Featured articleBrain metabolism differs in Alzheimer's disease and Parkinson's disease dementia

BackgroundFew comparative studies exist of metabolic brain changes among neurodegenerative illnesses. We compared brain metabolic abnormalities in Alzheimer's disease (AD) and in Parkinson's disease with dementia (PDD) as measured by proton magnetic resonance spectroscopy (MRS).MethodsTwelve patients with idiopathic PDD, 22 patients with probable mild AD, and 61 healthy older controls underwent posterior cingulate MRS.ResultsPatients with AD exhibited reduced N-acetyl aspartate (NAA)/creatine (Cr) (P < .05) and increased choline (Cho)/Cr (P < .05) and myo-inositol (mI)/Cr (P < .01) compared with controls. Patients with PDD exhibited reduced NAA/Cr (P < .05) and glutamate (Glu)/Cr (P < .01) compared with controls. There was reduced Glu/Cr in PDD compared with AD (P < .01).ConclusionsPatients with AD and patients with PDD exhibited distinct brain metabolic MRS profiles. Findings suggest that comparison of brain MRS profiles across dementias provides useful direction for future study.