Intracranial meningiomatosis causing foster kennedy syndrome by unilateral optic nerve compression and blockage of the superior sagittal sinus.

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.