UNUSUAL FINDINGS ON PET STUDY OF A PATIENT WITH POSTERIOR CORTICAL ATROPHY

We present a patient with posterior cortical atrophy in whom positron emission tomography (PET) showed unusual findings. This 65-year-old ma n had a 5-year history of slowly progressive apperceptive visual agnos ia and Balint syndrome, but with a relatively well-preserved intellige nce and language ability even in the later stages of illness. No relev ant features in this patient or his family were identified. Laboratory and radiographic investigations indicated that cerebral damage was du e to primary degeneration. His symptoms resembled those of patients wi th posterior cortical atrophy. A PET study revealed that cerebral meta bolism was reduced in the dorsal regions of the entire cortex and asym metrical with the main site of damage on the right. The severity in as ymmetry increased dorsally. These 2 types of predilection for dorsal r egions had not previously been reported in such patients. These unusua l PET findings may indicate the presence of pathological changes not y et identified.