34 Questions
Which condition is characterized by 'Stones, Bones, Abdominal Groans, & Psychiatric Overtones'?
Hypercalcemia
What is a common presentation of hypocalcemia?
Increased Muscle Spasticity
What is the most common cause of hypercalcemia?
Parathyroid adenoma
Which lab result is expected in primary hyperparathyroidism?
Elevated PTH and serum calcium
What is the treatment of choice for primary hyperparathyroidism?
Parathyroidectomy
Which condition presents with symptoms like 'Akathisia' and 'Tardive Dyskinesia'?
Chronic Hypocalcemia
What is the main clinical manifestation of pseudohypoparathyroidism?
Response resistance to PTH
What is the role of parathyroid hormone (PTH) in response to decreased blood calcium levels?
Stimulates osteoclasts to resorb bone and release calcium into the bloodstream
What effect does calcitriol have in response to PTH in the kidney?
Promotes calcium absorption in the small intestines
What is the function of PTH in calcium reabsorption in the kidneys?
Promotes renal tubular reabsorption of calcium
What is the main function of PTH when blood calcium levels are low?
Increase blood calcium levels
What diagnosis do you suspect for someone with kidney stones, nausea, vomiting, and bone pain? Labs: high serum calcium high PTH
Primary Hyperparathyroidism
Which condition is characterized by round face, short stature, short 4th metacarpal bone with obesity and developmental delays due to a congenital mutation in the maternal GNAS-1 gene leading to end organ resistance to PTH?
Pseudohypoparathyroidism
Which condition presents with similar features to pseudohypoparathyroidism but has no resistance to PTH and normal PTH and calcium levels?
Pseudopseudohypoparathyroidism
What parathyroid pathology is associated with an appropriate increased in PTH due to a problem with the end organ, such as the kidney or bone?
Secondary Hyperparathyroidism
In which condition is there a chronic stimulation of the parathyroid gland leading to hypertrophy and overproduction of PTH due to longstanding diseases like chronic kidney disease?
Tertiary Hyperparathyroidism
Which condition is characterized by a decrease in PTH levels alongside a rise in serum calcium?
Malignancy / non-parathyroid mediated hypercalcemia
What is a common cause of primary acquired hypoparathyroidism?
B or C
After a patient undergoes a partial parathyroidectomy, what complication may occur leading to severe hypocalcemia due to the suppression of remaining PTH?
Hungry Bone Syndrome
What is a common cause of low serum magnesium according to the text?
Alcohol use
How does serum magnesium levels affect PTH secretion?
As serum magnesium increases, PTH is inhibited
Which clinical sign results from tapping the facial nerve anterior to the earlobe?
Chvostek's sign
What is the name of the clinical sign involving carpal spasm induced by inflating a blood pressure cuff above systolic pressure?
Trousseau's sign
What is the primary function of parathyroid hormone (PTH) in response to decreased blood calcium levels?
Increases renal tubular reabsorption of calcium
Which of the following conditions could result from hyperalbuminemia?
Dehydration
What effect does parathyroid hormone (PTH) have on phosphate levels in the body?
Increases renal excretion of phosphate
What is the main function of calcitriol in response to parathyroid hormone (PTH) stimulation in the kidney?
Enhances calcium reabsorption from the kidney tubules
In primary hyperparathyroidism, what lab results are typically observed?
High serum calcium, high PTH
What is a common cause of secondary hyperparathyroidism?
Vitamin D intoxication
Which condition is associated with a really low or high magnesium levels alongside low PTH and corrected calcium?
2º Hypoparathyroidism
What condition results from longstanding chronic kidney disease and Vitamin D deficiency?
Secondary hyperparathyroidism
Which set of symptoms is more indicative of hypercalcemia?
Bone pain, constipation, nausea/vomiting
In primary hyperparathyroidism, what is the expected level of vitamin D?
Elevated
What is the most common etiology in primary hyperparathyroidism?
Parathyroid adenoma
Study Notes
Parathyroid Disorders
Anatomy
- Located on the posterior surface of the thyroid gland
- Most people have 4 parathyroid glands (2 on each lobe), but may have as few as 2 or as many as 6
Physiology
- PTH (parathyroid hormone) is secreted by parathyroid chief cells into the bloodstream in response to decreased blood calcium levels
- PTH stimulates:
- Osteoclasts to resorb bone and release calcium into the bloodstream
- Renal tubular reabsorption of calcium and stimulates calcitriol synthesis from calcidiol in response to increased Ca2+ in the kidney
- Renal excretion of phosphate
- Calcitriol promotes calcium absorption in the small intestines
Calcium
- Normal range: 8.5-10.2 mg/dL
- Corrected calcium = serum calcium mg/dL + (0.8 x [4.0 – serum albumin g/dL])
- Hyperalbuminemia: dehydration, Multiple Myeloma
- Hypoalbuminemia: chronic illness, malnutrition
Hypercalcemia Presentation
- Nephrolithiasis
- Bone Pain (Osteitis fibrosa cystica)
- Constipation; N/V
- Weakness
- Lethargy
- Stupor
- Coma
- "Stones, Bones, Abdominal Groans, & Psychiatric Overtones"
Hypocalcemia Presentation
- Acute:
- Paresthesias (perioral, hands, feet)
- Increased Muscle Spasticity
- Chronic:
- Extrapyramidal symptoms:
- Akathisia
- Chvostek sign – facial spasm to rub
- Dystonia
- Trousseau sign – carpal spasm during BP
- Tardive dyskinesia
- Extrapyramidal symptoms:
Cardiac Involvement
- Heart failure
- Prolonged QT
- Parkinsonism
- Dementia
- Cataracts
- Poor Dentition
- Dry skin
Hyperparathyroidism
- 1º Hyperparathyroidism: problem with the parathyroid glands themselves
- 2º Hyperparathyroidism: problem with the end organ (bone or kidneys)
- 3º Hyperparathyroidism: chronic stimulation of the parathyroid glands causing hypertrophy and ultimately autonomous overproduction of PTH
Primary Hyperparathyroidism
- Most common cause of hypercalcemia
- Epidemiology: most common in African Americans, Women, 7th decade of life
- Etiology:
- Parathyroid adenoma (~80%)
- Gland hyperplasia (~20%)
- Carcinoma (~1%)
- Clinical Presentation: "stones, bones, abdominal groans, psychiatric overtones"
- Diagnosis:
- Calcium – elevated
- PTH – elevated
- Vitamin D – normal or elevated
- Phosphorous – normal or low
- Treatment:
- Parathyroidectomy
- Refer to surgery in all symptomatic patients or if calcium is >1 above ULN
- Consider referral for asymptomatic patients
Learn about the basics of parathyroid anatomy and physiology, including the location of the parathyroid glands on the thyroid and the role of parathyroid hormone in regulating blood calcium levels. Explore disorders related to the parathyroid glands.
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