Diplopia Flashcards
Chapter 17
5 step approach to diplopia. Why is the first step so important?
Monoccular (eye problem) vs binonocular (misallignment of visual axis. Monooccular will not resolve if you close one eye, binocular will
Is there a restrctive or mechanical ussue in orbit or orbital structures
Is there a palsy of a cranial nerve
New brainstem process
Systemic neuromuscular disease
What is cerebral diploplia?
Also known as polyopia - when you see imany images instead of just double. Can be mono or bi. Associated with anything in the brain (stroke, vascular spasm, tumor, MS, trauma, infection or seizure of occipital or temporal region
Three types of diplopia and what they most commonly represent?
Horizontal (images side by side) = medial or lateral rectus problem
vertical (images on top of each other) = brainstem or CN 6
torsional (images off axis or rotating) = superior or inferior oblique problem or lateral medullary syndrome
3 red flags your diplopia represents MG?
Ptosis
Intermittent
Worse at the end of the day
What red flag cause do you worry about with sudden onset diplopia?
ischemia - espeically if maximal at onset
Most common EOM to be trapped with orbital fracture?
Inferior rectus - cant track on upward gaze (locked down and out)
CN palsy including a blown pupil. What and where is the cause you are worried about?
Anneursym at the junction of the posterior communicating artery PCoA. Smaller branch off internal carotid.
Blown pupil you worry about mass effect because those fibers are on the outside of the nerve
*not the posterior interior cerebellar artery - that comes off vertebral
What are the findings of myositis vs CN palsy? What is mechanical diplopia and what does it represent?
myositis abruptly impaired away from muscles whereas palsy is progressivly smoothly impaired towards weakened muscle.
Mechanical - having a patient look in the direction of the problem leads to symptoms. Seen with mass in orbit or swelling from trauma.
Why does thyroid disease cause double vision?
enlargement or fibrosis of the EOM. Most common in Graves, can occur before other systemic symptoms.
Stigmata of eyelid disease includes: proptosis, eyelide retraction, difuse conjunctival edema and vascular injection. (Buldging, eyelids back, red)
5 causes of an isolated CN palsy?
HTN
DM
MS (demylinating)
IIH
Trauma
Compression
Which isolated CN palsy is most common for diplopia?
CN 6 it is the super long nerve that gets stretched- can be bilateral too (compression from increased ICP)
Rapid fire - what are you worried about:
A - ipsilateral palsy of 3,4 and 6
B - symptoms are ipsilateral and you have V1 and V2 facial numbness
C - isolated CN 6 in someone who just got a dental block
D - also have nausea, vertigo, slurred speech
E - multiple CN palsy and autonomic signs
F - INO
G - crossed findings with neuro deficits on opposite side of body
H - Opthalmoplegia, ataxia and areflexia
I - Variably trigered symptoms in multiple direction without a distinct structural cause
A - cavernous sinus or orbital apex problem (nerves run in close proximity)
B - Orbital apex syndrome (trigeminal branches pass through same area)
C - cavernous sinus pathology (6 goes through there, not 3 or 4 they are in wall,)
D - brainstem issue
E - Botulism (dry mouth, ielus, postural hypotension, resp muscle weakness
F - MS
G - lacunar stroke
H - Miller Fischer syndrome (varient of GBS)
I - Nueromuscular (MG or botulism)
Most common CN problem in wernickes
Remember opthalmoplegia = palsy of cranial nerve affecting an eye
CN 6 - from metabolically induced lesions or certain regions (pontine tegmentum, abducens nucleas)
2 bedside tests for MG?
Ice test - put ice on closed eye for 5 minutes, eye lid moves 5mm or imporvement positive - 80 sensitive, 25 spec
Fatigability on upward sustained gaze - 80% sens and 63% spec
What is first step with assessment of monoocular diplopia?
Pinhole test (if refractory error will improve with this, then can send for outpatient opthomology). If no imporvement consult optho that day
Rosens important causes of Diplopia
