OVERVIEW

What is idiopathic hypoparathyroidism?

Idiopathic hypoparathyroidism, abbreviated as idiopathic hypoparathyroidism, refers to hypoparathyroidism without manifestations of genetic syndromes or identifiable causes such as neck surgery or known gene mutations. Its etiology remains unclear but may be associated with congenital parathyroid developmental abnormalities or acquired autoimmune destruction of the parathyroid glands.

Idiopathic hypoparathyroidism leads to insufficient secretion of parathyroid hormone, resulting in hypocalcemia, hyperphosphatemia, reduced parathyroid hormone levels, and increased neuromuscular excitability (such as tetany, epileptic seizures, etc.).

There is no definitive cure. Treatment primarily focuses on symptom management to improve the patient's condition and prevent or reduce complications.

Is idiopathic hypoparathyroidism common?

Idiopathic hypoparathyroidism is uncommon. The condition is mostly sporadic, more frequently observed in children and rarely in adults.

SYMPTOMS

What are the common manifestations of idiopathic hypoparathyroidism?

• Tetany: Common and recurrent. Typical symptoms include stiffness in the hands and feet, thumbs adducted toward the palm, other fingers tightly closed, straightened, and rigid, fingers flexed toward the palm, and wrists also bent. In severe cases, the upper arms press tightly against the chest with elbows flexed. The lower limbs are straightened, feet turned inward, the upper lip contracts, preventing a grin, and the entire body experiences muscle rigidity, pain, and a sense of fear. Adults remain fully conscious, while children may lose consciousness. Episodes can last minutes, hours, or even days. During recovery, symptoms disappear in reverse order—the first symptom to appear is the last to resolve.
• Seizures: The second most frequent manifestation after tetany.

Other manifestations can be found under the entry "Hypoparathyroidism."

CAUSES

What are the common causes of idiopathic hypoparathyroidism?

The cause of idiopathic hypoparathyroidism is unclear, but it may be related to congenital genetic defects or acquired autoimmune destruction.

Current data and research suggest that the causes of idiopathic hypoparathyroidism vary across different age groups. Congenital or genetic defects are the main pathogenic factors in children and adolescents, while autoimmune factors may be the primary cause in adults.

Who is commonly affected by idiopathic hypoparathyroidism?

Idiopathic hypoparathyroidism is more common in children and rare in adults.

Is idiopathic hypoparathyroidism contagious?

No, it is not contagious.

Is idiopathic hypoparathyroidism hereditary?

Some cases of idiopathic hypoparathyroidism may be related to currently unidentified genetic defects and can be hereditary. (Note: Isolated hypoparathyroidism with known genetic mutations and genetic syndromes are not considered within the scope of idiopathic hypoparathyroidism.)

DIAGNOSIS

How is idiopathic hypoparathyroidism diagnosed?

When diagnosing idiopathic hypoparathyroidism, doctors base their diagnosis on the following criteria:

• Recurrent episodes of tetany;
• Decreased blood calcium, elevated blood phosphorus, undetectable or abnormally low parathyroid hormone levels;
• No history of thyroid or parathyroid surgery, neck surgery, tumor radiotherapy, renal insufficiency, or significant alkalosis.

What tests are needed to diagnose idiopathic hypoparathyroidism?

Generally, the following tests are required: blood calcium, blood phosphorus, parathyroid hormone, 24-hour urinary calcium and phosphorus, head CT scan, and pathogenic gene screening.

• Blood calcium: Primarily confirms the presence of hypocalcemia.
• Blood phosphorus: Primarily confirms the presence of hyperphosphatemia.
• Parathyroid hormone: Confirms reduced parathyroid hormone secretion.
• 24-hour urinary calcium and phosphorus: Under low blood calcium conditions, 24-hour urinary calcium and phosphorus levels are reduced. However, after correcting hypocalcemia, urinary calcium often increases because patients with hypoparathyroidism excrete relatively higher amounts of urinary calcium. Reduced urinary phosphorus is diagnostically significant.
• Head CT scan: Typical findings include bilateral symmetric basal ganglia calcifications and widespread intracranial calcifications, which may enlarge or become more pronounced with disease progression and age. Calcifications are often symmetric, multiple, and vary in size, appearing as patches, dots, or bands. Intracranial calcifications are most commonly located in the basal ganglia, sometimes presenting as a typical "figure-eight" sign.
• Pathogenic gene screening: Assists in diagnosis.

Which diseases can idiopathic hypoparathyroidism be confused with? How to differentiate them?

Idiopathic hypoparathyroidism may be confused with other conditions causing intracranial calcifications, requiring differentiation.

• Idiopathic familial cerebrovascular ferrocalcinosis (Fahr syndrome): Also known as symmetric cerebral calcification syndrome, idiopathic symmetric basal ganglia calcification, or familial basal ganglia calcification. It is rare and of unknown cause, featuring symmetric intracranial calcifications. However, serum calcium and phosphorus levels are normal, and there is no hypoparathyroidism. Differentiation from idiopathic hypoparathyroidism can be achieved through serum calcium and phosphorus testing.
• Wilson's disease: A hereditary copper metabolism disorder where excess copper accumulates in the liver, brain, kidneys, and cornea. Symptoms usually appear in adolescence or adulthood, often with symmetric intracranial calcifications. Decreased serum ceruloplasmin levels are a key diagnostic marker, and copper deposits in the cornea may form Kayser-Fleischer rings, distinguishing it from idiopathic hypoparathyroidism.
• Physiological calcification: Common in the elderly, presenting with small intracranial calcifications that may be symmetric. However, blood calcium, phosphorus, and parathyroid hormone levels are normal, making it easily distinguishable from idiopathic hypoparathyroidism.

TREATMENT

Which department should I visit for idiopathic hypoparathyroidism?

Endocrinology.

Can idiopathic hypoparathyroidism resolve on its own?

No, there is currently no cure, and lifelong treatment is required.

How is idiopathic hypoparathyroidism treated?

Currently, there is no specific treatment for idiopathic hypoparathyroidism. The focus is on symptomatic treatment to alleviate symptoms and prevent or reduce complications.

• For acute episodes, such as tetany or seizures, intravenous injection of 10% calcium gluconate is administered immediately. Magnesium supplements should be given if hypomagnesemia is present. Severe cases may also require sedatives.

• For chronic maintenance therapy, treatment primarily involves vitamin D or related medications, along with calcium supplements. Parathyroid hormone therapy (e.g., teriparatide) may also be used.

For more information, refer to the relevant section on hypoparathyroidism.

Is hospitalization required for idiopathic hypoparathyroidism?

Hospitalization or observation is often necessary during acute episodes, but not during chronic stable periods.

DIET & LIFESTYLE

What should patients with idiopathic hypoparathyroidism pay attention to in their diet?

The diet for idiopathic hypoparathyroidism advocates high calcium and low phosphorus intake. Foods high in calcium and low in phosphorus mainly include: dried shrimp, kelp, seaweed, black fungus, leafy greens, legumes, etc.

Patients should consume foods high in calcium and easily absorbed, combined with high-protein or high-lactose foods to improve calcium absorption. At the same time, they should limit the intake of high-phosphorus foods, such as dairy products, cauliflower, egg yolks, and other phosphorus-rich foods.

Additionally, patients should drink an appropriate amount of water and prevent constipation.

What should patients with idiopathic hypoparathyroidism pay attention to in daily life?

Maintaining a positive mindset for both patients with idiopathic hypoparathyroidism and their families plays a crucial role in disease treatment and quality of life.

Does idiopathic hypoparathyroidism require follow-up examinations? How are they conducted?

Idiopathic hypoparathyroidism requires regular follow-up examinations, which are important for preventing and delaying long-term complications.

During treatment for hypoparathyroidism, blood calcium, phosphorus, and creatinine levels should be monitored. These indicators should be checked weekly to monthly during medication dosage adjustments. Once the dosage is stable, these indicators, along with urinary calcium and creatinine, should be checked every six months. If necessary, blood parathyroid hormone levels should also be monitored.

How should family members care for a patient with idiopathic hypoparathyroidism?

Family members of patients with idiopathic hypoparathyroidism are advised to learn some emergency measures during episodes, such as:

• During a seizure, immediately lay the patient flat without a pillow, tilt the head to one side, and clear secretions from the mouth, nose, and throat promptly to keep the airway open and prevent aspiration.
• A tongue depressor wrapped in gauze can be placed between the upper and lower teeth (if the teeth are clenched, do not force it in).
• Do not forcibly restrain the patient during convulsions to avoid fractures or dislocations. Ensure supervision to prevent falls or accidents.

PREVENTION

Can Idiopathic Hypoparathyroidism Be Prevented? How to Prevent It?

Since the cause of idiopathic hypoparathyroidism remains unclear, there are currently no effective preventive measures.

How Can Patients with Idiopathic Hypoparathyroidism Prevent Other Diseases?

Regular medication and follow-up visits are key to preventing or delaying the onset of complications.