Re-DoubleRe-Double

Ron Teed, M.D.12 January 2007Vanderbilt Eye Institute Alfred Bielschowsky

Patient History IPatient History I

cc: vertical binocular diplopia63 yo male with 4 week history of diplopia;

first intermittent, then constantWorse in right gazeNo antecedent trauma, CVA, craniofacial

surgeryNo history strabismusNo history thyroid disease, myasthenia

Patient History IIPatient History II

POH: nonePMH: DJD, herniasMeds: ibuprofenFH: no ocular diseaseSH: tobacco use in pastROS: no dizziness, weakness, HA, jaw

claudication, fatigue, numbness, paresthesia

Differential Diagnosis of Differential Diagnosis of Vertical Binocular DiplopiaVertical Binocular Diplopia

Superior Oblique Palsy Thyroid Ophthalmopathy Myasthenia Gravis Brown Syndrome Orbital fracture with entrapment Cyclovertical paresis or overaction Skew Deviation/Ocular Tilt Dissociated Vertical Deviation

Exam IExam I

General: alert and oriented; no anomalous head posture; no nystagmus

BCVA 20/20, 20/20 Fields: Full OU Tonometry: 15,14 Pupils: no rAPD, no anisocoria External Exam: no proptosis, ptosis, lid retraction;

no fatigue SLE: unremarkable, quiet eyes DFE: unremarkable, no optic nerve edema/pallor

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MeasurementsMeasurements

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5 LHT

8 LHT

3 LHT8 LHT

4 LHT 10 LHT

Additional Clinical Additional Clinical TestsTests

“fourth step”– Measurement of ocular torsion– Double Maddox Rod: 5° excylotorsion OS

Vertical Fusional Amplitudes- Large amplitudes suggest congenital etiology- 3 prism diopters

Superior Oblique Palsy Superior Oblique Palsy

Clinical diagnosis from Three-step testWhat do we do now?

Superior Oblique PalsySuperior Oblique Palsy

Determine if this is a ISOLATED CN IV palsy

No neurological symptoms on historyCursory neurological exam unremarkable

Isolated Superior Oblique PalsyIsolated Superior Oblique Palsy

Most common etiologies are congenital and traumatic

Also vascular; less commonly tumor, demyelinating

In absence of other neurological symptoms and presence of vascular risk factors, reasonable to observe

Isolated Superior Oblique Palsy: Isolated Superior Oblique Palsy: Management Plan Management Plan

Our patient did not have obvious vascular risk factors other than age– No known HTN, hyperlipidemia, DM

Patient was observed– To return if diplopia changes, ptosis develops,

or he has any numbness, weakness, paresthesias, disorientation, unsteadiness, vertigo, headache

Patient Follow-upPatient Follow-up

Pt returns 8 weeks later“double vision is a bit better…”“…ever since I had the radiation treatment”

Follow Up ExamFollow Up Exam

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2 LHT

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DMR: 5° excylotorsion OS

More HistoryMore History

A few weeks after first visit, pt developed unsteady gait, disequilibrium associated with flank pain

No longer isolated fourth nerve palsy– Measurements no longer map to superior

oblique palsyNow what do we think is going on?Now what would we do?

ImagingImaging

CT

MRI

Vertical Diplopia and Pontine Vertical Diplopia and Pontine MassMass

Does this lesion explain vertical diplopia?– Lesion to CN IV nucleus or nerve?– Lesion to other pathways encoding vertical gaz

e?

Back to the original Back to the original presentationpresentation

Was it right to observe an apparent isolated CN IV palsy?– Texts, review articles suggest that observation is

acceptable, particularly if the palsy is suspected to be congenital, traumatic, or there is a vascular risk factor

– Spontaneous resolution of CN IV palsy occurs within 3 months in 50-95% of patients (better in presumed vascular etiology)

– Up to one third have undetermined etiology

Watching the CN IV palsyWatching the CN IV palsy

“evaluation for an isolated fourth nerve palsy usually yields little information... Older patients should be followed” (BCS, Neuro-ophthalmology)

“MRI…for all patients younger than 45 years with no definite history of significant head trauma, and patients aged 45 to 55 years with no vasculopathic risk factors or trauma” (Wills Eye Manual)

The EvidenceThe Evidence

Multiple case series of presumed isolated CN IV palsies– No documented tumors as etiology (Keane 1993: 0/81)– But may fail to adequately confirm true isolation or

confirm true CN IV palsy

Lee et al (1998) reviewed cost-effectiveness of imaging– No need to image suspected congenital, traumatic, or

vasculopathic palsies

The RebuttalThe Rebuttal

A few case reports of isolated CN IV palsies from brainstem strokes

Feinberg and Newman (1999): 6/68 isolated CN IV palsies related to trochlear nerve Schwannoma

Scattered other reports of isolated CN IV palsy from other conditions:– Pituitary macroadenoma– MS, polycythemia rubra

So what do we do?So what do we do?

What is your level of comfort?How good is your neurological exam?

Reasonable and cost-effective to observe, but you may miss an important lesion

Take Home PointsTake Home Points

Determine if an apparent superior oblique palsy is truly isolated

If isolated, it may be reasonable to observe Understand basic anatomy of the pathways

encoding vertical eye movements

ReferencesReferences Brodsky MC, Donahue SP, Vaphiades M, and Brandt T (2006). Skew Deviation

Revisited. Survey of Ophthalmology. 51:105-128. Donahue SP, Lavin PJM, and Hamed LM (1999). Tonic Ocular Tilt Reaction

simulating a superior oblique palsy. Archives of Ophthalmology. 117:347-352. Feinberg AS and Newman NJ (1999) Scwannoma in patients with isolated unilateral

trochlear nerve palsy. American Journal of Ophthalmology 127:183-88. Keane JR (1993). Fourth nerve palsy: Historical review and study of 215 inpatients.

Neurology. 43:2439-2443. Kusher BJ (1989). Errors in the Three-Step Test in the Diagnosis of Vertical

Strabismus. Ophthalmology. 96:127-132. Lee AG, Hayman LA, Beaver HA, et al (1999). A guide to the evaluation of fourth

cranial nerve palsies. Strabismus 6(4): 191-200. Petermann SH and Newman NJ (1999). Pituitary Macroadenoma manifesting as an

isolated fourth nerve palsy. American Journal of Ophthalmology 127:235-6. Thomke F and Ringle K (1999). Isolated superior oblique palsies with brainstem

lesions. Neurology. 53(5):1126-27.

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T1 MRIT1 MRI

T2 MRIT2 MRI

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CN IV nucleusCN IV nucleus

Otolithic PathwaysOtolithic Pathways