Differential Diagnosis for Brief Amnesia in a Healthy 50-year-old Male with Mitral Valve Prolapse

• Single most likely diagnosis:
  • Dehydration or heat-related illness: Brief amnesia during intense physical activity could be related to dehydration or heat exhaustion, especially if the individual was working out in a hot environment without adequate hydration.
• Other Likely diagnoses:
  • Vasovagal syncope: A common cause of fainting spells, especially during or after intense physical activity, which could lead to brief amnesia.
  • Mitral valve prolapse-related arrhythmias: Although the patient has mitral valve prolapse, it's less likely to directly cause amnesia, but arrhythmias associated with it could potentially lead to reduced cerebral blood flow.
  • Hypoglycemia: If the individual hasn't eaten for a while before working out, hypoglycemia could cause confusion, amnesia, or even loss of consciousness.
• Do Not Miss diagnoses:
  • Cardiac arrhythmias (e.g., atrial fibrillation): These could lead to embolic events or significant reductions in cardiac output, causing cerebral hypoperfusion and amnesia.
  • Transient ischemic attack (TIA): A "mini-stroke" could cause brief amnesia and is crucial to diagnose promptly to prevent a full-blown stroke.
  • Seizure: Although less common, a seizure could cause a brief period of amnesia, and it's critical to diagnose and treat appropriately.
• Rare diagnoses:
  • Hypertrophic cardiomyopathy: Although the patient has mitral valve prolapse, other cardiac conditions like hypertrophic cardiomyopathy could potentially cause arrhythmias leading to amnesia during exertion.
  • Migraine with aura: Some migraines can present with neurological symptoms including amnesia, though this would be less common during physical exertion.
  • Multiple sclerosis or other demyelinating diseases: Very rare, but could potentially cause episodes of amnesia, especially if associated with exertion or heat.