A nine year old girl with cerebel lar ataxia that responded to thyrotropin-releasing hormone is reported from the Department of Pediatrics, Kyoto Prefectero University of Medicine, Kyoto, Japan. Clinical improvement occurred 18 months after the onset of cerebellar ataxia and neurological deficits which included speech impairment, gait disturbance, ataxia of the extremities and positional nystagmus. CSF examination demonstrated that the concentrations of 5-HIAA and HVA increased and that the 5-HIAA/HVA ratio rose from 0.243 to 0.358 during TRH treatment. The levels of monoamine metabolites in the CSF reflect CNS biogenic amine turnover. The changes observed suggested that TRH influenced serotonin neurons rather than catecholamine neurons. The preparation of TRH was protireline tartrate: Takeda Co. Ltd., Japan and the dose injected intravenously was 1 mg per day for 20 days. Improvement in gait began to improve immediately after the treatment was begun. 
COMMENT. Thyrotropin-releasing hormone (TRH) therapy has been used in several neurologic disorders, including spinocerebellar degeneration, amyotrophic lateral sclerosis, and infantile spasms with hypsarrhythmia (see Ped. Neur. Briefs June 1987; 1:3). The present patient had an acute cerebellar ataxia following an infection of unknown origin and persisting for 18 months before treatment with TRH was begun.