The most common cause of acute brain injury is trauma. In the United States, 1.5–2.0 million Traumatic Brain Injuries (TBI) occur each year, with a cost in excess of $10 billion. TBI is the leading cause of death and disability among young adults under the age of 35. TBI can have serious consequences, such as impairments in motor function, speech, cognition, and psychosocial and emotional skills. Clinical studies have recently documented the occurrence of pituitary dysfunction following TBI and another cause of acute brain injury, Sub Arachnoid Haemorrhage (SAH). Following a moderate to severe TBI or SAH, these studies have consistently shown a 30–40% occurrence of pituitary dysfunction involving at least one anterior pituitary hormone. Growth hormone (GH) deficiency is the most common pituitary hormone disorder, affecting roughly 20% of patients when multiple GH deficiency tests are performed. Adrenal insufficiency is the most serious concern within 7–21 days of acute brain injury. Pituitary function may fluctuate during the first year following TBI, but it is well established by the end of the first year. The effects of hormone replacement therapy on motor function and cognition in TBI patients are currently being studied. Any patient suffering from a moderate to severe acute brain injury should be tested for pituitary dysfunction.
