CN Nuclei: Function, Location, Lesion

Oculomotor nucleus

CN III (Oculomotor), rostral midbrain, ipsilateral eye movement (SR, IR, MR, IO, levator palpebrae), lesion: ipsilateral down-and-out eye/ptosis, blood supply: PCA/basilar branches

Edinger-Westphal nucleus

CN III (Oculomotor), rostral midbrain, ipsilateral parasympathetic pupil constriction/accommodation, lesion: ipsilateral dilated pupil, blood supply: PCA

Trochlear nucleus

CN IV (Trochlear), caudal midbrain, ipsilateral superior oblique muscle (depresses/adducts eye), lesion: vertical diplopia/difficulty looking down stairs, blood supply: PCA/SCA branches

Principal trigeminal nucleus

CN V (Trigeminal), mid pons, ipsilateral fine touch/vibration sensation of face, lesion: ipsilateral facial sensory loss, blood supply: basilar artery branches

Motor trigeminal nucleus

CN V (Trigeminal), mid pons, ipsilateral mastication muscles, lesion: weak chewing/jaw deviates toward lesion, blood supply: basilar artery branches

Abducens nucleus

CN VI (Abducens), caudal pons, ipsilateral lateral rectus muscle (eye abduction), lesion: inability to abduct ipsilateral eye/medial strabismus, blood supply: basilar artery branches

Facial nucleus: function, location, lesion: differentiate symptoms between UMN and LMN

CN VII (Facial), caudal pons, ipsilateral muscles of facial expression, lesion: ipsilateral facial paralysis/Bell palsy, (if UMN lesion, forehead spared; if LMN then whole ipsilateral face) blood supply: AICA

Superior salivatory nucleus

CN VII (Facial), rostral pons, ipsilateral lacrimation + salivation, lesion: dry eye/dry mouth, blood supply: basilar artery branches

Vestibular nuclei

CN VIII (Vestibulocochlear), caudal pons/rostral medulla, balance/equilibrium/head position, lesion: vertigo/nystagmus/imbalance, blood supply: AICA/PICA

Cochlear nuclei

CN VIII (Vestibulocochlear), caudal pons/rostral medulla, auditory processing/hearing, lesion: ipsilateral sensorineural hearing loss/tinnitus, blood supply: AICA

Nucleus ambiguus

CN IX/X (Glossopharyngeal/Vagus), rostral medulla, ipsilateral swallowing/pharynx/larynx motor control, lesion: dysphagia/hoarseness/decreased gag reflex, blood supply: PICA

Solitary nucleus

CN VII/IX/X (Facial/Glossopharyngeal/Vagus), medulla, taste + visceral sensory information, lesion: taste loss/autonomic dysfunction, blood supply: PICA

Dorsal motor nucleus of vagus

CN X (Vagus), medulla, parasympathetic visceral control (heart/lungs/GI), lesion: autonomic dysfunction, blood supply: PICA

Hypoglossal nucleus

CN XII (Hypoglossal), medulla, ipsilateral tongue movement, lesion: tongue deviates toward lesion, blood supply: ASA

Mesencephalic trigeminal nucleus

CN V (Trigeminal), midbrain, jaw proprioception/jaw jerk reflex, lesion: impaired jaw proprioception/reflex, blood supply: PCA/SCA branches