Alternating Skew Deviation in Association with Anti-Glutamic Acid Decarboxylase Antibodies

The presence of an elevated anti-glutamic acid decarboxylase (GAD) antibody level has been associated with a number of eye movement abnormalities as well as other findings, including cerebellar ataxia and insulin-dependent diabetes mellitus. Skew deviation in association with anti-GAD antibodies has not been previously reported. Here the authors report a case of alternating skew deviation along with cerebellar-brainstem signs in a patient with an elevated anti-GAD antibody titre. Follow-up neurologic evaluation after treatment with intravenous immunoglobulin revealed improvement in cerebellar-brainstem signs, whereas ophthalmic evaluation was stable.