Axial and Limb Spasms in a Woman With Hashimoto Thyroiditis

A 39-year-old woman diagnosed as having Hashimoto thyroiditis 1 month prior developed spasms in her axial and lower limb muscles, as illustrated in this video. She had elevated levels of thyroperoxidase, thyroglobulin, and anti–glutamic acid decarboxylase (GAD65) antibodies; normal imaging, cerebrospinal fluid measures, and paraneoplastic antibody levels; and electromyography findings showing continuous firing of normal motor unit potentials at rest within the axial and lower limb muscles, consistent with a diagnosis of progressive encephalomyelitis with rigidity and myoclonus (PERM). Her recent diagnosis of Hashimoto thyroiditis suggested an autoimmune etiology. Click the related article link for additional clinical images and patient videos and for complete details of the diagnosis, its differential, and the patient’s response to treatment.