Isolated hypogonadotropic hypogonadism in a man with a history of head trauma during childhood

To report a case of isolated hypogonadotropic hypogonadism as a delayed consequence of major head injury. We present the relevant history, findings on physical examination, and results of laboratory evaluation, and supportive data from appropriate reports in the literature are reviewed. A 37-year-old man with progressive loss of libido, impotence, and gradual loss of facial and axillary hair had sustained severe trauma to the head (sufficient to cause blindness in one eye) in a fall from a tree at 7 years of age. Physical examination and laboratory investigations substantiated the presence of isolated hypogonadotropic hypogonadism. Other causes of hypogonadotropic hypogonadism, including Kallmann's syndrome, were excluded. Severe head injury should be considered in the differential diagnosis of isolated hypogonadotropic hypogonadism. Long-term follow-up and endocrine assessment may be important in patients who have sustained severe head injury.