Anterior Pituitary Function May Predict Functional and Cognitive Outcome in Patients with Traumatic Brain Injury Undergoing Rehabilitation

Abstract

Traumatic brain injury (TBI) is the leading cause of death and disability in young adults. Growth hormone-insulin-like growth factor I (GH-IGF-I) system has an important role in the recovery of the central nervous system. The aim of the study was to evaluate the relationship between pituitary function (in particular, the GH-IGF-I axis) and outcome from TBI. We studied 72 patients (56 males; mean age 37.2 +/- 1.8 years) receiving rehabilitation after TBI. According to the Glasgow Coma Scale (GCS), 10 patients had moderate and 52 severe TBI. Ten patients had growth hormone GH deficiency (GHD), 10 LH-FSH, three TSH, and three ACTH deficiency. Overall pituitary dysfunction occurred in 22 (30.5%) patients, with anterior hypopituitarism in 19 (26.4%), isolated diabetes insipidus in one, and isolated hyperprolactinemia in two. GH response to GHRH + ARG (arginine) positively correlated with Functional Independence Measure (FIM D; r = 0.267, p < 0.02) and Level of Cognitive Functioning Scale (LCFS D; r = 0.287, p < 0.01) at discharge, and negatively with Disability Rating Score at discharge (DRS D; r = -0.324, p < 0.005). Unfavorable outcome measures (FIM D, LCFS D, and DRS D) occurred in patients with hypopituitarism as compared with normal pituitary function (p < 0.05). Multiple regression analysis identified both GCS (p < 0.005) and GH peak (p < 0.05) as strong independent predictors of outcome. In conclusion, recovery after TBI may be negatively influenced by concomitant pituitary dysfunction. The GH peak value is an independent predictor of outcome, indicating that recovery during an intensive rehabilitation program after TBI may be positively influenced by normal GH secretion.

Early endocrine alterations reflect prolonged stress and relate to 1-year functional outcome in patients with severe brain injury

“…Elevated stimulated 30 min cortisol was related to suppressed gonadal function (PZ0.02; Cramer's VZ0. 19) but not to suppressed thyroid function (PZ0.09; Cramer's VZK0.13).…”

“…Some have suggested that hypopituitarism was related to increased disability (16) and a decreased quality of life (16,17), whereas others have suggested that quality-of-life deficits were more closely associated with intracerebral haemorrhagic lesions than with hypopituitarism per se (18). Peak growth hormone (GH) has been shown to be an independent predictor of poorer outcomes, as measured by rehabilitation scales that evaluate cognition and disability (19), but such relations were recently questioned (20). Reduced testosterone concentrations were also recently described as being related to worse functional outcomes in TBI patients (21,22), which led the authors to suggest that secondary hypogonadism may limit the pace of recovery during neurorehabilitation.…”

Hypopituitarism following traumatic brain injury: prevalence is affected by the use of different dynamic tests and different normal values

“…Nine studies used basal free thyroxine (FT 4 ) and TSH levels only. Within these studies, the cut-off value for decreased FT 4 varied between 8 and 12 pmol/l (2,5,7,11,14,18,19). In two studies, reference values were not reported (4, 10), one of which (Bushnik et al) reported the highest prevalence of secondary hypothyroidism.…”

The Case of Hypopituitarism in Traumatic Brain Injury

“…Although not taking presence of cerebral lesions into account, we described that when adjusted for confounders such as trauma severity, posttraumatic hypopituitarism remained an independent predictor of the classical phoenotypic features of hypopituitarism, including an unfavourable lipid and body-composition profile, as well as worsened QoL (Klose et al, 2007d), which could point to an association. Bondanelli et al (Bondanelli et al, 2007) found that peak GH was an independent predictor of poorer outcome as measured by rehabilitation scales evaluating cognition, disability and functional dependency. Such association between cognitive function impairment and GH axis integrity was recently questioned by Pavlovic et al who applied a very extensive neuropsychological battery, selected for high sensitivity for subtle brain dysfunction.…”