Immune-mediated ophthalmoparesis with anti-GD1a antibodies

A young woman presented to neurology with a 1 month history of progressive diplopia on lateral gaze and a 1 week history of headaches. On examination she was found to have complex ophthalmoparesis with binocular horizontal diplopia, failure of abduction bilaterally and limited upgaze with convergence-retraction nystagmus. The rest of the neurological examination was normal. She was admitted for investigations: blood, CT brain, MR brain and lumbar puncture results were normal. Anti-GD1a antibodies were strongly positive; anti-GM1, anti-GM2 and anti-GD1b were also positive. On follow-up 3 weeks later, the complex ophthalmoplegia persisted. It was decided to treat with intravenous immunoglobulins (IVIgs) with good response but recurrence at 2 weeks post infusion. She was treated with 4 weekly IVIg courses and remains responsive and controlled over 1 year since presentation but becomes symptomatic in the week running up to each dose; thus, disease modifying treatment is currently being considered.