For the first time in nearly 30 years, the diagnostic criteria for Alzheimer’s disease (AD) have been updated in the April 19 online issue of Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association. The guidelines provide new criteria, including mild cognitive impairment (MCI) due to AD as well as specifically differentiating what can be used in clinical practice and what is intended to remain in research settings only.
The document establishes earlier stages of the disease in the hopes of spotting and possibly treating the condition much sooner than it is currently. However, despite the buzz about new scans and blood and fluid tests that claim to show early signs of AD, the guidelines specify that they are still just tools for research and do not advise physicians to modify how they evaluate and manage patients.
Three working groups were convened to cover AD dementia, MCI due to AD, and preclinical AD. Among the new and maintained recommendations, the working groups established some of the following key points:
The AD working group retained the core clinical criteria framework of probable AD dementia from the criteria published in 1984, which will continue to be the cornerstone of diagnosis in clinical practice. However, biomarker evidence is expected to enhance the pathophysiological specificity of the diagnosis of AD dementia.
The MCI working group included the use of biomarkers, such as advanced imaging of cerebrospinal fluid markers of disease, in the research setting. The final set of criteria for MCI has four levels of certainty:
• Concern regarding a chance in cognition
• Impairment in one or more cognitive domains
• Preservation of independence in functional abilities
• Not demented
The preclinical AD working group specified that there is no utility of this classification for the purposes of day-to- day practice. Since the preclinical is the most controversial, proposed guidelines were for research purposes only. The AD working group proposed a 3 staging framework to better define individuals at greatest risk:
Stage 1 — asymptomatic cerebral amyloidosis
Stage 2 — amyloidosis plus evidence of “downstream” neurodegeneration
Stage 3 — amyloidosis, neuronal injury, plus subtle cognitive/behavioral decline
Click New Criteria and Guidelines for Alzheimer’s Disease Diagnosis to access the documents.