Pituitary-testicular axis dysfunction in spinal cord injury.

Concentrations of testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) in serum and 17-ketosteroids (17-KS) in urine of 10 paraplegic and 10 quadriplegic subjects were measured from onset of injury and followed once a week for 4 months. Compared with age-matched normal controls, paraplegic subjects showed significantly lower serum levels of LH and FSH for 2 weeks and of testosterone for 6 weeks after spinal cord trauma, following which periods of time these hormones attained normal levels. By contrast, in quadriplegic subjects, serum testosterone concentrations remained significantly lower than those of the controls during the entire 4-month testing period. Furthermore, in another group of 10 chronic (1 to 6 years after onset of injury) paraplegic and 10 chronic quadriplegic subjects, serum testosterone and FSH concentrations were comparable to those of the normal controls. Serum LH concentrations were at control levels in chronic paraplegic but significantly depressed in chronic quadriplegic subjects. The concentrations of urinary 17-KS exhibited sharp fluctuations over the 4-month period and were below control levels in paraplegic but within control limits in quadriplegic subjects. The results indicate that the function of the hypothalamic-pituitary-gonadal axis is disturbed for at least 4 months in quadriplegic subjects.