Efficacy of thyrotropin-releasing hormone in the treatment of cerebellar ataxia.

We report a 9-year-old girl with cerebellar ataxia in whom the administration of thyrotropin-releasing hormone was effective in the treatment of a prolonged neurologic deficit. Ataxia persisted 18 months after its acute onset of unknown origin. Concentrations of homovanillic acid and 5-hydroxy-indoleacetic acid in the cerebrospinal fluid were measured repeatedly. Changes in the 5-hydroxy-indoleacetic/homovanillic acid ratio were observed, suggesting that thyrotropin-releasing hormone improved symptoms by influencing serotonin metabolism in the central nervous system.