Neuro-ophthalmology Flashcards
Distinguishing features in diplopia
Monocular or binocular, horizontal or vertical, other concurrent symptoms, onset, ocular motility
How many cardinal positions of gaze are there
9
Tests for ocular motility
Exmaination of eye movement range, cover and uncover test, alternate cover test, test for stereopsis
Causes of III nerve palsy
Idiopathic, vascular or aneurysm
Causes of vascular III nerve palsy
HTN, diabetes
Aneurysm causes of III nerve palsy
Posterior communicating artery
Position of eye in IV nerve palsy
Vertical deviation
What is the role of the muscle in the affected eye of IV nerve palsy
Depression and inortion (reading muscle)
What does the mneumonic WOOG mean
Worst on opposite gaze
Which palsy is WOOG true for?
Trochlear nerve palsy
What does the mneumonic BOOT mean
Best on opposite tilt (head)
Which palsy is BOOT true for
Trochlear nerve palsy
What are the causes of trochlear nerve palsy
Congenital, trauma (closed head injuries), and microvascular (less common)
Which palsy is the most common
Abducens
What can the eye not do in VI nerve palsy
Look up and to the effected side
Childhood causes of VI nerve palsy
Congenital, trauma, tumour, elevated ICP, meningitis
Adult causes of VI nerve palsy
Microvascular, tumour, GCA, idiopathic, stroke, vasculitis
What is papilloedema
BILATERAL disc swelling secondary to INCREASED ICP
Radiological findings of papilloedema
Empty sella, dilation of optic nerve sheath, posterior scleral flatterning, bilateral transverse sinus stenosis
Causes of papilloedema
Any cause of increased ICP - tumour, haemorrhage, trauma. Meningitis, cerebral venous thrombosis, and secondary to systemic causes
What is common childhood cause of papilloedema
Craniosynostoses
What is the LP opening pressure to confirm raised ICP
> 35cm
Symptoms of papilloedema
Headaches, nausea, tinnitus, diplopia, no symptoms, visual acuity and colour vision worse or same, pupils normal
What is the grading system used for papilloedema
Frisen on scale of 1-5
What is amaurosis fagux
Transient monocular vision loss or diming. May last minutes or hours. Normal eye examination, normal neurology exam, no GCA symptoms.
Causes of Amaurosis fagux
Carotid atheroma, cardiac valve disease, atrial myxoma, retinal migraine, GCA, hyperviscosity syndromes
What is myasthenia gravis
Autoimmune disorder characterised by presence of antibodies which block the ACh receptor sites on any muscle
What % of myasthenia gravis patients have eye problems
50%
Signs of myasthenia gravis
Ptosis, ocular motility distrubances, INO, variability, eyes getting tired as day goes on
Treatment of myasthenia gravis
ACh inhibitors, steroids, immunosupressants, plasmapheresis, thymectomy
Investigations when suspected myasthenia gravis
Clinical, tensilon test, serological, sleep test, ice pack test, CT chest, TFTs and ANA
