Pseudo-Foster Kennedy syndrome in a young woman with meningioma infiltrating the superior sagittal sinus

摘要

The original Foster Kennedy syndrome results from the uncommon combination of unilateral optic disc swelling in one eye and optic atrophy in the contralateral; it is usually due to a frontal lobe tumor compressing the optic nerve [1]. In the absence of an intracranial mass these findings may be labeled as pseudo-Foster Kennedy syndrome. The pathogenesis of the optic disc pallor is believed to be secondary to the direct compression of the pre-chiasmatic optic nerve fibers; whereas, the disc edema in the fellow eye is attributed to increased intracranial pressure from the space-occupying mass. Pseudo-Foster Kennedy is a more frequent clinical picture, resulting from more remote ischemia or demyelination in one eye, with subsequent atrophy, and often persistent visual loss, with new ischemia or demyelination in the second eye, with new visual loss [2]. Many mechanisms have been proposed for this syndrome including: (i) direct but asymmetric compression of both optic nerves, with severe compression causing pallor, and less severe compression causing optic disc edema owing to impaired axoplasmic flow; (ii) 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 [3].