Objective:

To describe a case of progressive ataxia and palatal tremor associated with anti-thyroid peroxidase (anti-TPO) antibodies. To enhance the learning experience, we will include a video demonstrating the patient's phenomenology before and after treatment as part of this case report.

Background:

Progressive ataxia with palatal tremor is an uncommon diagnosis, and association with anti-TPO antibodies has not yet been reported in literature. The discovery of elevated levels of serum anti-TPO antibodies and a clear clinical improvement after steroid therapy helps provide further conviction in the diagnosis.

Design/Methods:

Retrospective chart review of a patient chart who presented to our clinic with progressive ataxia.

Results:

A 46-year-old left-handed woman presented with a six-year history of progressive gait instability, near falls, oscillopsia, and dizziness. On examination, she displayed torsional nystagmus, spontaneous right lower facial myoclonus, and a persistent, rhythmic tremor of the soft palate. Further evaluation revealed gait ataxia, a positive Romberg’s sign, and right-hand dystonia when distracted. Brain MRI with and without contrast showed no significant structural abnormalities, including in the inferior olives or the Guillain-Mollaret triangle. Laboratory tests revealed an elevated anti-TPO antibody level of 756 IU/mL. She was treated with 1000 mg/day of methylprednisolone for five days, leading to marked improvement in her gait ataxia and balance perception.

Conclusions:

Movement disorders associated with anti-TPO antibodies are uncommon, and palatal tremor or progressive ataxia is particularly rare or unreported. This case is noteworthy as the presence of anti-TPO antibodies manifested primarily as a movement disorder, without clear signs of encephalopathy, seizures, or thyroid dysfunction, and with no abnormalities in imaging. Progressive ataxia with palatal tremor remains a treatable condition when associated with antibody positivity and neurologists should maintain a high index of suspicion when assessing patients with movement disorders. Early treatment may reduce morbidity in these patients.