Action-intentional spatial bias in a patient with posterior cortical atrophy.

Patients without sensory neglect might demonstrate a spatial deviation when drawing. To better understand the mechanism of this deviation, we examined a 61-year-old woman with probable posterior cortical atrophy (PCA) who on imaging showed right hemisphere atrophy and dysfunction. When drawing a clock she correctly made a circle, but when writing the numbers deviated to the left. A blindfolded midsagittal plane pointing test revealed that her leftward deviation was action-intentional rather than perceptual-attentional. This action-intentional deviation was made manifest by altering visual feedback such as having her focus her attention on the clock numbers.