Biochemical changes in the brains of healthy individuals can be identified by an imaging technique – proton MR spectroscopy – indicating whether they may be at risk for Alzheimer’s disease, researchers from the Mayo Clinic reported in the journal Neurology.

Kejal Kantarci, MD, MSc, and team carried out a study involving 311 participants aged over 70 years from the May Clinic Study of Aging. None of them had cognitive problems. Proton MR spectroscopy, an advanced brain imaging technique, was used to determine whether any of them had abnormalities in various brain metabolites that might be Alzheimer’s disease biomarkers.

PET scans were used to assess amyloid-beta deposits (plaques) in the brain. Plaques are one of the initial signs of Alzheimer’s disease onset. The volunteers also underwent various tests which assessed their language, memory and other skills.

Jonathan M. Schott, MD, of the Dementia Research Centre, University College London, England, said:

“There is increasing evidence that Alzheimer disease is associated with changes in the brain that start many years before symptoms develop.

If we could identify people in whom the disease process has started but symptoms have not yet developed, we would have a potential window of opportunity for new treatments – as and when they become available – to prevent or delay the start of memory loss and cognitive decline.”

33% of the volunteers had considerably high levels of amyloid-beta deposits. Those people also had high levels of brain metabolites choline/creatine and myoinositol/creatine. Those with high choline/creatine levels tended to score poorly on various cognitive tests, regardless of brain amyloid-beta deposit levels.

Dr. Kantarci said:

“This relationship between amyloid-beta deposits and these metabolic changes in the brain are evidence that some of these people may be in the earliest stages of the disease.

More research is needed that follows people over a period of years to determine which of these individuals will actually develop the disease and what the relationship is between the amyloid deposits and the metabolites.”

MR spectroscopy cannot currently be used for diagnosis.

Written by Christian Nordqvist