August and September are Parathyroid and Thyroid Awareness Months, respectively. Endocrinologists and surgeons treating parathyroid disorders are also experienced in thyroid disorders. People are familiar with thyroid diseases but have rarely heard about the parathyroid gland and its disorders. Did you know that we have four parathyroid glands located behind or around the thyroid gland? They produce parathyroid hormone (PTH), which regulates calcium and phosphorus levels in our bodies. If the parathyroid is overactive, it will produce more PTH that will raise our calcium and lower the phosphorus level. If the parathyroid gland is underactive, it will have the opposite effect.
The most common parathyroid problem is an overactive parathyroid gland, which can be primary or secondary hyperparathyroidism. In primary hyperparathyroidism, the problem starts within the parathyroid gland either with the development of a benign tumor in one or more glands (extremely rarely cancer) or overgrowth of all four glands. The underlying finding is high calcium levels. Low blood calcium, low vitamin D levels, or kidney failure causes secondary hyperparathyroidism. Rarely, patients with kidney failure can develop high calcium due to tertiary hyperparathyroidism.
Underactive parathyroid problems are a result of previous parathyroid or thyroid surgery. Because the parathyroid glands are embedded behind the thyroid gland, it can be inadvertently removed during thyroid surgery, causing hypoparathyroidism.
Signs and Symptoms:
The majority of patients with primary hyperparathyroidism (overactive) are asymptomatic and diagnosed on routine blood tests by their primary care provider. Hence, many patients go undiagnosed. If it remains untreated, it might cause osteoporosis and kidney stones. Other common symptoms are excessive fatigue, anorexia, mild depression, cognitive and neuromuscular dysfunction. It can also cause nausea, vomiting, abdominal pain, peptic ulcer, pancreatitis, excessive thirst, constipation, frequent urination, bone pain and kidney failure. These symptoms are commonly referred to as “bones, stones, abdominal moans and psychic groans.” If left untreated, it can increase the risk of cardiovascular disease like high blood pressure, irregular heart rhythms and other heart problems.
Symptoms from underactive parathyroid include tingling in the hands, fingers and around the mouth. If severe, it can cause muscle cramps, muscle spasm, abnormal heart rhythms and seizures, which can be life-threatening.
Ask your physician to check your calcium and parathyroid if somebody in your family has high calcium or parathyroid problems, or you are diagnosed with a fracture (with minor trauma), osteoporosis or kidney stones.
Diagnosis and Treatment:
A routine blood check for calcium and phosphorus can give hints of parathyroid problems. We also check other lab functions, including vitamin D, kidney function, parathyroid levels and urine calcium levels.
If calcium levels are found to be low your physician will recommend calcium replacement with vitamin D.
Primary treatment for hyperparathyroidism (overactive) is surgery. Many patients can be monitored without surgery unless they are younger than 50, have very high calcium levels, osteoporosis, kidney failure, very high calcium in the urine or have symptoms of hypercalcemia. For a patient who cannot undergo surgery, a medicine that lowers PTH levels and calcium is available. Before going for surgery, your clinician will have to order a few more tests to localize which of the four parathyroid glands are hyperactive.
Localization involves the use of radiological tests to identify the diseased parathyroid gland. The commonly used localizing tests are sestamibi scan (a nuclear medicine test), ultrasound, 4D CT computed tomography and magnetic resonance imaging (MRI). Sestamibi scan will display the hyperactive gland with a very high accuracy of about 90%. Ultrasound is non-invasive and inexpensive. However, the U.S. is operator dependent. Ultrasound helps identify glands in the neck but sometimes are unable to differentiate between thyroid nodules or lymph nodes. Four D CT scan resolution is higher than any other parathyroid scans. These scans are beneficial in patients who have had negative results with the other scans or in re-operative cases. Other imaging modalities like the MRI or the venous sampling are less frequently used. Radiologic studies require a high level of expertise.
The best treatment for primary hyperparathyroidism is the surgical removal of only the affected parathyroid gland. Surgeons will invariably perform the intraoperative parathyroid hormone (iPTH) monitoring to confirm that there is no additional parathyroid tissue, which is hyperactive after excision of the abnormal parathyroid gland. This surgery is typically performed with a small incision on the neck. The cure rate is about 95-98%.
Some surgeons may use video-assisted technique or the radio-guided parathyroid surgery.
hyperplasia is seen in about 10-15% of patients. The surgery includes
the removal of three and a half of the parathyroid glands, also called
subtotal parathyroidectomy. The remnant parathyroid gland is then
auto-transplanted into either the muscles of the neck or the forearm.
Prevention and Precaution:
Unfortunately, there is no way to prevent hyperparathyroidism and the non-surgeryinduced hypoparathyroidism cases. However, you can prevent hypoparathyroidism by choosing non-surgical treatment for thyroid problems when indicated and an experienced thyroid surgeon.
Patients with hyperparathyroidism should hydrate well, avoid dehydration and avoid medicines that cause high calcium, such as lithium and thiazide diuretics. They should remain active to minimize bone loss, take adequate dietary calcium (about 800- 1,000 mg elemental calcium) and vitamin D (400 to 600 units daily). Low calcium intake will stimulate further PTH hormone secretion, which causes more bone loss. Regular follow up with your physician is recommended to monitor for complications of hyperparathyroidism and determine if you are a candidate for surgery.
Patients with hypoparathyroidism need to take an adequate amount of calcium and vitamin D replacement to prevent symptoms of low calcium.
The Department of Otolaryngology/Head & Neck Surgery (Drs. Nathan, Chang and Asarkar), Division of Endocrinology (Drs. Scarborough, Levine and Bhusal) and Radiology Department of (Drs. Yang, Chadha and Nall) at LSU Health Shreveport have expertise in thyroid and parathyroid disorders. Dr. Nathan is president of the American Head and Neck Society that has an active endocrine section, and Drs. Asarkar and Nathan have written a “Best Practice” article featured in ENT Today on molecular testing for thyroid nodules that is routinely performed at Ochsner LSU Health Shreveport. Dr. Lindsay Boven, a resident in ENT, who worked in Dr. Nathan’s lab, just received first place in the National Triologic meeting for research on immune markers in thyroid cancers.