Clinical Progress For Alzheimer's Detection

Doctors can usually determine if a patient has dementia, and around 90 percent of the time they can accurately identify whether the dementia is due to Alzheimer's disease. This diagnoses however, usually takes place after the disease has profoundly affected the brain and is causing severe symptoms. At this point in time, Alzheimer's can only be diagnosed with complete accuracy after death, when microscopic examination of the brain reveals the characteristic plaques and tangles of the disease. In early April, The National Institute on Aging and the Alzheimer’s Association issued a new set of guidelines that categorize Alzheimer’s disease into three stages:
A phase when dementia has already developed and mental dysfunction is apparent.
A middle phase in which mild problems emerge but daily functions can still be performed.
The most recently discovered phase, in which no symptoms are evident but changes are taking place in the brain and are manifested by alterations of certain biomarkers (measurable substances in the blood or spinal fluid correlated with the disease) or in imaging studies such as MRI or PET scans.

This clarification is especially important since there are currently no drugs available that can effectively halt or significantly delay the onset of symptoms, although a few of the approved drugs can slow progression of the disease for a few months in a minority of patients. Currently, cerebral spinal fluid analyses and brain scans test for abnormal levels of the proteins beta-amyloid and tau, or shrinkage of certain brain areas, respectively. These tests, however, are still under investigation and are not yet reliably predictive for definite diagnosis of Alzheimer’s, except in advanced cases. The use of biomarkers in Alzheimer’s dementia and mild cognitive impairment due to Alzheimer’s was also proposed as a research agenda only, and is not intended for application in clinical settings at this time.

William Thies, Ph.D., Alzheimer’s Association Chief Medical and Scientific Officer said, “It is our hope that incorporating scientific knowledge gained and technological advances made over the past quarter century will improve current diagnosis, bring the field closer to earlier detection and treatment and, ultimately, lead to effective disease-modifying therapies.” He added that the “Development and publication of these articles is a major landmark in the field. That said, publication of these articles is not yet the end of the process of developing new diagnostic criteria for Alzheimer’s, but is another major step in the process.” The ultimate goal is to identify reliable biomarkers that will accurately predict the eventual development of Alzheimer’s. “The sooner we can get such indicators, the more likely we’ll be able to interfere with the disease’s progress, especially when we develop effective new pharmaceutical treatments,” says ACSH’s Dr. Gilbert Ross. “Building such a database of research will hopefully break the chain of events that, at this point, irrevocably lead to Alzheimer’s. Hopefully, we’ll be able to break this chain within ten years or less, when the pathogenesis is more clearly delineated and focused drug interventions will be accelerated.”