AntiGAD antibodies can cause prominent ocular motor deficits.
We describe opsoclonus with downbeat nystagmus in a patient with antiGAD antibody.
Paucity in GABA can cause downbeat nystagmus.
Anti-GAD antibody can impair action of GAD reduce degradation of glutamate.
Increased glutamate and hyperexcitability of burst neurons can cause opsoclonus.