National Institute on Aging and Alzheimer's Association Lead Effort to Update Diagnostic Criteria for Alzheimer's Disease

By Alzheimers Association, PRNE
Monday, July 12, 2010

News briefing/Q&A: AAICAD 2010, Tuesday, July 13, 2010, 11:45 am-12:45 pm - Hawai'i Convention Center, Room 321A, 1801 Kalakaua Avenue, Honolulu -

HONOLULU, July 13, 2010 - Scientists at the Alzheimer's Association International Conference on
Alzheimer's Disease 2010 (AAICAD 2010) today presented the first draft
reports from three workgroups convened by the National Institute on Aging
(NIA) and the Alzheimer's Association to update the diagnostic criteria for
Alzheimer's disease for the first time in 25 years.

The current criteria for the diagnosis of Alzheimer's were established by
a National Institute of Neurological Disorders and Stroke (NINDS)/Alzheimer's
Disease and Related Disorders Association (ADRDA) workgroup in 1984. These
criteria were almost universally adopted and have been useful; they have
survived intact without modification for more than 25 years. However, experts
note, the field has evolved to a great extent since then.

"Important scientific discoveries have been made in Alzheimer's, and
there have been significant changes in our knowledge and conception of the
disease," said Creighton H. Phelps, Ph.D., Director of the Alzheimer's
Disease Centers Program, Division of Neuroscience, National Institute on
Aging at the National Institutes of Health. "The NIA and the Alzheimer's
Association, after consultation with the Alzheimer's scientific and medical
community, concluded that the diagnostic criteria may need to be revised to
incorporate scientific advances. We decided to convene workgroups to examine
the literature and make recommendations."

At AAICAD 2010, leaders of the three workgroups - which covered
Alzheimer's disease dementia, mild cognitive impairment (MCI) due to
Alzheimer's disease, and preclinical Alzheimer's disease - presented
preliminary reports at a special session for initial comment by the
Alzheimer's community.

"The proposals would change the 1984 criteria by better reflecting the
various stages of the disease and the inclusion of Alzheimer's disease
biomarkers," said William Thies, PhD, Chief Medical and Scientific Officer at
the Alzheimer's Association. "While the role of biomarkers differs in each of
the three stages, much remains to be understood concerning their reliability
and validity in diagnosis. This makes it critical that we thoroughly test any
new recommendations."

Further input will be solicited by the NIA and the Association through a
website launched immediately after the AAICAD presentations at
www.alz.org/research/diagnostic_criteria. After that input is
incorporated, next steps are publication in a peer-reviewed journal followed
by systematic validation through incorporation of the criteria into clinical
trials.

"The proposed criteria for Alzheimer's disease dementia must be flexible
enough to eventually be used - once they are validated - by both general
health care providers without access to neuropsychological testing, advanced
imaging, and CSF measures, as well as specialized investigators involved in
research or clinical trial studies with access to these measures," said Guy
McKhann
, MD, of Johns Hopkins University School of Medicine, who chaired this
workgroup.

The Importance of Moving to Earlier Diagnosis

Alzheimer's is thought to begin years, perhaps even decades, before
symptoms are noticeable. But there is no single, generally accepted way to
identify the disease in its earliest stages - before symptoms are evident.

According to Phelps, earlier detection of people at highest risk for
Alzheimer's and those who have the earliest forms of the disease will
facilitate finding the right individuals to participate in risk reduction and
prevention research studies.

"The NIA and the Alzheimer's Association hope this process of updating
and revising the Alzheimer's diagnostic criteria with modern technologies and
the latest advances will provide standards that move the field further in the
direction of early detection and treatment," Thies said.

Significant Advances in Alzheimer Research Since 1984

Among the most important advances in the Alzheimer's field since the
publication of the 1984 NINDS/ADRDA diagnostic criteria are:

    -- Alzheimer's-driven changes in the brain, as well as the accompanying
       cognitive deficits, develop slowly over many years with dementia
       representing the end stage of years of pathology accumulation. At the
       same time, we know that some people have the brain changes associated
       with Alzheimer's and yet don't show symptoms of dementia.
    -- Predictive genes in early onset Alzheimer's indicate that the initial
       events ultimately leading to both clinical symptoms and pathological
       brain changes begin with disordered beta amyloid metabolism.
    -- The e4 allele of the APOE gene is well accepted as a major genetic
       risk factor for late onset Alzheimer's disease, which is defined as
       onset at 65 or older.
    -- Biomarkers for Alzheimer's have been developed and are being
       validated. These fall into several categories:
       -- Biomarkers of beta amyloid pathology, including amyloid PET
          imaging and levels of beta amyloid in cerebrospinal fluid (CSF).
       -- Biomarkers of neuronal injury, including levels of CSF tau and
          phospho-tau.
       -- Biomarkers of neuronal dysfunction, including decreased uptake of
          FDG on PET scans.
       -- Biomarkers of neurodegeneration, including brain atrophy on
          structural MRI scans.

In addition, it has been only in the past decade that a better
understanding of the distinctions and overlaps of Alzheimer's with
non-Alzheimer's dementias has begun to emerge. Knowledge of the
non-Alzheimer's dementias was rudimentary in 1984, and the current diagnostic
criteria are vague in defining distinctions between Alzheimer's and the major
alternatives. The common co-existence of Alzheimer's and cerebrovascular
disease is now appreciated. Much more is known about dementia resulting from
Lewy Body disease, and also about Pick's disease and other frontotemporal
dementias.

Three Work Group Reports Present New Ideas for Research Criteria and
Better Define Early Stages of Alzheimer's Disease

The NIA/Alzheimer's Association working groups were organized around the
three stages of Alzheimer's disease that are commonly thought to exist today
- pre-clinical Alzheimer's, mild cognitive impairment (MCI) due to
Alzheimer's, and Alzheimer's dementia.

    -- Pre-clinical - The group is laying out a research agenda to identify
       methods of assessment that may help predict risk for developing the
       disease. Biomarkers and other clinical assessment tools to identify
       early cognitive decline are being investigated to establish the
       presence of Alzheimer's brain changes in people with no overt symptoms
       and to identify those who may eventually develop the disease.
    -- Mild cognitive impairment - The group is refining the MCI criteria,
       which will help to indicate cognitive change before dementia and
       better differentiate MCI from Alzheimer's. Research is underway to
       better understand the cognitive changes taking place, how they may
       relate to biomarkers, and which of these methods best indicate the
       likelihood of imminent progression to Alzheimer's dementia.
    -- Alzheimer's dementia - The group is revising the existing criteria for
       diagnosing Alzheimer's to include possible biomarkers and other
       assessments that may aid in diagnosis.

About AAICAD

The Alzheimer's Association International Conference on Alzheimer's
Disease (AAICAD) is the world's largest conference of its kind, bringing
together researchers from around the world to report and discuss
groundbreaking research and information on the cause, diagnosis, treatment
and prevention of Alzheimer's disease and related disorders. As a part of the
Alzheimer's Association's research program, AAICAD serves as a catalyst for
generating new knowledge about dementia and fostering a vital, collegial
research community.

About the Alzheimer's Association

The Alzheimer's Association is the leading voluntary health organization
in Alzheimer's care, support and research. Our mission is to eliminate
Alzheimer's through the advancement of research, to provide and enhance care
and support for all affected, and to reduce the risk of dementia through the
promotion of brain health. Our vision is a world without Alzheimer's. Visit
www.alz.org or call +1-800-272-3900.

EMBARGOED FOR RELEASE UNTIL TUESDAY, JULY 13, 2010 AT 11:30 am HST / 5:30
pm ET

Alzheimer's Association media line, +1-312-335-4078, media at alz.org; AAICAD 2010 press room, July 10-15, +1-808-792-6523; or the National Institute on Aging media line, +1-301-496-1752, peggy.vaughn at nih.gov, cahanv at nia.nih.gov

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