Parathyroid

There are four parathyroid glands located adjacent
Produces parathyroid hormone (PTH)
PTH increases calcium concentration in the bloodstream in response to low serum calcium

Hyperparathyroidism

Affects women 3:1 over men
Primary
- Typically this is caused by an adenoma
- Maybe hyperplasia or carcinoma.
Secondary
- Chronic renal failure
  - Poor production of vitamin D which will decrease Calcium, thereby stimulating the parathyroid glands
- Malignant tumor — breast, lung, pancreas
- Calcium deficiency

Clinical Presentation

“Moans, groans, stones, and bones”
Patients will not usually come in complaining of any particular symptom. Hyperparathyroidism is usually an incidental finding.
Muscles
- Paresthesias
- Muscle weakness
- Decreased deep tendon reflexes
Mental changes (Moans)
- General malaise
- Depression
- Cognitive impairment
- Psychosis
Heart
- HTN
- Prolonged P-R interval
- Shortened Q-T interval
- Heart block
GI (Abdominal Groans)
- Constipation
- Nausea/vomiting
- Anorexia
- Abdominal pain
- Weight loss
Kidney (Stones)
- Hypercalcemia induced nephrogenic diabetes insipidous
- Polyuria
- Polydipsia
- Kidney stones
Bone (Bones)
- Bone pain
- Arthralgia
- Increased risk of pathologic fractures
Skin
- Pruritus

Labs and Studies

Blood work
- Ca > 10.5
- Elevated PTH is diagnostic
- Phosphate low less <2.5 in primary disease. Elevated in secondary disease
- Low vitamin D
Urine
- Ca elevated
- Phosphate elevated
Imaging
- CT/ MRI not helpful
- U/S is far more sensitive though not necessary
- X-ray
  - Demineralization
  - Subperiosteal bone resorption especially in the fingers
  - Cysts of the jaw
  - Salt and pepper skull
- DXA scan may help determine amount of bone loss

Treatment

Asymptomatic patients may not need medical or surgical treatment
Surgical removal
- 94% successful
- Parathyroidectomy is the recommended treatment for symptomatic and some asymptomatic patients
- Hypocalcemia is a common complication treat with Ca supplement if necessary
Medical treatment
- Fluid, Fluid, Fluid — admission and IV fluid if necessary
- IV Bisphosphonates
- Pamidronate
- Zoledronic Acid
- Cinacalcet — a calcimimetic
- Vitamin D
- Estrogen decreases serum Ca in a postmenopausal hyperparathyroidism
- Propranolol may be used to protect the heart against elevated Ca

Hypoparathyroidism

Causes

Acquired hypoparathyroidism post thyroidectomy is the most common
Post parathyroidectomy
Heavy metal damage
Low Mg
Granulomas
Tumors
Infection
Reidel’s thyroiditis
Autoimmune hypoparathyroidism
Congenital
Multiple genetic disorders

Clinical Presentation

Acute disease symptoms
- Irritability
- Tetany — the involuntary contraction of muscles
- Cramping
- Convulsions
- Tingling
Chronic disease symptoms
Lethargy
Parkinsonism
Mental retardation
Anxiety
Changes in personality
Cataracts → blurred vision
Dry skin
Decreased eyebrow hair
Nail and teeth defects — brittle nails
Hyperreflexia (possible)

Signs

Chvostek’s sign
Trousseau’s sign

Labs and Studies

Blood work
- Ca low
- Corrected Ca will be low (Ca is mostly bound to albumin so if albumin is low you need a corrected Ca)
- Parathyroid hormone is low
- Mg low
Urinary Ca low

-Other studies
– CT or x-ray may show dense bones
cutaneous calcifications, calcifications of basal ganglia
– EKG
– Prolonged QT
– T wave abnormalities
– Slit-lamp
– Early cataract formation

Treatment

Emergent
- Airway maintenance
- IV calcium gluconate
- Mg if appropriate
- Ca supplement
- Vitamin D supplement
- Close monitoring of Ca

Pseudohypoparathyroidism

Think about Diabetes type 1 and Diabetes type 2. In DM 1 you don’t make insulin. In DM 2 you make insulin, but your insulin receptors do not respond to it. In pseudohypoparathyroidism you make parathyroid hormone, but the receptors don’t respond to it.

Clinical Presentation

Similar to hypoparathyroidism

Labs and studies

Blood work
- Ca will be low
- Parathyroid hormone is elevated

Treatment

Cases are typically not as severe as true hypoparathyroidism
Ca supplement
Vitamin D supplement

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