
syringobulbia (pons, medulla, upper cervical cord)
Motor nucleus(dorsal pontine) Ipsilateral paresis, atrophy and fasiculations of muscles of mastication. Associated with long tract
signs in the region
Spinal nucleus of trigeminal Ipsilateral facial analgesia, hypesthesia and thermoasthesia. Associated with long tract signs in the
area (Eg: Lateral Medullary syndrome-Wallenburg) and midfacial anesthesia.
Mesencephalic nucleus Depression of jaw jerk
Root lesions Tumors, infection, trauma, aneurysms, extension of acoustic neuroma
Pre-ganglionic root lesions Ipsilateral facial pain, paresthesias, numbness and sensory loss, depressed corneal reflex,
masticatory paresis. Associated with VI, VII, VIII cranial nerve palsies
Trigeminal neuralgia(tic
doulourex)
Excruciating lancinating pain in distribution of one or more divisions of the trigeminal nerve.
Due to compression or irritation of the nerve root.
Ganglionic lesions Lesions of the middle cranial fossa, motor paresis may occur.
Peripheral branch lesions Tumors , fracture of facial bones or skull.
Ophthalmic division Sensory loss confined to this branch along its course. Associated with other lesions(III, IV,VI)
Maxillary division Sensory loss in the distribution along its course, numb cheek syndrome, numb cheek-limp lower
lid syndrome, trumpet player’s syndrome.
Mandibular division Sensory loss confined to the nerve distribution. Syndrome of numb chin(Roger’s sign).
Multiple cranial nerve palsy
Foix syndrome Sphenoidal fissure (III, IV, V,V1, VI)
Tolosa-Hunt syndrome Lateral wall of cavernous sinus (III, IV,V, V1, VI)
Jaccoud syndrome` Retrosphenoidal space (II, III, IV, V, VI )
Gradenigo syndrome Apex of petrous bone (V, VI)
Pontocerebellar angle V, VII, VIII, sometimes IX
 It is a mixed cranial nerve
 Sensory component :- (portio major)
 Gasserian ganglion receives sensory impulses from the
face--›reach the pons,divide into short ascending and long
descending fibres--›reach the sensory nuclei:- 3 nuclei
-mecencephalic nucleus
-principal V nerve sensory nucleus
- spinal nucleus of trigeminal nerve
 The short ascending fibres carrying touch and pressure end in
the mesencephalic nucleus.
 The pain and temperature sensations in the long descending
fibres end in the spinal nucleus at various levels. They descend
up to C2-C3 level.
 Finally they cross over and end in the thalamus.
 The sensory part leaves the pons,expands in the Meckel’s
cave,gives rise to three trunks/divisions :-
-ophthalmic division(V1) – sup.
orbital fissure -maxillary division(V2) - foramen
rotuntum -mandibular division(V3) - foramen
ovale.
 Motor component :-(portio minor)
-nucleus: midpontine level.
-supranuclear control: cortico-bulbar fibres from the
lower third of the pre-central gyrus.
-leaves the pons beneath the Gasserian ganglion, joins the
mandibular division of the nerve.