Cranial nerves Flashcards
1st cranial nerve
olfactory
2nd cranial nerve
optic
3rd cranial nerve
oculomotor
4th cranial nerve
trochlear
5th cranial nerve
trigeminal
6th cranial nerve
abducens
7th cranial nerve
facial
8th cranial nerve
vestibulocochlear
9th cranial nerve
glossopharyngeal
10th cranial nerve
vagus
11th cranial nerve
spinal accessory
12th cranial nerve
hypoglossal
What is the pneumonic to remember the order of the cranial nerves
Oh OH Oh to touch and feel virgin girls vaginas and hymen
what is the pneumonic to remember the modalities of the cranial nerves
some say money matters more but my brother says big boobs matter more
What is the pneumonic that helps remember where each cranial nerves exits the skull - and what is the only exception in the list
come on spicy(4) rabbits only inside(2) juicy(3) hipsters
SIJ 423
abducens out of order in spicy to go through the superior orbits fissure
what is the function of the olfactory nerve
smell
what is the function of the optic nerve
vision and pupil reflex
what is the function of the oculomotor nerve
motor movement of the eye controls the muscles MR,IR,SR,IO- upper eyelid
what is the function of the trochlear nerve
controls the superior oblique muscle of the eye - look to the nose
The trigeminal nerve is split into 3 nerves what are they
Ophthalmic
maxillary
mandibular
The ophthalmic nerve in a sensory nerve what does it innervate
scalp, forehead and nose
The ophthalmic nerve has 3 divisions, what are they?
frontal
lacrimal
nasocillary
The maxillary nerve is a sensory nerve what does it innervate
cheeks, lower eyelid , nasal mucosa, upper lip, upper teeth and palate
The mandibular nerve is both sensory and motor what is it functions
anterior 2/3 toungue, skin over mandible and lower teeth
motor to muscles of mastication
What nerve controls the muscles of mastications
The mandibular nerve - the trigeminal C nerve
what is the function of the motor nerve abducens nerve
lateral rectus
Function of the facial nerve
sensory
motor
facial - anterior
sensory to taste to anterior 2/3 of tongue
motor to facial muscles, lachrymal gland, sublingual and submandibular - salivating and tasting at the chorda tympani
function of the vestibulocochlear nerve
hearing and balance
glossopharyngeal nerve function
sensory
motor
autonomic
glosso- posterior
sensory to posterior third of tongue, pharynx and middle ear
motor to palate
autonomic to salivary glands
the glossopharyngeal nerve as an autonomic function what is this
salivary glands
the vagus nerve function is what
sensory
motor
sensory to tympanic membrane - ear
motor to palate and larynx and pharynx
what cranial nerve is motor to sternoclaidomastoid muscle and trapezius and can shrug the shoulders
spinal accessory
what cranial nerve is motor to intrinsic and extrinsic tongue muscles expect the palatoglossus
Hypoglossal nerve
How do you test, and what injury can be caused by injury the olfactory nerve
change in sense of smell
unilateral or bilateral anosmia
what is anosmia
smell blindness
where does the olfactory nerve exit
cribriform plate
where does the optic nerve exit
optic canal
How do you test, and what injury can be caused by injury the optic nerve
snellen chart
ipsilateral blindness _ ( retinal or optic lesson)
pituitary tumour creating tunnel Vision
what 4 nerves exit through the superior orbital fissure
oculomotor, trochlear and ophthalmic(TRIGa) and abducens
how do you test for the oculomotor nerve
H movement with eyes
injury to oculomotor nerve causes what
ptosis, double vision(diplopia) , divergent squint and pupil dilated
down and out
how to test for trochlea nerve
eyes to nose
injury to trochlear nerve symptoms
nstagmus ( involuntary eye movement)
diplopia - 2 images
how to test for the trigeminal nerves
corneal light reflex - light looking for symmetry - VII
clench jaw and open against my hand
injuries to the trigeminal nerve
ipsilateral anesthsia
paralysis of ipsilateral muscles of mastication
carcinoma of tongue on the lingual nerve causes severe earache
through what hole does the maxillary nerve exit
Foramen rotundamente
through what hole does the mandibular nerve exit
foramen ovale
how to test for abducens nerve
lateral rectus muscle so follow penlight to 4 quadrants
injuries to abducens - same as trochlear
nystagmus
diplopia
convergence of vision
how to test the facial nerve
raising eyebrows - temporal scrunching eyes- zygomatic blow cheeks - buccal show teeth - mandbiualr resist these motions nd assess power
Injury to the facial nerve
Ramsay hunt syndrome
Not really a neuro condition but kind of is because varicella zoster dominant in peripheral nerve endings
altered taste perception and saliva and tear production
what two nerves go through the internal acoustic meatus
facial
vestibulocochlear
How to test for the vestibulocochlear nerve
obscure ear canal and eyes and wisper and ask to repeat
injuries to vestibulochochlear nerve present as
hearing loss
vertigo
false sense of motion
The test for the gag reflex( vagus as well) and asking to cough and swallow and say ahhhh looking for uvula deviation is a test for what nerve
glossopharangeal
Accessing the patients voice quality but also doing ahhhhh and gag reflex what nerve is tested here
vagus
loss of taste sensation to posterior 1/3 of tongue and loss of saliva is injury to what nerve
glossopharangeal
a patient presents with stridor( noisy breathing) ,and aphonia ( difficulty speaking) what nerve is like to be injured
vagus
What three nerves go through the jugular foramen
Glossopharyngeal
vagus
spinal accessory
How to test for the spinal accessory nerve
ask person to shrug shoulders and turn face against hands
Winged scapula can be caused by injury and weakness of the trapezius muscles supplied by which cranial nerve
spinal accessory
Atrophy of the tongue on ipsilateral side , paralysis and wasting and deviation when pushed is associated with which nerve
Hypoglossal
sticking the tongue out and checking for abnormalities and then also pushing against the mouth to test resistance are test for what cranial nerve
Hypoglossal
what injury could be mistaken for hypoglossal nerve injury
UMN lesion in corticobulbar palsy - bilateral paralysis with no wasting
oculomotor nerve palsy describe
Key sign is that when light is shone in the affected eye, the pupil on the other side will constrict but the affected eye will not. This proves the optic nerve is not affected as the light is registered by the brain, but the affected eye doesn’t have the innervation to constrict the pupil
what is Ramsay hunt syndrome? what are the symptoms of this
herpes zoster , shingles of facial nerve
rash on one ear
paralysis of ipsilateral side
hearing loss on one side
afferent and efferent branches of the Corneal reflex
Afferent: Opthalmic branch of the Trigeminal (V1)
Efferent: Facial nerve (VII)
When the cornea is stimulated both eyes should close.
If both eyes do not close it suggests a V1 lesion on the tested side. If one side does not contract it suggests a VII lesion on the tested side.
neural pathway responsible for pupillary light reflex
Afferent pathway: Optic (II) nerve.
Efferent pathway: Parasympathetic component of the Oculomotor nerve (III) bilaterally (responsible for a consensual reflex)
Loop
Light stimulates optic nerve which synapses to the Pretectal nucleus situated in the brainstem.
Pretectal area on one side innervates Edinger-Westphal nuclei (parasympathetic pre-ganglionic nuclei of the Oculomotor nerve) bilaterally.
Edinger-Westphal nuclei then sends axons to the ciliary body on unilaterally via the parasympathetic branch of the oculomotor nerve resulting in constriction of pupils.
what causes bitemporal hemianopia
Suggests a lesion at the Optic chiasm
Pituitary tumours compress optic chiasm from below à affect the upper visual fields first and progress further down.
Look for signs of pituitary disease i.e. Cushings / Acromegaly / Hypopituitarism / Gynaecomastia.
Craniopharyngeal tumours compress optic chiasm from above à affect the lower visual fields first and progress upwards.
Differentials of causes of bitemporal hemianopia include:
Pituitary adenoma
Sarcoidosis/Tuberculosis
Metastatic disease
Internal carotid artery aneurysm
what are the clinical signs of complete unilateral oculomotor nerve palsy
Ptosis (levator palpebrae dysfunction)
Affected eye deviated to a “down and out position” (unopposed lateral rectus and superior oblique)
Diplopia
Patients don’t usually complain of diplopia due to ptosis but worst when looking up and out
Fixed, dilated pupil (parasympathetic nerve fibres from ciliary ganglion affected)
IIIrd nerve palsy Down and out eye + fixed dilated pupil Horner’s syndrome Ptosis + anhidrosis + miosis Myaesthenia Gravis Bilateral facial weakness + proximal weakness with fatiguability + weak voice Congenital
these cause what
unilateral pitosis
causes of 3rd nerve palsy
Compression from a posterior communicating artery aneurysm
Vascular occlusion (atheroma/diabetes)
Midbrain infarct / tumour
Temporal lobe coning
what is Horner syndrome
Disruption of the sympathetic nervous supply to the face resulting in:
Ptosis: unilateral partial drooping of eyelid
Miosis: unilaterally constricted pupil
Anhidrosis: unilateral loss of sweating
Normal light and accommodation reflexes/eye movements
what other cerebellar signs can you look for other than nystagmus
D = Dysdiadokinesis (impaired rapid alternating movements) + dysmetria (past-pointing when at full stretch) A = Ataxia N = Nystagmus (fast component is towards the side of the lesion) I = Intention tremor (gets worse as finger approaches the target) S = Slurred speech H = Hypotonia
which way does the toungue deviate in a XII lesion
The tongue deviates towards the side of the lesion
In a CN10 lesion which way does the uvula deviate
Uvula is deviated away from the side of the lesion
afferent and efferent pathways of the gag reflex
Afferent: Glossopharyngeal (IX)
Efferent: Vagus (X)
