Nerve regeneration and thyroid hormone treatment.

On the basis of 3 reports that thyroid hormone treatment stimulates axon outgrowth in rats with nervous system injuries, a 43-year-old patient with an ulnar nerve laceration was given desiccated thyroid (up to 360 mg/day) following nerve suture. The Hoffmann-Tinel sign of sensory axon outgrowth advanced at a rate of 5.0 mm/day in the forearm, approximately 200% faster than the anticipated rate. A good functional result was obtained in 7 months. On the maximum dosage of desiccated thyroid, the patient developed mild weight loss associated with an increased appetite; there was no other sign or symptom of hyperthyroidism. Further investigation of the role of thyroid hormone during nerve regeneration seems warranted.