I think this is an important paper reporting on a well-conducted study. Although cross-sectional, the results imply a subtle continuum from cognitive complaints through to mild cognitive impairment and on to Alzheimer disease. Using a good-sized cohort of 40 subjects with cognitive complaints, 40 MCI subjects, and 40 controls, Saykin and colleagues used both voxel-based methods and region-of-interest outlining to show that relative to the control group, the MCI group had lower hippocampal volumes and lower grey matter densities in medial temporal lobe and elsewhere; importantly, they also showed that the group with cognitive complaints (but without cognitive deficits to meet MCI criteria) had hippocampal and grey matter volumes intermediate between the two groups. The paper therefore provides further, albeit circumstantial, evidence that structural changes—and in particular medial temporal lobe grey matter losses—may be detectable before cognitive deficits become manifest. It also reminds us that in certain settings, cognitive complaints should be taken seriously...  Read more

I think this is an important paper reporting on a well-conducted study. Although cross-sectional, the results imply a subtle continuum from cognitive complaints through to mild cognitive impairment and on to Alzheimer disease. Using a good-sized cohort of 40 subjects with cognitive complaints, 40 MCI subjects, and 40 controls, Saykin and colleagues used both voxel-based methods and region-of-interest outlining to show that relative to the control group, the MCI group had lower hippocampal volumes and lower grey matter densities in medial temporal lobe and elsewhere; importantly, they also showed that the group with cognitive complaints (but without cognitive deficits to meet MCI criteria) had hippocampal and grey matter volumes intermediate between the two groups. The paper therefore provides further, albeit circumstantial, evidence that structural changes—and in particular medial temporal lobe grey matter losses—may be detectable before cognitive deficits become manifest. It also reminds us that in certain settings, cognitive complaints should be taken seriously even when formal neuropsychometry appears within normal limits.

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