Subcortical prosopagnosia and anosognosia.

A 59-year-old right-handed woman with acute hemorrhage affecting the head of the left caudate nucleus exhibited prosopagnosia and anosognosia. It is suggested that these symptoms are due to a disconnection syndrome affecting a putative cortico-limbic reticular loop involved in attention. Prosopagnosia can occur with lesions outside the main central visual pathways and is a material-specific motivational neglect to faces: alternatively prosopagnosia in this patient may represent abnormal gating sensory limbic activity since sensory (visual) modulated memory related cholinergic fibers arising from the nucleus basalis of the substantia innominata (Meynert's) were likely involved by surrounding edema.