Differential Diagnosis for Aphasia plus Mental Status Change

• Single most likely diagnosis:
  • Stroke (ischemic or hemorrhagic): This is the most likely diagnosis because aphasia is a common presenting symptom of stroke, and mental status changes can occur due to the acute brain injury.
• Other Likely diagnoses:
  • Traumatic brain injury: Head trauma can cause both aphasia and altered mental status, especially if the injury involves areas of the brain responsible for language.
  • Brain tumors: Tumors in areas responsible for language can cause aphasia, and increased intracranial pressure or tumor effects on other brain areas can lead to mental status changes.
  • Infections (e.g., meningitis, encephalitis): Central nervous system infections can cause a wide range of symptoms, including aphasia and altered mental status, depending on the areas of the brain affected.
  • Seizures or post-ictal state: Seizure activity, particularly involving the language areas, can cause aphasia, and the post-ictal state can be associated with altered mental status.
• Do Not Miss diagnoses:
  • Reversible posterior leukoencephalopathy syndrome (PRES): Although less common, PRES can cause aphasia and mental status changes and is reversible with prompt treatment, making it crucial not to miss.
  • Status epilepticus: Prolonged seizure activity can present with fluctuating mental status and aphasia, and missing this diagnosis can be fatal.
  • Hypoglycemia or hyperglycemia: Both can cause altered mental status, and in rare cases, focal neurological signs like aphasia, especially if there's a pre-existing condition affecting the brain.
  • Wernicke's encephalopathy: This condition, caused by thiamine deficiency, can present with confusion, ataxia, and ophthalmoplegia, but aphasia can occasionally be a feature, making it a critical diagnosis not to overlook.
• Rare diagnoses:
  • Creutzfeldt-Jakob disease: A rare, degenerative, fatal brain disorder that can cause a variety of neurological symptoms, including aphasia and rapid progression of mental status changes.
  • Hashimoto's encephalopathy: A rare condition associated with autoimmune thyroiditis, which can cause a range of neurological symptoms, including aphasia and altered mental status.
  • CNS vasculitis: Inflammation of the blood vessels in the brain can cause a wide range of symptoms, including aphasia and mental status changes, depending on the areas affected.
  • Mitochondrial encephalomyopathies: Rare genetic disorders affecting the mitochondria, which can cause a variety of neurological symptoms, including aphasia and altered mental status, often with a fluctuating course.