Alzheimer's dementia and post-traumatic stress disorder differences and similarities in neuroimaging.

There are studies supporting the suggestion that a severe psychological stress in the elderly can be the risk factor of Alzheimer's dementia (AB) and other types of dementia. We have reviewed the findings of single photon emission tomography, positron emission tomography, magnetic resonance imaging and functional magnetic resonance imaging (fMRI), related to brain function and structure in AD and in post traumatic stress disorder (PTSD). There is evidence that prefrontal and orbitofrontal cortices dysfunction contributes to PTSD symptomatology. Similarities between the two different aforementioned diseases exist in the areas of (a) medial temporal lobe, (b) hippocampus and (c) cingulated cortex.