There is a significant risk for hypoparathyroidism when a total thyroidectomy, bilateral subtotal thyroidectomy and central node dissection are done.
Postoperative hypoparathyroidism results in hypocalcemia. These are usually manifested as:
- Numbness and tingling sensations in the perioral area or in the fingers and toes.
- Twitching of the facial muscles in response to tapping over the areas of the facial nerve.
- Muscle cramps, particularly in the back and lower extremities; may progress to carpopedal spasm
Chvostek’s sign is the twitching of the facial muscles in response to tapping over the area of the facial nerve.
Trousseau’s sign is carpopedal spasm caused by inflating the blood-pressure cuff to a level above systolic pressure for 3 minutes.
- Positive Trousseau’s sign is indicated when carpopedal spasm occurs. This is the flexion of the metacarpophalangeal joints, and wrist, adduction of fingers and thumbs, as well as extension of the interphalangeal joints.
- Paresthesias located at the fingers may also be felt by the patient.
Administration of calcium alleviates the symptoms.
In 1991, I wrote my personal experience on gross identification of the parathyroid glands. I was advocating surgeons learning how to identify and recognize parathyroids so as to avoid hypoparathyroidism and to be prepared to do operation on the parathyroids.
Gross Identification of the Parathyroid Glands
Philippine Journal of Surgical Specialties
VoL 46 No. 3
July to September, 1991
How to avoid hypoparathyroidism during thyroid surgery –
l. Know where the usual locations of the parathyroid glands, superior and inferior.
2. Know how to recognize them (brownish and pea size).
3. Preserve the blood supply, usually coming from the inferior thyroid artery and at times from the superior thyroid artery – do capsular dissection as much as possible, do not ligate the inferior thyroid artery too laterally.
4. Do not go all out to positively identify the parathyroids during a thyroidectomy as to do so will damage the blood supply.
Chvostek’s sign picture – courtesy of: http://www.ihealthblogger.com/hypocalcemia-definition-symptoms-causes-tests-ecg-and-treatment