Elsevier

Surgical Neurology

Volume 67, Issue 1, January 2007, Pages 83-88
Surgical Neurology

Neoplasm
Oculomotor nerve schwannoma located in the oculomotor cistern

https://doi.org/10.1016/j.surneu.2006.06.012Get rights and content

Abstract

Background

OSs are extremely rare tumors, most often located in the interpeduncular cistern or the CS. We report an OS located predominantly within the oculomotor cistern, the arachnoid sac that surrounds the nerve for a short distance in the roof of the CS. We discuss a possible growth pattern for cavernous OSs.

Case Description

We report the case of a 34-year-old woman presenting with a right oculomotor nerve palsy. Magnetic resonance imaging revealed a mass within the borders of the roof of the CS extending forward toward the superior orbital fissure. A right pterional approach was undertaken, and the roof of the CS was opened just above the oculomotor nerve toward the superior orbital fissure. Although the part of the OS inside the oculomotor cistern was excised completely while preserving the anatomical continuity of the nerve, a subtotal removal was performed for the more anterior part of the tumor toward the superior orbital fissure. At 5 months follow-up, her third nerve paresis had improved dramatically.

Conclusions

Resection of cavernous OSs within the oculomotor cistern, where the third nerve is clearly separated from the adjacent neurovascular structures, is feasible with functional preservation of the nerve. The chance of occurrence of the nerve palsy may increase as the resection proceeds more anteriorly toward the superior orbital fissure.

Introduction

Schwannomas constitute about 7% of all intracranial tumors and commonly arise from vestibulocochlear and trigeminal nerves [17], [22], [32], [33]. The sensory division of cranial nerves is most likely to be affected [32]. Motor nerve schwannomas arising from ocular nerves are very rare in the absence of neurofibromatosis type II [13]. Only 32 cases of isolated schwannomas arising from the oculomotor nerve have been reported in the literature [1], [2], [3], [4], [5], [8], [9], [10], [12], [13], [14], [15], [16], [17], [18], [19], [21], [22], [23], [24], [25], [26], [27], [28], [29], [30], [33], [34], [35], [37], [38], [39], [40]. The most common site of occurrence for these lesions is the neuronal segment within the interpeduncular cistern and the CS. We report the case of an OS located predominantly within the oculomotor cistern, the arachnoid sac that surrounds the nerve for a short distance in the roof of the CS and extends forward to where the nerve passes under the anterior clinoid process.

Section snippets

Case report

A 34-year-old woman presented to our clinic with intermittent headaches for the last 6 months. She had developed ptosis, an enlarged pupil on the right side, and experienced lateral deviation of her right eye 3 weeks before her admission. Examination of the extraocular muscles revealed right oculomotor nerve palsy. The right pupil was irregularly shaped and mydriatic. The right optic disc appeared pale upon ophthalmoscopic examination. Examination of her left eye was normal.

An MRI scan

Surgical anatomy—oculomotor cistern

The oculomotor nerve arises in the interpeduncular cistern from the midbrain on the medial side of the cerebral peduncle and courses between the posterior cerebral and superior cerebellar arteries [39]. The nerve courses medial to the uncus before piercing the dura at the roof of the CS. The oculomotor nerve enters the roof of the CS approximately 5 mm posterior to the initial supraclinoidal segment of the ICA and slightly lateral to the posterior clinoid process (Fig. 3) [7], [31]. A short

Conclusions

In conclusion, isolated OSs are very rare, and the oculomotor cistern creates a favorable site for these tumors to expand for those cases with CS involvement. The part of the OS within the cistern can be removed while preserving the anatomical continuity of the nerve. OSs should be considered in the differential diagnosis among lesions along the roof of the CS.

Acknowledgments

The anatomical dissections have been performed by one of the authors (NT) in the Microsurgical Anatomy Laboratory at the University of Florida, Department of Neurosurgery. The authors thank Özlem Tanriover, MD, for her assistance in preparation of the manuscript.

References (41)

  • B. Bataille et al.

    Neurinome du nerf oculomoteur. A propos d'un cas

    Neurochirurgie

    (1987)
  • G. Broggi et al.

    Value of serial stereotactic biopsies and impedance monitoring in the treatment of deep brain tumors

    J Neurol Neurosurg Psychiatry

    (1981)
  • F.S. Harris et al.

    Anatomy of the cavernous sinus. A microsurgical study

    J Neurosurg

    (1976)
  • M. Hashimoto et al.

    A case of neurinoma developing from the oculomotor nerve in cavernous sinus

    Neuroopthalmology (Jpn)

    (1996)
  • H. Hatakeyama et al.

    Schwannoma in the crural cistern removed without permanent functional deficits. Case report

    Neurol Med Chir (Tokyo)

    (2003)
  • P. Hiscott et al.

    An unusual presentation of neurofibroma of the oculomotor nerve. Case report

    J Neurosurg

    (1982)
  • C.F. Huang et al.

    Stereotactic radiosurgery for trigeminal schwannomas

    Neurosurgery

    (1999)
  • N. Ishige et al.

    Neurinoma with intrasellar extension. A case report

    No Shinkei Geka

    (1985)
  • R. Kachhara et al.

    Oculomotor nerve neurinoma: report of two cases

    Acta Neurochir (Wien)

    (1998)
  • T. Kansu et al.

    Neurinoma of the oculomotor nerve: case report

    J Clin Neuro-ophtalmol

    (1982)
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