7.2 - Pituitary Disorders. Flashcards
What’s the most common cause of a pituitary malfunction?
A benign tumour (adenoma)
How can non functioning pituitary tumours have a negative effect?
non functioning = don’t produce any hormone
Result in inadequate production of one or more of the pituitary hormones due to physical pressure from the growing tumour on glandular tissue
What are the symptoms of a non functioning pituitary tumour?
Pressure on surrounding structures causes headaches, visual problems (compression of optic nerve), vomiting and nausea.
What are the functions of secreting tumours?
Usually correspond to the systemic effect of the over secreted hormone and may/may not show some degree of hormonal regulation in term of negative feedback
What is the investigation for a suspected pituitary tumour?
MRI
Assessment of visual field defects
Assessment of endocrine function to determine whether there is hormonal excess/ deficiency = can do with blood sample
What is panhypopituitarism?
Deficiency of all anterior pituitary hormones
Usually GH and LH/FSH are the first hormones to be affected
What are the symptoms of growth hormone deficiency in adults?
Decrease in tolerance to exercise
Decreased muscle strength
Increased body fat
Reduced sense of well-being
Deficiency is usually a result of a pituitary adenoma
What are the possible causes of growth hormone deficiency in children?
Usually idiopathic
Specific gene mutations and autoimmune inflammation is a possible effect.
What can gonadotropin deficiency cause?
Hypogonadism due to pituitary adenoma can cause:
- lack of libido
- infertility
- oligomenorrhea
- amenorrhea
- impotence in men
What are the consequences of ADH deficieny?
Deficiency leads to
- excess excretion of dilute ruin = dehydration and increased sensation of thrirst = polydispsia
- condition represents the disease diabetes insipdus
What is Normal prolactin function and what can inhibit it?
Normal prolactin = maintain lactation
Inhibited nay dopamine
What symptoms come with hyperprolactinaemia?
- galactorrhoea (unexplained milk production)
- gynecomastia (hard breast tissue)
- amenorrhea (cessation of menstrual cycle)
- erectile dysfunction
How can hypogonadism result from hyperprolactinaemia?
Higher level of dopamine in the hypothalamus (resulting from negative feedback of increased plasma prolactin) inhibits GnRH secretion from the hypothalamus and therefore FSH and LH secretion from ant pit
Whats the most common cause of hyperprolactinaemia?
A prolactioma, a pituitary adenoma that secretes prolactin
NB: physiology causes e.g stress, pregnant you, exercise, drugs etc can cause it as well.
What’s the treatment for hyperprolactinaemia?
Dopamine receptor agonist e.g cab ergo line used as the first line of treatment
However, if this doesn’t work = surgery
