In myasthenia gravis, antibodies against muscle-specific kinase (MuSK) are found in a subset of seronegative patients. Which clinical feature is most characteristic of MuSK antibody-positive MG?

• A Prominent bulbar and respiratory muscle weakness with neck and shoulder atrophy ✓
• B Thymic hyperplasia in most cases
• C Excellent response to cholinesterase inhibitors alone
• D Ocular muscles affected in isolation without generalization

Explanation

MuSK antibody MG predominantly affects women, with prominent bulbar weakness, respiratory crisis, and facial/neck muscle atrophy. Thymic pathology is minimal (unlike AChR MG). Response to pyridostigmine is often poor. Isolated ocular involvement is rare. Distinguishing MuSK MG from AChR MG guides management and prognosis.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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