High Prevalence of Pituitary Dysfunction following Blast Traumatic Brain Injury and associated diffusion tensor imaging findings: Results from the United Kingdom Blast Injury Outcome Study of Armed Forces Personnel (BIOSAP)


Claire Feeney, David Baxter, David Sharp, Debbie Peters, Timothy Ham, Sagar Jilka, Peter Hellyer, Alex Bennett, Alan Mistlin, Mark Midwinter, Anthony Goldstone.


Background: Pituitary dysfunction is a recognised consequence of traumatic brain injury (TBI) causing significant cognitive, psychological and metabolic impairment. Hormone replacement offers an important therapeutic opportunity. Blast traumatic brain injury (bTBI) from improvised explosive devices (IEDs) is commonly seen in soldiers returning from recent conflicts. We investigated: (i) the prevalence and consequences of pituitary dysfunction following moderate-severe bTBI, and (ii) whether it is associated with particular patterns of brain injury.


Methods: Nineteen soldiers with moderate-severe bTBI (all male, age: 28.3 years [26.8-32.2], median [interquartile range]), and 39 controls with moderate-severe non-blast TBI (nbTBI) (all male, age: 32.3 [23.1-36.7]), >2 months since injury, underwent full dynamic endocrine assessment. In addition, soldiers had structural brain magnetic resonance imaging (MRI) including diffusion tensor imaging (DTI) and cognitive assessment.


Results:  Six of 19 (32.0%) soldiers with bTBI, but only 1 of 39 (2.6%) nbTBI controls, had evidence of pituitary dysfunction (P=0.038). Standard MRI failed to show differences between the bTBI subjects with and without pituitary dysfunction. However, DTI measures of white matter structure showed evidence of greater traumatic axonal injury in those bTBI subjects with than without pituitary dysfunction (P=0.023) Pituitary dysfunction negatively impacted symptoms, quality of life and cognitive function in soldiers with bTBI. Four out of 19 (21%) soldiers commenced hormone replacement(s) for hypopituitarism.


Conclusions: We reveal a high prevalence of pituitary dysfunction in soldiers suffering moderate-severe bTBI, which was more frequent than after moderate-severe nbTBI. We recommend that all patients with moderate-severe bTBI should routinely have comprehensive assessment of endocrine function.