Alzheimer's Detected Decades Before Symptoms

Some of the earliest signs of Alzheimer's disease have been found in the brain, more than two decades before the first symptoms usually appear. Treating the disease early is thought to be vital in order to prevent damage to memory and thinking. A study, published in the Lancet Neurology, found differences in the brains of people destined to develop an early form of Alzheimer's. Experts said the US study may give doctors more time to treat people. Alzheimer's disease starts long before anyone would notice; previous studies have shown an effect on the brain 10-15 years before symptoms. It is only after enough brain cells have died that the signs of dementia begin to appear - some regions of the brain will have lost up to 20% of their brain cells before the disease becomes noticeable. However, doctors fear so much of the brain will have degenerated by this time that it will be too late to treat patients. The failure of recent trials to prevent further cognitive decline in patients with mild to moderate Alzheimer's disease has been partly put down to timing.