Hypopituitarism Flashcards
What is hypopituitarism?
Hypopituitarism is the decreased secretion of one or more of the eight hormones normally produced by the anterior pituitary gland at the base of the brain. If there is decreased secretion of one specific pituitary hormone, the condition is known as selective hypopituitarism. If there is decreased secretion of most or all pituitary hormones, the term panhypopituitarism (pan meaning “all”) is used.
What are the causes of hypopituitarism?
Causes are at the three levels: 1) Hypothalamus - Kallmans’s syndrome, tumours, inflammation, infection 2) Pituitary stalk - trauma, surgery, mass lesion, meningioma, carotid artery aneurysm 3) Pituitary - tumour, irradiation, inflammation, autoimmunity, infiltration, ischaemia (Sheehan;s syndrome)
What are the symptoms of each hormone lack in hypopituitarism?
Features are due to hormone lack and causes (pituitary tumours can lead to mass effect or hormone secretion with decreased secretion of other hormones)
What are the symptoms of growth hormone lack in hypopituitarism?
GH: - Central obesity - Atherosclerosis - Dry wrinkly skin - Decreased well being - Decreased exercise ability - Decreased cardiac output - Osteoporosis - Decreased glucose
What are the symptoms of gonadotropin hormone lack in hypopituitarism for females?
FSH/LH: - Oligomenorrhoea or amenorrhoea - Decreased fertility - Decreased libido - Decreased muscle bulk - Hypogonadism
What are the symptoms of gonadotropin lack in hypopituitarism for males?
Erectile dysfunction Decreased libido Decreased muscle bulk Decreased hair all over Small testes Decreased ejaculate volume Decreased spermatogenesis
What are the symptoms of thyroid lack in hypopituitarism?
Weight gain Menorrhagia Cold intolerance Depression Thin skin Loss of outer 2/3rds of eyebrow Tiredness Lethargy Weakness Decreased memory
What are the symptoms of corticotropin lack in hypopituitarism?
Extreme fatigue. Weight loss and decreased appetite. Darkening of your skin (hyperpigmentation) Low blood pressure, even fainting. Salt craving. Low blood sugar (hypoglycemia) Nausea, diarrhea or vomiting (gastrointestinal symptoms) Abdominal pain
What are the tests for hypopituitarism?
Basal hormone tests - decreased Dynamic tests - Short synacthen test - Insulin tolerance test - Arginine and growth hormone releasing test - Glugacon stimulation test (alternative when insulin tolerance test is contraindicated) MRI scan for hypothalamic or pituitary lesion
What is the insulin tolerance test?
An insulin tolerance test (ITT) is a medical diagnostic procedure during which insulin is injected into a patient’s vein, after which blood glucose is measured at regular intervals. This procedure is performed to assess pituitary function, adrenal function, and GH secretion. ACTH and growth hormone should both be released as a part of the stress mechanism triggered by hypoglycaemia.
What are the contraindications for the insulin tolerance test?
Epilepsy Ischaemic heart disease Adrenal failure
How is hypopituitarism treated?
Hydrocortisone for secondary adrenal failure before other hormones are given Thyroxine for hypothyroidism Testosterone enanthate - to prevent symptoms and osteoporosis Transdermal oestrodiol patches or contraceptive pill, DHEA and testosterone Gonadotropin therapy to induce fertility in both men and women Growth hormone and somatotrophin which mimics growth human GH
How does somatotrophin help with hypopituitarism?
It address problems of:
- Increase fat mass
- Decreased muscle bulk
- Decreased exercise capacity
- Heat intolerance
What is Sheehans syndrome?
- Sheehan’s syndrome occurs due to pituitary ischaemia secondary to blood loss during or after childbirth.
- It presents with symptoms consistent with global hypopituitarism, such as agalactorrhoea (prolactin), amenorrhoea (FSH and LH), cold intolerance and constipation (thyroid hormones) and weight loss (steroid hormones).
