Stroke-blind for colors, faces and locations: Partial recovery after three years.

Purpose. To study and follow-up achromatopsia, prosopagnosia, and topographagnosia in a patient who suffered a bilateral stroke of the posterior cerebral arteries. Methods. Ophthalmological, neuropsychological and neuroradiological examinations were conducted over a span of 3 years to assess the amount of brain damage and look for signs of functional recovery. Results. After the onset of achromatopsia, perception of the color green re-appeared first, followed by red, yellow, and brown. Blue which had appeared entirely black was last to return. While reading and color naming have largely recovered, color discrimination after three years remains poor especially in dim lighting. Similarly, with prosopagnosia, while the patient has learn to identify people (including photographs) by individual features, his ability to perceive and recognize faces and facial expressions holistically remains severely impaired. Recognition of streets, houses, and topographical layouts also continues to be affected, while the perception of speed and distance has somewhat improved. Perimetry further suggests a mild improvement of the superior hemianopia in his visual fields. Conclusions. Although major deficits in color, face and place perception remain, some functions impaired by the stroke have returned par-alleling a partial recovery from the brain lesion as demonstrated by NMR.