Spontaneous Downbeat Nystagmus in Anti-GAD-Antibody-Associated Paraneoplastic Syndrome.

Spontaneous downbeat nystagmus and ocular flutter are rare clinical signs. Such findings are commonly related to cerebellar pathology, predominantly ischemia. In a significant percentage of patients, the cause may not be found. If these signs are associated with ataxia, cognitive decline, and seizure, anti-glutamic acid decarboxylase-associated neurological syndrome must be suspected. Background history of tumor has to be enquired. Treatment with immune modulation helps in partial recovery of such cases.