The following tests are indicated to identify pituitory impairment.

Urea and Electrolytes (U&E):

 

Thyroid Function Tests are measured as an indicator of reduced Thyroid Stimulating Hormone (TSH) release:

  • If LOW repeat:
    • If repeat test is also LOW and LOW TSH, commence replacement.
  • If there are any other abnormal patterns refer to Endocrinology.

 

Short Synacthen test is measured as an indicator of Adrenocorticotrophic Hormone (ACTH) release:

  • If LOW response, refer to Endocrinology.

 

Testosterone in males aged under 65 years is measured as an indicator of reduced Follicle Stimulating Hormone (FSH)/Luteinising Hormone (LH) release:

  • If LOW measure LH/FSH:
    • If FSH/LH also LOW treat as Traumatic Brain Injury related insufficiency.
  • If HIGH refer to Endocrinology.

 

Female gonadotrophins in female age under 50 is measured as an indicator of reduced FSH/LH release:

  • If menstrual cycle is regular there is no need to test.
  • If oligomenorrhoea (infrequent/light menstrual periods)/amenorrhoea (no menstrual periods) measure FSH/LH:
    • LOW levels suggest pituitary insufficiency.  Refer to Endocrinology.
    • HIGH levels suggest ovarian insufficiency.  Refer to Endocrinology.
  • LOW FSH/HIGH LH suggests Polycystic Ovary Syndrome. Refer to Gynaecology.

 

Prolactin:

  • A raised Prolactin level in the absence of any other pituitary abnormality is probably not clinically significant. Asymptomatic Hyperprolactimaemia can arise for a variety of reasons other than TBI. It usually does not need to be treated:
    • But consider visual field testing and pituitary imaging to exclude non-traumatic causes or discuss with Endocrinology.
  • If symptomatic, refer to Endocrinology.
  • To exclude a Prolactinoma as a cause of Panhypopituitarism (inadequate or absent production of the anterior pituitary hormones):
    • If single endocrine deficiency a tumour is unlikely.
    • If multiple deficiencies but normal prolactin a tumour is unlikely.
    • If there are multiple deficiencies with raised prolactin or elevation of other hormones carry out pituitary fossa CT scan or review the previous CT scan.

 

In all cases, ensure appropriate follow up arrangements and only prescribe medications with which you have appropriate experience.

 

Further reading: Glynn N, Agha A. Which patient requires neuroendocrine assessment following traumatic brain injury, when and how? Clin Endocrinol 2013 Jan;78(1):17-20.