Differential Diagnosis for Altered Mental Status

• Single most likely diagnosis
  • Delirium: This is the most common cause of altered mental status, especially in hospitalized or elderly patients. It is characterized by an acute onset of fluctuating cognitive impairment, often accompanied by changes in level of consciousness and attention.
• Other Likely diagnoses
  • Dementia: A chronic and progressive condition that affects memory, thinking, and behavior, which can lead to altered mental status, especially in advanced stages.
  • Seizure or Post-Ictal State: A seizure can cause altered mental status, and the post-ictal state (after a seizure) often presents with confusion and altered consciousness.
  • Infection (e.g., Sepsis, Meningitis, Encephalitis): Infections, particularly those affecting the central nervous system, can cause altered mental status due to inflammation and direct neuronal damage.
  • Substance Intoxication or Withdrawal: Various substances, including alcohol, drugs, and certain medications, can induce altered mental states through intoxication or withdrawal effects.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Hypoglycemia: Low blood sugar can rapidly lead to altered mental status, seizures, and even death if not promptly treated.
  • Hyperglycemia (Diabetic Ketoacidosis or Hyperosmolar Hyperglycemic State): Severe hyperglycemia can cause altered mental status and is life-threatening if not addressed.
  • Stroke or Transient Ischemic Attack (TIA): Acute vascular events in the brain can present with sudden onset of altered mental status among other focal neurological deficits.
  • Traumatic Brain Injury: Especially in the context of recent trauma, altered mental status could be indicative of a serious and potentially life-threatening brain injury.
• Rare diagnoses
  • Hashimoto's Encephalopathy: A rare condition associated with autoimmune thyroiditis, characterized by altered mental status, seizures, and stroke-like symptoms.
  • Whipple's Disease: A systemic bacterial infection that can affect the central nervous system, leading to altered mental status, among other symptoms like diarrhea and weight loss.
  • Creutzfeldt-Jakob Disease: A rare, degenerative, and fatal brain disorder that can present with rapidly progressive dementia and altered mental status.
  • Wilson's Disease: A genetic disorder leading to copper accumulation in the brain and liver, which can cause neurological symptoms including altered mental status, particularly in young adults.