Differential Diagnosis for 66 yo Female with Hallucinations and Found Down

• Single Most Likely Diagnosis
  • Delirium: Given the patient's history of being found down and experiencing hallucinations, delirium is a strong consideration. It is a common condition in elderly patients, especially those with a history of psychiatric disorders and recent surgeries (e.g., Roux-en-Y), which can lead to metabolic imbalances, infections, or medication side effects.
• Other Likely Diagnoses
  • Psychotic Episode (related to BPD, GAD, or MDD): The patient's psychiatric history suggests that a psychotic episode could be a contributing factor to her hallucinations. The stress of recent health issues or changes in medication could trigger such an episode.
  • Postoperative Cognitive Dysfunction: After undergoing a significant surgery like Roux-en-Y, patients can experience cognitive impairments, including hallucinations, due to anesthesia effects, pain, or metabolic disturbances.
  • Medication-Induced Psychosis: Many medications, including those used to treat psychiatric conditions or manage postoperative pain, can induce psychotic symptoms such as hallucinations.
• Do Not Miss Diagnoses
  • Sepsis: Infections can lead to delirium and hallucinations, especially in elderly patients. Given the patient's recent surgery, sepsis is a critical diagnosis not to miss due to its high mortality rate if untreated.
  • Hypoglycemia or Hyperglycemia: Both conditions can cause altered mental status, including hallucinations. Given the patient's history of Roux-en-Y surgery, which affects glucose metabolism, monitoring blood glucose levels is crucial.
  • Stroke or Transient Ischemic Attack (TIA): Although less likely, stroke or TIA can present with sudden onset of hallucinations and altered mental status. These conditions require immediate medical attention to prevent further brain damage.
• Rare Diagnoses
  • Neuroleptic Malignant Syndrome (NMS): A rare but life-threatening side effect of neuroleptic medications, characterized by altered mental status, which could include hallucinations, along with other systemic symptoms.
  • Wernicke's Encephalopathy: A condition caused by thiamine deficiency, which can occur in malnourished patients or those with absorption issues post-Roux-en-Y surgery, leading to hallucinations among other symptoms.