diplopia Flashcards
What are the 5 differential diagnosis of diplopia?
- emergent
- refractive
- functional
- neuropathological
- mechanical
Patient presents with diplopia. How do we rule out an emergency?
! all of the oculomotor, including the pupil, and / or the abducens nerve involved
! the pa+ent is distressed, not well
! the pa+ent displays other neurological signs
! eg, change in mental status ! severe headache
Patient presents with
- sudden onset
- focal neurological signs/symptoms
- CN 7 (drooping on one side of face)
- mental status
- patient has risk factors for stroke
stroke
Within how many minutes of the onset of a stroke, may be possible to reduce morbidity significantly?
180
What are the two types of stroke? and which is easier to save?
Type 1: occlusive **easier to save
Type 2: hemorrhagic
patient presents with emergency diplopia, what do we check for next?
is it monocular or binocular?
number one cause for monocular diplopia
astigmatism
which of the diplopias are acquired?
binocular
if its monocular diplopia, what do we do?
refract, then check the media (opacities or dislocated lens)
what if its binocular diplopia?
check for comitant deviation
what is comitant?
size of the deviation is within 5 or fewer prism diopters in ALL positions of gaze
what is incomitant?
size of the deviation is greater than 5 prism diopters in some positions of gaze
3 characteristics of comitancy testing
- be a good observer
- muscle field testing
- projection testing
what are 2 types of muscle field testing?
red lens and cover test
what are 3 types of projection tests?
- allied ring fusion test (ARFT)
- Hess Lancaster Screen
- Foster torches
What do you do if the deviation is comitant?
- perform functional analysis
- manage
- remember spread of comitancy
whats important about spread of comitancy
deviation started incomitant then became comitant over time
5 signs that spread of comitancy: problem has been there for a while
- abnormal head position
- large fusional reserves
often associated with: - diplopia related to fatigue
- cyclophoria
- A or V syndrome
what do we check for next, if deviation is not comitant?
does it match CN control?
how do we check if it matches CN control?
- identify the paretic EOM
2. is the ocular misalignment horizontal, or does it have a vertical component?
what do we check for if deviation is purely horizontal?
eso vs exo
> on L or R gaze
an exo deviation greater on left gaze: what muscle?
RMR
exo deviation greater on right gaze: what muscle?
LMR
eso deviation greater on left gaze: what muscle?
LLR
eso deviation greater on right gaze: what muscle?
RLR
What are the 3 questions to ask for vertical component deviations?
- which is the hyper eye
- is the deviation greater on left or right gaze
- is the deviation greater on head tilt to the left or to the right
how do you interpret the pattern of paretic EOMS? (2)
- pattern of EOM paresis conforms to the innervation of a single cranial nerve.
- the pattern of impaired muscles does NOT match single nerve damage
what do you do when the pattern conforms to the innervation of 1 nerve (3)?
locate the pathology
locate the neuropathology
analysis
✿ oculomotor nerve - nerve, fascicle, nucleus
✿ superior oblique muscle: 4th cranial nerve
✿ abducens nerve
✿ more than one cranial nerve
✿ spread of comitancy
locate the pathology and analysis
! Testothercranialnerves
! Remember that the normal eye exam includes tests of CNs 2 through 8
! Testthepyramidalmotorsystem
locate the neuropathology
4 DDX for SO EOM affected
- blunt head trauma
- small vessel disease
- congenital
- idiopathic
- pertinent history, head tilt
- risk factor (e.g., DM, HTN)
- large vertical fusional reserves
- cylco-deviation
what to look for when SO EOM affected
3 DDX when LR EOM affected
- small vessel disease
- elevated ICP
- myasthenia gravis
3 things to look for when LR EOM is affected
- risk factors (DM and HTN)
- papilledema, (-) SVP
- worse with fatigue, repeated use
5 DDX when MR, IR, IO, SR, and levator is affected
- small vessel disease
- space occupying cranial mass
- brainstem stroke
- cavernous sinus
- orbital apex
4 things to look for when MR, IR, IO, SR, and levator is affected
- risk factor
- papilledema, loss of SVP
- focal brainstem signs
- other CN involvement
3 DDx when LR &/or SO &/or MR, IR, IO, SR, & levator are affected
- cavernous sinus
- orbital apex
- MG
4 things to look for when LR &/or SO &/or MR, IR, IO, SR, & levator are affected
- CN V involvement
- orbital bruit
- red eye
- pulsating exophthalmos
2 DDx when SR & levator or
MR, IR, IO are affected
- orbital apex disease affecting superior or inferior division of cn 3
- MG
4 things to look for whe SR & levator or
MR, IR, IO are affected
- exophthalmos
- resistance to retropulsion
- papilledema (loss of SVP
- other CN involvement
If the third nerve is involved, including the pupil, it is an ___________ unless you are confident it is not.
EMERGENCY
5 Ddx if the pattern does not fit cranial nerve damage
- MG
- INO
- Duane’s retraction syndrome
- aberrant regeneration syndromes
- mechanical impediments to EOM action
if the levator or variable is affected what do you think of (Dx)?
MG
what are two things to look for if levator or variable is affected?
- worse with fatigue
2. better with rest
4 things to do when its MG?
- History
- tensilon test
- ocular and systemic forms
- review swallowing and breathing
! Mode of action: anti-anticholinesterase
! Finding goes away for 2-10 minutes
! Remember actions of the cholinergic (parasympathetic) system
! Be prepared for fainting, vomiting
tensilon test in suspected MG
4 DDx when MR (isolated or bilateral) is affected
- MS
- TRO
- trauma/surgery (orbit)
- stroke (MLF)
5 things to look for when MR (isolated or bilateral) is affected
- INO
- exophthalmos
- periorbital edema
- inferior corneal staining
- worse with fatigue
what are the 3 main defining characteristics of INO?
- ADduc+on of 1 or both eyes is impaired (cf isolated MR palsy)
- Convergence is spared
ie: MR(s) “impaired” on versions but spared on convergence - Nystagmus of the ABducting eye only (unilateral nystagmus)
what are the 3 forms of INO?
- unilateral
- bilateral
- 1.5
what is 1.5 INO?
INO to one side + gaze palsy to other side
what do u think of if its unilateral and 1.5?
stroke
what do u think of if its bilateral in right age group?
think MS
what are 2 things to look for in MS?
- internuclear ophthalmoplegia, esp bilateral
in right age group - Optic neuropathy, esp. +APD. 20% of MS presents with optic neuropathy
somatic symptoms, such as weakness or paresthesia in arms & feet, stumbling, clumsiness, decreased bladder control, Uthoff’s sign
MS
whats the basic picture of Duane’s Retraction Syndrome?
eye retracts into globe on attempted eye movement
whats the most common form of Duane’s retraction Syndrome?
looks like esotropia at first glance
T/F: Duane’s retraction syndrome is congenital and benign
true
how many types of Duane Retraction Syndrome are there?
- type 1: intermittent congenital esotropia
2 type 2: exotropia
combinations of muscle actions “don’t make neurological sense”
e.g. lid elevation on down gaze
from sub-acute or previous pathology
aberrant regeneration syndromes
what do you think (Dx) of when theres a mechanical impediments to EOM action?
orbit
what Dx do you think of when IO (isolated) is affected?
blow out orbital fracture
what to look for when IO (isolated) is affected?
pertinent history
What are the 2 Ddx when IR (isolated) is damaged?
- TRO
2. MG
What are the 4 things to look for when IR is damaged?
- exophthalmos
- periorbital edema
- inferior corneal staining
- worse with fatigue
5 Ddx when MR (isolated or bilateral) are affected?
- MS
- TRO
- MG
- Trauma/surgery (orbit)
- stroke (MLF)
what are the 5 things to look for when MR is affected?
- INO
- exophthalmos
- perioorbital edema
- inferior corneal staining
- worse with fatigue
what are the 4 things to rule out when there are mechanical impediments to EOM action?
- orbit mass
- cellulitis
- trauma
- surgery
Thyroid related orbitopathy accounts for 90% of what?
exophthalmos
thyroid related orbitopahy accounts for probably more than 90% of diplopia due to what?
orbital pathology
! binocular diplopia
! ocular irrita+on
! “my eyes look funny”
TRO symptoms
emergent ! refractive (monocular) ! functional (comitant misalignment) ! neuropathological (incomitant misalignment) ! onenerve ! notonenerve ! mechanical impediments to EOM action
diplopia