This document discusses the differential diagnosis, examination, and management of diplopia presenting in the emergency department. It begins with an example case of a 65-year-old man with diabetes and hypertension presenting with acute onset binocular diplopia and left eye ptosis. Physical examination reveals a left third nerve palsy with pupillary sparing, consistent with a "diabetic third" palsy. For isolated third nerve palsies with pupillary sparing, imaging may not be necessary and outpatient follow up is appropriate. The document reviews cranial nerve anatomy, causes of diplopia, techniques for cranial nerve examination, and indications for emergent neuroimaging.

1. Double Vision
Emergency Department
Diagnosis and Management
J. Stephen Huff, MD
Departments of Emergency Medicine and
Neurology University of Virginia
Charlottesville

2. J. Stephen Huff, MD
Objectives
• Questions
– What is the differential diagnosis of diplopia?
– What causes ptosis and why is it important?
– What examination techniques are useful?
– What are the indications for emergent imaging?
• Neuroimaging
– Tests
– Tempo
• Management - referral, consultation

3. J. Stephen Huff, MD
The Case
A 65-year-old man presented to the ED
complaining of acute onset double
vision. He denied headache, fever,
weakness, dizziness, trauma, or change
in mental status. Past medical history
was positive for diabetes and
hypertension. Medications included
insulin and enalapril. He denied tobacco
use or alcohol use.

4. J. Stephen Huff, MD
The Case - continued
On physical exam: BP 160/90, P 80, RR 16, HR
98, pulse oximetry 99%. Head atraumatic, no
scalp tenderness; eyes visual acuity 20/30
(corrected); pupils 4 mm and reactive; OS
ptosis; OS pupil in a down and out position.
Diplopia was minimal when looking to the left
and pronounced when looking to the right.
Fundi sharp discs. Remainder of neurologic
examination was normal.

5. J. Stephen Huff, MD
Patient looking at target straight ahead

6. J. Stephen Huff, MD
Neurologist’s Diagnostic
Approach
• Is there a problem of the nervous
system?
• Where is the problem?
• What is the problem?
• Many esoteric and uncommon
problems...

7. J. Stephen Huff, MD
Solomon and Aring remarked in a
1934 paper,
“A knowledge of the more common causes of coma [read
diplopia] as a presenting sign, and the relative frequency of
these causes, would obviously be helpful in making the
diagnosis.…The textbooks are of little assistance. They
mention many causes of coma [diplopia] and discuss at
length some that are rare, while others that are more
common they do not include at all. They do not attempt to
give any idea of the relative frequency of the various
causes.”

8. J. Stephen Huff, MD
Evidence-based approach
• Diplopia in the Emergency Department
• ISOLATED chief complaint
–Not part of more complex
symptomatology
• Medline / Ovid
• Other data bases….

9. J. Stephen Huff, MD
Evidence-based approach
• Little data….many opinions….
• One hit!
• Morris RD: Double vision as a
presenting symptom in an
Ophthalmic Casualty Department.
Eye 1991;5:124

10. J. Stephen Huff, MD
From the Casualty Department
of Moorfield’s Eye Hospital
• 275 consecutive patients over 9 months
– Ambulatory patients
– Referrals by general practitioners, opticians
– Excluded referrals for second opinion by
ophthalmologists
• 1.4% of all patients to this specialized ED

11. J. Stephen Huff, MD
275 consecutive patients
• 25% - monocular diplopia
• 75% - binocular diplopia

12. J. Stephen Huff, MD
Monocular diplopia
• Extra-ocular
– problems with optical lens or contacts
• Ocular (most common)
– Lids - chalazion
– Cornea - infections, trauma, keratoconus (25%)
– Iris - pharmacologic mydriasis
– Lens - opacities, cataracts, IOP (39%)
– Retinal - detachment, CRVO, neovascularization
• Trauma
• No cause established -psychogenic? (12%)

13. J. Stephen Huff, MD
Binocular diplopia - 206 patients
• Cranial nerve palsies- infranuclear-(39%)
• Muscular (14%)
– Thyroid
– Myasthenia
• Orbital sinusitis, cellulitis, tumor (4%)
• Trauma - blowout fracture, blunt trauma,
post-surgical (13%)
• Supranuclear lesions (7%)
• No cause established (11%)

14. J. Stephen Huff, MD
Cranial nerve palsies-
infranuclear (39%)
• Cranial Nerve III
– Diabetes / Vascular
– Pituitary tumor
• Cranial Nerve IV
– Congenital
– Diabetes / Vascular
– Trauma
• Cranial Nerve VI
– Diabetes / Vascular
– MS
– CNS tumor
– Pseudotumor

15. J. Stephen Huff, MD
Supranuclear lesions (7%)
• Internuclear ophthalmoplegia (MS)
• Brainstem ischemia
• Migraine
• Wernicke’s encephalopathy

16. J. Stephen Huff, MD
Ophthalmologic Casualty
Department
Summary
• Wide range of ocular and
neurologic disorders
• “Don’t miss” diagnoses uncommon
–CNS tumor
–Aneurysm

17. J. Stephen Huff, MD
Questions
Approach to the patient
• Are there associated signs and symptoms?
• Is the diplopia monocular or binocular?
• Is there any exophthalmos or proptosis?
• Is there any associated ptosis?
• Was the onset acute or gradual?
• Is there any variability or remission?
• Was there any pain?

18. J. Stephen Huff, MD
Are there associated signs and
symptoms?
• Severe headache?
• Weakness?
• Fatigue?
• Paralysis?
• Clumsiness / unsteady gait?
• Multiple cranial nerve palsies?
– If so, there are other problems...

19. J. Stephen Huff, MD
Is the diplopia
monocular or binocular?
• Monocular - likely refractive or
ocular problem
• Binocular - likely an isolated cranial
nerve problem

20. J. Stephen Huff, MD
Is there any exophthalmos
or proptosis?
• Infiltrative lesions
• Myopathy
–Thyroid
• Sinusitis
• Orbital abscess
• Orbital cellulitis

21. J. Stephen Huff, MD
Is there any associated ptosis?
• Bilateral- may suggest myasthenia
• Unilateral-suggests cranial nerve III
problem
–Horner’s?

22. J. Stephen Huff, MD
Was the onset acute or gradual?
• Acute
–Vascular
–Stroke
–Ocular?
• Gradual
–Infiltrative lesions
–Myopathies

23. J. Stephen Huff, MD
Is there any variability or
remission?
• Variability
–Multiple sclerosis
–Myasthenia

24. J. Stephen Huff, MD
Was there any pain?
• Folklore...
• Aneurysms may be painful
–infections
• Vascular lesions may be painless
–MS
–Myopathy

25. J. Stephen Huff, MD
Questions - Our Patient
• Are there associated signs and symptoms?
No
• Is the diplopia monocular or binocular?
Binocular
• Is there any exophthalmos or proptosis? No
• Is there any associated ptosis? Yes
• Was the onset acute or gradual? Acute
• Is there any variability or remission? No
• Was there any pain? No

26. J. Stephen Huff, MD
Summary
Our Patient
Painless isolated binocular diplopia
of acute onset with ptosis but
without proptosis or exophthalmos
in a patient with diabetes and
hypertension...

27. J. Stephen Huff, MD
Physical examination
• Monocular or binocular?
– Cover eye...
– Glasses / contacts off...
– Pinhole-may correct monocular diplopia
– Cataract or disc problem?
• Proptosis or exophthalmos?
– Look
– Feel

28. J. Stephen Huff, MD
Physical examination
• Associated neurologic
abnormalities?
• Define cranial nerve problem
–Observe
–Tracking / yoke movements
–Pupillary reaction

29. J. Stephen Huff, MD
Physical examination-review
• H - tracking movements eyes
• Cranial nerve III
– Actions- moves globe up, down, in
– Pupillary constriction
– If weak, may have unopposed abduction (down and
out)
• Cranial nerve IV
– Superior oblique (SO4)
– Actions- Intorsion, depression
• Cranial nerve VI
– Lateral rectus
– Actions - Abduction
– If weak, may have unopposed adduction

30. J. Stephen Huff, MD
“Laws of diplopia” - DeMyer
• Describe the images; identify the
position of maximum diplopia...
• Identify the eye that produces the false
image; the false image is projected
peripheral to the true image and is often
less sharp...
• When the patient looks in the direction of
action of the paretic muscle, the
distances between images increases...

31. J. Stephen Huff, MD
“Laws of diplopia” - DeMyer
• Allows reasoning of which muscle is
weak and identification of cranial
nerve abnormality...

32. J. Stephen Huff, MD
Patient looking at target straight ahead

33. J. Stephen Huff, MD
Our patient
• Cranial nerve III problem
• Patient’s left eye deviated laterally
from unopposed action of lateral
rectus (IV)
• In our patient (not this picture!)
pupil reactivity is spared...

35. J. Stephen Huff, MD
Cranial nerve III caveats
• Aneurysmal compression common
– Generally, painful
– Generally, pupillary reactions affected
• Diabetic III neuropathy (“vasculopathic”)
– Generally, pupil reactivity spared
– Generally, painless

36. J. Stephen Huff, MD
Diabetic III palsy
• Pupillary sparing “almost always”
present
• Pupillomotor fibers travel on outside III
– Selectively vulnerable to compression
– Resistant to ischemia which often affects
central portion of III

37. J. Stephen Huff, MD
The Case
A 65-year-old man presented to the ED
complaining of acute onset double
vision. He denied headache, fever,
weakness, dizziness, trauma, or change
in mental status. Past medical history
was positive for diabetes and
hypertension. Medications included
insulin and enalapril. He denied tobacco
use or alcohol use.

38. J. Stephen Huff, MD
The Case - continued
On physical exam: BP 160/90, P 80, RR 16, &
98, pulse oximetry 99%. Head atraumatic, no
scalp tenderness; eyes visual acuity 20/30
(corrected); pupils 4 mm and reactive; OS
ptosis; OS pupil in a down and out position.
Diplopia was minimal when looking to the left
and pronounced when looking to the right.
Fundi sharp discs. Remainder of neurologic
examination was normal.

39. J. Stephen Huff, MD
Physical examination
• Associated neurologic abnormalities?
No
• Define cranial nerve problem
– Cranial nerve III, isolated, with pupillary
sparing
• This is likely a patient with a “diabetic
third” palsy; consultation and outpatient
followup is an option….

40. J. Stephen Huff, MD
Objectives-revisited
• Questions
– What is the differential diagnosis of diplopia?
– What causes ptosis and why is it important?
– What examination techniques are useful?
– What are the indications for emergent imaging?
• Neuroimaging
– Tests
– Tempo
• Management - referral, consultation

41. J. Stephen Huff, MD
Neuroimaging-general remarks
• Our patient
– Painless isolated III palsy with pupillary sparing
– Consensus--may forego imaging with followup
– If pupillary reactivity impaired (or becomes
impaired), consider emergent neuroimaging,
consultation
• Isolated VI palsy suggests increased ICP
• Multiple cranial nerve palsies or other
abnormalities on examination - image and
consult

42. J. Stephen Huff, MD
Take a closer look at this patient--
Pupils are asymmetric!