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Show ORIGINAL CONTRIBUTION Intracranial Meningiomatosis Causing Foster Kennedy Syndrome by Unilateral Optic Nerve Compression and Blockage of the Superior Sagittal Sinus X. Acebes, MD, J. Arruga, MD, PhD, J. J. Acebes, MD, PhD, C. Majos, MD, PhD, S. Mun˜oz, MD, and Isaac Alarcon Valero, MD Abstract: The original description of the Foster Kennedy syndrome included the clinical triad of optic disc pallor in one eye, optic disc edema in the other eye, and reduced olfaction caused by space-occupying anterior fossa masses. The optic disc pallor was attributed to direct compression of the intracranial optic nerve, the optic disc edema to increased intracranial pressure from mass effect, and the reduced olfaction to direct compression of the olfactory nerve. We report a patient with the ophthalmic features of the Foster Kennedy syndrome from meningiomatosis. A meningioma compressed one optic nerve to cause impaired visual function. Convexity meningiomas compressed the superior sagittal sinus to impair cerebral venous drainage, increased intracranial pressure, and papilledema in the other eye. This is the first report of the Foster Kennedy syndrome caused by this mechanism. (J Neuro-Ophthalmol 2009;29:140-142) The original 1911 description of the Foster Kennedy syndrome included the triad of optic disc pallor in one eye, optic disc edema in the fellow eye, and anosmia or hyposmia in association with anterior cranial fossa mass lesions (1,2). The pathogenesis of the optic disc pallor was believed to be direct compression of the prechiasmatic optic nerve. The optic disc edema in the fellow eye was attributed to increased intracranial pressure from the space-occupying mass. The subnormal sense of smell was ascribed to direct compression of the olfactory nerve. Subsequently, other mechanisms have been proposed for this eponymic syndrome (3), including 1) direct but asymmetric compression of both optic nerves, with severe compression causing pallor, and less severe compression FIG. 1. Fundus photography performed at our initial examination shows optic disc pallor in the right eye and optic disc edema in the left eye. FIG. 2. Visual field examination of the left eye performed at our initial encounter shows a nerve fiber bundle defect. Ophthalmology (XA, JA, JJA, SM, IAV), Neurosurgery (JJA), and Radiology (CM) Departments, Bellvitge Hospital, L'Hospitalet de Llobregat, Spain. Address correspondence to Xenia Acebes, Ophthalmology Depart-ment, Bellvitge Hospital, Feixa Llarga s/n, 08907 L'Hospitalet, Spain; E-mail: xacebes@uoc.edu 140 J Neuro-Ophthalmol, Vol. 29, No. 2, 2009 causing optic disc edema owing to impaired axoplasmic flow; and 2) chronic increased intracranial pressure initially causing bilateral papilledema, with one optic disc eventually developing pallor as the result of axonal death and the other optic disc remaining swollen. In previously reported cases of this syndrome, the increased intracranial pressure has been caused either by a space-occupying mass or by blockage of cerebrospinal outflow (3). We present an example of the Foster Kennedy syndrome in which meningiomatosis caused direct com-pression of one optic nerve (and ipsilateral optic disc pallor) and increased intracranial pressure from blockage of the dural venous sinus outflow (and fellow eye papilledema). CASE REPORT A 33-year-old woman with neurofibromatosis type 2 underwent surgery for bilateral vestibular acoustic schwan-nomas and for a foramen magnum astrocytoma. She had been aware of long-standing subnormal vision in her right eye (without medical explanation) but had had no difficulties with the vision in her left eye. Eight years after the intracranial surgery, she noticed declining vision in both eyes, but particularly in her left eye. She denied other neuro-ophthalmic symptoms. On our examination, visual acuity was light perception in the right eye and 20/30 in the left eye. A right relative afferent pupillary defect was present. FIG. 3. MRI performed at the time of our initial examination. A. Postcontrast T1 sagittal image shows multiple lesions occupying the superior sagittal sinus and posterior fossa. B. Postcontrast T1 axial image shows a mass around the anterior clinoid process (black arrow), intracanalicular right optic nerve, and anterior aspect of the chiasm (white arrows). There is also an intraorbital mass affecting the right medial rectus muscle (asterisk). C. Postcontrast T1 coronal image shows that the prechiasmal right optic nerve is surrounded by meningioma (arrow). D. Coronal short time inversion recovery (STIR) image shows that the prechiasmatic right optic nerve, hypointense in this sequence, is compressed by meningioma (black arrow). 141 Foster Kennedy Syndrome J Neuro-Ophthalmol, Vol. 29, No. 2, 2009 No relevant biomicroscopic findings were present, and on ophthalmoscopy optic disc pallor was present in the right eye and optic disc edemawas present in the left eye (Fig. 1). Humphrey perimetry of the left eye disclosed an inferior nerve fiber bundle defect (Fig. 2). Neurologic examination revealed residual bilateral facial palsy with lagophthalmos but was otherwise unremarkable. MRI of the brain and orbits (Fig. 3) showed multiple supratentorial and infratentorial meningeal-based masses that strongly enhanced, consistent with the diagnosis of meningiomatosis. Meningiomas extensively involved the brain convexity, particularly the superior sagittal sinus (Fig. 3A). One of the meningiomas extended from the right orbital apex through the optic canal and into the intracranial space (Fig. 4B-D). Bilateral acoustic masses were also present. We diagnosed compressive optic neuropathy of the right eye and papilledema of the left eye due to impaired venous drainage in the superior sagittal sinus. To treat the increased intracranial pressure, we prescribed 250 mg acetazolamide QID and placed a ventriculoperitoneal shunt. Over the ensuing 20 months, visual acuity improved in the right eye from light perception to 20/400 and remained 20/30 in the left eye. The papilledema in the left eye had resolved after 5 months, and the visual field defect in the left eye had improved slightly (Fig. 4). The acetazolamide treatment was discontinued at 5 months. The patient's ophthalmic status has remained stable for 20 months and there have been no complications from the shunt. DISCUSSION We have described a patient who developed the ophthalmic manifestations of the Foster Kennedy syndrome- optic disc pallor in one eye and optic disc edema in the other eye-from a meningioma compressing one optic nerve (to produce optic disc pallor) and another meningi-oma compressing the superior sagittal sinus and causing increased intracranial pressure from impaired dural venous sinus drainage (to produce papilledema). We believe that this mechanism has not been described previously as underlying these ophthalmic manifestations. Meningiomas arising from the anterior third of the falx cerebri or in the subfrontal region, as Foster Kennedy described (1), may become quite large before they are discovered. By that time, the most common signs and symptoms are caused by long-standing increased intra-cranial pressure from mass effect (4). Such patients complain of headache or they display deterioration of mental function (5). Our patient differs from these reported cases in that the increased intracranial pressure was caused by impaired dural venous sinus drainage. The importance of this observation is that treatment does not involve tumor removal but rather lowering of intracranial pressure, first with acetazolamide and definitively with cerebrospinal fluid diversion. In our patient, visual function apparently improved not only in the eye with papilledema but also in the eye whose optic nerve was being compressed by meningioma, indicating that a component of visual loss in that eye probably also came from increased intracranial pressure. We emphasize that prompt cerebrospinal fluid diver-sion is critical in preventing visual loss in this setting even though the brain ventricles are typically of normal size. REFERENCES 1. Kennedy F. Retrobulbar neuritis as an exact diagnostic sign of certain tumors and abscesses in the frontal lobes. Am J Med Sci 1911;142: 355-68. 2. Miller NR, Newman NJ, Biousse V, et al. Walsh and Hoyt's Clinical Ophthalmology. 6th ed. Philadelphia: Lippincott Williams & Wilkins; 2005. 3. Watnick RL, Trobe JD. Bilateral optic nerve compression as a mechanism for the Foster Kennedy syndrome. Ophthalmology 1989;96:1793-8. 4. Avisar R, Davidovich S, Savir H, et al. Meningioma of the falx cerebri, optic atrophy and erosion of the clinoids: coincidence or cause effect? Ann Ophthalmol 1982;14:378-9. 5. Giombini S, Solero CL, Lasio G, et al. Immediate and late outcome of operation for parasagittal and falx meningiomas: report of 342 cases. Surg Neurol 1984;21:427-35. FIG. 4. Visual field examination performed 5 months after placement of the ventriculoperitoneal shunt shows slight improvement in the defect relative to Fig. 2. 142 q 2009 Lippincott Williams & Wilkins J Neuro-Ophthalmol, Vol. 29, No. 2, 2009 Acebes et al |
