Scientists have developed a new blood test that detects early Alzheimer's disease.
With 100% accuracy.

The blood test uses autoantibody biomarkers to accurately detect AD at an early point in the course of the disease when treatments are more likely to be beneficial - that is, before too much brain devastation has occurred.

The test is designed to detect an early stage of AD called Mild Cognitive Impairment (MCI), and distinguish it from similar cases of mental decline that are caused by other factors e.g., vascular issues, chronic depression, alcohol abuse, and the side effects of certain drugs.

The MCI patients had been diagnosed based on having low levels of amyloid-beta 42 peptitde in their CSF, which has been identified as a predictor of rapid AD progression.

Using this biomarker method, the test was also successful in detecting mild-moderate AD (98.7%), early-stage PD (98.0%), MS (100%) and breast Ca (100%).

While at this stage, knowing that you have AD earlier rather than later won't prevent it from developing altogether, but it could give patients the opportunity to sign up for clinical trials for new drugs and treatments, plan out future medical care, and even explore ways to help delay its progression.

source: http://www.sciencealert.com/scientists-have-developed-a-blood-test-that-detects-early-alzheimer-s-disease