Acromegaly Clinical Demonstration

Question 1

What is the presentation of acromegaly

Answer 1

• Headache
• Arthritis
• Carapl tunnel
• Dabetes
• Hypertension
• Visual field defec
• Obstructive sleep apnoea
• Coronary artery disease
• Menstrual upset
• Headache

Question 2

describe the growth hormone axis

Answer 2

• Hypothalamus releases GnRH
• this causes GH production from the anterior pituitary
• GH has direct effects on bone and skeletal muscle
• skeletal muscle produces IGF-1 which acts as a feedback loop
• it also has indirect effects = GH acts on the liver and produces IGF-1 in the liver
• IGF-1 acts on the bone and the muscle
• when IGF-1 rises too much it causes negative feedback to the hypothalamus
• GnRH is also inhibited by somatostatin

Question 3

what can cause acromegaly

Answer 3

pituitary adenoma

Question 4

how do you remove a pituitary adenoma

Answer 4

transsphenoidal surgery in order to remove the adenoma

Question 5

what can you use to stop growth hormone release

Answer 5

somatostatin agonist

Question 6

what is a side effect of dopamine agonist use

Answer 6

• inability to understand risk

Question 7

How do you diagnose acromegaly

Answer 7

• This is because they are released in a pulsatile moment
• Screen for growth hormone excess by a growth hormone and IGF-1 level
• Confimriatory test for acromegaly is a dynamic test – if you think they are producing too much cortisol they give them something to reduce cortisol, if it doesn’t fall then it is pathological,
• Have to give something that will reduce growth hormone level – give glucose tolerance test – get 75g of glucose and supress growth hormone to 0 and if it doesn’t then diagnosis is made
• Then move onto scans
• Pituitary MRI scan

Question 8

How do you treat acromegaly

Answer 8

• Radiotherapy – exepct them to become hypopituitarism as the radiotherapy damages the exisiting tissue
• Gamma knife – know used
• Surgery more likely now
• somatostatin agonists