OCB03-2007 Flashcards
How do you test C.I?
Strong smelling things (eg coffee) at the nose
What could cause bilateral anosmia?
Trauma
Parkinson’s disease
COVID-19
What is anosmia?
Partial or complete loss of sense of smell
What could cause unilateral anosmia?
Frontal lobe lesion
What is functional anosmia?
Only able to detect odours occasionally
How do you test the cranial nerves associated with the eyes?
Inspection of eyes, eyelids, iris and pupils for any cloudiness
Pupillary reactions
- light reflex with hand separation
- focusing on finger
Visual acuity with standardised Snellen chart and Ishihara test
Visual fields (peripheral vision)
Eye movement (following a finger)
Fundoscopy with ophthalmoscope
What is the Ishihara test used for?
Test for colour blindness/deficiency
What pupillary reactions are normal?
Light with hand separation should result in one pupil constricting
Focusing on a finger should result in equal constriction of both pupils
What is a direct pupillary reaction?
Reaction in the eye you are testing
What is a consensual pupillary reaction?
Reaction in the eye you are not testing
What structures should you see in a fundoscopy?
Optic cup
Optic disc
Fovea
Macula
Arteries and veins
What will you see in a fundoscopy of someone with papilloedema?
Swelling of optic disc
Margins of optic disc are not clear (blurred)
What is papilloedema often seen with?
Brain tumours
What will you see in a fundoscopy of someone with optic atrophy?
Paler and larger optic disc
How do you test eye movement?
Ask patient to follow finger with their eyes
Do not move head
Which cranial nerve controls eyelid elevation and what muscle is involved?
Oculomotor nerve (C.III)
Levator palpebrae superioris
What will you see in a patient with an oculomotor nerve palsy?
Pupil dilation in affected eye
Affected eye will look down and laterally at rest
What will you see in a patient with a trochlear nerve palsy?
Affected eye will look up and medially at rest
What will you see in a patient with an abducens nerve palsy?
Affected eye will not be able to look to the same side/laterally (abduct)
What is abducens nerve palsy often associated with?
Brain tumours
Increased intracranial pressure
What are the two rules of double vision?
Double vision is maximal in the direction of gaze of the affected muscle
The false image is the outer image that arises in the affected eye
What may cause single palsies of the cranial nerves controlling eye movement?
Medical = diabetes, atherosclerosis
Surgical = Tumour, aneurysm, trauma
What causes a single cranial nerve pathology?
Supranuclear lesion (CNS) or peripheral lesion
What causes multiple cranial nerve pathology?
CNS lesion of systemic diseases
Describe external ophthalmoplegia.
Paralysis of multiple extraocular muscles
Common with myopathic or mitochondrial conditions
Not due to single nerve lesions
How do you test the sensory aspect of C.V?
Touch face lightly with cotton for each branch of trigeminal (forehead, cheek, chin)
Unconscious corneal reflex with cotton on the cornea
How do you test the motor aspect of C.V?
Patient tries to push jaw against clinician’s fingers to assess strength
Palpation to assess bulk
Describe Frey’s syndrome.
Affects auriculotemporal branch of C.V near parotid
May be due to trauma or parotid surgery
Sweating and redness around nerve when patient smells/tastes certain chemicals
What are some common causes of inferior alveolar nerve damage?
Implants
Root treatment
Wisdom tooth surgery
What is loss of sensation of half the face often associated with?
Herpes infection
How do you test C.VII?
Scrunch eyes closed
Wrinkle forehead
Blow out cheeks
Smile
Unconscious corneal reflex with cotton on cornea
Why do we do the corneal reflex when the patient is unconscious? What does this test?
Very uncomfortable if awake
C.V and C.VII
What is Bell’s palsy?
Unilateral lower motor neuron lesion of facial nerve
Which part of the face is often spared with an upper motor neuron lesion of the facial nerve? Why?
Forehead
Both hemispheres contribute to muscles in this area, allowing for compensation
What is a common cause of unilateral upper motor neuron lesions of the facial nerve?
Cerebrovascular accidents
What are the two auditory assessments and which nerve do they test?
Rinne’s test
Weber’s test
Cochlear branch of vestibulocochlear nerve (C.VIII)
Describe the Rinne’s test.
Tests for conductive hearing
512Hz tuning fork vibrated both near the ear and on the mastoid process
Normally, hearing will be better near the ear/via air than on mastoid process
Describe Weber’s test.
Tests for sensineural hearing loss
256Hz tuning fork vibrated on centre of top of head
Normally, sound will be heard equally in both ears
How do you test the vestibular division of C.VIII?
Observe gait
Hallpike manouevre for nystagmus
What is the Hallpike manouevre?
Rapidly moving from sitting to supine position with head turned 45º to one side then returning to sitting after 20-30s
Repeat for the other side
Observe for nystagmus
Which cranial nerve tests involve the mouth and tongue?
Asking about taste
Listening to voice
Visual inspection of surfaces and uvula
Gag reflex
Tongue movement and appearance
What observations may indicated pathology of tongue?
Small tongue with:
- fasciculations = bilateral LMN lesion
- reduced movement = bilateral UMN lesion
Unilateral tongue deviation with:
- wasting = LMN lesion
- normal bulk = UMN lesion
How do you test C.XI?
Turn head to each side and check SCM size (equal or unequal)
Ask patient to try to turn head against resistance/clinician’s hand
Check trapezius size on each side
Ask patient to shrug against resistance from clinician’s hands
What may a bilateral accessory lower motor nerve lesion actually be the result of?
Myopathy
What cranial nerves will a cerebellopontine angle lesion affect?
Trigeminal nerve (C.V)
Facial nerve (C.VII)
Vestibulocochlear nerve (C.VIII)
(Unilateral)
What cranial nerves will a cavernous sinus lesion affect?
Oculomotor (C.III)
Trochlear nerve (C.IV)
Ophthalmic division of trigeminal nerve (V1)
Abducens nerve (C.VI)
(Unilateral)
Describe Horner syndrome.
Damage to sympathetic trunk, congenital or acquired
Ptosis/bletharoptosis (drooping of upper eyelid)
Anhidrosis (inability to sweat normally)
Miosis (excessive pupil constriction)
Enophthalmos (posterior displacement of eyeball in orbit, bony changes)
May be caused by CNS stroke or demyelination or PNS trauma, carotid dissection, aortic aneurysm, tumour
Describe myotonic dystrophy.
Most common muscular dystrophy in adults (1/8000) and subject to anticipation
Possible anaesthetic complications
Facial involvement:
- forehead muscle wasting
- bilateral eyelid drooping
- malocclusion
- muscle weakness causes general tired appearance
Describe myasthenia gravis.
Treatable, generalised neuromuscular acquired weakness due to AChR antibodies
Facial involvement:
- droopy eyelids
- unusual eye movements
