Hypothyroidism (Hypoparathyroidism): Causes

Pathogenesis (development of disease)

Hypoparathyroidism (parathyroid hypofunction) most commonly occurs after surgery in the neck (postoperative), especially after surgery on the thyroid gland. This is due to the close spatial relationship between the parathyroid glands (lat.: Glandulae parathyroideae) and the thyroid gland (lat. Glandula thyreoidea or Glandula thyroidea). Risk factors for postoperative hypoparathyroidism are mainly insufficient experience of the surgeon, the extent of the operation, indications such as Graves’ disease, retrosternal (behind the sternum) goiter, tumor operation, lymph node dissection (removal of lymph nodes) or a recurrent operation. Rarely, hypoparathyroidism occurs idiopathically (without an identifiable cause) and even more rarely due to aplasia (nonformation) of the parathyroid glands and thymus.

Etiology (causes)

Genetic causes

  • Genetic burden
    • Genetic diseases
      • Autoimmune polyglandular syndromes – e.g., autoimmune polyglandular syndrome type 1 (APS-1; synonym: hypoparathyroidism in the setting of autoimmune polyendocrinopathy type 1) (autosomal recessive inheritance).
      • Defects of the T-cell series such as Di-George syndrome – defect immunopathy with defect of T lymphocytes and aplasia / hypoplasia of the thymus; most common microdeletion syndrome.
      • Hemochromatosis (iron storage disease) – genetic disease with autosomal recessive inheritance with increased deposition of iron as a result of increased iron concentration in the blood with tissue damage.

X-rays

Other causes

  • Post-operative – after operations in the neck area (most common cause), e.g.:
    • Parathyroidectomy (parathyroidectomy).
    • Radical neck surgery
    • Strumectomy (removal of thyroid tissue).
    • Total thyroidectomy (TT; surgical removal of the entire thyroid gland).
    • Accidental injury to the parathyroid glandulae (parathyroid glands) during cervical surgery.