Hypoparathyroidism

Hypoparathyroidism is a rare endocrine disorder characterized by the underproduction of parathyroid hormone (PTH) by the parathyroid glands.

Causes

• Agenesis or hypoplasia of the parathyroid glands, which can be congenital or acquired
• Destruction or removal of the parathyroid glands during surgery, such as thyroidectomy or parathyroidectomy
• Autoimmune disorders, such as autoimmune polyendocrine syndrome type 1 (APS-1)
• Genetic mutations, such as those affecting the calcium-sensing receptor (CaSR) or the PTH gene
• Magnesium deficiency, which can impair PTH secretion and function
• Certain medications, such as phenytoin and phosphate supplements, which can interfere with PTH production or function

Symptoms

• Muscle cramps and spasms
• Tingling or numbness in the hands and feet
• Weakened tooth enamel and increased risk of cavities
• Dry skin and hair loss
• Fatigue and weakness
• Seizures, in severe cases
• Tetany, a condition characterized by muscle cramps, spasms, and rigidity

Diagnosis

Diagnosis of hypoparathyroidism is based on:

• Low serum calcium levels (hypocalcemia)
• Low PTH levels
• High phosphate levels (hyperphosphatemia)
• Normal or low magnesium levels
• Imaging studies, such as neck ultrasound or sestamibi scan, to evaluate parathyroid gland function and anatomy

Treatment

Treatment of hypoparathyroidism typically involves:

• Calcium supplements to maintain normal serum calcium levels
• Vitamin D supplements to enhance calcium absorption
• Magnesium supplements, if necessary
• Phosphate binders, such as sevelamer or lanthanum, to reduce phosphate levels
• PTH replacement therapy, such as recombinant human PTH (rhPTH), in some cases

Complications

If left untreated or undertreated, hypoparathyroidism can lead to:

• Severe hypocalcemia, which can cause seizures, tetany, and even death
• Bone disease, such as osteoporosis or osteopenia
• Kidney damage, due to hyperphosphatemia and calcium-phosphate deposits
• Cognitive impairment and neurological symptoms, such as fatigue, weakness, and depression

Prognosis

The prognosis for hypoparathyroidism varies depending on the underlying cause, severity of symptoms, and effectiveness of treatment. With proper management, most patients can lead normal lives, but some may experience persistent symptoms or complications.