Cognitive

Amnesia

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Amnesia, Amnestic Syndrome, Amnestic Disorder, Memory Loss, Retrograde Amnesia, Anterograde Amnesia, Post-Traumatic Amnestic Disorder

  • See Also
  1. Psychogenic Amnesia (Dissociative Amnesia)
  2. Transient Global Amnesia
  3. Memory Evaluation
  • Definitions
  1. Amnesia
    1. Systematic and extensive loss of memory, due to psychological or organic cause
  2. Retrograde Amnesia
    1. Inability to recall past experiences
  3. Anterograde Amnesia
    1. Inability to form new memories after a certain time point
  • Background
  1. Term Amnesia is derived from the greek for a (without) and mnesis (memory)
  • Pathophysiology
  1. Organic causes most often affect the Hippocampus and medial Temporal Lobes
  2. Longterm memories are often preserved better than memories acquired in closer proximity to Amnesia onset
  3. Working memory is often preserved despite Amnesia
  • Causes
  1. Psychological (transient)
    1. Psychogenic Amnesia (Dissociative Amnesia)
    2. Transient Global Amnesia
  2. Organic (chronic)
    1. Post-Traumatic Amnestic Disorder
      1. Traumatic Head Injury
      2. Cerebrovascular Accident
      3. Neurosurgery
      4. Electroconvulsive Therapy
      5. Anoxic or hypoxic brain injury
    2. Infection
      1. Herpes Simplex Encephalitis
    3. Chronic Thiamine deficiency
      1. Alcohol Amnestic Disorder (Wernicke-Korsakoff Syndrome)
      2. Beriberi
    4. Drug-Induced Amnesia
      1. Alcohol Intoxication (e.g. blackout)
      2. Benzodiazepines
  • Differential Diagnosis
  1. Dementia
  2. Delirium
  3. Complex Partial Seizure
  4. Classic Migraine Headache
  • References
  1. Allen (2018) F1000Res +PMID:29623196 [PubMed]
  2. Brown and Hachinski in Wilson et. al. (1991) Harrison's Internal Medicine, Twelfth Edition, McGraw-Hill, St. Louis, p.188-9