Neuro cranial nerves Flashcards
(53 cards)
Olfactory nerve function
smell
parkinsons, kallman
optic n function
vision
oculomotor nerve innervates…? what is their function
medial rectus, inferior rectus, superior rectus, inferior oblique > MOST EYE MOVEMENTS
palpebral muscles > HOLDS EYELIDS OPEN
ciliary muscles > PUPIL CONSTRICTION and ACCOMODATION
palsy: down and out eye, ptosis, dilated, fixed pupil
trochlear nerve innervates…? what is function
SO4: superor oblique - down and out eye movement
PALSY = VERICAL DIPLOPIA
trigeminal nerve innervates…? what is function
sensation: forehead (opthalmic), cheeks (maxillary), jaw (mandibular), corneal reflex
motor: muscles of mastication = temporalis and masseter
abducens nerve innervates…? what is function
LR6: lateral rectus –> abduction
Palsy results in defective abduction → horizontal diplopia
facial nerve innervates…? what is function
- motor: muscles for facial movement, stapedius (damage leads to HYPERACUSIS)
- sensory: taste to anterior 2/3 of tongue, salivation/lacrimation
- flaccid paralysis of upper + lower face
- loss
Lesions may result in:
vestibulocochlear nerve innervates…? what is function
balance
hearng
glossopharyngeal nerve innervates…? what is function
poost 1/3 of tongue (taste+ sensation)
AND gag reflex
vagus nerve innervates…? what is function
sensation and motor to pharynx and laynx
include swallowing and speech
accessory nerve innervates…? what is function
SCM, trapezius
hypoglossal nerve innervates…? what is function
tongue muscles > tongue movement
what dermatome are the nipples
T4
what dermatome is the umbilicus
T10
CNIII palsy presentation
DOWN and OUT
ptosis (drooping eyelid –> unable to open eye)
fixed dilated pupil (if PNS fibres also affected)
causes of CN3 palsy
stroke (posterior cerebral artery)
MS
basal skull fracture
What are causes of ptosis
Unilateral:
- Horner’s
- CN3 palsy
Bilateral:
- Myasthenia gravis
- Myotonic dystrophy
- congenital absence of muscles
Either: infection, inflammation, tumour
What is Horner’s syndrome, and what general pathophysiology is it caused by
CAUSED BY DAMAGE to SYMPATHETIC TRYNK
TRIAD OF:
- miosis (constricted pupil)
- ptosis
- facial anhydrosis
what can cause Horner’s syndrome
Vascular (carotid dissection, brainstem stroke)
Infection (pneumonia of lung apex)
Neoplasm (incl Pancoast tumour)
Idiopathic
Causes of Ptosis
nerve: (unilateral) CN3 palsy, Horner’s
NMJ: MG (bilateral)
muscle: myotonic dystrophy
How does pupil size vary between CN3 palsy and Horner’s
CN3: dilated
Horner’s: constricted
What is pupil like in MG
normal
how does CN4 palsy present
unable to turn eye down and out + diplopia
How does C5 palsy present
Loss of sensation to face (location depends on whether it is V1,2,3)
Absent corneal reflex (V1)
Muscle of mastication weakness (V3)