The diagnosis of Alzheimer's disease (AD) is made on the basis of clinical<unk>  described by either the National Institute on Aging and the Alzheimer's Association (NIA-AA) or DSM-V<unk>  and Statistical Manual of Mental Disorders, fifth edition). Histopathologic examination for diagnosis of Alzheimer's disease is rarely done. Elderly patients presenting with progressive decline in memory and other cognitive impairments such as aphasia, agnosia or apraxia should be suspected for Alzheimer's disease. In these patients, mental status examination (MSE) and neuropsychological testing should be performed to further evaluate the status of cognitive abilities. Laboratory investigation are not required to diagnose Alzheimer's and are done to exclude other conditions which may present with similar symptoms as seen in Alzheimer's disease (such as vit B12 deficiency, syphilis, or tuberculosis). Patients with atypical clinical presentation may also be tested for biomarkers such as  Aβ and total and phosphorylated tau protein.
Alzheimer's disease diagnostic criteria
Delirium classification
Delirium diagnostic criteria
Alzheimer's disease epidemiology and demographics
Amnesia classification scheme
Creutzfeldt-Jakob disease diagnostic criteria
Parkinson's disease epidemiology and demographics
Amnesia classification