Recombinant Human Growth Hormone During Rehabilitation From Traumatic Brain Injury.

Growth Hormone (GH) deficiency, defined by insufficient GH response to a variety of stimulating compounds, is found in 20-35% of adults who suffer traumatic brain injuries (TBI) requiring inpatient rehabilitation1. However, there is no accepted gold standard for diagnosing GH deficiency in this population. Further, the major effector molecule of the somatotropic axis, Insulin-Like Growth Factor-1 (IGF-1) has recently been recognized as an important neurotrophic agent. Since most repair and regeneration after TBI occurs within the first few months after injury, absolute or relative deficiencies of GH and IGF-1 in the subacute period after TBI are potentially important factors why some patients fail to make a good functional recovery. The proposed study is a randomized, double-blind, placebo-controlled trial of rhGH, starting at 1 month post TBI, continuing for 6 months. This study has one primary hypothesis, that treatment with recombinant human Growth Hormone (rhGH) in the subacute period after TBI results in improved functional outcome 6 months after injury. As secondary hypotheses, we will investigate what is the optimal method to diagnose GH deficiency in TBI survivors and study the relationship between GH deficiency and insufficiency and functional recovery.