Progressive Non-familial Adult onset Cerebellar Degeneration: An Unusual Occurrence with Hashimoto's Thyroiditis.

Progressive non-familial adult onset cerebellar degeneration has been rarely associated with hypothyroidism and is known to be reversible after therapy. We report a case of cerebellar atrophy in a 31 year old female whose detailed evaluation had revealed sub-clinical hypothyroidism secondary to autoimmune thyroiditis with a very high anti-TPO (anti-thyroid peroxidase) antibody levels. MRI (Magnetic Resonanace Imaging) of brain showed diffuse bilateral cerebellar atrophy. She was treated with thyroid hormone supplementation and after one year of follow up, cerebellar signs had disappeared completely with significant reduction in anti-TPO antibody levels. Imaging of the brain post one year of follow-up revealed normal cerebellum. Hence, we opine that thyroid dysfunction should always be kept in mind while evaluating patients presenting with acute onset cerebellar ataxia as it can be easily reversed with thyroid hormone replacement therapy.