Differential Diagnosis

• Single most likely diagnosis
  • Wernicke-Korsakoff syndrome: This diagnosis is likely due to the patient's history of alcohol use disorder and the subacute onset of altered mental status, which includes symptoms such as confusion, disorientation, and memory loss. The patient's initial episode of lethargy and difficulty arousing after opioid use, followed by a return to baseline, and subsequent progression to bizarre behavior and neurological deficits after a head injury, also supports this diagnosis.
• Other Likely diagnoses
  • Traumatic brain injury (TBI): The patient's fall and head injury could have contributed to her altered mental status and neurological findings, such as apraxia, aphasia, and selective mutism.
  • Opioid-induced neurotoxicity: The patient's recreational use of opioids, including morphine, oxycodone, and heroin, could have caused neurotoxicity, leading to her initial episode of lethargy and subsequent neurological symptoms.
  • Chronic subdural hematoma: The patient's head injury and subsequent progression of symptoms could be indicative of a chronic subdural hematoma, which requires prompt medical attention.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Meningitis or encephalitis: Although less likely, these diagnoses could present with altered mental status, fever, and neurological deficits, and would require prompt antibiotic or antiviral treatment to prevent serious complications or death.
  • Subarachnoid hemorrhage: A head injury could have caused a subarachnoid hemorrhage, which would require immediate medical attention to prevent further complications or death.
  • Brain tumor: Although rare, a brain tumor could present with altered mental status, neurological deficits, and a history of head injury, and would require prompt diagnosis and treatment to prevent serious complications or death.
• Rare diagnoses
  • Hashimoto's encephalopathy: This rare condition is characterized by altered mental status, neurological deficits, and elevated anti-thyroid antibodies, and could be considered in the differential diagnosis.
  • Creutzfeldt-Jakob disease: This rare, degenerative brain disorder could present with altered mental status, neurological deficits, and a rapidly progressive course, and should be considered in the differential diagnosis, although it is unlikely.
  • Marchiafava-Bignami disease: This rare condition is characterized by damage to the corpus callosum and could present with altered mental status, neurological deficits, and a history of alcohol use disorder, making it a rare but possible diagnosis.