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Which of the following is the most likely cause of his altered mental status?
Dr. Shoaib Ahmad Baig
January 05, 2025
🔍 Question of the day
A 54-year-old man with a history of hepatitis C presents to the emergency department after several episodes of vomiting bright red blood. He is admitted and receives appropriate treatment. The following day, during rounds, he appears disoriented, unable to identify the date or his location. Examination reveals significant abdominal distension, gynecomastia, and repetitive flicking movements of the hands when asked to extend his arms and dorsiflex his wrists.
Which of the following is the most likely cause of his altered mental status?
A. Accumulation of blood urea nitrogen
B. Bacterial infection of the meninges
C. Decreased gamma-aminobutyric acid receptor stimulation
D. Increased absorption of nitrogenous substances by the gut
E. Occlusion of the middle cerebral artery
Correct Answer 🎯: D. Increased absorption of nitrogenous substances by the gut
Why Correct:
1. GI Bleed → ↑ Nitrogenous Substances in Gut (blood breakdown 🧠)
2. Absorbed into Portal Circulation → Liver Dysfunction (↓ Detoxification)
3. Hyperammonemia → Neurotoxicity → Hepatic Encephalopathy (🧠)
⚙️
Chronic Hepatitis C Infection (Liver damage over time)
⬇
Cirrhosis Development (Scar tissue replaces healthy liver tissue 🧠)
⬇
Portal Hypertension
⬇
1. Esophageal Varices Formation → Bleeding Varices (bright red vomitus)
2. ↓ Liver Function
⬇
↓ Detoxification of Nitrogenous Substances (e.g., ammonia 🧠)
⬇
↑ Ammonia in Blood (Hyperammonemia)
⬇
Crosses Blood-Brain Barrier
⬇
↑ Neurotoxicity in Brain (Hepatic Encephalopathy)
⬇
• Altered Mental Status
• Asterixis (flapping tremor 🧠)
⚖️ Explanation of Other Differentials
Differential ⚖️ | Mechanism ⚙️ | Why Incorrect? 🔴 |
|---|---|---|
Bacterial Meningitis | Infection could explain confusion, fever, or neck stiffness. | ⚠ No fever, headache, or neck stiffness. Signs like asterixis are specific for hepatic encephalopathy 🧠. |
Decreased GABA Receptor Stimulation | Neurotoxicity can involve GABA receptor dysfunction. | ⚠ Hepatic encephalopathy increases GABA receptor activity 🧠 due to neurotoxins like ammonia. |
Middle Cerebral Artery (MCA) Stroke | MCA occlusion can cause focal deficits and altered mental status. | ⚠ Stroke causes focal neurological deficits, not diffuse findings like confusion, asterixis, or gynecomastia. |
Accumulation of Blood Urea Nitrogen (BUN) | Kidney dysfunction causes ↑ BUN. May lead to confusion. | ⚠ This is not kidney disease. The altered mental status here is from hyperammonemia, not elevated BUN. |
📝 Flashcards
Stay Hungry, Stay Curious!
Your Brother In This Struggle
Dr. Shoaib Ahmad
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