Memory impairment (amnesia)

Page most recently updated 7 September 2026

This page focuses on presentations with memory-predominant cognitive impairment of insidious onset and progressive course suggestive of a neurodegenerative process. Key differential diagnoses to consider include:

  • Alzheimer disease spectrum, including amnestic mild cognitive impairment

The approach below begins with relevant features on history and neurocognitive testing, followed by the relevant differential diagnoses, with further distinctive history and examination findings provided for each diagnosis.

The specific type of memory discussed on this page is episodic memory; that is, memory for personally experienced events, rather than semantic memory for general facts (such as remembering the capital cities of countries).

● History (direct and collateral)

Symptoms reported or elicited typically include difficulty with:

  • Remembering names

  • Remembering conversations (e.g., repeating questions or requiring repetition of information, with compensatory strategies such as making notes)

  • Remembering dates (e.g., with confusion between dates of different events)

  • Remembering appointments

  • Remembering where they placed objects (e.g., mobile phone, keys, glasses)

  • Remembering to turn off the stove or the faucet

● Neurocognitive testing

▪ Tasks that show impairment on initial screening (and are typically included in routine neurocognitive screening instruments) may include:

◦ Brief verbal or visual memory tasks

These generally include repeated learning trials followed, after several minutes, by assessment of delayed recall. Delayed recall is typically assessed first by free recall, without prompts, and may then be followed by cued recall, for example using a category cue, and, if needed, finally by recognition of the items from a list of multiple choices. Poor delayed recall accompanied by impaired recognition is more suggestive of an encoding/storage deficit, with loss of the learned information over time (e.g., due to medial temporal lobe pathology, as is seen in Alzheimer disease), whereas poor delayed recall with relatively preserved recognition is more consistent with a retrieval deficit (e.g., due to frontal-subcortical network pathology).

▪ Supplementary tests that may be performed to corroborate initial findings and to further characterize deficits may include:

◦ More extensive verbal memory tests, such as:

CERAD Verbal Learning Test

Free and Cued Selective Reminding Test

Hopkins Verbal Learning Test–Revised

Rey Auditory Verbal Learning Test

◦ Visual memory tests involving copying of a complex figure followed by recall after several minutes

● Differential diagnoses, including distinctive history and examination findings

▪ Alzheimer disease spectrum, including amnestic mild cognitive impairment

Patients with amnestic mild cognitive impairment or Alzheimer disease typically initially present with an amnestic cognitive profile, particularly impaired retention of newly learned information and rapid forgetting. Neurocognitive testing typically demonstrates prominent episodic memory impairment, with other cognitive domains variably affected depending on the stage and clinical phenotype. General physical and neurological examination, including cranial nerves, motor examination, and gait, is typically unremarkable in the early stages.

Selected references and further reading — Cognitive lens

Tang-Wai DF, Freedman M. Bedside approach to the mental status assessment. Continuum (Minneap Minn). 2018 Jun;24:672-703.

Hodges JR. Cognitive assessment for clinicians. 3rd ed. Oxford: Oxford University Press; 2017.

Dickerson BC, Atri A, editors. Dementia: comprehensive principles and practices. Oxford: Oxford University Press; 2014.

Jankovic J, Mazziotta JC, Pomeroy SL, Newman NJ, editors. Bradley and Daroff's neurology in clinical practice. 8th ed. Philadelphia: Elsevier; 2022.

Dening T, Thomas A, editors. Oxford textbook of old age psychiatry. 3rd ed. Oxford: Oxford University Press; 2021.

Blazer DG, Steffens DC, Busse EW, editors. The American Psychiatric Publishing textbook of geriatric psychiatry. 5th ed. Washington (DC): American Psychiatric Publishing; 2015.

Arciniegas DB, Yudofsky SC, Hales RE, editors. The American Psychiatric Association Publishing textbook of neuropsychiatry and clinical neurosciences. 6th ed. Washington (DC): American Psychiatric Association Publishing; 2018.

Agrawal N, Faruqui R, Bodani M, editors. Oxford textbook of neuropsychiatry. Oxford: Oxford University Press; 2020.

Boland R, Verduin M, editors. Kaplan and Sadock's comprehensive textbook of psychiatry. 11th ed. Philadelphia: Wolters Kluwer; 2024.