Cranial nerves and ophthalmology Flashcards
What are the common pathologies which can affect a cranial nerve?
Diabetes mellitus MS Tumours Sarcoid Vasculitis SLE Syphilis
What should you look for on general inspection when performing a cranial nerve exam? (SWIFTLY)
Scars Wasting Involuntary movements Fasciculations, facial drop (asymmetry) Tremor Lids- ptosis, Horner's You- personal aids- glasses, hearing aids, walking stick
What is the medical term for a loss of sense of smell?
Anosmia
What can cause anosmia?
Ageing Traumatic brain injury Parkinson's Alzheimer's Tumour
What should you assess for in the optic nerve?
Acuity Fields Reflexes Ophthalmoscopy Special tests (colour)
Apparently F’ing Remembering OSCE Sucks
How should you assess the Pt’s acuity? What should you ensure?
Using a SNELLEN CHART
Make sure the patient wears their glasses if they normally wear glasses for reading
- position 6m away from chart
- cover one eye
- read from the lowest eye they can
- repeat with other eye
IN THE EXAM: ASK PT TO READ BOTTOM OF ID CARD
What are the causes of a loss of acuity?
REFRACTIVE ERROR (ocular media)
- cataracts
- diabetes
RETINA
- age related macular degeneration
- diabetic retinopathy
OPTIC NEUROPATHY
- MS
- ischaemia
What is conjunctivitis?
Inflammation of the conjunctiva
What are the symptoms of conjunctivitis?
Conjunctival hyperaemia Chemosis (conjunctival swelling) Crust/discharge Foreign body sensation Photophobia
What are the causes of conjunctivitis?
Bacterial
Viral
Allergic
How can you typically differentiate a bacterial conjunctivitis from viral conjunctivitis?
BACTERIAL- unilateral, thick discharge, reduced vision, ?urethritis/vaginal discharge
VIRAL- bilateral, watery discharge, normal vision, signs of viral infection
What is allergic conjunctivitis?
Type 1 hypersensitivity reaction
What are the common triggers of allergic conjunctivitis?
Pollen, dust, chemical scents
What are the clinical features of allergic conjunctivitis?
Conjunctivitis
Itching
Sneezing
Red, watery, oedematous eye
What are cataracts?
Clouding of the lens of the eye
What are the clinical features of cataracts?
Visual impairment
Glare/halos around light
Painless
Reduced red reflex
What are the risk factors for cataracts?
Old age
Congenital
Diabetes
Steroids
What is glaucoma?
Vision loss from optic nerve damage due to raised intraocular pressure
2nd leading cause of blindness
In an acute red painful eye, you need to rule out closed-angle glaucoma
What is affected in open-angle glaucoma?
Dysfunction of trabecular meshwork
What is affected in closed-angle glaucoma?
Compression of trabecular meshwork
What are the differences between open-angle and closed-angle glaucoma?
OA- 90%, bilateral, progressive vision loss, initially asymptomatic, non specific symptoms
CA- 10%, unilateral, sudden onset, severe pain, N+V, cloudy cornea, headache, dilated pupil
What are the investigations for glaucoma?
Fundoscopy
Gonioscope
Slit lamp
Tonometry
What is the uvea made up of?
Choroid
Ciliary body
Iris
What is uveitis?
Inflammation of the uvea
Can be anterior, posterior, complete, and intermediate
What are the causes of uveitis?
Systemic inflammation
Infection
What is affected in anterior uveitis?
Iris
Ciliary body
Most common
What is affected in posterior uveitis?
Vitreous body
Choroid
Retina
What are the investigations for uveitis?
Fundoscopy
slit lamp examination
What visual defect will present in a chiasmal lesion?
Bitemporal hemianopia
What visual defect will present in a pre-chiasmal lesion?
Ipsilateral monocular loss
What are the causes of a pre-chiasmal lesion?
Ischaemia- TIA (amaurosis fugax)
Inflammation- MS
What are the causes of a chiasmal lesion?
Pituitary adenoma
Chraniopharyngioma
A lesion in which part of the optic pathway can cause a contralateral homonymous hemianopia?
Optic tract lesion
A lesion in which part of the optic pathway can cause a contralateral homonymous superior quadrantanopia?
Lateral optic radiation lesion
A lesion in which part of the optic pathway can cause a contralateral homonymous inferior quadrantanopia?
Medial optic radiation lesion
A lesion in which part of the optic pathway can cause a macular sparing contralateral homonymous hemianopia?
Occipital visual cortex lesion
What is the cause of visual neglect?
Damage to the contralateral parietal lobe
What are some causes of Marcus Gunn pupil (RAPD)?
Optic neuritis
Retrobulbar optic neuritis
What is anisocoria?
Unequal size of the pupils
What does Horner’s syndrome consist of?
Ptosis
Miosis
Anhydrosis
What are some causes of Horner’s syndrome?
Loss of sympathetic innervation due to either: Carotid artery dissection Pancoast tumour SOL/stroke MS Cavernous sinus thrombosis
What is the sympathetic pathway that supplies the eye?
Hypothalamus T1 Superior cervical ganglion Carotid artery Cavernous sinus Target sites (dilator pupillae, lacrimal gland)
What are the investigations for Horner’s syndrome?
CXR (Pancoast)
CT Head (stroke)
MRI/MRA (tumour/dissection)
Refer
What signs may you see on fundoscopy?
Diabetic retinopathy
Hypertensive retinopathy
Papilloedemea
How will a Pt with a COMPLETE CN3 palsy present?
- Ptosis (levator palpebrae dysfunction)
- Affected eye deviated to a “down and out position” (unopposed lateral rectus and superior oblique)
- Diplopia- worst when looking up and out
- Fixed, dilated pupil (mydriasis) - PSNS from ciliary ganglion affected
What are the causes of a unilateral ptosis?
3rd 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
What is the difference between a medical and surgical CN3 palsy?
MEDICAL- pupil sparing, painless
- centre of CN3 is affected
- PSNS fibres are intact until the entire nerve affected
- diabetes, atherosclerosis + vasculitis
SURGICAL- fixed, dilated pupil
- PSNS fibres located on outside of CN3 trunk- first to be affected by compression
- eg by posterior communicating artery aneurysm, SOL, coning
Causes of ptosis
First Order Neurone lesion:
- Brainstem demyelination (MS)
- Brainstem tumour
- Brainstem infarct (lateral medullary infarct) /haemorrhage
Second Order Neurone lesion:
- Apical lung tumour – classically Pancoast tumour
- Apical TB
- Cervical rib
- Brachial plexus trauma
- Dissections + aneurysms of carotid and subclavian artery
Third Order Neurone lesion:
- Herpes Zoster
- Internal carotid artery dissection
How may a Pt with a CN4 palsy present?
HEAD TILT + UPWARDS GAZE (CANT FOCUS IN + DOWN)
CN4 palsy results in PT being unable to look down and in towards nose - diplopia especially on reading
Affected eye will be slightly raised compared to the unaffected eye
To counteract the diplopia Its raise level of the affected eye by tilting their head away
What are the commonest causes of a CN4 palsy?
Idiopathic
Head trauma
Diabetes
How may a Pt with a CN6 palsy present?
Failure to abduct ipsilateral eye
What are the causes of a CN6 palsy?
Due to the long course of the 6th nerve it is easily affected: Stroke Trauma Viral illness SOL Inflammation
How does a Pt with internuclear ophthalmolegia present?
Eyes do not move together – dissociative conjugate movements
- Impaired adduction of the ipsilateral eye
- Nystagmus in the abducting contralateral eye
What are the causes of internuclear ophthalmoplegia?
If young and bilateral, MS
If old and unilateral, stroke
What are the pathways for the corneal reflex?
V1 -> VII
What are the pathways for the jaw jerk reflex?
V3 -> V
Which part of the trigeminal nerves would be affected if there was a higher central lesion?
Contralateral nerves
What are the causes of a higher central trigeminal lesion?
Stroke
Which part of the trigeminal nerves would be affected if there was a brainstem lesion?
Ipsilateral nerves
What are the causes of a brainstem trigeminal lesion?
Stroke
Raised ICP
Which part of the trigeminal nerves would be affected if there was a peripheral lesion?
Branch distribution
What are the causes of a peripheral trigeminal lesion?
Raised ICP
Trauma
What are the branches of the facial nerve?
Two Zebras Bit My (Massive) Cock
Temporal Zygomatic Buccal Marginal mandibular Cervical
What is Bell’s palsy?
Facial paralysis of the ipsilateral side
What are the causes of Bell’s palsy?
Idiopathic
Compression of the facial nerve
Inflammation (eg. viral)
-herpes simplex type 1, varicella zoster
What are the risk factors for Bell’s palsy?
Diabetes
What are the investigations for Bell’s palsy?
Serology
-Lyme, herpes, zoster
What is the management for Bell’s palsy?
Prevent corneal abrasions- wear an eye patch
Steroids- prednisolone
What is Ramsay Hunt syndrome?
LMN facial palsy due to varicella zoster
What are the features of Ramsay Hunt syndrome?
Pain
Vesicles in ipsilateral ear, hard palate, anterior tongue
Deafness/vertigo/other CN features
If the forehead is spared in a CN7 pathology, where is the lesion?
UMN lesion
What is Weber’s test assessing for?
Sensorineural and conductive hearing loss
What is Rinne’s test assessing for?
Conductive hearing loss
What is a Rinne’s positive sign?
Air is louder than bony conduction
What is the diagnosis:
Weber’s: lateralises to the left
Rinne’s L: negative
Rinne’s R: positive
Left conductive hearing loss
What is the diagnosis:
Weber’s: lateralises to the right
Rinne’s L: negative
Rinne’s R: positive
Mixed hearing loss
What is the diagnosis:
Weber’s: lateralises to the left
Rinne’s L: positive
Rinne’s R: positive
Right sensorineural hearing loss
What is the diagnosis:
Weber’s: no lateralisation
Rinne’s L: positive
Rinne’s R: positive
No abnormality
What are the causes of conductive hearing loss?
EAM:
- wax
- foreign body
- otitis externa
Drum:
-perforation
Middle ear:
-acute/serous otitis media
Oval window:
-otosclerosis
What are the causes of sensorineural hearing loss?
Inflammation:
- meningitis
- MMR
Tumour:
-acoustic neuroma (neurofibromatosis T2)
Ototoxic drugs:
- aminoglycoside ABx
- aspirin overdose
- loop diuretics
Trauma
Meniere’s disease
What are the inheritance patterns for neurofibromatosis type 1 and 2?
Autosomal dominant
What is the gene and chromosome affected in NF1?
NF1 Chr 17 (neurofibromatosis: 17 letters)
What is the gene and chromosome affected in NF2?
NF2
Chr 22
What is the presentation of NF1?
Cafe-au-lait spots Freckling in skin folds Neurofibromas Lisch nodules spinal scoliosis Short stature Mild intellectual disability
What is the presentation of NF2?
Sensorineural hearing loss
Bilateral acoustic neuromas
Symptomatic at the age of 20
Possible tinnitus/vertigo
What can you do/look at to assess CN IX and X?
Soft palate and uvula Gag reflex Cough Swallow Assess speech quality and hoarseness
What two muscles are supplied by CN XI?
Sternocleidomastoid
Trapezius
What are you looking for when assessing CN XII?
Wasting
Fasciculations
Deviation of the tongue
Power of the tongue
What is a bulbar palsy?
Lesion affecting the medulla oblongata and its associated cranial nerves IX-XII
What are the clinical features of a bulbar palsy?
Absent gag reflex Wasting/fasciculation of the tongue Absent palatal movement Absent/normal jaw jerk Nasal speech Normal emotions Signs of underlying cause eg. limb fasciculations
(LMN signs)
What is a pseudobulbar palsy?
Lesion affecting the UMN supplying the medulla oblongata
What are the clinical features of a pseudobulbar palsy?
Increased/normal gag reflex Spastic tongue Absent palatal movement Increased jaw jerk Monotonous, slurred, high-pitched Donald Duck dysarthria Labile emotions Bilateral UMN limb signs
(UMN signs)
What are some causes of a bulbar palsy?
MND
Guillain-Barre
What are some causes of a pseudobulbar palsy?
Stroke
MND
MS
A 24 year old woman presents to her GP with a red painful eye with blurry vision. She has noticed a lot of clear discharge coming from her eye. She has otherwise been well, apart from some recent diarrhoea. What is the most likely diagnosis?
A. Viral conjunctivitis B. Bacterial conjunctivitis C. Anterior uveitis D. Posterior uveitis E. Closed angle glaucoma
C. Anterior uveitis
Firstly, because this is not an acute presentation (she’s presented to her GP), we can rule out closed angle glaucoma.
Posterior uveitis and viral conjunctivitis are usually painless making them unlikely.
Although bacterial conjunctivitis is painful, it normally gives thick muculopurent discharge.
The clear discharge is most likely to be increased lacrimation, which is in keeping with anterior uveitis.
A 50 year old patient presents to A&E with diplopia. The doctor examines their cranial nerves and finds a palsy in the oculomotor nerve. Peripheral nerve exam demonstrated a length dependent sensory neuropathy. What did the doctor most likely see during the cranial nerve examination:
A. Internuclear ophthalmoplegia B. Anhidrosis, miosis and ptosis C. Down and out pupil D. Mydriasis E. Down and out pupil with mydriasis
C. Down and out pupil
The palsy is why the patient has diplopia. The length dependent sensory neuropathy is indicative of diabetes, and if the peripheral sensory nerves are affected then a cranial nerve may be affected.
DM can cause a medical palsy, so the oculomotor nerve is affected first before the sympathetic, therefore will see down and out pupil. Wont see mydriasis yet until parasympathetic is affected, ruling out D and E.
A is not associated with DM, and B is describing Horner’s.
A 28 year old lady presents to A&E thinking she is having a stroke, worried as she cannot move the right side of her face. On examination, the patient cannot smile, puff up her cheeks or wrinkle her forehead on the right side. Serology comes back positive for herpes simplex virus 1. What is the most likely diagnosis?
A. Stroke B. Bell’s Palsy C. MS D. Ramsay Hunt syndrome E. Horner’s
B. Bell’s Palsy
As the patient is young a stroke is very unlikely, given she cannot wrinkle her forehead. This also makes MS unlikely.
MS also unlikely as there is an infective cause, but not Ramsay Hunt since this would normally be varicella zoster, not HSV1.
A 20 year old lady sees her GP after having some hearing difficulties in the last week. On examination, Weber’s test lateralises to her left ear. Rinne’s test is negative in her left ear also, but positive in the right ear. She reported having a cold at the start of the month. Which of these is most likely?
A. Meningitis B. Otitis media C. Foreign body D. Meniere's disease E. Neurofibromatosis type 2
B. Otitis media
As Rinne’s test is negative in the left ear we know it is a conductive problem in left ear, further supported by fact Weber’s lateralises to the left as well. This rules out meningitis and NF2 as they are a sensorineural problem, as is Meniere’s – Meniere’s is triad of sensorineural hearing loss, vertigo and tinnitus.
the fact they had a cold earlier points more towards B as this is an inner ear infection.
A 60 year old man presents to his GP with dysphagia. The GP notices he speaks with a nasally voice. Examination demonstrates a reduced gag reflex, as well as fasciculations and wasting of the tongue. Jaw jerk is normal. Which of these is the most likely cause of their dysphagia?
A. Stroke B. Parkinson’s C. Motor neuron disease D. MS E. Achalasia
C. Motor neuron disease
With this question the patient is old, making MS and achalasia unlikely – this is further supported by the LMN signs.
Stroke and Parkinson’s would give UMN signs, although both can cause dysphagia. The jaw jerk is normal suggesting that CNV is not affected, as is the case with a bulbar palsy.
A 66 year old woman presents with left sided upper and lower facial weakness as well as vertigo, which has worsened over the past few days. She is also suffering from a burning sensation over the left side of her face . This morning, she noticed a new rash in her left ear. On examination, clusters of vesicles on an erythematous base are noted in the patient’s left ear.
A. Bells Palsy
B. Ramsay Hunt syndrome
C. NF T2
D. Stroke
B. Ramsay Hunt syndrome
Name the 12 CN
- Olfactory I
- Optic II
- Oculomotor III
- Trochlear IV
- Trigeminal V
- Abducens VI
- Facial VII
- Vestibulocochlear VIII
- Glossopharyngeal IX
- Vagus X
- Accessory XI
- Hypoglossal XII
Role of CNI
SENSORY from nose
Role of CN II
SENSORY from eye
Role of CN III
MOTOR to eye:
- autonomic, parasympathetic to intrinsic muscles
- somatic: all extrinsic muscles except lateral rectus and superior oblique
Role of CN IV
MOTOR to superior oblique
this pulls the eye infero-medially
Role of CN V
SENSORY to face
MOTOR to jaw
Role of CN VI
MOTOR- to lateral rectus
this abducts the eye
Role of CN VII
SENSORY- anterior 2/3rds of tongue
MOTOR- to face
Role of CN VIII
SENSORY- to ear
Role of CN IX
SENSORY- to posterior 1/3rd of tongue (afferent to gag reflex)
MOTOR- to tongue and throat
Role of CN X
multiple functions
MOTOR- mouth and throat, efferent to gag reflex. autonomic (PSNS) to heart, lungs, and GI
SENSORY- throat, heart, lungs, and abdomen
Role of CN XI
MOTOR- to the sternocleidomastoid and trapezius muscles
Role of CN XII
MOTOR- to tongue
for each cranial nerve, state whether is is motor, sensory or mixed.
some say marry men but my brother says bad business marry money
Olfactory - Sensory - smell Optic - Sensory - eye Oculomotor - Motor - all eye Trochlear - Motor - superior oblique Trigeminal - Both - face + jaw Abducens - Motor - lateral rectus Facial - Both - ant 2/3 tongue, face Vestibulochoclear - Sensory - ear Glossopharyngeal - Both - post 1/3 tongue, throat Vagus- Both- throat, heart, lungs, abdo Accessory - Motor - trapezius, SCM Hypoglossal - Motor - tongue
CN exam introduction
“I’d like to perform an examination of the nerves in your head and neck if that’s okay? In this examination I’ll be looking at the face, feeling different parts of the head and asking you to do some special movements if that’s okay?”
Ideally for this examination, I’ll need you to be undressed from the shoulders upwards, so would you be happy to take your shirt off?”
WIPER
WIPER
Wash hands Introduce yourself + examination Permission, Pain Exposure Reposition
In facial drop, what should you take special note of?
FOREHEAD SPARING
2 most common causes of facial drop are Bell’s palsy and ischaemic stroke.
BELLS: forehead is NOT spared
STROKE: forehead SPARING- the upper face is supplied by both brain hemispheres so compensates
note: in stroke, there will also be associated facial numbness
How do you check olfactory nerve?
“Have you noticed any changes in your sense of smell?”
“I would ideally like to assess smell more formally using for example the Pennsylvania smell identification test”
What questions do you first ask before performing further examination of the optic nerve?
“Do you wear glasses or contact lenses?”
“Have you noticed any changes in your vision recently?”
How do you test for visual inattention?
Tell patient: “look at my nose”
Put your arms out to the sides with fingers pointed upwards
Tell patient: “keep looking at my nose and point to the finger that moves”.
-Wiggle Left
-Wiggle Right
-Wiggle both at once
How do you test for visual fields?
“Look at my nose and cover your left eye with your left hand”
“With your right eye look into my left eye”
Close/cover your right eye
“Keep looking at my eye and tell me when you see my fingers out of the corner of your eye”.
Move your fingers towards the centre from all 4 corners of the visual field
Cause of monocular blindness
Optic nerve lesion- aka optic neuritis
- demyelinating disease- commonly MS
- autoimmune neuropathies, such as systemic lupus erythematosus
- compressive neuropathies, such as meningioma (a type of brain tumor)
State a common cause of bitemporal hemianopia
pituitary tumour- anything that compresses the optic chiasm
What causes nasal hemianopia?
a lesion involving the left perichiasmal area.
What causes homonymous hemianopia? give common pathologies
damage to the L/R visual cortex or optic tract
- stroke
- tumour
- abscess.
What are the 3 responses you are testing for in the reflex component of the optic nerve exam?
Direct response
When the light enters a pupil, it dilates
Consensual response
When the light enters one pupil, the contralateral pupil also dilates
Relative response (aka: swinging torch test) If one pupil inappropriately dilates, suggests a sensory deficit from the other pupil
What would you ideally examine using opthalmoscopy?
the fundus
What are the 2 special tests used to further test the optic nerve?
Colour vision
“Ideally I’d test colour vision using Ishihara plates”
Blind Spot
“Ideally I’d test the patient’s blind spot using a red Q-tip”
Which muscles are affected in a CNIII palsy? What is the effect of this? State a common cause.
SR, IR, MR, IO
DOWN AND OUT appearance
commonly caused by diabetes
Which muscles are affected in a CNIV palsy? What is the effect of this? State a common cause.
Superior oblique
Head tilting- down and to the unaffected side to compensate for the vertical diplopia
can be caused by orbit trauma
State some unilateral causes of ptosis
CN III palsy (CNVII closes eyelid)
Horner’s syndrome
Congenital
State some bilateral causes of ptosis
Myasthenia Gravis
Myotonic Dystrophy
Congenital
Which muscles are affected in a CNVI palsy? What is the effect of this? State a common cause.
Lateral rectus
causes a convergent squint
raised ICP can be a cause
Describe how you would test for the oculomotor, trochlear and abducens nerve
H TEST
“Keep your head still and follow my finger with your eyes – tell me if at any point you see double or if moving your eyes is painful”
Finger ~50cm from face
Move slowly in a ‘H’ shape
Look for obvious Ophthalmoplegia and nystagmus
Causes of ophthalmoplegia
Myasthenia gravis
Cranial nerve palsy (e.g. due to raised ICP)
Grave’s disease
Wernicke’s encephalopathy (particularly failure of up-gaze)
Progressive supranuclear palsy (especially vertical gaze)
What is Internuclear Ophthalmoplegia
A disorder of conjugate lateral gaze (i.e. inability to move both eyes together in complete lateral abduction and adduction) caused by a lesion in the medial longitudinal fasciculus.
Causes a failure of adduction in the eye on the affected side
Describe the signs on H test of a Left internuclear opthalmoplegia
Lateral gaze to the left is normal
On attempting lateral gaze to the right:
- The right eye abducts normally
- However, the left eye cannot full adduct and remains looking straight ahead
- The right eye will consequently display nystagmus in an attempt to compensate
- The patient will experience lateral diplopia
Convergence is preserved however (i.e. the left can adduct normally if the goal is not lateral gaze)
Causes of internuclear opthalmoplegia
Multiple Sclerosis (almost always the cause in a young patient) Stroke Lyme disease (rare) Tricyclic antidepressant overdose (rare)
3 branches of the trigeminal nerve
temporal
maxillary
mandibular
What are the 3 components of testing the trigeminal nerve?
Sensory- light touch to face
Motor- jaw clenching and opening against resistance
Reflexes- jaw jerk and corneal
Describe how you would test the sensory component of the trigeminal nerve
- Ask patient to close their eyes
- Test the cotton wool on their sternum
- “Say yes when you feel the cotton wool touching your face”
- Test all branches
- Move from side to side and ask if it feels the same on both sides.
- “Ideally I’d offer to test pain sensation with a neurotip
Describe how you would test the motor component of the trigeminal nerve
- Palpate for masseter contraction over angle of the jaw
- Palpate for temporalis contraction
- push up against patient’s chin, ask to open jaw against resistance
When opening the jaw against resistance, if there is a trigeminal nerve palsy the jaw will deviate where?
towards the side of resistance
What 3 things do you look for when inspecting facial tone?
Reduced wrinkling of the forehead
Drooping of the corner of the mouth
Flattening of the nasolabial folds
What 2 questions do you ask to check the sensory component of the facial nerve?
“Have you noticed any change in your taste recently?”
“Do you feel you’re particularly sensitive to loud noises at the moment?”
How do you test the motor component of the facial nerve?
Raise eyebrows Screw up eyes Puff out cheeks Smile Purse lips
What is Bell’s sign?
up-gaze on attempted eye closure
3 components of CNVIII exam
- Crude test of hearing (whisper in ear, scratch on tragus of other ear)
- Rinne’s test
- Weber’s test
Which test tells you whether the auditory defect is conductive or sensorineural?
Rinne’s test
Describe Rinne’s test
- Vibrate the 512Hz fork against the patient’s mastoid bone
- Ask PT to say when the sound is no longer heard.
- Place fork 1–2 cm from the auditory canal- ask PT to indicate when sounds is no longer heard
Which auditory test helps identify the side of the auditory defect?
Weber’s test
Describe Weber’s test
Vibrate the tuning fork
Place tuning fork heel on the centre of the patient’s forehead
“Do you hear the sound more on the left or right, or just in the middle of your head?”
What is the meaning of a positive Rinne’s test?
If the patient is not able to hear the tuning fork after it is moved from the mastoid to the pinna, BC>AC
Indicates inhibition of sound waves through the ear and into the cochlea
(i.e., there is a conductive hearing loss).
What are the components of the glossopharyngeal and vagus nerve exam?
- soft palate assessment
- say ‘british constitution’
- cough assessment
- swallow assessment
- offer gag reflex
When do you assess swallow? What do you assess for?
only when other tests normal
Look for choking/spluttering (signs of possible bulbar defect)
Look for coughing or altered voice afterwards suggestive of insufficient swallow
afferent efferent gag reflex
Afferent: glossopharyngeal
Efferent: Vagus
What is a sign in the mouth of a vagus nerve lesion?
Vagus Nerve Lesion: Uvula deviates AWAY from the affected side
How do you test accessory nerve?
- Inspect muscle bulk for wasting
- Shrug shoulders against resistance
- Turn head against resistance
Components of the Hypoglossal nerve examination
- stick tongue out for inspection
- tongue movement (side to side)
- push tongue against resistance
What are you inspecting the tongue for signs of?
Wasting Fasciculations Flaccidity Spasticity Deviation
How do you test the tongue against resistance?
“Put your tongue in one cheek and push against my finger”
Press one finger against the tough and push medially
Repeat on the other side
feature of a hypoglossal nerve lesion
Hypoglossal Nerve Lesion: Tongue deviates TOWARDS the affected side
tongue appearance in bulbar palsy
Tongue appearance:
- Flaccid
- Wasting
- Fasciculating
Other features
- Inability to move the tongue
- Inability to move the palate
- Drooling (due to difficulty in swallowing)
- Dysphonia (inability to make a sound in order to speak, voice can be described as hoarse, rough, raspy, strained, weak, breathy, or gravely)
- Tremulous lips
Causes of bulbar palsies
Motor Neurone disease Diphtheria Polio Myasthenia Gravis Guillain Barre Syndrome Syringiobulbia
What is pseudobulbar palsy?
An upper motor neurone lesion in the corticobulbar tract supplying the bulb
tongue appearance in psuedobulbar palsy
Tongue Appearance
- Spastic
- Contracted
Other features
- Drooling
- Dysphonia
- Emotional Lability
causes of psuedobulbar palsy
Motor Neurone Disease
Bilateral internal capsule stokes
Multiple Sclerosis
Pontine Glioma (tumour)
to complete the examination I would….(cranial nerve exam)
Take a full neurological history
Perform a complete neurological examination of the upper and lower limbs
Perform a mini mental state examination
Assess gait and balance
the following can cause pretty much ANY cranial nerve palsy….
Diabetes Stroke Multiple Sclerosis Tumour Sarcoid SLE Vasculitis