Alzheimer disease

Last reviewed: 27 Aug 2023
Last updated: 05 Sep 2023



History and exam

Key diagnostic factors

  • memory loss
  • disorientation
  • nominal dysphasia
  • misplacing items/getting lost
  • apathy
  • decline in activities of daily living and instrumental activities of daily living (IADLs)
  • personality change
  • unremarkable initial physical exam
More key diagnostic factors

Other diagnostic factors

  • mood changes
  • poor abstract thinking
  • constructional dyspraxia
  • prosopagnosia
  • autoprosopagnosia
Other diagnostic factors

Risk factors

  • advanced age
  • family history
  • genetics
  • Down syndrome
  • cerebrovascular disease
  • lifestyle factors and medications
  • less than high school education
  • traumatic brain injury
  • depression
  • hearing loss
  • hyperlipidemia
  • female sex
  • elevated plasma homocysteine level
  • artificially sweetened soft drink consumption
More risk factors

Diagnostic investigations

1st investigations to order

  • bedside cognitive testing
  • CBC
  • metabolic panel
  • serum thyroid-stimulating hormone (TSH)
  • serum vitamin B12
  • urine drug screen
  • CT
  • MRI
More 1st investigations to order

Investigations to consider

  • cerebrospinal fluid (CSF) analysis
  • serum rapid plasma reagin/Venereal Disease Research Laboratory (VDRL)
  • serum HIV
  • formal neuropsychological testing
  • genetic testing
  • fluorodeoxyglucose-PET (FDG-PET)
  • single-photon emission CT (SPECT)
  • electroencephalogram (EEG)
More investigations to consider

Emerging tests

  • amyloid-PET

Treatment algorithm


all patients



Judith Neugroschl, MD

Associate Professor of Psychiatry

Alzheimer's Disease Research Center

Icahn School of Medicine at Mount Sinai

New York



JN participates in research funded by National Institutes for Health (NIH) grants. The Alzheimer's Disease Research Center is a site for clinical research but JN is not the site Principal Investigator, has no role in purchasing nor choosing the studies, and gains no compensation if they succeed. JN helps to edit the Focus on Healthy Aging Alzheimer's yearly report.


Dr Judith Neugroschl would like to gratefully acknowledge Dr Brandy R. Matthews, Dr Asif S. Bhutto, and Dr Julie K. Gammack, the previous contributors to this topic.


BRM, ASB, and JKG declare that they have no competing interests.

Peer reviewers

Roy J. Goldberg, MD, FACP, AGSF, CMD

Medical Director

Kings Harbor Multicare Center

New York



RJG declares that he has no competing interests.

Philip Scheltens, MD, PhD

Professor of Neurology

Department of Neurology/Alzheimer Center

VU University Medical Center


The Netherlands


PS declares that he has no competing interests.

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