Endocrine Abstracts

Pituitary dysfunction is a common, treatable consequence of traumatic brain injury (TBI), and is associated with poorer outcomes. Identifying prognostic factors that allow targeted endocrine testing will ensure that patients at higher risk of pituitary dysfunction are identified and screened.

Analysis of 176 adults at least 6 weeks after TBI attending the multidisciplinary Imperial TBI clinic found an overall prevalence of pituitary dysfunction of 13.7% (deficiency of growth hormone 7.4%, gonadotrophins 3.7%, ACTH 1.1%, hyperprolactinaemia 2.5%, SIADH 0.6%). Diagnosis of GH or ACTH deficiency required failure in 2 dynamic endocrine tests. Retrospective analysis was performed to find predictive factors related to TBI severity.

Using the Mayo classification for TBI severity (incorporating duration of post-traumatic amnesia (PTA) and loss of consciousness, lowest GCS and acute CT brain findings), the prevalence of pituitary dysfunction was 15.7% after moderate-severe TBI and 7.1% after possible-mild TBI.

Pituitary dysfunction was more prevalent in those with than without PTA >24 h (n=160, 19.7 vs 7.4%, OR 2.6, P=0.02) or >1week (25.0 vs 10.3%, OR 2.4, P=0.04). However findings on acute CT brain imaging (n=132) including presence of basal skull fracture, cerebral oedema, subdural haemorrhage, subarachnoid haemorrhage, intraventricular haemorrhage or cerebral contusions were not associated with greater prevalence of pituitary dysfunction (P=0.4=0.9). Neither were male sex, need for craniotomy, or post TBI epilepsy associated with post-TBI pituitary dysfunction.

Duration of PTA, an important marker of TBI severity, appears to be the best predictor of post-TBI pituitary dysfunction and could help target appropriate screening strategies.