Yet Another Atypical Presentation of Anti-GQ1b Antibody Syndrome.

Variants of Guillain-Barre syndrome such as Bickerstaff encephalitis and Miller-Fisher syndrome have been reported. We report a 15-year-old boy who presented, after a prodromal illness, with 3-day progressive limb weakness, diplopia, and acute urinary retention. Clinically, he had horizontal gaze-evoked and upbeat nystagmus, bilateral extensor plantars in addition to quadriparesis and areflexia. Magnetic resonance imaging of the brain and spine was unremarkable and cerebral spinal fluid analysis showed lymphocytic pleocytosis. Nerve conduction study revealed symmetrical axonal neuropathy. Anti-GQ1b antibody was positive. A combination of IV methylprednisone followed by IVIg was instituted which led to remarkable clinical recovery. This case underpins the importance of recognizing atypical presentations of acute autonomic dysfunction and central nervous system features such as nystagmus, which may be associated with anti-GQ1b antibody syndrome. Features mimicking myelitis and brainstem encephalitis may pose diagnostic and therapeutic dilemma among the treating physicians.