Abstract Background Paroxysmal dyskinesia associated with hyperthyroidism (HT) is a well-described disorder in humans and has not been previously reported in cats. Hypothesis/Objectives Paroxysmal dyskinesia might develop as a consequence of HT in cats, with improvement or cessation of the episodes once normal thyroid function is restored. Animals Seven client-owned cats. Methods Multicenter retrospective observational study comprising cats with clinical signs consistent with the clinical phenotype of paroxysmal dyskinesia based on video recordings, and a concurrent diagnosis of HT. Follow-up information was obtained by contacting referring veterinarians and owners. Results Seven cats were included. No signs of neurological disease were observed between the episodes except for plantigradism in one cat. Brain MRI studies were performed in 2 cats, revealing no intracranial abnormalities. In 1 cat, a 2-h video-assisted wireless electroencephalography confirmed the absence of epileptic activity. Clinical signs associated with HT were noted in all but 1 cat. After treatment for HT, complete remission of paroxysmal dyskinesia episodes was achieved in all cases, with euthyroid state confirmed in 6 cats. Conclusions and clinical importance HT should be considered a differential diagnosis in cats with paroxysmal dyskinesia, even in the absence of other suggestive signs. Similar to the analogous disorder in humans, the prognosis appears excellent once appropriate treatment for HT is initiated.
Espinosa et al. (Thu,) studied this question.