Cranial Nerves

Question 1

CN I

Discharge of CSF from the nose (rhinorrhea) in fractures of cribriform plate & dural tear

Answer 1

Cribriform plate

Question 2

Middle cranial fossa

Answer 2

Optic canal (CN II)

Superior orbital fissure (CN III, IV, V1, VI)

Foramen rotundum (CN V2)

Foramen ovale (CN V3, lesser petrosal nerve)

Foramen spinosum (Middle meningeal artery) 
- epidural hemorrhage

Foramen lacerum (empty)

Question 3

Posterior cranial fossa

Answer 3

Internal acoustic meatus (CN VII, VIII)

Jugular foramen (CN IX, X, XI, sigmoid sinus- a mass in jugular foramen ➡️ dysphagia, dysarthria, paralysis of uvula, inability to shrug shoulders)

Hypoglossal canal (CN XII)

Foramen magnum (medulla of brain stem, CN XI, vertebral arteries)

Question 4

Discharge of CSF from external acoustic meatus (otorrhea) in fracture of mastoid process and dural tear

Answer 4

Internal acoustic meatus

Question 5

Anterior cranial fossa

Answer 5

Cribriform plate