cranial nerves Flashcards
(27 cards)
what are the names of the cranial nerves ?
CN 1 - olfactory nerve
CN 2 - optic nerve
CN 3 - occulomotor nerve
CN 4 - trochlear nerve
CN 5 - trigeminal nerve
CN 6 - Abducens
CN 7 - Facial
CN 8 - vestibulocochlear
CN 9 - glossopharyngeal
CN 10 - vagus
CN 11 - accessory nerve
CN 12- hypoglossal nerve
what is the exit point of each cranial nerve ?
olfactory - cribriform plate
optic - optic canal
occulomotor - superior orbital fissure
trochlear - superior orbital fissure
trigeminal opthalmic - superior orbital fissure
trigeminal maxillary - foramen rotundum
trigeminal mandibular - foramen ovale
abducens - superior orbital fissure
facial - auditory canal
vestibulocochlear - jugular foramen
glossopharyngeal - jugular foramen
vagus - jugular foramen
accessory - jugular foramen
hypoglossal - hypoglasssal canal
what are the muscles innervated by the occulomotor nerve ?
everything but the lateral rectus and the superior oblique
what does CN 3 palsy look like ?
eye down, out and pupil dilated , ptosis
what muscles are innervated by the trochlear nerve ?
superior oblique muscles
what are the palsy symptoms associated with trochlear nerve ?
diplopia
head tilting away from affected side
eye tilted outwards
what are the divisison of the trigeminal nerve and what is its main function ?
main function is sensation to the face
divided to V1, V2 and V3
V1 - opthalmic
V2- maxillary
V3- mandibular
what are the other important features associated with the trigeminal nerve ?
part of the corneal reflex
associated withthe muscles of mastication
what is the treatment and presentation of trigeminal neuralgia ?
affection of the trigeminal nerve usually associated pain behind the eye , painful with non painful stimulus like the wind
goes away on its own but for prophylaxis use carbamezapine
what are the cranial nerves involved with the corneal reflex ?
touch the eye with a q tip
sensed by V1 of the trigeminal nerve
blinking is caused by cranial nerve 7
what muscles of the eye are innervated by the abducens ?
lateral rectus
what does palsy of the abducens nerve look like ?
diplopia
cant laterally move the affected eye
what are the different facial nerve affection ?
UMN lesion - the lower half is affected but the forehead is fine - seen in stroke
LMN lesion - half of the face is affected as the nerve itself is affected - seen in bells palsy
what does facial nerve plasy present with ?
loss of corneal reflex
loss of taste in the anterior 2/3 of the tongue
hyperacusis
what is the most common pathology associated with bell’s palsy ?
associated with HSV-1 nerve induced damage
how is testing of cranial nerve 8 done ?
1- doll’s eye test
head rotated from side to side wih eyelids are open
positive - eyes dont turn , CN 8 is working
negative - eyes move with the head, CN 8 lesion
2- inject cold water
eyes moves slowly towards the cold water side , followed by rapid correction to the opposite side
if there is a lesion - no fast away
opposite is seen with warm water
what is the function of CN 9 ?
taste sensation in the posterior 1/3 of the tongue
carotid body and sinus
stylopharyngeaus
what does a CN 9 palsy look like ?
loss of gag reflex
loss of taste in the posterior 1/3 of the tongue
loss of sensation upper pharynx/tonsils
what CN is dysphagia associated with ?
vagus nerve CN 10
what does Kuh kuh kuh test ?
CN 10
raise the palate
what does mi mi mi test ?
CN 7
move the lips
what does la la la test ?
CN 12
move the tongue
what are the pathologies associated with compression of the recurrent laryngeal nerve ?
dilated left atrium
aortic dissection
where does the recurrent laryngeal nerve wrap around ?
loops around the R subclav
left RL : loops around aortic arch
