Traumatic Brain Injury

What is traumatic brain injury?

Traumatic brain injury (TBI) is damage to the brain that can occur when the head is injured. A closed head injury occurs when the head hits something hard, an object hits the head, or the head is shaken. A penetrating head injury occurs when the skull is damaged. Damage can be sudden or take some time to happen.

Examples include:

• Falls
• Motor vehicle accidents
• Violence, such as gunshot wounds, child abuse, or beatings
• Injuries from sports or during combat (such as explosions) 

How can TBI affect the endocrine system?

Two important parts of the endocrine system—the pituitary gland and the hypothalamus—are located in or near the brain. The hypothalamus and the pituitary gland are like orchestra conductors. Their job is to tell other endocrine glands throughout the body to make the hormones that affect and protect every aspect of your health. TBI can injure the pituitary and hypothalamus, causing hormone problems. A person with TBI may have hormone problems right away or months after the injury. There is a higher chance for hormone problems if the injury is severe.

What hormone problems can happen with TBI?

Someone with TBI can have one or more problems, depending on the injury. Problems that often occur soon after TBI include:

Adrenal Insufficiency (not enough cortisol)

When the adrenal glands don’t make enough hormones; results in fatigue, weight loss, low blood pressure, vomiting, and dehydration. Adrenal insufficiency can be life-threatening if not treated.

Diabetes Insipidus

When the pituitary doesn't make enough antidiuretic hormone (ADH); results in frequent urination and extreme thirst.

Syndrome of Inappropriate ADH Secretion (SIADH)

When the pituitary doesn't make enough antidiuretic hormone (ADH); results in frequent urination and extreme thirst. Too much ADH can upset the balance of salt and water in the body; can result in headache, fatigue, vomiting, confusion, and convulsions. 

Problems that may occur later and their symptoms include:

• Hypothyroidism(not enough thyroid hormone): fatigue, constipation, weight gain, irregular menstrual periods, cold intolerance
• Hypogonadism (not enough sex hormones): in women, a stop in menstruation and loss of body hair; in men, sexual dysfunction, breast enlargement, loss of body hair, and muscle loss
• Growth hormone deficiency (not enough growth hormone): in adults, increased fat, loss of muscle and bone, and decreased energy; in kids, growth problems
• Hyperprolactinemia (too much prolactin): irregular menstrual periods, nipple discharge, and erectile dysfunction in men 

How are TBI-related hormone problems diagnosed?

Your doctor will ask about your medical history and do a physical exam. Blood tests are done to check your hormone levels. You may have an MRI to look at the pituitary gland.

What is the treatment for TBI-related hormone problems?

Often, you will take hormones to replace what's missing (called hormone therapy). Other problems require various treatments, depending on how severe the injury is.

What's the long-term outlook for TBI-related hormone problems?

The outlook depends on the type of problem and how severe it is. Some endocrine problems may be temporary and disappear within a year after TBI. Hormone therapy is a very important part of treatment. It can restore your health, relieve symptoms, and improve your quality of life. In some cases, it can save your life.

Questions to Ask Your Healthcare Team

• What specific hormones are affected by my injury and how can they be replaced?
• Will treatment relieve my symptoms?
• How long will I need treatment?
• What are the risks and benefits of the treatment?
• How will I know whether my hormone function is returning on its own?
• How often will I need to be checked?
• Will the dose of hormones change as I get older?