Cranial Nerves Flashcards
Name the cranial nerves in order.
Olfactory Optic Occulomotor Trochlear Trigeminal Abducens Facial Vestibulocochlear Glossopharyngeal Vagus Spinal Accessory Hypoglossal
Where does the olfactory nerve arise and leave the cranial cavity?
Cerebrum
Cribiform plate.
Where does the optic nerve arise and leave the cranial cavity?
Cerebrum
Optic canal.
Where does the occulomotor nerve arise and leave the cranial cavity?
Midbrain-pontine junction
Superior orbital fissure.
Where does the trochlear nerve arise and leave the cranial cavity?
Midbrain
Superior orbital fissure.
Where does the trigeminal nerve arise and leave the cranial cavity?
Pons
Ophthalamic V1 - Superior Orbital Fissure
Maxillary V2 - Foramen Rotundum
Mandibular V3 - Foramen Ovale
Where does the abducens nerve arise and leave the cranial cavity?
Pontine-medullary junction
Superior orbital fissure.
Where does the facial nerve arise and leave the cranial cavity?
Pontine-medullary junction
Internal acoustic meatus.
Where does the vestibulococchlear nerve arise and leave the cranial cavity?
Pontine-medullary junction
Internal acoustic meatus.
Where does the glossopharyngeal nerve arise and leave the cranial cavity?
Medulla posterior to the olive
Jugular foramen.
Where does the vagus nerve arise and leave the cranial cavity?
Medulla posterior to the olive
Jugular foramen.
Where does the spinal accessory nerve arise and leave the cranial cavity?
Medulla oblongata posterior to the olive
Jugular foramen.
Where does the hypoglossal nerve arise and leave the cranial cavity?
Medulla anterior to the olive
Hypoglossal canal.
How do you test the olfactory nerve?
Ask patient to sniff something familiar e.g. coffee or toothpaste. Ensure it isnt an irritant (as this stimulates V1 also). Check each nostril.
How do you test the optic nerve?
Test visual fields by asking patient to look at you whilst wiggling finger in 4 quadrants.
Check pupillary reflex.
How do you test the occulomotor, trochlear and abducens nerve?
Draw a H shape.
Vertical - superior/inferior rectus and superior and inferior oblique muscles.
Horizontal - medial and lateral rectus muscles.
How do you test the trigeminal nerve?
Sensory: Close eyes and toch the 3 areas innervated by branches of V - forehead, cheeks and chin.
Motor: Ask patient to clench jaw and palpate masseter and temporalis. Check pterygoids by opening mouth against resistance. Jaw should not deviate.
How do you test the facial nerve?
Ask patient to perform movements.
e.g. show teeth, raise eyebrows, keep eyes closed against resistance, puff cheeks against resistance, purse lips.
How do you test the vestibulococchlear nerve?
Rinnes test: Tuning fork against mastoid process and once it stops vibrating next to the external ear and ask if they can still hear it.
Webers test: Tuning fork is placed in centre of forehead and ask which ear it is louder in. Should be the same.
Neural deafness heard louder in the intact ear.
Conductive heard louder in the affected ear.
Turning test for vestibular: Ask patient to march on spot with arms outstretched and eyes closed. If lesion, patient will turn towards the side the lesion is on.
How do you test the glossopharyngeal nerve?
Check gag reflex.
Ensure no dysphagia.
Ask them to cough and swallow.
How do you test the vagus nerve?
Ask patient to speak to assess larynx/pharynx muscles.
Check uvula is central when patient says ahhhhh…
How do you test the spinal accessory nerve?
Check trapezius and SCM.
Should be able to shrug shoulders and turn the head against resistance.
How do you test the hypoglossal nerve?
Stick out tongue and move it side to side. Check muscles of the tongue are symmetrical.
