Brainstem Cross Sections: Midbrain, Pons, Medulla

Pons rostral

Function of following CN nuclei and where they belong:

1. Facial nucleus

2. Hypoglossal nucleus

3. Principal trigeminal nucleus

4. Edinger-Westphal nucleus

5. Nucleus ambiguus

6. Abducens nucleus

7. Solitary nucleus

8. Oculomotor nucleus

9. Motor trigeminal nucleus

10. Vestibular nuclei

11. Trochlear nucleus

12. Cochlear nuclei

13. Mesencephalic trigeminal nucleus

14. Dorsal motor nucleus of vagus

15. Superior salivatory nucleus

• Facial nucleus: caudal pons, facial expression, lesion: ipsilateral facial paralysis

• Hypoglossal nucleus: medulla, tongue movement, lesion: tongue deviates toward lesion

• Principal trigeminal nucleus: pons, face touch sensation, lesion: ipsilateral facial sensory loss

• Edinger-Westphal nucleus: midbrain, parasympathetic pupil constriction, lesion: dilated pupil

• Nucleus ambiguus: medulla, swallowing, lesion: dysphagia/hoarseness

• Abducens nucleus: caudal pons, eye abduction, lesion: cannot abduct eye

• Solitary nucleus: medulla, taste/visceral sensory, lesion: taste loss

• Oculomotor nucleus: midbrain, eye movement, lesion: down-and-out eye/ptosis

• Motor trigeminal nucleus: pons, mastication, lesion: weak chewing

• Vestibular nuclei: pons-medulla, balance, lesion: vertigo/nystagmus

• Trochlear nucleus: caudal midbrain, superior oblique, lesion: vertical diplopia

• Cochlear nuclei: pons-medulla, hearing, lesion: hearing loss

• Mesencephalic trigeminal nucleus: midbrain, jaw proprioception, lesion: impaired jaw reflex

• Dorsal motor nucleus of vagus: medulla, parasympathetic visceral control, lesion: autonomic dysfunction

• Superior salivatory nucleus: pons, lacrimation/salivation, lesion: dry eyes/mouth