Download Snydsman, Brian - American Academy of Optometry

American Academy of Optometry Annual Meeting 2009
Resident’s Day Case Presentation
Brian Snydsman, OD
Abstract: Patient presents with diplopia due to bilateral sixth nerve palsies. An intracranial
mass is present in the absence of papilledema, which is identified as a chordoma, a brain tumor
commonly associated with extra-ocular motility dysfunction.
A 65 year old Caucasian male presented to the San Francisco VAMC with a chief complaint of
horizontal diplopia of slow, progressive onset over the last 2-3 years. His diplopia is currently managed
with prism but the patient has been told that he has the maximum possible in his glasses. He is still
symptomatic for diplopia and has taken to wearing a patch over one eye when he wishes to eliminate
his diplopia. His medical history is significant for non-Hodgkin’s lymphoma, in remission since 2001,
depression, gastro-intestinal reflux disease, hypertension, coronary artery disease, and
hypercholesterolemia. Current medications include amlodipine, buproprion, lisinopril, metroprolol,
omeprazole, rosuvastatin, and sertraline. Ocular history is significant for a left fourth nerve palsy
diagnosed at the San Francisco VA in 2005.
Upon physical exam a non-comitant left esotropia is noted with bilateral sixth nerve palsies,
with the left sixth nerve more severely affected. Best corrected acuity is 20/20 in either eye. Optic
nerve findings are consistent with previous exams with C/D ratios of 0.40 in either eye with distinct
margins and no obscuration of blood vessels. The on-call neurology resident examined the patient,
concurred with the diagnosis of bilateral sixth nerve palsies in the absence of papilledema or other
neurological signs, and ordered a MRI with and without gadolinium contrast and a MRA to determine
the cause of the bilateral sixth nerve palsies. The T1 weighted MRI showed a 2.8 cm X 2.4 cm
heterogenous mass originating from and destroying most of the clivus. The mass extends anteriorally
into the cavernous sinus bilaterally and impinges posteriorally on the brain stem. No structures are
affected superiorally or inferiorally. The mass results in lateral deflection of the left basilar artery and
mild narrowing of the left and right cavernous carotid arteries.
Based on the patient’s history and the location of the tumor, the mass was likely to be either a
recurrence of non-Hodgkin’s lymphoma or a chordoma. Biopsy identified the mass as a chordoma.
Chordomas are benign bone tumors that rarely metastasize but are often locally invasive. Chordomas
originate from remnants of the notochord, an embryologic structure, that become trapped in the
vertebral bone structures. 50% of all chordomas arise in the sacro-coccygeal region of the spinal cord,
15% along the vertebral column, and 35% intracranially, usually originating in the clivus. Median age
upon diagnosis is 40 years of age with no sex predilection.
Due to the proximity of the clivus to the brain stem, cranial nerve palsies commonly cause
presenting symptoms of chordoma. Diplopia is the most commonly found symptom, occurring in 7080% of patients. Of the cranial nerves that control the extra-ocular muscles, the left sixth nerve is the
most likely to be affected. Multiple cranial nerve palsies affecting extraocular motility are common and
can be contralateral or ipsilateral, possibly leading to complete ophthalmoplegia. One interesting
finding is that fourth nerve palsies are only found concomitantly with third or sixth nerve palsies.
Other ocular findings include visual acuity loss, visual field defects, ptosis, and papilledema. Orbital
chordomas primarily form as a recurrence of a primary tumor but can be part of a primary tumor.
Orbital chordomas typically present with proptosis, extra-ocular motility dysfunction, and orbital pain
with proptosis being an identifying factor for orbital involvement.
Retrospective analysis of the patient’s previous visit the San Francisco VA that led to diagnosis of
a fourth nerve palsy would suggest that the patient’s chordoma may have been manifesting at that
exam and was causing the fourth nerve palsy. The patient’s chief complaint for that visit was horizontal
diplopia with the left eye turning in. Distance cover test results showed a left hypertropia and left
esotropia. A Parks 3 step test correctly identified a left superior oblique palsy, and subjective
neutralization of the deviation required 4 BD OS and 10 BO to fuse. While the superior oblique does
act to abduct to eye, this is a tertiary action and would not explain the magnitude of the base out prism
needed to fuse. Given the previous stated findings regarding fourth nerve palsies caused by chordomas,
that the left eye was esotropic at the previous exam, and the left sixth nerve palsy is more severe at the
most recent exam, it is possible the chordoma was present causing a mild left sixth nerve palsy in
addition to the correctly diagnosed fourth nerve palsy. This findings is an example of the importance of
ensuring that the chief complaint, exam findings, and diagnosis of cranial nerve palsies or any other
ocular condition are all in agreement.
Treatment of intracranial chordomas begins with maximal resection of the tumor. Due to
invasive nature of the tumor and the number of delicate structures near the clivus, total resection of
intracranial chordoma is often not possible. Local radiation treatment follows the resection using either
photons or charged particles as the source of the radiation. Currently proton beam radiation is used
due to rapid fall-off of intensity of the radiation as it penetrates tissue, limiting treatment to the residual
chordoma and preventing damage to the surrounding cranial tissue. Local control rates vary between
67 to 81% over 5 years. Factors that positively affect the rate of recurrence include size less than 25 mL,
overall diameter less than 45 mm, and no compression or abutment of the brain stem.
Clinical pearls:
1. Intracranial chordomas commonly manifest as extra-ocular motility dysfunction
or other visual system deficiencies
2. Highlights role of neurological consult and imaging in cranial nerve palsies in the
absence of papilledema
3. Importance of agreement between chief complaint, exam findings, and
diagnosis.
References
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Durkin SR, et al. Bilateral Sixth Nerve Palsy. Ophthalmology 2006; 113:2108-2109.
Bagan SM, Hollenhorst RW. Ocular Manifestations of Intracranial Chordomas. Trans Am
Ophthalmol Soc 1980; 78:148-155.
Yoneoka Y, et al. Cranial Base Chordoma – Long Term Outcome and Review of the
Literature. Acta Neurochirurgica 2008; 150:773-778.
Bowyer J, et al. Visual Complications of Proton Beam Therapy for Clival Chordoma. Eye
2003; 17: 318–323.
Amichetti M, et al. Proton Therapy in Chordoma of the Base of the Skull: a Systematic
Review. Neurosurgical Review 2009; Epub.
Ares CA et al. Effectiveness and Safety of Spot Scanning Proton Radiation Therapy for
Chordoma and Chondrosarcomas of the Skull Base: First Long Term Report. Int. J. Rad.
Oncology Biol. Phys., Article in Proof.
Noel G, et al. Radiation therapy for chordoma and chondrosarcoma of the skull base and the
cervical spine. Prognostic factors and patterns of failure. Strahlentherapie und Onkologie,
2003, 179 (4): 241-248
Vidor I, et al. Chordoma of the Anterior Cranial Fossa and Ethmoids with Orbital
Involvement. Orbit 2008; 27: 444-450
Bowyer J, et al. Visual Complications of Proton Beam Therapy for Clival Chordoma. Eye
(2003) 17, 318–323.