Dubois et al reported criteria from an international working group (IWG) for the diagnosis of Alzheimer's Disease (AD). Typical Alzheimer's disease can be diagnosed if certain findings are present. The authors are from multiple institutions in Europe and North America.
Criteria for atypical Alzheimer's disease - all of the following:
(1) one specific clinical phenotype
(2) one in vivo finding associated with Alzheimer pathology
(3) no other explanation
Specific clinical phenotype - at least one of the following:
(1) posterior variant of Alzheimer's disease, occipitotemporal (early, predominant and progressive impairment of visuoperceptive function or of visual identification of objects, words, symbols or faces)
(2) posterior variant of Alzheimer's disease, parietal (early, predominant and progressive difficulty with visuospatial function; features of Gerstmann syndrome, of Balint syndrome, limb apraxia or neglect)
(3) logopenic variant of Alzheimer's disease (early, predominant and progressive impairment of single word retrieval and in repetition of sentences)
(4) frontal variant of Alzheimer's disease (early predominant and progressive behavioral changes; may include primary apathy, disinhibition or executive dysfunction)
(5) Down's syndrome variant of Alzheimer's disease (dementia with early behavioral changes and executive function in a patient with Down's syndrome)
In vivo evidence of Alzheimer's pathology - at least one of the following:
(1) decreased amyloid beta(1-42) with increased T-tau or P-tau in the CSF
(2) increased tracer retention on amyloid PET scan
(3) Alzheimer's disease autosomal dominant mutation (PSEN1, PSEN2, APP)
Exclusions:
(1) sudden onset
(2) early and prevalent episodic memory disorders
(3) major depression
(4) cerebrovascular disease
(5) toxic, inflammatory or metabolic disorders
