Partially Reversible Quadruple Sectoranopia Caused by Vascular Steal Due to an Arteriovenous Malformation

Background: Lateral, homonymous upper and lower field blind sectors sparing a horizontal zone define quadruple sectoranopia. This rare campimetric deficit involves ischemia or infarction of parts of the lateral geniculate body supplied by the distal anterior choroidal artery.

Methods: A 41-year-old patient presented with a complaint of blurred vision. Visual acuity was 20/20 on both sides. Visual field showed a left quadruple sectoranopia. CT scan, MRI, MRA and conventional angiography showed a right cerebral arteriovenous malformation supplied partly by the right anterior choroidal artery. Partial retinal nerve fiber layer atrophy matched to the campimetric deficit proved that some degree of infarction involved the lateral geniculate body.

Results: The arteriovenous malformation was treated with stereotactic radiosurgery. Two years after treatment, the nidus had completely disappeared. The campimetric deficit began improving from 19 months onwards after stereotactic radiosurgery. Twenty-eight months after treatment, the superior defect had completely reversed.

Conclusions: Quadruple sectoranopia involves ischemia or infarction of parts of the lateral geniculate body supplied by the distal anterior choroidal artery. Following radio-induced angioma thrombosis, blood was no longer shunted away from the right lateral geniculate body, whose viable areas resumed their activity. Accordingly, a partial campimetric recovery occurred.