Soldiers suffering from traumatic brain injury (TBI) caused by an explosive blast had a higher rate of anterior pituitary dysfunction than people who sustained a non-blast TBI, suggesting pituitary dysfunction is a particular problem after blast exposure, according to a study published online Sept. 24 in Annals of Neurology.

“Our results suggest that all patients after moderate to severe [blast TBI] should undergo endocrine assessment,” wrote Anthony P. Goldstone MD, PhD, of Imperial College Healthcare NHS Trust, Charing Cross Hospital, London, and colleagues.

Findings were based on the U.K. Blast Injury Outcome Study of Armed Forces Personnel (UK BIOSAP) and included 19 male soldiers with moderate to severe blast TBI. A group of 39 civilian males with moderate to severe non-blast TBI served as the control group. All patients received structural brain MRI, including diffusion tensor imaging (DTI), and underwent dynamic endocrine assessment between two and 48 months after injury.

Results showed that six of the 19 soldiers (32 percent) had anterior pituitary dysfunction compared with only one (2.6 percent) of the non-blast TBI controls. The soldiers had a range of conditions, including hyperprolactinemia, growth hormone deficiency, adrenocorticotropic hormone deficiency, and gonadotrophin deficiency.

DTI measures of white matter structure showed the cerebellum and corpus callosum sustained greater traumatic axonal injury in soldiers with pituitary dysfunction than in those without, according to Goldstone and colleagues. Soldiers with pituitary dysfunction were also more likely to have skull or facial fractures and worse cognitive function.

“Blast appears to produce a distinct pattern of TBI, although the mechanism by which blast injury damages the brain remains unclear, limiting our ability to identify those patients at high risk of pituitary dysfunction,” wrote the authors. They suggested that all patients with moderate to severe blast TBI should routinely have comprehensive assessment of endocrine function.