188. Ocular Flutter, Ataxia, and Myoclonus Associated With CSF Pleocytosis and GAD65 Antibodies Years After Curative Treatment of Follicular Thyroid Carcinoma: A Case Report and Literature Review

Article type: Letter to the Editor
Article title: Ocular Flutter, Ataxia, and Myoclonus Associated With CSF Pleocytosis and GAD65 Antibodies Years After Curative Treatment of Follicular Thyroid Carcinoma: A Case Report and Literature Review

Journal: Journal of Neuro-Ophthalmology
Year: 2025
Authors: Ana Letícia Fornari Caprara, Jamir Pitton Rissardo, Jesse Thon, Olga R. Thon
E-mail: jamirrissardo@gmail.com

ABSTRACT
Opsoclonus–myoclonus syndrome (OMS), a rare neuroimmunological disorder characterized by involuntary eye movements, ataxia, and myoclonus, is typically associated with paraneoplastic or autoimmune etiologies. This case report describes a 47-year-old woman who developed ocular flutter, truncal ataxia, and stimulus-induced myoclonus in the context of persistent cerebrospinal fluid (CSF) lymphocytic pleocytosis and elevated anti-GAD65 antibodies, ten years after curative treatment for follicular thyroid carcinoma. Despite remission of her malignancy, neurological symptoms persisted and worsened over time. Imaging and serological studies ruled out recurrent cancer and infectious causes. Immunotherapy with IVIg and rituximab yielded minimal improvement, suggesting irreversible neuroinflammatory damage. A literature review revealed this to be the first documented case of anti-GAD65–associated OMS linked to thyroid carcinoma with prolonged CSF abnormalities. The findings underscore the importance of early recognition and treatment of autoimmune OMS to prevent long-term neurological sequelae.
Keywords: GAD; GAD65; GAD2; ataxia; thyroid; opsoclonic; opsoclonus-myoclonus-ataxia; Kinsbourne syndrome; oculomotor; flutter.

Full text available at:

DOI
10.1097/WNO.0000000000002194

Citation
Fornari Caprara AL, Pitton Rissardo J, Thon JM, Thon OR. Ocular Flutter, Ataxia, and Myoclonus Associated With CSF Pleocytosis and GAD65 Antibodies Years After Curative Treatment of Follicular Thyroid Carcinoma: A Case Report and Literature Review. J Neuroophthalmol 2024;45:e173-e174. doi: 10.1097/WNO.0000000000002194.
Supplementary Table. Literature review of clinical and diagnostic features of opsoclonus-myoclonus associated with GAD antibodies.