Early Biomarkers for Alzheimer Disease


This is the Medscape Neurology Minute. I am Dr. Alan Jacobs. Researchers from the Banner Alzheimer's Institute in Phoenix, Arizona, have published a case-control study on the preclinical phase in Alzheimer disease. They compared 18- to 26-year-old presenilin 1 E280A mutation carriers to noncarriers from the Colombian Alzheimer's Prevention Initiative registry. Forty-four participants underwent structural MRI, functional MRI during memory and coding tasks, and cognitive assessments. They also had lumbar punctures and venipunctures. Outcome measures were task-dependent hippocampal or parahippocampal activations and precuneus or posterior cingulate deactivations, regional grey matter reductions, CSF A-beta, total tau, and phospho-tau concentrations, and plasma A-beta concentrations. The 2 groups did not differ significantly in dementia ratings, neuropsychological test scores, or proportion of apolipoprotein E ɛ4 carriers. Compared with noncarriers, carriers had greater right hippocampal and parahippocampal activation, less precuneus and posterior cingulate deactivation, and less grey matter in parietal regions. Mutation carriers also had higher CSF A-beta concentrations and plasma A-beta concentrations than noncarriers. The researchers concluded that young adults at genetic risk for autosomal dominant Alzheimer disease have functional and structural MRI findings and CSF and plasma biomarker findings consistent with A-beta overproduction. This study was selected from Medscape's Practice-Changing Articles in Neurology. I'm Dr. Alan Jacobs.

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