Discs and Neurology Flashcards
What are the common causes of bilateral swollen optic discs?
Papilloedema (e.g from cerebral venous thrombosis, meningitis, tumour, bleed, IIH)
Hypertensive retinopathy
Pseudopapilloedmea (elevated but not swollen optic discs) - can be due to optic disc drusen
What are important Qs to ask in history in patient with papilloedema?
Headaches? (worse in morning, bending over, waking up from sleep) (raised ICP)
Nausea/vomiting? (raised ICP)
Transient Visual obscurations? (very short lasting greying/blacking/blurring out of vision (don’t last as long as amaurosis fugax which is between 2-30mins).
Also need to check if enlarged blind spot on testing?
Fever, rash, photophobia, neck stiffness, FLAWS. (meningitis)
Previous blood clots, blood disorders, COCP, Pregnant (assessing venous thrombosis risk)
Weight/recent weight gain (IIH)
NB// the main life-threatening cause you want to rule out urgently is cerebral venous thrombosis
What investigations needed in papilloedema?
Urgent CT Venogram + CT Head
(if MRI Head possible, then do that for SOL)
If no SOL found -> patient will need LP
Remember IIH is a diagnosis of exclusion
What is the management of IIH?
Medical Referral (who may start acetazolamide)
Weight loss and diet change
From ophthalmology perspective, regular follow up of visual field testing
In cases refractory to medical treatment, surgical shunts are option
What are the symptoms of IIH?
Persistent headache
Transient visual obscurations
Bilateral swollen optic discs
Enlarged blind spots
Blurring of vision, especially if lying down
Pulsatile tinnitus (raised ICP compresses veins, increases turbulence upstream)
What are the symptoms of optic neuritis?
Reduced VA, eye pain at rest and on movement, reduced colour vision
RAPD
Causes of optic neuritis?
Typical = demyelinating lesions i.e MS
Atypical = range of random stuff e.g autoimmune optic neuropathy
The main role of ophthalmologist is to differentiate the two, because the visual loss in the latter is responsive to prompt steroid treatment.
What investigations would you do for optic neuritis?
MRI Head and Spine (to check for MS)
I think LP is only performed if MRI inconclusive (to check for oligoclonal bands, which are atypical IgG antibodies seen in the CSF but not serum in MS.
What are the causes of a unilateral swollen optic disc?
- Anterior Ischaemic Optic Neuropathy (AION) (of which there are two types, arteritic vs non-arthritic)
- Optic Neuritis
-CRVO
What is the most common cause of arteritic AION?
GCA
What is the most common cause of non-arthritic AION?
CVS Risk factors i.e. patient will be a vasculopath
- high cholesterol, high BP, smoking, diabetes
What is the investigation and management of suspected GCA?
Investigations:
Urgent Bloods (ESR) - in first instance
USS Temporal Arteries
Temporal Artery Biopsy
Management:
-Admit under medics
-High dose oral steroids or IV methylprednisolone
-Rheumatology follow up and eventual tapering of steroids after response - total steroid duration usually 1-2 years including tapering.
NB// GCA with vision affected is an ophthalmological emergency
What is the prognosis if vision affected in GCA?
Prompt steroid treatment should improve vision
I think if only small amount of vision lost, there’s chance of some improvement with prompt
treatment, but if significant loss of vision, unlikely to be recovered.
What are the signs/symptoms of 3rd nerve palsy?
Down and Out Pupil
Dilated ‘blown’ pupil - as a general rule, suggests surgical 3rd nerve palsy although the rule CANNOT BE RELIED ON
Inability of pupil to constrict to light or accommodation reflexes. (the sphincter papillae is innervated by parasympathetic fibres running along CN3.
Ptosis
What is the most important cause of 3rd nerve palsy that needs to be urgently excluded? What are other causes?
You must rule out PCA aneurysm as a matter of urgency (i.e. through CT angiogram)
Other causes:
-tumour
-cavernous sinus thrombosis or carotid-cavernous fistula (CCF) - both of which essentially increase pressure in cavernous sinus and compress CN3.
-medical causes - HTN and diabetes
What investigations/management needed for 3rd nerve palsy?
medical referral -> CT angiogram of head +/- neurosurgery discussion if pathology present
Also do,
blood pressure
Hba1c
What are the signs/symptoms of trochlear nerve palsy?
You lose function of superior oblique, so eye moved in opposite direction -> up and in (when looking straight ahead)
Vertical diplopia which is worse on downgaze e.g reading a book, looking at phone
What are the causes of trochlear nerve palsy?
SOL
trauma
congenital
infection
etc etc.
What is myasthenia gravis?
Antibodies against Acetylcholine receptors on post synaptic membrane
Causing muscle fatiguability
What are the signs/symptoms of myasthenia gravis?
muscle fatiguability which particularly affects EYES, MOUTH, LUNGS
Therefore you get
eyelid drooping, double vision, issues with speech, difficulty swallowing, difficulty breathing
What investigations would you do in Myasthenia Gravis?
ACHr antibodies
SPIROMETRY
CT Thorax to exclude thymoma
Tensilon test is not really done anymore
Management of MG?
NEUROLOGY REFERRAL
REGULAR SPIROMETRY IS KEY TO MONITOR RESPIRATORY EFFORT
(immediate treatment) Increase ACH
-Acetylcholinesterase inhibitors - pyridostigmine (4-5 times/day)
Suppress immune system/Reduce antibodies
-Steroids to suppress the immune system
-In severe cases, IV Immunoglobulins and/or Venesection
