Neuro Paces Flashcards
How to test upper limb myotomes and peripheral nerve
C5- shoulder abduction
C6- elbow flexion and wrist extension
C7- elbow extension
C8- thumb extension
T1- finger abduction
Median - flexion and pronation
Ulnar- flexion of ring and little finger DIP, intrinsic muscles of the hand
Radial- extension
How to differentiate ulnar nerve palsy from C8/T1 pathology
Abductor pollicis brevis would be weak in a C8-T1 lesion, it is supplied by the median nerve
Normal sensation in T1 if ulnar lesion
What are the signs of an ulnar nerve palsy?
- Relevant scar
- ‘Ulnar claw’ Extension at 4th and 5th metacarpal phalangeal joint and flexion at distal joint
- Wasting of small muscles of the hand
- Weak abduction of fingers
- Normal strength in abductor pollicis brevis
- Altered sensation in ulnar distribution
Types of diabetic neuropathy
- Distal symmetric polyneuropathy - progressive distal sensory loss in a glove and stocking distribution results in axonal loss in nerve conduction studies, motor involvement in severe cases
- Autonomic neuropathy- postural hypotension, gastroparesis, gustatory sweating, resting tachycardia
- Diabetic amyotrophy- microvasculitis presents with asymmetric pain then weakness in the proximal leg along with weight loss
Causes of peripheral neuropathy
1) Metabolic
- Diabetes (chronic, sensory predominant, length dependent)
- B12, B1, B6 deficiency
- Uraemia
- Hypothyroidism
2) Infective
- HIV (distal sensory, often painful)
- Lyme disease
3) Immune
- CIDP (relapsing course, often not length dependent)
- Paraprotrinaemic (myeloma or MGUS)
- Connective tissue disease (RA, sjogren, SLE, sarcoidosis)
- paraneoplastic (most commonly lung ca
- GBS
4) Genetic
- Charcot Marie Tooth
- Acute intermittent porphyria
5) Toxic
- isoniazid
- pyridoxine
- lead
- chemotherapy
Investigating diabetic neuropathy
Nerve conduction studies show a sensory axonal loss with reduced or absent sensory nerve action potentials in a length- dependent manner with the legs being most affected
Management of diabetic neuropathy
Optimise diabetes control
Foot care
Pain management
Postural hypotension managed with fludrocortisone
GI symptoms with prokinetics and antiemetics
Clinic signs of hereditary sensory motor neuropathy (Charcot Marie Tooth)
Wasting of distal lower limb muscles with preservation of the thigh muscle bulk
Pes cavus
Stocking distribution sensory loss
High steppage gait due to foot drop and stamping due to loss of proprioception
Wasting of hand muscles
Palpable lateral popliteal nerve
What causes hereditary sensory motor neuropathy
Most common types are I (demyelinating) and II (axonal) therefore nerve conduction studies are useful
Autosomal dominant inheritance (test for PMP22 mutations in HSMN I)
Tests for HSMN
Nerve conduction studies
Genetic testing
Management of HSMN
Physiotherapist/ occupational therapist
Orthotics
Genetic counselling
Causes of predominantly sensory peripheral neuropathy
DM
Alcohol
Drugs eg. Isoniazid and vincristine
Vitamin deficiencies - b12 and b1
Causes of predominantly motor peripheral neuropathy
Guillain barre and botulism present acutely
Lead toxicity
Porphyria
HSMN
Causes of mononeuritis multiplex
DM
Connective tissue disease eg. SLE and RA
Vasculitis
HIV
Malignancy
What causes a central scotoma?
Optic nerve disease eg. Optic neuritis
Affects ipsilateral side
What causes a bitemporal haemianopia?
Chiasmal lesion
Upper fields worse affected in pituitary tumours
Lower fields worse affected in craniopharynhiomas
What causes a homonomous superior quadrantanopia?
Temporal lobe lesion
What causes a homonymous inferior quadrantanopia?
Parietal lobe lesion
What causes a homonymous hemianopia?
Post chiasmal lesion, the more congruous the more posterior the lesion is
A posterior cerebral stroke can cause macular sparing due to dual blood supply
What is the Pathophysiology of MS?
BBB is more permeable to immune cellls. T cells enter the CNS. T cells attack the myelin sheath leading to inflammation.
How does MS present?
Sensory- Parasthesia, hypoaesthesia, pain, MS hugs
Optic neuritis- diminished visual acuity, decreased colour perception, periorbital pain preceding vision loss
Weakness- exercised induced weakness is characteristic, UMN signs
Spasticity
Bladder dysfunction
Constipation
Sexual dysfunction
Uthoff’s phenomenon- symptoms worse after hot bath
Lhermitte’s sign- lightening pains down the spine on neck flexion due to cervical cord plaques
Disease course of MS
Relapsing remitting
Secondary progressive
Primary progressive
Differentials for MS
Inflammatory conditions- neuromyelitis optica, shortens, ADEM, CNS lupus/vasculitis
Infection - syphilis, Lyme disease, HIV
Metabolic- B12 deficiency, mitochondrial disease
Diagnosis and investigation of MS
Need to prove dissemination of disease activity in time and space.
1. Clinical history
2. MRI
3. Unpaired oligoclonal bands in the CSF (not specific for MS, occur in 85% of cases)
Management of MS
Multidisciplinary approach
DMARDs:
- interferon B and glariramer reduce relapse rate but don’t affect prognosis, they are 1st line for mild disease
- mabs offer greater benefit, used if 2 disabling relapses in 1 year
Stem cell transplantation
Management of acute MS flare
Rule out psueudo relapse (ie. Worsening of existing symptoms by underlying stressor eg. Infection
Methyl pred
Management of MS complications
Baclofen for spasticity
Anti- depressants
Neuropathic analgesics
Antichoniergics/self catherisation for bladder symptoms
How is MS affected by pregnancy?
Reduced relapse rate in pregnancy
Increased risk of relapse in postpartum
What causes MS?
Both genetic (HLA-DR2 and interleukin 2&7 receptors) + environmental factors (EBV)
Clinical signs of cerebellar syndrome
Dysdiadochokinesis
Ataxia
Nystagmus
Intention tremor
Scanning dysarthria
Hypotonia/ hyporeflexia
How does the direction of nystagmus help determine side on the lesion?
The fast phase of the nystagmus is towards the side of the lesion and is maximal on looking towards the lesion
Causes of cerebellar syndrome
Stroke
Paraneoplastic
Alcoholic cerebellar degeneration
Multiple sclerosis
SOL in the posterior fossa
Fredrich’s ataxia and ataxia telangiectasia
Phenytoin toxicity
Hypothyroidism
Clinical signs pointing to different causes of cerebellar syndrome
Internuclear ophthalmoplegia, spasticity, younger female = MS
Optic atrophy = MS or Fredrichs ataxia
Clubbing/ cigarette fingers, radiotherapy burn = bronchial carcinoma
Liver disease = alcohol excess
Neuropathy = alcohol or fredrichs ataxia
Gingival hypertrophy = phenytoin
What happens in internuclear ophthalmoplegia?
The side of the brain affected is the same side as the eye that cannot adduct. Eg. A left sided lesion will result in the left eye not addicting when looking right and the right eye will have nystagmus.
Caused by a lesion affecting the medial longitudinal fasciculus (a heavily myelinated tract).
How can you differentiate sensory ataxia from cerebella ataxia
Sensory ataxia - impaired sensation particularly vibration and joint position, pseudoathetosis, able to finger nose test with eyes open but not with eyes closed
Cerebella ataxia - other cerebellar signs
How does ALS present?
UMN and LMN signs
Upper limb weakness> lower limb weakness
Fasciculations
Asymmetrical
Slurred speech
Dysphagia/dysarthria
How does progressive bulbar palsy present?
Facial muscle weakness
Dysphagia
Dysarthria
Emotional lability
Upper and lower weakness
How does progressive muscular atrophy present
LMN
Muscle atrophy
Fasciculations
Muscle weakness
Best prognosis
How does primary lateral sclerosis present?
Spastic weakness of the limbs
Spastic dysarthria
Dysphagia
Aggressive course
How is a case of suspected MND investigated?
Blood tests inc. vitamin levels, CK assay and anti-GM1 antibodies
EMG showing Fasciculations
Nerve conduction studies
Serum protein electrophoresis
Muscle biopsy
MRI - so assess for other key differentials
What is Kennedy disease?
X linked spinobulbar muscular atrophy
Associated with a CAG trinucleotide repeat mutation
Lower motor neurone disease
Causes progressive weakness and wasting of the limb and bulbar muscles with an absence of spasticity and slight sensory neuropathy
Associated with gynaecomastia and reduced fertility
Causes of generalised wasting of hand muscles
Anterior horn cell
- MND
- syringomelia
- cervical cord compression
- polio
Brachial plexus
- cervical rib
- Pancoast’s tumour
- trauma
Peripheral nerve
- combined median and ulnar nerve lesion
- peripheral neuropathy
Muscle
- disuse atrophy
What are Fasciculations?
Caused by axonal loss resulting in the surviving axons recruiting and innerating more myofibrils than usual resulting in large motor units
Seen commonly in MND and syringomelia
Clinical signs of myelopathy
UMN signs: hypertonia, ankle clonus, generalised weakness, hyperreflexia with up going plantars, hyperreflexia
How to differentiate cause of myelopathy
Sensory level which might suggest where the lesion is
Scars or spinal deformity
Signs of MS
Bladder symptoms/catheter
Suggest testing anal tone
Causes of myelopathy
MS
Spinal cord compression
Trauma
MND
Anterior spinal cord thrombosis
Syringomelia
Hereditary spastic paraplegia
Subacute combined degeneration of the cord (absent reflexes with upgoing plantars)
Lower limb myotomes
Hip flexion - L2/3
Knee extension - L3/4
Foot dorsiflexion- L4/5
Knee flexion - L5/S1
Foot plantarflexion - S1/2
What are the key features of Kennedy disease?
Slow progression
Perioral Fasciculations
Associated with gynaecomastia and reduced fertility
How does poliomyelitis present?
Acute flaccid paralysis, typically unilateral.
Reduced reflexes and atrophy of the affected limb.
GI prodrome.
What is post- poliomyelitis syndrome?
Weakness, fatigue and wasting of affecting muscles
How does GBS present?
Flaccid paralysis
Hyporeflexia
Ascending weakness
Variable sensory loss
Differential diagnosis for GBS?
CIDP if more chronic onset of symptoms
Investigations for GBS
CSF: normal wcc and glucose with raised protein
NCS: delayed conduction velocities indicating demyelination of peripheral nerves
Spirometry to monitor FVC
Treatment of GBS
IVIG and plasma exchange
Nutritional support
Ventilatory support
Pressure care
Analgesia
Causes of spastic paraparesis
Group based on onset time:
Hyper acute- vascular (less likely to spastic, more likely spastic shock)
Acute - spinal cord compression, transverse myelitis
Gradual onset - subacute combined degeneration of the cord, Frederichs ataxia, hereditary spastic paraparesis
Investigating spastic paraparesis
MRI spine
Check b12, copper
Clinical signs of spastic paparesis
Wheelchair/ walking aides
Increased tone and ankle clonus
Generalised weakness
Hyper- reflexia and extensor plantars
Scissoring gait
Signs to look for cause:
Assess for sensory level
Check back for scars or deformity
MS signs
Anal tone
Clinical presentation of Parkinson’s
Bradykinesia
Cogwheel rigidity
Resting pill rolling tremor
Shuffling gait
Postural instability
Mask like facies
Reduced blink frequency
Dysphasia
Micrographia
Hypophonia
Freezing
Depression
Fatigue
Sleep disturbance
Cognitive impairement
Anosmia
Signs and symptoms more consistent with Parkinson’s disease
Unilateral onset and persistent asymmetry
Resting tremor
Good response to levodopa
Long disease course
Differential diagnosis for Parkinsonism
Drug induced
Vascular
Dementia with Lewy bodies
Multiple system atrophy
Progressive supranuclear palsy
Signs/ symptoms consistent with multiple system atrophy
Prominent early autonomic features (postural hypotension, urinary incontinence, erectile dysfunction)
Cerebellar signs
Prominent pyramidal signs
Poor levodopa response
Sighs and symptoms consistent with progressive supranuclear palsy
Vertical supranuclear gaze palsy
Early falls (within first year)
Poor levodopa response
Early dementia
What is the aetiology of Parkinson’s disease?
Early onset Parkinson’s is associated with mutation of the PARK-1 gene encoding alpha synuclein
Around 20% of cases of Parkinson’s have a first degree relative affected
What medications can cause Parkinsonism?
Antipsychotic drugs
Metoclopramide
Prochlorperazine
Sodium valproate
Lithium
How is Parkinson’s diagnosed?
Clinical diagnosis - if at least 2/4 clinical signs
SPECT
CT/MRI to rule out alternative causes
Management of Parkinson’s disease
1) Levodopa + dopa decarboxylase inhibitor
2) Dopamine agonist (eg. Pramipexole, ropinirole, rotigotine)
3) MAO-B inhibitors (selegiline)
4) COMT inhibitors (eg. Entacapone)
DBS
Pathology of Parkinson’s disease
Degeneration of the dopaminergic neurones between the substantia nigra and basal ganglia
Differential diagnosis for tremor
Resting tremor: Parkinson’s
Postural tremor: benign essential tremor, anxiety, thyrotoxicosis, co2, hepatic, alcohol
Intention tremor: cerebellar disease
Causes of ischaemic stroke
Thrombotic, most commonly caused by atherosclerosis
Embolic, most common in patients with AF, but also valve defects or endocarditis
Causes of haemorrhagic stroke
Intracranial haemorrhage most commonly secondary to uncontrolled hypertension
SAH secondary to AV malformations or Berry aneurysms
Risk factors for stroke
Hypertension
DM
Hypercholesterolaemia
AF
IE
Carotid artery disease
CCF
congenital/structural heart disease
Age
Genetics
Gender
Sickle cell disease
Antiphospholipid syndrome
CKD
Smoking
Alcohol
What is the Pathophysiology of ischaemic stroke
Acute occlusion of an intracranial vessel leads to reduced blood flow to the brain region supplied by the vessel resulting in infarction via 2 pathways:
1. Necrotic pathway with rapid cytoskeletal breakdown
2. Apoptotic pathway
Bamford classification of stroke
TACS- contralateral hemiplegia, homonomous hemianopia, higher cortical dysfunction (ie. Aphasia, dyspraxia, neglect)
PACS- 2/3 of the above
LACS- pure hemi- motor/sensory loss
POCS- cranial nerve impairement, unilateral or bilateral sensory/motor impairment, disorder of conjugate eye movement, cerebellar dysfunction, homonymous hemianopia, cortical blindness
Management of suspected stroke
History+ collateral (onset time, functional baseline)
Examination
BM
ECG
CT head
+/-CT perfusion
MRI
Echo
Carotid doppler
Clotting screen and vasculitis screen if young
Management of ischaemic stroke
<4.5 hours from symptoms onset- thrombolyse with alteplase, start aspirin 24 hrs after thrombolysis
If cannot thrombolyse consider perfusion imaging +/- thromboectomy
If not able to do the above then 300mg aspirin as a stat and continue for 2 weeks, then long term clopidogrel
Management of haemorrhagic stroke
Control BP
Neurosurgical discussion
Management of TIA
Aspirin 300mg stat and continue for 2 weeks then clopi.
Start statin immediately
Stroke review within 24 hours
If crescendo TIA, ongoing neurological symptoms, severe cardiac stenosis or suspected cardio- Embolic cause they need admission
When is a decompressive hemicraniectomy considered in stroke?
Clinical deficits which suggest an infarct in the middle cerebral artery with a NIHSS score of > 15, decreased consciousness, signs on CT of an infarct of at least 50% of the middle cerebral artery territory
MRC power grade
0- none
1- flicker
2- moves with gravity neutralised
3- moves against gravity
4. Reduced power against resistance
5. Normal
Common triggers for migraine
Stress
Menstruation
Fasting/missed meals
Caffeine
Irregular sleep pattern
Risk factors for developing chronic migraine
Sleep disorders
Excessive use of anti- migraine medication
Emotional stress
Obesity
Increased episodic migraine attacks
Anxiety/depression
Head injury
Clinical presentation of migraine
Unilateral pulsation headache
Photophobia
N&V
Zigzags, scotoma or flashing lights in vision
Increased sense of smell
Dizziness
Pins and needles
Prodrome and postdrome
Important points to examine in headache history
Fundoscopy
Eye movements (palsy and nystagmus)
Visual fields
Cerebellar signs
Localising signs
Red flag symptoms for headache
Sudden onset
New and persistent headache
Age >50
Early morning headache
Postural symptoms
Fevers/rash/neck stiffness/photophobia
Management of migraine
Education
Avoid analgesia over use
Stop COCP
Simple analgesia
Triptans
Antiemetic
Prophylaxis- propranolol, topiramate, amitriptyline
Investigating polyneuropathy
FBC
B12
Fasting glucose/HbA1c
LFTs
U&Es
TFTS
Serum immunoglobulins and electrophoresis
NCS
EMG
CT/MRI/ nerve biopsy
What is the aetiology of Huntington’s disease?
Caused by mutations in the Huntington gene on chromosome 4 encoding a CAG- repeat expansion within the gene.
It has the genetic characteristics of complete penetrance and anticipation whereby earlier age of onset occurs in later generations due to expansion of the CAG repeat
Clinical presentation of Huntingtons
- prodrome of mild psychotic and behavioural symptoms
- chorea
- slow saccadic eye movements
- psychosis
- depression
- irritability
- dementia
Differential diagnosis for chorea
Huntington’s
SLE
Wilson’s
Stroke (asymmetrical)
Hypoglycaemia
Polycythaemia
Sydenham’s chorea (group a beta haemolytic strep)
Diagnosis of Huntingtons
FHx (inc. missed diagnosis ie. Psychiatric illness)
MRI shows changed in mod-severe disease
Genetic testing
Testing for alternative cause
Management of Huntingtons
MDT
Neurologist
Neuropsychologist
Dietitian (increased BMR)
Occupational and physical therapists
What causes myasthenia gravis?
Acquired autoimmune condition caused by autoantibodies against post-synaptic neuromuscular junction receptors
How does myasthenia gravis present?
Fatiguable weakness
Ptosis
Diplopia
Proximal weakness
Loss of facial expression
Dysarthria
Dysphagia
Slurred speech
Dysphonia
How would you investigate myasthenia gravis?
Anti- AChr antibodies in 90% of cases
Anti- MuSK (muscle specific kinase) antibodies in 10% of cases particularly Afro Caribbean
EMG: decremented response to a titanic train of impulses and EMG jitter
Tensilon test - less used now due to risk of cardiac arrest (have arrest trolley and atropine ready)
CT mediastinum to look for thymoma
TFTS (Graves present in 5% of cases)
Spirometry
Assess for infection in myasthenia crisis
Treatment of myasthenia crisis
Spirometry
Screen for infection
Critical care input if:
- FVC <20ml/kg
- progressive decline in FVC
- can’t manage secretions
- sniff nasal insp pressure <40
- can’t complete sentences or lift head off pillow
IVIg and plasmapheresis
Treatment of myasthenia gravis
Sussman protocol (steroids and pyridostigmine)
Steroids- uptitrating, at risk of steroid dip, if significant symptoms they need inpatient monitoring
Pyridostigmine (cholinesterase inhibitor)
Steroid sparing agents (MMF, aza, ect.)
Thymectomy
What is Lambert- Eaton myasthenic syndrome?
Diminished reflexes that become brisker after exercise
Lower limb girdle weakness
Associated with malignancy eg. Small cell lung cancer
Antibodies block pre-synaptic calcium channels
EMG shows a second wind phenomenon on repetitive stimulus
How does Fredereich’s ataxia present?
Young adult
Wheelchair
Ataxic gait
Pes cavus
Bilateral cerebellar ataxia
Leg wasting with bilateral upgoing plantars and absent reflexes
Posterior column signs ( loss of vibration and joint position sense)
Kyphoscoliosis
HOCM
Optic atrophy
Hearing loss
What causes Fredreich’s ataxia?
Autosomal recessive
Defect in the FXN gene which carries the code for the frataxin protein
GAA repeat expansion
Mutations cause oxidative injury associated with excessive iron deposits in the mitochondria
How would you investigate someone with suspected Friedreich’s ataxia?
NCS
Genetic analysis
ECG
Exclude vitamin E deficiency
MRI - atrophy changes
Treatment of Friedreichs ataxia
MDT
Physio
SALT
OT
Monitor cardiac function
What are the clinical signs of dystrophia myotonica?
Myopathic facies
Wasting of facial muscles and SCM
Bilateral ptosis
Frontal balding
Dysarthria
Percussion myotonia- percuss thenar eminence and watch for involuntary thumb flexion
Cataracts
Cardiomyopathy
Diabetes
Testicular atrophy
Dysphagia
What causes dystrophia myotonica?
Type 1: expansion of CTG trinucleotide repeat sequence within DMPK gene on chromosome 19
Type 2: expansion of CCTG tetranucleotide repeat sequence within ZNF9 gene on chromosome 3
Autosomal dominant
Genetic anticipation present
How is dystrophia myotonica diagnosed?
Clinical features
EMG: Dive-bomber potentials
Genetic testing
How is dystrophia myotonica managed?
Phenytoin may help myotonia
Advice against GA
MDT
Causes of ptosis
Bilateral - myotonic dystrophy, MG, congenital
Unilateral - third nerve palsy, horners syndrome
How does syringomelia present?
Weakness and wasting of small muscles of the hand
Loss of reflexes in upper limbs
Loss of pain and temperature with preservation of position and vibration sense
Charcot joints
Pyramidal weakness in lower limbs with upgoing plantars
Kyphscoliosis
Hornets syndrome
What causes syringomelia?
Progressively expanding fluid filled cavity within the cervical cord - causes LMN weakness at level of syrinx with loss of pain and temp sensation and UMN weakness below the level of the syrinx
What is a Charcot joint?
Painless deformity and destruction of a joint with new bone formation following repeated minor trauma secondary to loss of pain sensation
Causes of Charcot joint
Tabes dorsalis- hip and knee
Diabetes - foot and ankle
Syringomelia - elbow and shoulder
How does facial nerve palsy present
Unilateral facial droop
Absent nasolabial fold and forehead creases
Bell’s phenomenon: eyeballs roll upwards in attempted eye closure
Locating level of the lesion causes facial nerve palsy
Pons (MS/stroke) + 6th nerve palsy and long tract signs
Cerebellar- pontine angle (acoustic neuroma) + 5th,6th,8th palsy + cerebellar signs
Auditory/facial canal (cholesteatoma or abscess) + 8th nerve palsy
Neck and face - scars or parotid mass
Management of Bells Palsy
Steroids
Eye protection
Aciclovir if severe
Clinical signs of tuberous sclerosis
Adenoma sebaceum in butterfly distribution
Periungual fibroma
Shagreen patch
Ash leaf macules
Cystic lung disease
Renal enlargement
Transplanted kidney/evidence of dialysis
Retinal phakomas
Seizures
Signs of anti-epileptic therapy
Genetics of tuberous sclerosis
Autosomal dominant
Type 1- chromosome 9
Type 2 - chromosome 16
Renal manifestations of tuberous sclerosis
Renal angiomyolipomas, renal cysts and RCC
Investigating tuberous sclerosis
Skull films show railroad tract calcification
CT/MRI head showing tuberous masses in the cerebral cortex
Echo and US abdo show hamartomas and renal cysts
Clinical signs of neurofibromatosis
Cutaneous neurofibromas
Cafe au lait patches
Axillary freckles
Lisch nodules
Hypertension
Honeycomb lung/fibrosis
Palpable enlarged nerves
Poor visual acuity due to optic glioma/compression
Clinical signs of Horner’s pupil
Ptosis
Enophthalmos (sunken eye)
Anhydrosis
Miosis (small pupil)
Look at the ipsilateral side of the neck for scars and tumours (Pancoast’s)
Causes of Horner’s pupil
MS
Stroke (Wallenberg)
Syrinx
Aneurysm
Trama
Pancoast’s
Clinical signs of a Holmes-Adie pupil
Moderately dilated pupil that had a poor response to light and a sluggish response to accommodation
Absent or diminished ankle and knee jerks
This is a benign condition more common in females. Provide reassurance.
Clinical signs of an Argyll Robinson pupil
Small irregular pupil, accommodates but doesn’t react to light. Atrophied and depigmented iris.
Look for sensory ataxia (tabes dorsalis)
Causes of Argyll Robertson pupil
Syphilis
- tabes dorsalis
- demyelination predominantly in dorsal root ganglia
- will also have sensory ataxia and pain
- test using TPHA or FTA
- treat with penicillin
Diabetes
Clinical signs of a 3rd nerve palsy
Ptosis, usually complete
Dilated pupil
Eye points down and out
On looking nasally the eye will intort suggesting normal trochlear nerve function
Causes of a 3rd nerve palsy
Medical:
- mononeuritis multiplex
- midbrain infarct (Weber’s)
- MS
- Migraine
Surgical:
- Posterior communicated artery aneurysm
- cavernous sinus pathology
- cerebral uncus herniation
How does optic atrophy present?
Relative afferent pupillary defect: dilation of the pupil on moving the slight source from the normal eye (consensual reflex) to the abnormal eye (direct reflex)- also known as Marcus Gunn pupil
Disc pallor on fundoscopy
Causes of optic atrophy
MS
Friedreichs ataxia
Paget’s disease
