Multiple pituitary hormone deficiencies in a patient with spinocerebellar ataxia: magnetic resonance imaging and hormonal studies

Degenerative spinocerebellar ataxia has a rare association with hypogonadotropic hypogonadism. In this report we present the results of the detailed endocrine evaluation and magnetic resonance imaging in one such patient. A 20-year-old male with progressive cerebellar ataxia, hypogonadism, and short stature was investigated. Basal testing revealed hypogonadotropic hypogonadism (LH < 5 mU/L, FSH < 5 mU/L, testosterone 2.5 nM/L). There was no rise in LH after stimulation with LHRH, peak LH level being < 5 mU/L. Insulin hypoglycemia testing was consistent with GH deficiency, with peak GH being 3.2 mU/L. On TRH stimulation, there was no significant rise in prolactin, though the TSH response was normal. Magnetic resonance imaging revealed cerebellar atrophy. The anterior pituitary was atrophic, with a height of 1.4 mm. The posterior pituitary and the pituitary stalk were normal in size and position. This patient with degenerative spinocerebellar ataxia had multiple pituitary hormone deficiencies. The results of our endocrine evaluation and MR imaging lead us to believe that these deficits may result from a lesion at the level of the pituitary gland.