The brain of the elderly between normality and pathology: Techniques and technologies for the evaluation

Increasing attention has been devoted in recent years to elderly subjects s uffering from a cognitive impairment which is greater than that expected wi th normal aging but still insufficient to fulfil the diagnostic criteria fo r dementia. Mild cognitive decline (MCI) is the term most widely used to de fine these subjects from the clinical point of view. Among the different ap proaches that have been undertaken to recognize MCI and to characterize its progression or stability, interesting results are emerging from neuroimagi ng studies, both morphological (computerized tomography: CT, magnetic reson ance imaging: MRI) and functional (positron emission tomography: PET, singl e photon emission computed tomography: SPECT proton magnetic resonance spec troscopy: H-1-MRS). Using H-1-MRS we demonstrated that MCI subjects have a white matter biochemical pattern similar to those of early Alzheimer diseas e (AD) patients, but different from healthy elderly subjects. These results provide additional evidence that MCI does not belong to the normal aging o f the brain.