Differential Diagnosis for Amnesia and Agitation

The patient's symptoms of amnesia to prior days, only remembering a week ago, and agitation can be caused by various substances and conditions. Here's a categorized differential diagnosis:

• Single Most Likely Diagnosis

  • Benzodiazepine or Alcohol Withdrawal: These substances can cause significant memory impairment, including anterograde amnesia (inability to form new memories), and agitation due to withdrawal symptoms. The timeline of remembering only up to a week ago could be related to the onset of withdrawal symptoms.

• Other Likely Diagnoses

  • Traumatic Brain Injury (TBI): A head injury could result in post-traumatic amnesia, where the patient may forget events leading up to and including the injury. Agitation can also be a symptom due to frustration, pain, or the injury itself affecting brain regions responsible for emotional regulation.
  • Infections (e.g., Meningitis, Encephalitis): Certain infections can cause inflammation of the brain or meninges, leading to symptoms like amnesia and agitation. The amnesia could be due to the direct effect of the infection on brain tissue.
  • Hypoglycemia: Low blood sugar can cause confusion, amnesia, and agitation. If the patient has diabetes or another condition affecting blood sugar regulation, hypoglycemic episodes could explain these symptoms.

• Do Not Miss Diagnoses

  • Wernicke's Encephalopathy: This is a medical emergency caused by thiamine deficiency, often seen in alcoholics. Symptoms include confusion, ataxia, and ophthalmoplegia, but amnesia and agitation can also be present. Prompt treatment with thiamine is crucial to prevent permanent brain damage.
  • Postictal State (After a Seizure): If the patient had a seizure, the postictal phase could involve confusion, amnesia for the seizure and possibly preceding events, and agitation.
  • Carbon Monoxide Poisoning: This can cause a range of neurological symptoms, including memory problems and agitation, due to the hypoxic effects on the brain.

• Rare Diagnoses

  • Transient Global Amnesia (TGA): A rare condition characterized by sudden, temporary memory loss and confusion, typically lasting only a few hours. While agitation can occur, it's less common than in other conditions listed here.
  • Psychogenic Amnesia: A condition where memory loss is attributed to psychological rather than physical causes. Agitation could be part of the presentation, especially if the underlying psychological issue is severe.