ELFH: Endocrinology (parathyroid and pituitary) Flashcards
What is the role of the parathyroid gland?
They are crucial in maintaining the levels of calcium in the blood, which are usually 2.2-2.6 mmol/l.
They release parathyroid hormone when calcium levels are low whose role is to stimulate the release of calcium from bone (activate osteoclasts and bone resorption) and reduce its excretion from the kidney.
disorders of the parathyroid gland can result in what?
Hypocalcaemia and hypoparathyroidism
Hypercalcaemia and hyperparathyroidism
main causes of hypoparathyroidism?
post thyroid surgery, autoimmune, and rare congenital disease, such as Di George syndrome
what occurs in hypoparathyroidism?
These result in reduced pseudohypoparathyroidism (PTH) release and subsequent hypocalcaemia and a raised phosphate level.
other than hypoparathyroidism, what are other causes of hypocalcaemia?
- Chronic renal failure (reduced vitamin D activation)
- Vitamin D deficiency (rickets and osteomalacia)
- Resistance to PTH Drugs such as calcitonin (from C cells of thyroid) and bisphosphonates
- Acute pancreatitis and citrated blood transfusion (chelates calcium)
The most likely presentation of hypoparathyroidism would be through the clinical effects of hypocalcaemia. As calcium is important for neuromuscular function, what symptoms or signs may result if the calcium levels fall below 2.2 mmol/l?
Symptoms or signs may include any of the following:
- General increased excitability of nerves
- Peri-oral paraesthesia in the fingers and toes
- Tetany, carpopaedal spasm, convulsions and, if untreated, death
- Chvostek’s sign, circumoral twitching following tapping of the ipsilateral facial nerve
- Trousseau’s sign: extension of the hand and thumb apposition (carpopaedal spasm) when a blood pressure cuff is applied to ipsilateral arm
- Laryngospasm and bronchospasm
Cataracts
Main investigations for hypoparathyroidism include..?
- Low PTH levels
- Low calcium
- Possible parathyroid antibodies
- Check the vitamin D level
management for hypoparathyroidism?
- IV calcium (gluconate)
- Maintenance with alfacalcidol (vitamin D compound)
considerations for the dentists with apt with hypoparathyroidism?
Consideration should be given that this may be a manifestation of signs/symptoms of multiple endocrine neoplasia syndrome (MEN) type 1. MEN Type I involves dysfunction, neoplasias of the pituitary, pancreas, adrenal gland and thyroid.
If Addison’s is present then oral fungal infections may be difficult to treat.
what are the different types of hyperparathyroidism?
primary
secondary
tertiary
what is hyperparathyroidism?
results in an increased release of parathyroid hormone (PTH) which will increase the calcium blood levels above 2.6 mmol/l
primary hyperparathyroidism?
- Mostly adenoma though some will be due to hyperplasia
- Rare carcinoma
- Raised PTH and calcium
secondary hyperparathyroidism?
- Physiological response to calcium loss (hypocalcaemia, e.g. renal failure of vitamin D deficiency)
- Raised PTH but normal or low calcium
tertiary hyperparathyroidism?
- Persistence of hyperparathyroidism after underlying calcium losing pathology has been treated
- Raised PTH and calcium
what can also raise PTH levels?
- PTH levels may also occasionally be released by ectopic PTH-related peptide being released from a tumour.
disease?
hyperparathyroidism
Pain due to increased bone lysis
Osteitis fibrosa cystica (cysts in bones)
Resorption of bone in the terminal phalanges
Salt and pepper skull
in pt with hyperparathyroidism: symptomatic or asymptomatic?
The majority of cases will present asymptomatically. Some however will show signs of hypercalcaemia
What are some causes of hypercalcaemia you should consider?
- Primary hyperparathyroidism (Fig 1)
- Malignant disease, e.g. multiple myeloma
- Abnormal vitamin D metabolism
- Drugs such as thiazide diuretics
- Renal disease
Hypercalcaemia is classically asymptomatic but can present with…?
bones
stones
groans
abdominal moans
extremely high calcium levels
effect of hypercalcaemia/hyperparathyroidism or bones?
- Pain due to increased bone lysis
- Osteitis fibrosa cystica (cysts in bones)
- Resorption of bone in the terminal phalanges
- Salt and pepper skull
symptoms/effects of hyperparathyroidism/hypercalcaemia?
- Depression
- General malaise
- Weakness
- Renal calculi will form and may lead to renal failure
- Calcium in the renal tubules may lead to polyuria and nocturia
- Constipation
- Peptic ulceration
- Pancreatitis
Extremely high calcium levels
- Dehydration, thirst, confusion and even cardiac arrest.
Bones
- Pain due to increased bone lysis
- Osteitis fibrosa cystica (cysts in bones)
- Resorption of bone in the terminal phalanges
- Salt and pepper skull
management of hyperparathyroidism?
- The primary hyperparathyroid disease requires removal of the affected gland which is one gland if an adenoma but all four glands if it is due to hyperplasia
- Raised calcium levels requires urgent treatment and involves:
Rehydration
Bisphosphonates
Prednisolone
Prevent recurrences
The dentist needs to be alert to the signs and symptoms of hyperparathyroidism, but also recognise the changes specific to the oral cavity which include:
- Possible brown tumours of the jaw, giant cell lesions which may present as an epulis (Fig 1)
- Loss of lamina dura around the teeth which will recover if the condition is reversed
- Association with other autoimmune disease
most common reason for pituitary disease to arise?
tumours of the pituitary gland (Fig 1). This will lead to increased hormone release.
how may a pt present if they have pituitary disease?
The patient may present with signs of the hormone dysfunction but may also present with disturbance of the visual pathways.
The classical presentation is with bitemporal hemianopia, as the pituitary gland lies at the decussation of the optic nerves and interrupts flow of information in the decussating medial retina fibres, thus affecting the temporal visual fields.
The dentist needs to be alert to the signs and symptoms of pituitary disease: (2)
- Raised ACTH secretion will affect the adrenal gland and Cushing’s disease
- TSH levels, if increased, will give rise to hyperthyroidism
features of increased GH release (pituitary gland)?
adults and children
Prognathic mandible
Visual disturbance (bitemporal haemianopia)
Macroglossia
Goitre
Carpal tunnel syndrome
Prominent supra-orbital ridge
Heart failure
Rings become tight, hats do not fit, gloves do not fit and dentures do not fit
Ankylosed teeth
In a child you would expect to see:
Visual problems
Gigantism
A. Correct.
B. Correct.
C. Incorrect. You would expect to see high blood pressure.
D. Correct.
E. Incorrect. There would be spacing of teeth.
what can cause the pituitary gland to underperform?
hypothalamic disease or directly by pituitary tumours, surgery or radiotherapy.
Infection
- Meningitis
- Syphilis
Vascular
- Sheehan’s syndrome, hypovascularity associated with child birth and post partum haemorrhage
- Stroke via infarction of haemorrhage (pituitary apoplexy)
Congenital
- Kallman’s syndrome, gonadotrophin deficiency associated with facial abnormalities, colour blindness and loss of smell.
Trauma
- Skull fracture.
Infiltration
- Sarcoidosis.
Functional
- Anorexia.
management of hypopituitary function?
steroid and thyroid hormone replacement for life in addition to other hormones shown to be lacking.
B
C
D
A. Tumours
B. Autoimmune
C. Hasimotos
Hyperparathyroidism can manifest with lesions on the mouth with soft tissue, bony abnormality involving giant cells. What is this called?
Brown’s tumour
A. Chronic renal failure
B. Vitamin D deficiency
