Hypoparathyroidism

00:01 Our topic still continues with hypoparathyroidism.

00:03 Botched thyroidectomy… apart from where the patient initially might have started with primary hyperparathyroidism and there might have been inadvertent, excessive parathyroidectomy resulting in hypoparathyroidism.

00:17 If the patient is required to have a thyroidectomy because of its proximity to the parathyroids may result in excess or collateral damage to the parathyroids rendering your patient hypoparathyroid, hypocalcemic.

00:34 Congenital deficiency... here, you should be thinking about DiGeorge syndrome.

00:38 You have your chromosome 22, a long arm 11 deletion, therefore third and fourth pharyngeal pouches are missing, no parathyroids are present.

00:46 In addition, the third pharyngeal pouch responsible for developing the inferior parathyroids, the patient, the child is hypocalcemic; in addition, the thymus does not form properly.

00:57 Therefore; look for a child that is suffering from tetany, hypocalcemia; result in tetany, muscle twitching.

01:06 In addition, there might be recurrent infection.

01:08 Usually, it will be the viral type; malformed third and fourth pharyngeal pouches resulting in hypoparathyroidism.

01:19 Abnormal facies, sometimes with your chromosome 22, you want to be familiar with the syndrome congenitally that the boards love asking about called velocardiofacial abnormalities.

01:32 The velocardiofacial abnormalities may result in facies issue, congenital heart defects and cognitive behavior and psychiatric problems, autism.

01:44 Velocardiofacial issues with chromosome 22, something that you want to know from a embryologic, pathologic point of view.

01:54 Increased susceptibility to infection, why is that? Because the thymus may not be present, inadequate education of your T-cells, therefore rendering the patient susceptible to infection, the child.

02:06 Other causes of hypoparathyroidism: Idiopathic, autoimmune disease resulting in parathyroid destruction. Here’s an interesting example to keep in mind: Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome, also known as polyglandular autoimmune syndrome type 1, is an inherited disorder that causes hypoparathyroidism and is associated with chronic mucocutaneous candidiasis and adrenal insufficiency.

02:37 Lastly, infiltrative diseases are a rare cause, such as hemochromatosis, Wilson disease, granulomatous disease, or metastatic cancer.

02:48 Clinical features include the following: whenever there is decrease in parathyroid, there will obviously be decrease in calcium and therefore, the muscle, the skeletal muscle is extremely sensitive to certain tapping.

03:03 Tapping of the facial nerve may result in contraction of muscles of the eyes, nose and mouth and we then refer to as being Chvostek sign.

03:13 There might be circumoral numbness or paraesthesia of distal extremity and perhaps carpopedal spasms, especially when there is a, let’s say, a brachial cuff that is placed around the arm.

03:27 Mental status changes, QT prolongation might be seen with hypoparathyroidism and hypocalcemia; serum calcium will be low here because there’s decreased levels of PTH; decreased ability to properly evacuate the phosphate from your kidney.

03:44 So, therefore, there will be increased phosphate levels.

03:48 In addition, because of decreased PTH in circulation, the osteoclasts will not function as well as they should.

03:58 And so, therefore, there will be thickening of the bone.

04:01 The thickening of the bone, pay attention here, we’re now referring to osteoporosis, this is osteosclerosis and that to you should indicate or def-defines thickening of your bone.

04:15 Topic… hypoparathyroidism.