Pediatric Brain Injury: Endocrine System and Puberty
Despite being a relatively common occurrence, brain injury continues to be a silent epidemic. According to the Centers for Disease Control and Prevention (CDC), an estimated 2.87 million people suffer from some form of brain injury each year. Of those, approximately 56,000 die as a result of their injuries, while the remaining 2.81 million are left to cope with the long-term effects of brain damage. Traumatic brain injury (TBI) can have a number of effects on the endocrine system, which in turn will have an effect on how puberty is experienced by both the parent and the child who sustained the brain injury. The most common endocrine problems after TBI are growth hormone deficiency and alterations in puberty.
When a child sustains a brain injury at a young age, the outcome is often dependent on where the injury occurred. For example, an acceleration-deceleration injury – which is caused by the head suddenly being placed into motion or abruptly stopped – can often result in a diagnosis of diffuse axonal injury. This type of brain damage is typically seen in car accident and falls and can cause a wide range of long-term problems, including cognitive impairment, memory loss, personality changes and difficulty with motor skills.
Fortunately, there has been an increasing amount of research conducted on pediatric brain injuries in recent years. But an area that still seems to be not well developed is how hormones affect the injured brain. Because transient and permanent hypopituitarism is common after TBI, survivors should be screened serially for possible endocrine disturbances. In a consensus conference in 2005, systematic endocrine screening was recommended for all patients after moderate to severe TBI, because those found to have hormone deficiencies benefit from appropriate hormonal replacement . Endocrine dysfunction in children after TBI is common, can evolve after injury, resolve, or persist.
Growth hormone deficiency is the most common type of hormone deficiency seen in children after suffering a TBI. This can result in short stature and delayed pubertal development. Other common types of hormone deficiencies seen in children after suffering a TBI include adrenocorticotropic hormone deficiency, hypogonadism, and hypothyroidism.
It’s important to note that while growth hormone deficiency is the most common type of hormone deficiency seen in children after suffering a TBI, it’s not always permanent. In fact, many children who suffer from growth hormone deficiency after a TBI will see their levels return to normal over time. However, there is a small percentage of children who will continue to experience growth hormone deficiency long-term. For these children, growth hormone replacement therapy may be necessary.
Adrenocorticotropic hormone (ACTH) deficiency can also occur after a TBI. ACTH helps to regulate the stress response by stimulating the release of cortisol from the adrenal gland. Cortisol is a stress hormone that helps the body to deal with physical or emotional stressors. In children with ACTH deficiency, cortisol levels may be low, which can lead to fatigue, weight gain, and low blood pressure. Testosterone levels may also be affected in boys who have suffered a TBI. Testosterone is responsible for the development of secondary sex characteristics during puberty, such as facial hair and deepening of the voice. Testosterone levels may also affect bone density and muscle mass in boys who have suffered a TBI. Lastly, thyroid function may also be affected in children who have suffered a TBI. The thyroid gland produces hormones that help to regulate metabolism. Hypothyroidism (a condition in which the thyroid gland doesn’t produce enough hormones) can result in fatigue, weight gain, hair loss, and cold intolerance.
Endocrine dysfunction is common in children who have survived a traumatic brain injury. Growth hormone deficiency and alterations in puberty are the most common problems seen; however, every hormonal axis can be affected by TBI . Because transient and permanent hypopituitarism is common after TBI, survivors should be screened serially for possible endocrine disturbances . Systematic endocrine screening is recommended for all patients after moderate to severe TBI because those found to have hormone deficiencies benefit from appropriate hormonal replacement . Early diagnosis and treatment of endocrine problems can help improve long-term outcomes for survivors of childhood TBI
Brain injuries are relatively common, yet they continue to be a silent epidemic. While much progress has been made in recent years in terms of understanding and treating these types of injuries, there is still more work to be done. With further research and education, we can hope to improve outcomes for all those who suffer from brain damage.
.References: Levin HS et al., Hormonal deficits following traumatic brain injury., J Neurotrauma 2005; 22(9):859-69