[Progressive cerebellar ataxia with diencephalic symptoms (Toyokura)--a case report].

We reported a 16-year-old boy suffering from dwarfism, diabetes insipidus and progressive cerebellar ataxia. The disease entity here reported was originally reported by Toyokura et al. in 1967, under the title of "progressive cerebellar ataxia with diencephalic symptoms". Ten similar cases have been reported in literature so far, all of which were Japanese except for two sibling cases reported by Robinson et al. The topographic distribution of the lesion in this disorder, however, had been conjectured to be at spinocerebellar tract and diencephalon only on a clinical ground. By applying the modern techniques of neuroimaging, electrophysiological and endocrinological test in our patient, the authors were able to demonstrate the lesion of the disorder more precisely. CT and MRI of the head revealed degenerative changes in deeper structures of the bilateral cerebellar hemispheres. ABR abnormality suggested the presence of a wide lesion in the brain stem. Pituitary hormones (GH and ACTH) sufficiently responded to the loading of hypothalamic hormones such as growth hormone releasing factor and corticotropin releasing factor, in spite of poor responses of GH under the insulin stimulation or sleep. These clinical and laboratory findings suggested that the patient has a systemic degenerative disease which preferentially involves hypothalamus, brain stem and cerebellum.