Cranial Nerves & Neuro-ophtho

Question 1

What nerves/vessels pass through these foramina?
1. Cribriform plate
2. Optic Canal
3. Superior orbital fissure
4. Foramen Rotundum
5. Foramen Ovale
6. Foramen Spinosum
7. Foramen lacerum
8. Internal acoustic meatus
9. Stylomastoid
10. Jugular Foramen
11. Hypoglossal Canal
12. Foramen Magnum

Answer 1

1. Cribriform plate
   - olfactory n.
2. Optic Canal
   - Optic n.
3. Superior orbital fissure
   - Oculomotor n.
   - Trochlear n.
   - Trigeminal V1
   - Abducens n.
4. Foramen Rotundum
   - V2
5. Foramen Ovale
   - V3
6. Foramen Spinosum
   - Middle meningeal artery
7. Foramen lacerum
   - ICA
8. Internal acoustic meatus
   - Facial n.
   - Vestibulocochlear n.
9. Stylomastoid
   - Facial n.
10. Jugular Foramen
    - Glossopharyngeal n.
    - Vagus n.
    - Accessory n.
    Jugular vein
11. Hypoglossal Canal
    - Hypoglossal n.
12. Foramen Magnum
    - spinal cord
    - vertebral arteries

Question 2

Central Nystagmus Features

Answer 2

• non-fatiguing
• not suppressed by visual fixation
• no latency
• > 1 min duration
• any direction, most likely in vertical/torsional

Question 3

Nucleus Ambiguus

Answer 3

Motor nuclei to pharynx and larynx vis CN IX and X

Question 4

Nucleus Tractus Solitarius

Answer 4

Rostral portion = Taste from anterior 2/3 of tongue (Facial), posterior 1/3 of tongue (glossopharyngeal), and palate/pharynx/larynx (Vagus)

Caudal portion = Baroreceptor reflex (Afferent from carotid sinus via glossopharyngeal, efferent to dorsal n. of vagus nerve and then to heart)

Question 5

Dorsal motor nucleus of vagus nerve

Answer 5

parasympathetic output to chest, thorax, and GI tract

Question 6

Superior Salivary nucleus

Inferior Salivary nucleus

Answer 6

SSN - Parasympathetic innervation of head and neck

ISN - Parasympathetics for parotid vis hypoglossal n.

Question 7

Order of Facial N. branches

Answer 7

Starts as nervus intermedius (sensory afferents, parasympathetic efferents from SSN) and motor efferents from CN7 n. that come together after emerging from medullopontine angle
1. Greater petrosal n. = Facial parasympathetics to oral and nasal mucosa, lacrimal glands
2. Stapedius
3. Chorda tympani = anterior taste + parasympathetics for sumandibular/sublingual
4. face muscles

Question 8

Cause, symptoms?

Adie’s Tonic Pupil

Argyll Robinson Pupil

Marcus Gunn pupil

Answer 8

Adie’s tonic
- idiopathic, usually unilateral
- Minimal or absent light response
- Starts big but becomes tonically constricted
- Accommodation is very slow

Argyll Robinson
- Neurosyphilis, usually b/l
- Light unreactive
- Accommodation normal

Marcus Gunn = RAPD
- No direct pupil response but consensual response intact