Neuroendocrine function and associated mental health outcomes following mild traumatic brain injury in OEF‐deployed service members

Abstract

Mild traumatic brain injury (mTBI) has been linked to mental health disorders (MHDs) and pituitary function alterations. Due to the complex relationship of mTBI, the neuroendocrine system, and MHDs, we propose that neuroendocrine dysfunction (NED) may play a role in negative long-term health outcomes. The goal of this study was to determine if blast-concussed service members (SMs) have a stronger likelihood of developing NED. We hypothesized that NED either pre-or post-injury is associated with poor mental and physical health outcomes. Serum samples from the Armed Forces Health Surveillance Branch were obtained from concussed (n = 59) and nonconcussed (n = 72) SMs treated at the Concussion Restoration Care Center (CRCC) in Afghanistan. Serum was collected within 2 years prior to deployment and one or two times within 3 years following their CRCC visit. Samples were analyzed for luteinizing hormone (LH), testosterone, human growth hormone, cortisol, and prolactin to assess post-injury neuroendocrine function. Results indicate that SMs who incurred an mTBI exhibited long-term LH and testosterone deficiencies 3 years following injury compared to controls. Specifically, 47.6% of head-injured SMs displayed hypofunction in at least one of five hormones at 3 years post-injury. Anxiety disorders were the most common MHD observed in concussed SMs with hypopituitarism, while there was also a trend for SMs with chronic pituitary dysfunction to have MHD diagnoses. Findings indicate blast-related mTBI may be associated with long-term health outcomes following a period of incubation. Neuroendocrine screenings may increase treatment opportunities, inform rehabilitation strategies, and improve overall quality of life for patients. K E Y W O R D S concussion, military, neuroendocrine, pituitary, traumatic brain injury Published 2020. This article is a U.S. Government work and is in the public domain in the USA.| 1175 CIARLONE Et AL.

Neuroendocrine Disruptions Following Head Injury

“…Limited evidence suggests a similar increase in hormone dysfunction following blast injury as well as non-blast TBI incurred during military service. Several studies have examined pituitary hormone levels in US or UK military personnel who have sustained injury: one focused on mild blast-related TBI [ 44 ], one compared the effects of blast to non-blast moderate to severe TBI [ 45 ], and one compared hormonal profiles in service members deemed concussed vs non-concussed after being seen at a concussion center [ 46 ]. All results suggested higher rates of pituitary dysfunction after TBI during military service, but none of the study designs allowed for full pituitary evaluations.…”

Basic considerations on growth hormone deficiency in traumatic brain injury

“…The prevalence of hypopituitarism and quality of life in patients who survive traumatic brain injury is subject to factors such as skull fracture, duration of ventilatory support, initial imaging related to Marshall's classification and coma [19]. Although head trauma is common in certain high-risk occupations such as military service, a clear association between pituitary hormone dysfunction and head trauma in the military has not been established, but a long-term negative psychological effect may possibly be generated [14,20,21,22].…”