Brain magnetic resonance spectroscopy: Role in assessing outcomes in Alzheimer's disease

Contemporary H-magnetic resonance spectroscopy (MRS) techniques can estimate the levels of brain metabolites with a high reproducibility and add only 10 minutes to a routine or volumetric magnetic resonance imaging scan. In patients with Alzheimers disease (AD), H-MRS demonstrates decreases in N- acetylaspartate (NAA) and increases in myo-inositol (Ino) levels. Changes in NAA and Ino levels correlate with dementia severity and may predict future cognitive decline. H-MRS could be a valuable outcome measure in clinical trials of individuals with AD for monitoring disease progression (using NAA and Ino levels) and evaluating therapeutic response to novel drugs (using NAA, choline and Ino levels). Further studies are warranted to evaluate the relative utility of H-MRS compared with other imaging markers, such as cerebral blood flow and volumetric measures of atrophy. Protocols combining magnetic resonance perfusion, volumetry and spectroscopy in AD may prove to be powerful research tools.