Neurology Flashcards
Define meningitis
Infection of the meninges associated with infection
Types of meningitis
Bacterial - serious infection with 5-10% mortality
- 0-3 months = GBS, E.coli, listeria monocytogenes
- 1 month - 6 years = Neisseria meningitides, streptococcus pneumonia
- 50 + = listeria monocytogenes, strep pneumonia
Viral - more common, less severe, usually self-limiting
Risk factors for meningitis
Less than 5 or 65 + Non-immunisation Immunodeficiency Cancer - leukaemia and lymphoma Asplenia - increased risk of overwhelming infection with encapsulated bacteria - strep pneumoniae, n. meningitis Summer and autumn Exposure to mosquitos
Pathophysiology of meningitis
Pathogens reach the CNS by haematogenous spread or direct extension
Cross BBB via infection of endothelial cells or migrating leukocytes
Pathogens multiple in subarachnoid space stimulating immune response
Release of inflammatory mediators and activated leucocytes and endothelial damage causes
- cerebral oedema
- raised ICP
- decreased cerebral blood flow
Presentation of meningitis
Headache N+V Photophobia Neck stiffness - resistance to passive neck flexion Fever Altered mental state/confusion Seizures - strep pneumonia and h. influenzea Infants - hypothermia - irritability - lethargy - poor feeding - apnoea - high pitched cry Focal neurological deficit - dilated non-reactive pupil - ocular motility abnormality - abnormal visual field defects - gaze palsy - arm or leg drift - facial palsy - balance problems Rash Kerning's sign - severe stiffness of hamstring causing inability to straight leg when hip is flexed at 90 Brudzinski's sign - severe neck stiffness causes patient hip and knees to flex when the neck is flexed
Ix for meningitis
LP
CSF gram stain, culture, viral PCR and antigen detection - identify causative organism
Blood culture
FBC - leukocytosis, anaemia and thrombocytopenia
CRP - elevated
Blood gas - acidosis
Clotting profile
CT head - brain infarct, cerebral oedema, hydrocephalus in bacterial
MRI - if focal neuro signs present
Features of meningitis of LP
Bacterial - polymorphonocular pleocytosis - elevated protein - low glucose Viral - elevated WCC - normal or elevated protein - normal or low glucose
When is LP contraindicated
Cardioresp instability Focal neuro signs Signs of raised ICP Coagulopathy Thrombocytopenia
Mx of meningitis
Viral
- supportive care
- antiviral therapy - HSV, varicella zoster or CMV
Bacterial
- empirical abx until organism identified - meropenem 1g
- ceftriaxone for strep pneumoniae and h.influenzae
- gentamycin and ampicillin for GBS
- benzylpenicillin for n.menigitidis
- dexamethasone
Complications of meningitis
Hearing impairment - inflammation of cochlear hair cells Local vasculitis - cranial nerve palsies Local cerebral infarction Subdural effusion Hydrocephalus - fibrin blocks Cerebral abscess
DDx for meningitis
Encephalitis
- abnormal cerebral function with fever
- ix with CT or MRI head
Prophylaxis for meningitis
· Rifampicin/ciprofloxacin to eradicate nasopharyngeal carriage of all household contacts for meningococcal meningitis or Hib infection
· Household contacts of patient who has had men C should receive the men C vaccine
Define encephalitis
Inflammation of the brain parenchyma associated with neurological dysfunction
Epidemiology of encephalitis
Peak incidences at < 1 year and > 65 years
Risk factors for encephalitis
<1 or > 65 years Immunodeficiency Viral infection Insect bites Swimming in warm freshwater Vaccination - a/w acute disseminated encephalomyelitis
Pathophysiology of encephalitis
Most commonly caused by viruses - herpesvirus - enterovirus Pathogens reach CNS by haematogenous spread or retrograe axonal transport Colonise the brain paranchyma
Presentation of encephalitis
Insidious onset Fever Rash Altered mental state and confusion Focal neurological deficit Meningismus Signs of resp/GI infection Seizures
Ix for encephalitis
FBC - elevated WCC Peripheral blood smear LFTs - abnormal in rickettsia, CMV, EBV Blood culture Throat swab Nasopharyngeal aspirate Sputum culture LP CT head - hypodense lesion MRI head - hyperintense lesion, oedema and breakdown of BBB EEC - background slowing
Mx of encephalitis
IV acyclovir
DDx of encephalitis
Meningitis
Define idiopathic intracranial hypertension
Raised ICP with no known cause
Epidemiology of IIH
Incidence of 1/100,000
Mean age at diagnosis 30
Risk factors for IIH
Female Weight gain Sleep apnoea Nalidixic acid use Nitrofurantoin Isotretinoin Thyroid replacement therapy Previous inflammation - meningitis
Pathophysiology of IIH
Increased resistance to CSF absorption via arachnoid granulations and/or nerve root sheaths
ICP must then rise for CSF to be absorbed
Presentation of Idiopathic Intracranial Hypertension
Headache - severe, daily headaches, pulsatile
Visual field loss - usually mild
Transient visual obscuration - transient visual loss that lasts for < 30 secs
Pulse-synchronous tinnitus
Photophobia
Retrobulbar pain - pain with eye movements
Optic disc swelling
Decreased visual acuity - normally only if longstanding
Ocular motility defects
Diplopia
Relative afferent pupillary defect
IX for idiopathic intracranial hypertension
Visual field testing - enlargement of physiological blind spot and loss of inferonasal
Fundoscopy - grading of papilloedema
MRI brain - axial and sagittal views, assess for intracranial and intraorbital pathology
LP - L3/4
- opening pressure > 250mmH2O indicated raised ICP
- must exclude intracranial mass lesion by CT or MRI
Features of IIH on fundoscopy
o Stage 0 (normal optic disc) – 3-4mm to the nasal side of the fovea. Vertically oval with a central depression (optic cup). Normally orange/pink in colour
§ Retinal nerve fibre layer is prominent at nasal, superior and inferior poles in inverse proportion to disc diameter
§ Radial nerve fibre layer striations may be seen, without tortuosity
o Stage 1 (very early papilloedema)
§ Disruption of the normal radial nerve fibre layer with grey opacity accentuating nerve fibre layer bundles
§ Subtle grey halo with temporal gap. Obscures underlying retinal details but leaves temporal disc margin normal
o Stage 2 (early papilloedema)
§ Complete peripapillary halo
§ Elevation of the nasal border
§ No major vessel obscuration
o Stage 3 (moderate papilloedema)
§ Obscuration of one or more segments of major blood vessels leaving the disc
§ Complete peripapillary halo, which has an irregular outer fringe
§ Elevation of all borders
o Stage 4 (marked papilloedema)
§ Total obscuration of a segment of a major blood vessel on the disc
§ Elevation of whole nerve head, including the cup
§ Complete border obscuration
§ Complete peripapillary halo
o Stage 5 (severe papilloedema)
§ Obscuration of all vessels, both on the disc and leaving the disc
Mx of IIH
Conservative
- weigh reduction
- elimination of possible causal factors - medications, low sodium diet, advise mild fluid restriction
- optical prism glasses - diplopia
Medical
- Acetazolamide - reduce intra-ocular pressure, avoid 1st trimester
- Furosemide - reduce BP
- Topiramate
- Amitriptyline - 1st line analgesia
Surgical
- CSF shunting - relieves headache in 50% and may help recover vision and reduce papilloedema
- optic nerve sheath fenestration - may help recover vision and reduce papilloedema
Complications of IIH
Irreversible visual loss
Brain herniation
- preceded by Cushing reflex - hypertension, irregular breathing and bradycardia
Define epilepsy
Recurrent seizure disorder secondary to increased neuronal excitability
Types of epilepsy
Generalised - discharge in both hemispheres
- absence - interruption in activity often with blank stare of inaction
- Typical
- Atypical
- Myoclonic absence
- Eyelid myoclonia
- motor
- clonic - rhythmic muscular jerking
- tonic - extension or flexion of extremities
- tonic-clonic - tonic then clonic
- myoclonic - brief arrhythmic muscular jerking
- atonic - brief loss of muscle tone - drop attack
Focal - seizures arise from one part of hemisphere
- frontal - clonic movements or tonic with upper arms raised
- temporal - lip smacking
- occipital - stereotyped visual hallucinations
- parietal - contralateral dysaesthesias
Risk factors for epilepsy
Fhx Metabolic/neurodegenerative disorders Head trauma Autism - focal Hx of febrile seizures
Presentation of epilepsy
Depends on type
Incontinence
Tongue biting
Post-ictal phenomena - sleepiness, headaches, amnesia, confusion
Ix for epilepsy
EEG - seizures provoked if not video EEG or 24 hr EEG
Blood glucose, FBC, metabolic panel - ix metabolic or infective causes
ECG - rule out convulsive syncope
Mx of epilepsy
Valproate
Lamotrigine
Carbamazepine
Monotherapy 1st
Define Idiopathic Parkinson’s Disease
Neurodegenerative disorder characterised by cardinal features of
- resting tremor
- rigidity
- bradykinesia
- postural instability
Epidemiology of Idiopathic Parkinson’s disease
Most common neurodegenerative disorder
- prevalence of 1.6%
Incidence increases with age
Mean onset 65 years
Presentation of Idiopathic Parkinson’s Disease
Bradykinesia - slowness of movements, progressive reduction in amplitude of repeated movements, delay in initiating movements Resting tremor - 4-6Hz pill rolling tremor Cogwheel rigidity Postural instability Masked face - loss of facial movement and expression Hypophonia Micrographia Stooped posture Shuffling gait Conjugate gaze disorders Dementia Constipation, depression and fatigue Progressive symptoms
Ix for Idiopathic Parkinson’s Disease
Diagnosis made on Parkinson’s exam
- observation, basic movements, fine movements, tone, gait, pull test
Dopaminergic agent trial - improves symptoms
MRI brain - normal with age related changes
Functional neuroimaging - decreased basal ganglia dopamine uptake
Mx of Idiopathic Parkinson’s Disease
Levadopa + co-careldopa
- benefits last 5-10 years
- SE - excessive movements and nausea
Physical activity
- under supervision with falls prevention
Trihexyphenidyl or propranolol for tremor
DDx for Idiopathic Parkinson’s Disease
Essential tremor - fast, postural and kinetic, improves with rest, involves head and neck
Dystonic tremor - task-specific, flurries, thumb extension
Progressive supranuclear palsy - vertical gaze palsies, significant postural instability, midbrain atrophy on MRI
Multi-system atrophy - poor response to levodopa, autonomic dysfunction, pyramidal or cerebellar dysfunction
Lewy-body dementia - hallucinations and fluctuating mental state first
Drug induced parkinsonism
Define Amyotrophic Lateral Sclerosis
Most common motor neurone disease
Upper and lower motor neurone findings
Epidemiology of Amyotrophic Lateral Sclerosis
Mean onset is 57
Prevalence of 5 per 100,000
Pathophysiology of Amyotrophic Lateral Sclerosis
Progressive loss of cortical, bulbar and ventral cord motor neurones
After motor cell death, retrograde axonal degeneration follows
Subsequent denervation and reinnervation in corresponding muscles
Presentation of Amyotrophic Lateral Sclerosis
Upper extremity weakness Stiffness with poor coordination Spasticity, unsteady gait Painful muscle spasms Difficulty getting out of chairs Foot drop Head drop/stooped posture/lumbar lordosis Muscle atrophy Hyper-reflexia Dyspnoea Dysphagia Dysarthria
Ix for Amyotrophic Lateral Sclerosis
Generally diagnosed due to progression of symptoms and no other explanation
EMG - evidence of ongoing, chronic denervation
Repetitive nerve stimulation - modest decrease in motor action amplitude
MRI brain and spine - normal
Mx of Amyotrophic Lateral Sclerosis
Riluzole - slows disease progression - monitor LFTs every 3 months and neutrophils BiPAP - for resp symptoms Baclofen + physio - spasticity Supportive care
Differentials of Amyotrophic Lateral Sclerosis
Primary lateral sclerosis - isolated UMN disorder, weakness and spasticity
Progressive muscular atrophy - isolated LMN disorder, weakness and fasciculations
Define MS
Inflammatory CNS demyelination causing episodic neurological dysfunction in 2 areas
Types of MS
Relasping- remitting - active/not active within a specified time - assess annually
Progressive - primary (from onset) or secondary (after an initial relapsing course)
Epidemiology of MS
Incidence of 6 per 100,000
Commonly diagnosed aged 20-40
3 times more likely in females
Pathophysiology of MS
Lymphocytes activated by infection or metabolic stress
Enter CNS via receptor or endothelial cells
Breach in BBB -> further influx of inflammatory cells
Demyelination occurs by direct toxicity and macrophage activity
Multi-focal demyelination and loss of oligodendrocytes
Presentation of MS
Optic neuritis
- sudden onset, reduced visual acuity, reduced visual fields, red desaturation and RAPD
Abnormal sensation
- numbness, tingling, patch of burning/wetness
Foot dragging/slapping
- gradual weakness onset with activity, resolves with rest
Leg cramping
Fatigue
Urinary frequency
- damage to CNS causes detrusor instability
Bowel dysfunction
Spasticity/increased muscle tone and hyperreflexia - often asymmetrical
Incoordination
- wide based gait or limb ataxia
Memory problems
Ix for MS
MRI brain
- hyper-intensities in periventricular white matter
MRI spinal cord
- demyelinating lesions, particularly cervical spine
FBC, metabolic panel, TFTs, B12 - exclude alternate diagnoses as normal in MS
Mx of MS
Modafinil - for fatigue not improved by lifstyle modification Oxybutynin - for urinary symptoms Gabapentin - for pain Gentle stretching + beclofen - hypertonia Propranolol - tremor Physio - gait distrubance Acute relapse - Methylprednisolone - 3-5 days high dose to relieve symptoms - plasma exchange Relapsing-remitting - immunomodulators Primary progressive - ocrelizumab - monoclonal antibody Secondary progressive - methyprednisolone
Define Myasthenia Gravis
Chronic autoimmune disorder of post-synaptic membrane at the neuromuscular junction
Epidemiology of MG
15 per 100,000
Bimodal peak
- women 20-30s
- men 50-70
Differentials of children presenting with myasthenic symptoms
Transient neonatal myasthenia - occurs in 10-15% of babies born to mothers with MG - disappears after a few weeks Congenital myasthenia - rare Juvenile myasthenia gravis - more common in females
Pathophysiology of MG
Abnormal antibodies generated which attack normal synaptic tissues
Destruction of nicotinic acetylcholine receptor or related protein MuSK (Muscle-Specific Kinases)
Presentation of MG
Painless fatigability of specific muscles
- progressively worse during activity
- resolves with rest
Ptosis - weakness of levator palpebrae superiororis
Diplopia - weakness of extraocular muscles
Dysphagia - facial and oropharyngeal muscles
Dysarthria - nasal speech
Facial paresis
Proximal limb weakness
Shortness of breath
Ix for MG
Serum AChR antibody analysis
MuSK antibodies
Pulmonary function tests
Mx of MG
Emergency - intubation and mechanical ventilation - plasma exchange or IV Ig - supportive care - DVT prophylaxis, ulcer prophylaxis, nutrition, hydration - short term corticosteroid - Rituximab Ongoing disease - Pyridostigmine - acetylcholinesterase inhibitor - immunosuppressant
Define vestibular schwannoma (acoustic neuroma)
Benign cerebellopontine angle tumour
- grows from superior vestibular component of vestibulocochlear nerve
Epidemiology of vestibular schwannoma
- 5 per 100,000
3: 2 F:M
Pathophysiology of vestibular schwannoma
Tumour growth occurs due to p22 abnormalities
- sporadic
- familial autosomal dominant - neurofibromatosis type 2
Presentation of vestibular schwannoma
Unilateral hearing loss Progressive episodes of dizziness Facial numbness - starts with tongue and jaw Tinnitus Headaches Swallowing difficulties
Ix for vestibular schwannoma
Audiogram - asymmetrical sensorineural hearing loss
Gadolinium-enhanced MRI head - uniformly dense mass extending into internal acoustic meatus
Auditory brainstem reflexes - asymmetrical hearing losss
Mx of vestibular schwannoma
Observation - small or non-growing tumours
Focused radiation - hearing preserved in 70%
- risks = secondary malignancy, hydrocephalus, hearing loss
Surgery - hearing preserved in 70%
- risks = hearing loss, facial weakness, CSF leak
Define dementia
Chronic or progressive syndrome of brain disease leading to disturbance of multiple higher cortical functions
Epidemiology of dementia
1% of over 60s
45% of over 95s
Risk factors for dementia
Age Female Genetics Smoking Alcohol Obesity Hypertension CVS disease Psychosocial - no physical activity - depression
Define Alzheimer’s
Deposition of amyloid plaques and neurofibrillary tangles (tau proteins)
Presentation of Alzehmier’s
Short term memory loss Problems with language - shrinking vocab Disorientation Mood swings Apraxia with fine motor tasks
Medications for Alzehmier’s
Acetylcholinesterase inhibitors
Memantine
Define vascular dementia
Stepwise cognitive decline with progressive vascular occlusions
Presentation of vascular dementia
Symptoms may include cognitive decline and memory impairment
- stepwise
Focal neurological signs may be present
Brain imaging shows cerebrovascular disease
Define Lewy Body Dementia
Abnormal deposits of alpha-synuclein (Lewy-bodies) in the brain
Presentation of Lewy Body Dementia
Symptoms of parkinsonism Impaired cognition Sleep disorders Visual hallucinations Fluctuations in attention Slowness of movement Mood changes
Define Parkinson’s disease dementia
Parkinson’s disease well established before cognitive symptoms
Features of frontotemporal dementia
Changes in behaviours, social conduct, impulsivity, loss of comprehension
MRI shows frontal/temporal lobe atrophy in later disease
Ix for dementia
Physical exam - looking for other causes (infection, focal neurology)
Bloods - U+Es, B12, folate, TFTs
ECG, CXR, EEG, MSU
CT/MRI - cerebral atrophy in late stages
Mx for dementia
MDT - psychiatrist, GP, occupation therapist, support worker
Psychological intervention - cognitive stimulation therapy, cognitive rehab
Comorbidities
- vascular risk modification
- avoid polypharmacy
- depression screen
Risk assessment - driving, career strain, social care
Future planning - follow up, power of attorney, will
Define polyneuropathy
Generalised disease of peripheral nerves
Epidemiology of polyneuropathy
5% of population Often a neurological manifestation of systemic illness - hypothyroidism - HIV - Hep C - SLE - chronic renal failure - paraneoplastic - B12 deficiency
Presentation of polyneuropathy
Glove and stocking distribution
Symmetrical numbness with paraesthesia and dysesthesia in feet and lower extremities
Distal impairment of temperature, pinprick and vibration - small-diameter sensory fibres
Balance and gait impaired
Atrophy of muscles and ankle weakness
Autonomic involvement - diarrhoea, constipation, sweating, orthostatic light-headedness
Reduced or absent distal reflexes
Investigations for polyneuropathy
FBC ESR Fasting glucose Cholesterol panel TSH Vit B12 levels Hepatitis serology HIV and antinuclear antibodies Nerve conduction, EMG - distinguish axonal and demyelinating disease
Causes of polyneuropathy
Axonal - axons degenerate distal-to-proximally - longer axons affected first - diabetes - alcohol - hypothyroidism - B12/folate deficiency Demyelinating - Guillain-Barre syndrome - paraneoplastic syndromes
Mx of polyneuropathy
Treat cause Axonal - minimise exposure to offending agent Demyelinating - IV IgG, glucocorticoids, plasma exchange Pain - gabapentin/carbazepine/TCA
Features of diabetic neuropathy
Occurs in 50% of diabetic patients
- greater hyperglycaemia = greater risk
Define spondylosis
Spontaneous degenerative disease of the disc or facet joints of the spine
Types of spondylosis
Cervical
Lumbar - most common cause of lower back pain in adults
Risk factors for spondylosis
Increasing age
Genetic influence
Trauma/excessive exertion
Pathophysiology of spondylosis
Loss of hydration of nucleus pulposus and narrowing
Stress increases on facet joints
Loss of disc height, herniation and nerve root irritation
Presentation of cervical spondylosis
Often asymptomatic
Spontaneous onset neck pain
Cervical muscle pain and spasm - scalene, trapezius, interscapular
Headaches or occipital pain
Numbness/arm weakness
Radiating arm pain - radiculopathy
Reflex changes - decreased in radiculopathy, increased in myelopathy
Presentation of lumbar spondylosis
Persistent low back pain - worsens with axial loading
Radicular leg pain - nerve root compression
Restricted lumbar motion
Positive straight leg raise - pain reproduced by passively raising extended leg
Ix for spondylosis
X-ray (cervical/erect lumbar)
- osteoporosis, fractures, vertebral mets, degenerative changes
- osteophytes
- disc space narrowing
- foraminal stenosis
- endplate sclerosis
- ligament calcification
MRI spine
- signs of degeneration - decreased signal on T2 weighted
- disc height
- annular tearsMx of spondylosis
Physiotherapy NSAIDs Muscle relaxants if spasms present - diazepam Dexamethasone - facet joint injections for pain - orally for radiculopathy Surgical decompression Immobilisation Facet joint blocks - local anaesthetic + local corticosteroid
Define Bell’s Palsy
Acute unilateral peripheral facial nerve palsy
Epidemiology of Bell’s Palsy
28 per 100,000
15-45 years
Risk factors for Bell’s Palsy
Pregnancy
Recent URTI
FHx
Pathophysiology of Bell’s Palsy
Reactivation of HSV-1
- destruction of ganglion cells and infection of Schwann cells
- demyelination and neural inflammation
Presentation of Bell’s Palsy
Unilateral symptoms
All nerve branches
Facial weakness - raising eyebrows, clenching eyes shut, puff out cheeks
Dry eye - loss of blink
Pain - post-auricular and otalgia
Synkinesis - involuntary synchronous movement of facial region with voluntary movement of another region
Hyperacusis - increased sound perception in ipsilateral ear
- impairment of stapedius reflex
Dysgeusia - taste disturbance
Ix for Bell’s Palsy
Clinical presentation
Scoring system for Bell’s Palsy
Grade 1 = normal
Grade 2 = slight weakness/asymmetry
Grade 3 = obvious weakness, intact ability to close eye
Grade 4 = obvious weakness, inability to fully close eye
Grade 5 = barely perceptible movement
Grade 6 = no movement
Mx of Bell’s Palsy
Prednisolone - 10 day course Eye protection - artificial tears - overnight eyelid taping Surgical decompression
Define Carpal Tunnel Syndrome
Entrapment neuropathy of median nerve within the carpal tunnel
- rapid pressure can lead to ischaemia and nerve scarring
- demyelination and axonal loss
Risk factors for carpal tunnel syndrome
Myxoedema Obesity DM Idiopathic Acromegaly Neoplasm Trauma RA Amyloidosis Pregnancy
Presentation of carpal tunnel syndrome
Night-time worsening - waking through the night
Numbness in median nerve distribution
- palmar surface of first 3.5 digits and distal dorsal surface of first 3 digits
- thenar eminence
Intermittent symptoms with gradual onset
Weakness/atrophy of thenar muscles
Ix for carpal tunnel syndrome
Phalen’s test
- hold wrists in flexion for 60 seconds to elicit symptoms
Tinel’s sign
- tap carpal tunnel to elicit pain
EMG - focal slowing of conduction in median sensory across carpal tunnel
Mx of carpal tunnel syndrome
Wrist splint NSAIDs Corticosteroids injection Thiazides - if oedema present Surgical release
Causes of ulnar nerve palsy
Elbow - trauma at medial epicondyle - compression in cubital tunnel Wrist - lacerations to anterior wrist
Presentation of ulnar nerve palsy
Elbow
- flexion of wrist accompanied by abduction - flexor carpi ulnaris and flexor digitorum profundus
- loss of abduction and adduction of fingers - interossei
- loss of movement in 4th and 5th digits - medial 2 lumbricals and hypothenar muscles
- loss of thumb adduction - adductor pollicis
- loss of sensation over medial hand
Wrist
- motor as above
- dorsal sparing
- loss of sensation over palmar aspect of medial 1.5 fingers
Define ischaemic optic neuropathy (CN II)
Sudden-onset, painless, monocular visual loss in older adults
Presentation of ischaemic optic neuroapthy
With arteric involvement
- headache, malaise, myalgia and jaw claudication
Segmental swelling of pallid optic disc
ESR > 46
CRP elevated
Temporal artery biopsy - focal areas of inflammation, giant cells seen
Risk factors for ischaemic optic neuropathy
Hypertension
Diabetes
Smoking
Viral infection of CII mononeuropathy
Child with recent viral infection or immunisation
Presenting with peri-occular pain
Triad of visual loss, swollen optic disc and macula star
Diagnosed on clinical presentation
Features of vascular malformations of CN V
Unilateral often progressive paroxysmal pain
- lasts seconds to minutes
- precipitated by triggers - touch, chewing
- commonly V2/3 distributions
Diagnosis of CNV mononeuropathies due to vascular malformation
Brain MRI
- aberrant vessel at cerebellopontine angle
Presentation of Herpes Zoster
CN V mononeuropathy
3-4 days burning pain +/- vesicular rash
Erythematous maculopapular rash followed by clear vesicles
- does not cross midline
Diagnosed on clinical presentation
Presentation of Ramsay Hunt Syndrome
Shingles outbreak in CN VII Unilateral facial weakness - affects upper and lower face - constant dull ear pain - hearing loss, tinnitus or vertigo Erythematous herpetic rash of ipsilateral ear or mouth
Features of cerebrovascular accident affecting CN VII
Acute onset Contralateral limb weakness Dysphagia Dysarthria Sparing of upper facial muscles
Features of neural presbycusis
Age-related disorder of CN VIII Difficulty in speech discrimination Slow gradual hearing loss Usually bilateral Normal otoscopic exam Bilateral sensorineural hearing loss - usually high frequency
Features of drug effect of CN VIII
New-onset vestibulocochlear nerve dysfunction after starting medication - aminoglycosides - platinum based chemotherapeutic agents - salicylates - quinine - loop diuretics Tinnitus bilateral Rinne's test positive
Features of iatrogenic CN X nerve damage
Recent thoracic neck surgery
- horse voice
No palatal droop or uvular deviation
Laryngoscopy shows ipsilateral vocal fold paralysis
Features of apical lung tumour on CN IX, X
New-onset hoarseness
Hx of smoking
Cough
Decreased air entry, decreased percussion note or normal auscultation
Ix for CN IX, X mononeuropathies
Laryngoscopy - ipsilateral vocal cord paralysis
CXR - apical lung tumour
Chest CT - lung tumour and relationship surrounding structures
CT-guided thoracoscopic biopsy - malignant cells present
Features of iatrogenic damage to CN XI
Isolated accessory nerve palsy - weakness of sternocleidomastoid and trapezius muscles, mild scapular winging
Recent lymph node biopsy, neck dissection, jugular vein cannulation or carotid enterectomy
High-resolution USS - hypoechoic tubular structure in posterior triangle
Nerve conduction studies - prolonged latencies
EMG - signs of denervation
Features of cerebrovascular accident damage to CN XII
Acute, onset contralateral limb weakness with associated cranial nerve deficits
Progressive bulbar palsy
- difficulty chewing, swallowing and talking
- tongue weakness
- deviated to ipsilateral side on protrusion
- fasciculations
Contralateral hemiplegia with facial sparing, contralateral loss of position and vibration sensation
Brain MRI - ischaemic regions appear high-density
