Hemiachromatopsia of unilateral occipitotemporal infarcts.

Two patients developed unilateral occipitotemporal infarcts that produced inferior quadrantic achromatopsia and an accompanying superior quadrantanopia. Magnetic resonance imaging and single-photon emission computed tomographic studies of both patients supported the current view that color vision is encoded in the lingual and fusiform gyri. Although the quadrantic defect in color processing was profound, neither patient was aware of it. Simple bedside testing of patients with superior quadrantanopia may disclose an unrecognized quadrantic achromatopsia.