Cranial Nerve Neuro examination Flashcards
general inspection?
list 5/6
speech abnormalities facial asymmetry eyelid abnormalities pupillary abnomalities limbs
speech abnormalities could point to?
glossopharyngeal / vagus nerve
facial asymmetry
facial palsy
eyelid abnormality?
ptosis= oculomotor
pupillary defects?
oculomotor palsy if
Mydriasis refers to the dilation of the pupil, which normally occurs in response to low amounts of light in the environment. In some cases, prolonged mydriasis occurs when an individual’s pupil remains dilated regardless of the amount of light in the environment.
Strabismus?
Strabismus (crossed eyes) is a condition in which the eyes do not line up with one another. In other words, one eye is turned in a direction that is different from the other eye. Under normal conditions, the six muscles that control eye movement work together and point both eyes at the same direction
how to test olafactory?
is it motor/sensory?
sensory
any changes to sense of smell?
causes of anosmia?
mucous blockage head trauma genetics PARKINSONS covid-19
order of optic nerve examination?
optic nerve inspect visual acuity reflexes visual field blind spots fundoscopy
inspect pupils ?
what does peaked pupils suggest?
asymmetry in pupils could be due to what?
assess pupil size/ shape
globe injury
drugs, oculomotor nerve pasly, horners syndrome
large pupil- pupil asymmetry
oculomotor nerve palsy
small and reactive pupil ?
horners syndrome
how can you tell which pupil is the abnormal one?
If the pupil is more pronounced in bright light this would suggest that the larger pupil is the abnormal pupil, smaller pupil is abnormal in the dark
how can you tell which pupil is the abnormal one?
If the pupil is more pronounced in bright light this would suggest that the larger pupil is the abnormal pupil, smaller pupil is abnormal in the dark
horners syndrome?
decreased pupil size, a drooping eyelid and decreased sweating on the affected side of your face
disruption of the pathway of the sympathetic nerves that connect the brain stem to the eyes and face
visual acuity- distance
snellen chart
6 metres
read lowest line
if snellen chart visual acuity is improved by pinhole?
refractive component to the patients poor vision
Recording visual acuity
Visual acuity is recorded as chart distance (numerator) over the number of the lowest line read (denominator).
If the patient reads the 6/6 line but gets 2 letters incorrect, you would record as 6/6 (-2).
If the patient gets more than 2 letters wrong, then the previous line should be recorded as their acuity.
When recording the vision it should state whether this vision was unaided (UA), with glasses or with pinhole (PH).
if someone cannot read snellen chart from 6 then what?
move closer 3m 1m than fingers count - CF then Gross hand movement - HM then light perception? PL / NPL
decreased visual acuity causes?
cataracts / corneal scarring
retinal diseases
optic nerve pathology : optic neuritis
lesions higher in visual pathways
papilloedema first presents with decrease in acuity?
false
optic disc swelling from raised intracranial pressure does not usually affect visual acuity until it is at a late stage
direct pupillary reflex
pupillary restriction in ipsilateral eye
consensual pupillary reflex
what is a normal consensual reflex?
same pupil but now look for pupillary restriction in contralateral eye
contralateral pupil will restrict due to light entering eye being tested
how to test for RAPD
what nerve pathway can cause this?
relative afferent pupillary defect
swinging light test
the contralateral pupil will dilate paradoxically
optic nerve only, its the only one in front of the lateral geniculate body
how many eye reflexs are there?
pupillary reflex: direct / consensual
swinging light test
accommodation reflex
colour vision assessment
ishihara plates - cover one eye
test page : contrast
continue all pages
13/13 if all correct
acquired colour vision?
optic neuritis
vit A deficient
chronic solvent exposure
visual neglect / inattention
deficit in awareness of one side of their visual field
parietal lobe injury after stroke
inability to process or percieve stimuli
side of visual field affected is CONTRALATERAL to location of parietal lesion
NOT CAUSED BY OPTIC NERVE LESION
visual fields defects
bitemporal hemianopia : pituitary adenoma - optic chiasm compression by a tumour = central tunnel vision
homonymous field defects : affect same side of visual field in each eye ; stroke/ tumour / abscess pathology affecting visual pathways posterior to the optic chiasm
3rd nerve palsy
down and out
as LR6 - out
SO4 - down so overpowers the CN 3 and eye is down and out
also ptosis of eyelid as levator palpebrae superioris is innervated by CN III and so no longer can hold eyelid up
Inspect for oculomotor, trochlear and abducens nerves
eyelids - ptosis can be oculomotor nerve palsy , horners syndrome ( symp innervation trunk impacted - pancoast tumour), neuromuscular pathology - myasthenia gravis
actions of extraocular muscles
Actions of the extraocular muscles
Superior rectus: primary action is elevation, secondary actions include adduction and medial rotation of the eyeball.
Inferior rectus: primary action is depression, secondary actions include adduction and lateral rotation of the eyeball.
Medial rectus: adduction of the eyeball.
Lateral rectus (6): abduction of the eyeball.
Superior oblique (4) : depresses, abducts and medially rotates the eyeball.
Inferior oblique: elevates, abducts and laterally rotates the eyeball.
trochlear nerve palsy
vertical diplopia
eye no longer pulled downward as loss of SO muscle action
abducens nerve palsy
innervated lateral rectus muscle would pull pupil out but that action doesnt happen convergent squint horizontal diplopia (double vision)
trigeminal nerve
subdivisions
ophthalmic - v1
maxillary - v2
mandibular - v3 - motor and sensory
muscles of mastication
what are the muscles of mastication?
masseter temporal muscle medial / lateral pterygoids tensor tympani tensory veli palatini mylohyoid and digastric muscles
trigeminal nerve examination
sensory
modality , demonstrate on sternum as that has no sensory deficits in the region overlying the sternum
trigeminal nerve examination
sensory
modality , demonstrate on sternum as that has no sensory deficits in the region overlying the sternum
trigeminal nerve examination
sensory
modality , demonstrate on sternum as that has no sensory deficits in the region overlying the sternum
facial nerve
motor assessment?
sensory and motor
Raised eyebrows: assesses frontalis
Closed eyes: assesses orbicular oculi
Blown out cheeks: assesses orbicularis oris –
Smiling: assesses levator anguli oris and zygomaticus major – “
Pursed lips: assesses orbicularis oris and buccinator – “
facial nerve palsy LMN
weakness of ipsilateral muscles of facial expersion - bells palsy
facial nerve UMN
unilateral facial muscle weakness
unilateral facial weakness but forehead spared due to bilateral cortical representation
stroke
