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 Ron Teed, M.D.
 12 January 2007
 Vanderbilt Eye Institute   Alfred Bielschowsky
          Patient History I
 cc: vertical binocular diplopia
 63 yo male with 4 week history of diplopia;
  first intermittent, then constant
 Worse in right gaze
 No antecedent trauma, CVA, craniofacial
  surgery
 No history strabismus
 No history thyroid disease, myasthenia
          Patient History II
 POH: none
 PMH: DJD, hernias
 Meds: ibuprofen
 FH: no ocular disease
 SH: tobacco use in past
 ROS: no dizziness, weakness, HA, jaw
  claudication, fatigue, numbness, paresthesia
      Differential Diagnosis of
     Vertical 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 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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                Measurements


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        8 LHT     5 LHT   3 LHT

                  8 LHT
4 LHT                             10 LHT
           Additional Clinical
                 Tests
   “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
 Clinical diagnosis from Three-step test
 What do we do now?
       Superior Oblique Palsy
   Determine if this is a ISOLATED CN IV
    palsy

 No neurological symptoms on history
 Cursory neurological exam unremarkable
 Isolated 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:
       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-up
 Pt returns 8 weeks later
 “double vision is a bit better…”
 “…ever since I had the radiation treatment”
             Follow Up Exam


                      0


         5 LHT      2 LHT    5 LHT

                    4 LHT
10 LHT                               8 LHT

  DMR: 5° excylotorsion OS
               More 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 palsy
 Now what do we think is going on?
 Now what would we do?
          Imaging
   CT



   MRI
Vertical Diplopia and Pontine
             Mass
   Does this lesion explain vertical diplopia?
    – Lesion to CN IV nucleus or nerve?
    – Lesion to other pathways encoding vertical
      gaze?
            Back to the original
               presentation
   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 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 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 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?
 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 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
                         References
   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.
CT




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T1 MRI
T2 MRI
Axial




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CN IV nucleus
Otolithic Pathways

								
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