Alzheimer's treatment improves with new diagnostic method

Mar 22 2005

Earlier detection and treatment for Alzheimer's Disease are now more practical for larger segments of the population through a more refined use of existing, well-validated neuropsychological tests.

A study completed by Dr. William Rodman Shankle, M.S., M.D., et al and published in The Proceedings of the National Academy of Sciences showed that by applying statistical modeling to the neuropsychological test battery used by the National Institute of Aging's Disease Research Centers, the overall accuracy for distinguishing normal aging from the mildest stage of Alzheimer's disease increased to 97%. This accuracy surpasses that of other more expensive and more invasive diagnostic methods. The statistical model developed by Shankle et al allows doctors to more accurately detect patients with mild cognitive impairment, a condition which precedes dementia caused by AD, enabling patients to start treatment at an earlier, more beneficial stage. The study was conducted over the course of 15 years and included 471 subjects who were drawn from a university dementia research clinic and a community dementia clinic. A comprehensive battery of neuropsychological tests, diagnostic laboratory testing and imaging studies were used to validate the stage and diagnosis of each subject.

The implications of the findings are potentially far reaching because access to accurate, cost effective AD screening could make it possible for mass populations to be screened and provided with appropriate treatment to delay AD progression. Early intervention holds the promise of extending patient independence, easing caregiver burdens and reducing associated healthcare costs by $200,000 per patient. While current treatments are most effective when started early in the course of the disease, most AD patients are diagnosed at later stages when they are losing the ability to dress, bathe, cook, and manage personal affairs. If diagnosed early and provided proper treatment, the course of the disease in a typical AD patient will be delayed enough to potentially avoid the need to live in a nursing home.

Copies of the study entitled Methods to Improve the Detection of Mild Cognitive Impairment can be obtained free of charge at PNAS.org