The videos show for the first time the destruction of brain tissue that moves in a systematic fashion through the brain. Memory functions are affected initially, then comes destruction of the areas of the brain that emotion, then inhibition and finally sensation. These videos also show that some areas of the brain are not affected, including areas that control vision explaining why some brain functions remain intact in Alzheimer's patients.
"For the first time, you can see Alzheimer's disease progressing in living patients," said Paul Thompson, an assistant professor of neurology at the David Geffen School of Medicine at UCLA and the study's chief investigator. "We were stunned to see a spreading wave of tissue loss."
"This type of imaging will allow doctors and researchers to pinpoint where and how fast the disease is spreading," said Thompson, a researcher at the UCLA Laboratory of Neuro Imaging. "We will urgently apply this method to reveal how drugs and vaccines combat the wave of brain damage caused by Alzheimer's disease."
Alzheimer's disease affects at least 10% of the population over the age of 65 in the United States. Brain lesions, called amyloid plaques and tangles accumulation in the brains of Alzheimer's Disease patients causing brain cells to die. As these brain cells die they have experience memory loss, disorientation and declining ability to cope with everyday life. As they decline they lose the ability to control basic bodily functions, the ability to communicate or even swallow food when fed.
In conducting this study the researchers scanned 12 Alzheimer's patients and 14 healthy elderly volunteers with MRI brain scans every three months for two years.
Using the new image analysis technique they developed, the researchers found that the Alzheimer's patients lost an average of 5.3 percent of their gray matter per year. Brain cells were destroyed even faster in some areas of the brain, with patients losing up to 10 percent in memory regions each year. In contrast, healthy elderly volunteers lost only 0.9 percent of their brain tissue annually.
By the end of the study the researchers found that the disease had virtually engulfed the entire brain of the Alzheimer's patients and shown in video sequences.Alzheimer's Disease is a progressive disease with no cure. Present treatments can help to lessen and stabilize symptoms of brain tissue loss but do nothing to inhibit the loss of brain tissue caused by the disease. The class of drugs used to treat Alzheimer's symptoms is cholinesterase inhibitors. The three cholineserase inhibitors commonly prescribed are donepezil (Aricept®), rivastigmine (Exelon®), and galantamine (Reminyl®). Tacrine (Cognex®), the earliest of this class of drugs is rarely prescribed today due to the possibility of serious side effects, including liver damage.
