Impact of pituitary dysfunction on cognitive and global outcome after traumatic brain injury and aneurysmal subarachnoid haemorrhage

Abstract

Traumatic brain injury and aneurysmal subarachnoid haemorrhage are leading causes of physical, cognitive and behavioural disabilities. Traumatic brain injury and aneurysmal subarachnoid haemorrhage may affect the hypothalamus and pituitary gland, which are of major importance for our hormone balance. The purpose of the study was to investigate the relationship between the pituitary dysfunction after traumatic brain injury and aneurysmal aneurysmal subarachnoid haemorrhage, and cognitive and global outcomes at 12 months after the injury. In total, we included 127 patients during neurointensive care. Follow-up was at a rehabilitation medicine department. The study showed negative associations between high level of growth hormone and prolactin and behavioural and cognitive function; and between low gonadotropins and high prolactin and global outcome. We conclude that some pituitary dysfunctions during the first year after traumatic brain injury and aneurysmal subarachnoid haemorrhage may have clinically relevant, independent effects on clinical outcome at 12 months. Objective: To explore associations between pituitary dysfunction and clinical outcome at 12 months after traumatic brain injury and aneurysmal subarachnoid haemorrhage. Methods: Prospective cohort study of 82 patients with traumatic brain injury and 45 with aneurysmal subarachnoid haemorrhage, included at one neurointensive care unit. Baseline data comprised age, sex, Glasgow Coma Scale (GCS) score, S100B and pupil light reactions. Hormone data were collected in the neurointensive care unit and after 3, 6 and 12 months. Outcome was assessed with Barrow Neurological Institute Screen for Higher Cerebral Functions (BNIS), Rancho Los Amigos Cognitive Scale-Revised (RLAS-R) and Glasgow Outcome Scale Extended (GOSE). Results: The most frequent hormonal deviations were hypogonadotropic hypogonadism (38%) and hypercortisolism (52%). At 12 months, performance on BNIS was impaired in 54% and GOSE in 37%. Controlling for baseline variables, low levels of gonadal hormones were associated with lower GOSE score (b =-0.80, p = 0.033), high levels of prolactin with lower RLAS (b =-1.42, p = 0.034) and high levels of serum insulin-like growth factor I (S-IGF-I) with lower RLAS level (b =-1.78, p = 0.002) and lower GOSE score (b =-1.49, p = 0.006). Conclusion: These data suggest that pituitary dysfunctions during the first year after traumatic brain injury and aneurysmal subarachnoid haemorrhage may have clinically relevant, independent effects on clinical outcome at 12 months.