Experts Propose New Lexicon for Alzheimer's Disease

AD redefined as a clinical-biological syndrome, allowing earlier diagnosis and targeted treatment

13 oct 2010-- The International Working Group for New Research Criteria for the Diagnosis of AD (Alzheimer's disease) has proposed a new lexicon as a point of reference for earlier diagnosis of AD patients in a position paper published online Oct. 11 in The Lancet Neurology.

Bruno Dubois, M.D., of the Institute for Memory and Alzheimer's Disease in Paris, and colleagues provide a broader diagnostic definition of AD as a clinical-biological syndrome. The definition aims to enable earlier diagnosis of AD by using biomarkers to diagnose patients with the condition instead of requiring a post-mortem examination.

According to the proposed lexicon, patients must present with episodic memory impairment and at least one positive biomarker shown on magnetic resonance imaging, neuroimaging with positron emission tomography, or cerebrospinal fluid analysis to meet the criteria for the diagnosis of AD. The authors write that the new definition could aid in selecting patients for trials of disease-modifying drugs and help in diagnosing patients at an earlier stage of disease to target treatment more effectively.

"The value of these definitions is their potential application in clinical trials of disease-modifying drugs," the authors write. "Individuals identified as 'asymptomatic at risk for AD' or 'presymptomatic AD' might be enrolled in trials aimed at delaying the onset of clinical signs. Patients with prodromal AD could be included in trials of drugs targeting progression to more severe stages of AD (AD dementia)."

Multiple authors disclosed financial relationships with medical device and pharmaceutical companies, including companies developing drugs for Alzheimer's disease.

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