Changes in thyroid hormones, thyroid stimulating hormone and cortisol in acute spinal cord injury.

To determine the hormonal response to acute spinal cord injury, serial serum samples were collected from 18 patients with acute spinal cord injury and from 14 control patients with spinal fractures without cord injury. The first sample was taken within 24 hours of injury, the second at 24-48 hours; and the third at 7 days for determination of thyroxine (T4), free T4 (FT4), triiodothyronine (T3), reverse T3 (rT3), T3 uptake (T3U), thyroid stimulating hormone (TSH), thyroxine binding globulin (TBG), growth hormone (GH), cortisol, and insulin. Significant increases were observed in rT3 levels and transient changes were observed in the T4 and T3 levels in the spinal cord injured group but not in the group with spinal fractures alone. The changes in the spinal cord injured patients are consistent with the 'low T3 syndrome'. However, the persisting rise of rT3 at 7 days was an unexpected finding. In addition to the cord injury, these changes may also be related to dexamthasone administration and nutritional factors.