NV - Double Vision I - Week 4 Flashcards
List 8 history questions that should be asked if a patient complains of double vision.
Does it disappear if you cover one eye? Are both images the same? Orientation? Change with D/N viewing? Change with gaze direction? Onset? Better or worse over time? Constant or varying?
What should be done for double vision cases?
Basic neurological screening examination
What is the most common cause of double visiond?
Ischaemic oculomotor nerve palsies
Is it common or uncommon for ocular media to cause double vision? What kind of double vision would you expect?
Uncommon
-monocular double vision
List 6 examples of ocular media that can result in double vision.
High astigmatism Incorrect Rx Corneal disease Iridectomy Decentred IOLs Cataract
What are three vital clues that indicate monocular double vision may be present?
2 images are unequal
-one is clearer, the other is a ghost
2 images that are almost touching each other
Double vision persists despite covering one eye
What is one of the most common causes of double vision involving the orbit/EOMs and how does it cause double vision? List three additional causes of double vision involving the orbit/EOMs.
Thyroid orbitopathy -resitricts one of the EOMs Orbital myositis Mitochondrial myopathy CPEO -chronic progressive external ophthalmoplegia
List a condition that can mimic double vision.
Myasthenia gravis
What three nerves are often the most dangerous if involved with double vision and why?
CN3, 4, and 6 because they are often caused by an intracranial aneurysm or brain tumour compression
What percentage of CN3 palsies are life-threatening?
Up to 33%
If a patient has a life-threatening CN3 palsy, how long after onset of double vision may death occur?
They may die within hours or days of onset
What is often the first presenting complaint in patients with an undiagnosed brain aneurysm?
Double vision
Are partial CN3 palsies easy or hard to diagnose? Explain why.
Hard because they can present with various patterns of motility deficits
Is the rule of pupil a good way to gauge whether a brain aneurysm is present or not?
No
What three things can cause double vision originating in the brain?
Stroke
Tumour
Degenerative disease
List 6 possible causes of CN3 palsies. Note the most common.
Compression -aneurysm Tumours Raised intracranial pressure Ischaemia (most common) Inflammation Trauma
List four ischaemic causes of CN3 palsies.
Diabetes
Hypertension
GCA
Atherosclerosis
List two inflammatory causes of CN3 palsies.
Multiple sclerosis
Infection
What is one of the earliest ocular changes that can occur with double vision?
Ptosis
What pupil change is often present with double vision?
Increased size
What two causes of double vision generally result in pain? What about persistent severe pain?
Compressive
Ischaemic
-aneurysm more likely than ischaemic with persistent severe pain