A 30-year-old man develops diplopia, gait ataxia, and areflexic ophthalmoplegia 10 days after a febrile diarrheal illness. Deep tendon reflexes are absent and CSF protein is elevated with normal cell count. Which antibody is most likely present?
- A Anti-AQP4
- B Anti-GM1
- C Anti-GQ1b ✓
- D Anti-P/Q-type VGCC
Correct answer: C. Anti-GQ1b
Explanation
Miller Fisher syndrome, a Guillain-Barre variant with the triad of ophthalmoplegia, ataxia, and areflexia, is strongly associated with IgG antibodies against the ganglioside GQ1b, which concentrates at cranial nerve paranodes. Anti-GM1 relates to axonal motor GBS and multifocal motor neuropathy, while P/Q-type VGCC antibodies define Lambert-Eaton myasthenic syndrome.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.