A BRAIN scan study has [...].
Scientists hope the findings will improve understanding and diagnosis of the disease, the most common form of dementia.
In 2002, the 56-year-old patient became the first person in the world to undergo a PET brain scan for signs of Alzheimer's. PET (positron emission tomography) scans use a radioactive tracer to produce images based on bodily functions such as blood flow, oxygen use and glucose uptake. Doctors can use a PET scan to monitor the build-up of beta amyloid protein deposits in the brain, a key feature of Alzheimer's. Researchers at the Karolinska Institute in Sweden found high concentrations of beta amyloid early on when their patient was only suffering slight memory loss.
Levels remained unchanged during the course of the disease.
In contrast, the scans showed energy metabolism in the brain reduced as the patient's memory deteriorated.
Greater accumulation of beta amyloid "plaques" was accompanied by a reduction in neuronal nicotinic receptors - brain molecules crucial to memory function.
Inflammatory changes in the brain with low levels of beta amyloid, suggested the two may not be linked.