Myasthenia Gravis is the most common neuromuscular junction disorder, and it’s high-yield for Step 1!

Key Features:

• Fluctuating muscle weakness that worsens with activity
• Ptosis, diplopia, dysphagia, and proximal weakness
• Myasthenic crisis → Respiratory failure risk

Diagnosis:

• Ice pack test improves ptosis
• ACh receptor antibodies (highly specific)
• Chest CT to check for thymoma

Treatment:

• Pyridostigmine (AChE inhibitor)
• Thymectomy if thymoma
• Immunotherapy for severe cases
• Myasthenic crisis → IVIG or plasmapheresis

Know how to differentiate it from Lambert-Eaton syndrome (which improves with use)!