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Traumatic Brain Injury and Pituitary Hormones

hormone deficiency diagnosis on an iPad with a stethoscope

Pituitary Deficiency and Brain Injury

By Flora Hammond, M.D. and Rhona Shapiro, R.N., M.S.N.

Originally published 06/09/2009

Traumatic brain injury and the pituitary

Pituitary hormone deficiency may result from head trauma or subarachnoid hemorrhage. Two recent studies show that one or more pituitary hormones may be affected by traumatic brain injury or subarachnoid hemorrhage.1,2

Symptoms of hormone deficiency can mimic other effects of a traumatic brain injury, which can prevent suspicion of this disorder. A deficiency of one or more of the hormones regulated by the pituitary gland may have physical and/or psychological effects such as:

  • reduced muscle mass
  • weakness
  • decreased exercise capacity
  • fatigue
  • irritability
  • depression
  • impaired memory
  • reduced sex drive.

Most patients do not even realize that they have the hormone deficiency until specific laboratory tests for this disorder are performed. However, individuals with a history of a moderate to severe brain injury are more likely to have a pituitary deficiency than those with a mild brain injury.

The likelihood of pituitary damage exists even if the injury occurred years ago and a good rehabilitative outcome has been achieved. The pituitary gland, hypothalamus, and surrounding structures, including their blood supply, may have been injured.

Damage to the pituitary gland causes a condition called hypopituitarism: a loss or reduction in the normal activity of the pituitary gland. Hypopituitarism means that any pituitary hormone can be deficient.

Picture of the brain from the side to show the location of the pituitary gland

The pituitary is a pea-sized gland at the base of the brain. Pituitary hormones are important because they regulate other hormones from the thyroid, gonads (ovaries and testes), and adrenals (cortisone). Prolactin, oxytocin, and ADH (antidiuretic hormone) may also be effected by brain injury, but the incidence is less common. These hormones are chemical messengers that target vital organs that control vital functions.

Listed below are the hormones produced by the pituitary along with the symptoms commonly seen with a deficiency of each. Diagnostic testing for pituitary hormone deficiency involves blood and urine testing. Hormonal replacement requires monitoring by a physician.

Thyroid stimulating hormone deficiency may cause…

  • reduced memory
  • slowed metabolism
  • reduced energy
  • altered mood
  • failure to thrive
  • slowed growth
  • lethargy
  • muscle aches
  • cold intolerance
  • decreased appetite
  • dry hair or skin
  • numbness or tingling in extremities

Adrenocortical stimulating hormone deficiency may cause…

  • weakness
  • fatigue
  • altered mood
  • electrolyte abnormalities
  • weight loss
  • low or fluctuating blood pressure
  • increased body fat
  • decreased bone mass
  • reduced exercise capacity

Sex hormone deficiency may cause…

  • decreased energy
  • decreased muscle mass

in males, it may cause…

  • decreased sex drive
  • shrunken testes
  • loss of beard growth
  • decreased sperm production

in females, it may cause…

  • infertility
  • amenorrhea (lack of menstruation)
  • loss of female characteristics

Growth hormone deficiency may cause:

  • decreased lean body and muscle mass, particularly in the shoulders
  • increased fat mass, especially around the waist and trunk
  • high “bad” cholesterol levels (higher ldl and lower hdl) which may increase risk of stroke and heart disease
  • decreased bone density, which may cause osteoporosis
  • fatigue, regardless of the amount of sleep
  • decreased interest in socialization
  • a sense of isolation and depression


Kelly DF, Gaw Gonzalo IT, Cohan P, Berman N, Swerdloff R, Wang C. Hypopituitarism following traumatic brain injury and aneurismal subarachnoid hemorrhage: a preliminary report. J Neurosurg.2000; 93: 743-752.

Lieberman SA, Oberoi AL, Gilkison CR, Masel BE, Urban RJ. Prevalence of neuroendocrine dysfunction in patients recovering from traumatic brain injury. J Clin Endocrinol Metab. 1998:83:382-395.

About the Authors

Flora Hammond, M.D.

Dr. Hammond is the Chairman of Physical Medicine and Rehabilitation at of Medicine and Chief of Medical Affairs at the Rehabilitation Hospital of Indiana. Much of her research on traumatic brain injury has focused on outcome prediction, post-traumatic irritability, depression, relationships, and motor and cognitive recovery over time.

She graduated from the Tulane University School of Medicine in 1990 in New Orleans, LA. Her Physical Medicine and Rehabilitation residency was done at Baylor College of Medicine. Dr. Hammond earned a Brain Injury Fellowship at the Rehabilitation Institute of Michigan in Detroit, Michigan. She is a diplomat of the American Board of Physical Medicine and Rehabilitation. She has served as an invited participant to both the Aspen Conference and Galveston Brain Injury Conference (brain injury think tanks). Her excellence in research, teaching, and administration were acknowledged by her receipt of the 2001 Young Academician Award from the Association of Academic Physiatrists (AAP), and the 2001 AAP Best Faculty Paper Presentation Award.

Rhona Shapiro, RN, MSN

Rhona Shapiro is an experienced nursing educator and clinician. She specializes in adult growth hormone deficiency and in traumatic brain injury and pituitary deficiency.

An experienced educator, she has also served as nursing faculty in a community college setting. A member of the Endocrine Nurses’ Society, Ms Shapiro is an experienced clinician in both acute care and home care settings.

This article is not a substitute for medical advice. Please contact your physician for more information and questions about your condition.

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