A 24-year-old man develops diplopia, gait ataxia, and areflexia 10 days after a diarrhoeal illness. Brain MRI is normal and CSF protein is elevated with a normal cell count. Which antibody is most likely present?
- A Anti-AQP4
- B Anti-ganglioside GM1
- C Anti-GQ1b ✓
- D Anti-MuSK
Correct answer: C. Anti-GQ1b
Explanation
The triad of ophthalmoplegia, ataxia, and areflexia without limb weakness defines Miller Fisher syndrome, a GBS variant strongly associated with IgG antibodies against ganglioside GQ1b, often following Campylobacter jejuni infection. Anti-GM1 is linked to acute motor axonal neuropathy and multifocal motor neuropathy. Anti-AQP4 and anti-MuSK belong to demyelinating disease and myasthenia gravis respectively.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.