The pituitary-gonadal axis in spinal cord injury

Our study documented that serum levels of luteinizing hormone, follicle-stimulating hormone, testosterone, and estradiol in 14 of 15 males with spinal cord injury (SCI) were within the normal range of those of age-matched controls. One patient had gynecomastia with compensated gonadal insufficiency of undetermined etiology. Five males with SCI showed a normal rise in serum testosterone levels following stimulation with human chorionic gonadotropin. Testicular biopsy in one of two males with SCI showed spermatogenic arrest. One of the biopsies showed immunoglobulin G immunofluorescence around the seminiferous tubule; the other demonstrated immunoglobulin A immunofluorescence in the spermatogonia. These findings suggest that, if a high incidence of impaired spermatogenesis does occur in spinal cord-injured patients, it is unlikely to be secondary to hormonal imbalance.