Update of Endocrine Dysfunction following Pediatric Traumatic Brain Injury

Abstract

Traumatic brain injuries (TBI) are common occurrences in childhood, often resulting in long term, life altering consequences. Research into endocrine sequelae following injury has gained attention; however, there are few studies in children. This paper reviews the pathophysiology and current literature documenting risk for endocrine dysfunction in children suffering from TBI. Primary injury following TBI often results in disruption of the hypothalamic-pituitary-adrenal axis and antidiuretic hormone production and release, with implications for both acute management and survival. Secondary injuries, occurring hours to weeks after TBI, result in both temporary and permanent alterations in pituitary function. At five years after moderate to severe TBI, nearly 30% of children suffer from hypopituitarism. Growth hormone deficiency and disturbances in puberty are the most common; however, any part of the hypothalamic-pituitary axis can be affected. In addition, endocrine abnormalities can improve or worsen with time, having a significant impact on children's quality of life both acutely and chronically. Since primary and secondary injuries from TBI commonly result in transient or permanent hypopituitarism, we conclude that survivors should undergo serial screening for possible endocrine disturbances. High indices of suspicion for life threatening endocrine deficiencies should be maintained during acute care. Additionally, survivors of TBI should undergo endocrine surveillance by 6-12 months after injury, and then yearly, to ensure early detection of deficiencies in hormonal production that can substantially influence growth, puberty and quality of life.

Keywords: adrenal insufficiency; adult; central hypothyroidism; growth hormone deficiency; hyperprolactinemia; hypogonadotropic hypogonadism; hypopituitarism; pediatric; precocious puberty; traumatic brain injury.

Figure 1

Hypothesized model for progression from Primary to Secondary Injury after trauma to the central nervous system.

Figure 2

The pituitary gland is suspended via the infundibulum. Long hypophyseal blood vessels surround the pituitary stalk, supplying the anterior pituitary with small perforating vessels. The surrounding vessels and axons are susceptible to shearing from external forces and swelling [13].