Hypopituitarism

Question 1

Causes of hypopituitarism

Answer 1

Congenital (developmental abnormalities, perinatal asphyxia)

Pituitary lesions (Vascular - Sheehan, Trauma, surgery, irradiation, Hormonally inactive adenoma, intrasellar metastasis, infection, “empty sella”)

Hypothalamic injuries (Craniopharyngeoma, hypothalamic tumor)

Question 2

Typical progression of hormone loss

Answer 2

FSH-LH, GH, TSH, ACTH, PRL, ADH

Question 3

Growth hormone deficiency

Answer 3

Occurs when ACTH, TSH, and GnRH is decreased or absent.
Will lead to obesity, decreased BMR, bone fractures, increased HDL/LDL ratio, increased insulin and hypoglycemia. Growth retardation in children.
Tests used: insulin tolerance test, IGF-1 test

Question 4

Gonadotropin deficiency

Answer 4

In males it leads to decreased testicular volume, decreased hair growth and libido.
In females it leads to secondary amenorrhea, breast atrophy, and vaginal dryness.
In both sexes it leads to thin skin and decreased BMR

Question 5

ACTH deficiency

Answer 5

Leads to weakness, tiredness, hypotension and vomiting. Hypoglycemia and hyponatremia is also often present.
Tests used: measuring cortisol level at peak time around 6-8 am. If it is lower than 100nmol/L, it will be a symptom and thus no further testing is needed.
Insulin stimulation test: increased insulin will lead to decreased glucose, and will increase the ACTH which will increase the cortisol level.

Question 6

TSH deficiency

Answer 6

mild and asymptomatic presentation (milder than hypothyroidism). Low TSH and fT4. Symptoms are like hypothyroidism: fatigue, tiredness, bradycardia, menstrual abnormalities, hyponatremia and anemia.
Can be determined by a TSH test where you administer it IV and you will normally observe an increase in TSH