Memory and MRI-based hippocampal volumes in aging and AD

Objective: To demonstrate structural-functional relationships between MRI-b ased volumetric measurements of medial temporal lobe structures and cogniti ve function. Background: Previous work has documented the ability of MRI-ba sed measurements of the hippocampus to discriminate between age-matched con trol subjects and patients with very mild AD. Relatively less is known abou t the;correlation between medial temporal lobe structures and cognitive fun ctions. Method: We evaluated structural-functional relationships among the hippocampal formation, para-hippocampal gyrus, and amygdala, and measures o f memory, language, and general cognitive performance in 220 probable AD pa tients and normal control subjects. Standardized instruments of memory and general cognitive function were used-to assess subjects enrolled in a longi tudinal study Of aging and dementia, Results: The volume of the hippocampal formation predicted performance on most acquisition and recall measures ac ross the spectrum of normal aging and AD. If the groups were segregated, mo st of the expected associations between medial temporal lobe structures and memory measures were observed in the AD patients. Conclusion: MRI-based hi ppocampal volumetry accurately depicts the. structural-functional relations hips between memory loss and hippocampal damage across the spectrum from no rmal aging to dementia.