Differential Diagnosis for 68 yo with Recent Confusion, Difficulty Walking, Foot Drop, and History of Alcohol Use Disorder

• Single Most Likely Diagnosis

  • Wernicke's Encephalopathy: This condition is strongly suggested by the patient's history of alcohol use disorder, recent confusion, ataxic gait, and difficulty walking. Wernicke's encephalopathy is a neurological disorder caused by thiamine (vitamin B1) deficiency, often seen in individuals with alcohol use disorder. The clinical triad of confusion, ataxia, and ophthalmoplegia (though not all symptoms need to be present) points towards this diagnosis.

• Other Likely Diagnoses

  • Alcoholic Neuropathy: Given the patient's history of alcohol use disorder and symptoms like foot drop and left foot weakness, alcoholic neuropathy is a plausible diagnosis. This condition results from damage to the peripheral nerves due to chronic alcohol abuse, leading to symptoms such as muscle weakness, ataxia, and sensory deficits.
  • Chronic Subdural Hematoma: Although less directly linked to alcohol use disorder than the first two options, chronic subdural hematoma could explain confusion and difficulty walking, especially if there was a recent fall. Alcohol use increases the risk of falls and subsequent head injuries.
  • Nutritional Deficiencies (other than thiamine): Other vitamin deficiencies, such as vitamin B12 deficiency, can also cause neurological symptoms including weakness, gait disturbances, and confusion, particularly in the context of poor nutrition often associated with alcohol use disorder.

• Do Not Miss Diagnoses

  • Stroke or Transient Ischemic Attack (TIA): While the patient's presentation might not classically suggest a stroke, the sudden onset of confusion, difficulty walking, and focal weakness (foot drop) necessitates consideration of a cerebrovascular event. A stroke or TIA would require immediate medical attention.
  • Spinal Cord Compression: This condition can cause sudden onset of weakness, gait disturbance, and could potentially explain the foot drop. It's a medical emergency that requires prompt diagnosis and treatment.
  • Infections (e.g., Meningitis, Encephalitis): Infections affecting the central nervous system can present with confusion, ataxia, and focal neurological deficits. Given the potential for severe consequences if missed, these diagnoses must be considered, especially if there are signs of infection or immunocompromise.

• Rare Diagnoses

  • Guillain-Barré Syndrome: An autoimmune disorder that can cause rapid-onset muscle weakness, often following an infectious illness. While rare, it's a consideration in the differential for acute weakness and could potentially explain some of the patient's symptoms.
  • Tabs Dorsalis (Neurosyphilis): A late manifestation of syphilis that affects the spinal cord and can cause ataxia, weakness, and sensory deficits. Given its rarity and the specific constellation of symptoms required for diagnosis, it is less likely but should be considered in the appropriate clinical context.
  • Vitamin B12 Deficiency Myelopathy: A condition caused by vitamin B12 deficiency that affects the spinal cord, leading to symptoms such as gait disturbance, weakness, and sensory changes. While not as directly linked to alcohol use as thiamine deficiency, it remains a consideration in patients with poor nutrition.