Source / episode info

• **Episode:**495
• **Title:**Divine Intervention Episode 495: USMLE Step 2/3 Rapid Review Series 107
• **Published:**2023-12-07
• Source:Episode page

One-liner

This episode provides a high-yield review covering neurological differentials like Bell's palsy versus MCA stroke; the spectrum of cirrhosis etiologies including NAFLD and chronic hepatitis markers; metabolic disorders such as hemochromatosis and Wilson's disease; and vascular/pulmonary syndromes like Budd-Chiari syndrome and Alpha-1 antitrypsin deficiency.

High-yield summary

• Bell's Palsy vs. MCA Stroke: Bell's palsy (CN VII nucleus lesion, brainstem) causes upper AND lower facial weakness bilaterally. An MCA stroke (cortical lesion) causes only the contralateral lower face weakness.
• Cirrhosis Etiologies: Must differentiate between Primary Biliary Cholangitis (AMA positive), Primary Sclerosing Cholangitis (IBD associated, direct bilirubinemia), and Autoimmune Hepatitis (ASMA positive).
• NAFLD LFT Pattern: Elevated ALT > AST is not exclusive to alcoholism; it can also be seen in Non-Alcoholic Fatty Liver Disease.
• Budd-Chiari Syndrome (BCS): Characterized by rapid onset abdominal pain, ascites, and hepatic vein thrombosis, often secondary to a hypercoagulable state (e.g., Protein C deficiency, Polycythemia Vera).
• Alpha-1 Antitrypsin Deficiency: Leads to emphysema/cirrhosis because the misfolded protein is synthesized in the liver but cannot properly function as an anti-protease in the lungs.
• Hemochromatosis: Iron overload disorder presenting with chronic fatigue, arthralgia, skin hyperpigmentation (bronze diabetes), and cardiac involvement (restrictive cardiomyopathy).

Learning objectives

• Differentiate the neurological deficits caused by central (cortical/brainstem) versus peripheral nerve lesions of the facial nerve.
• Identify the characteristic serological markers and clinical presentations distinguishing various causes of cirrhosis (PBC, PSC, AIH).
• Recognize the systemic manifestations of iron overload disorders (Hemochromatosis) and copper accumulation (Wilson's disease).
• Understand the pathophysiology and risk factors associated with hepatic vein thrombosis (Budd-Chiari syndrome).
• Correlate genetic/protein deficiencies (e.g., Alpha-1 antitrypsin, ceruloplasmin) with specific organ damage (lung emphysema, neurological symptoms).