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19 Cards in this Set
- Front
- Back
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Relationship between the parathyroid glands and the lateral lobe of the thyroid gland
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Posterio-lateral relationship
Two superior parathyroid glands arise from the fourth branchial arch and have a relatively constant position relative to the lateral lobe. Inferior- arise from the third pharingeal arch and descent with the thymus very variable in position and may be found within or adjacent to the thymus or within the superior mediastinum |
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How common are ectopic/supranumary parathyroid glands?
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common, found in >10% of the population- may even be located in the pericardium or within the carotid sheath
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What happens to parathyroid glands as they enlarge?
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migrate from their original location
superior move down the oesophagus- posterior to RLX inferior - ,oce anteriorly, anterior to RLX |
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Blood supply to the parathyroid glands?
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branches of the inferior thyroid artery
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T 1/2 of PTH
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5 min
Broken down by reticuloendothelial cells of the liver |
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Cause of primary hyperparathyroidism
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single or multiple parathyroid adenoma in >90% if cases
Other causes: parathyroid hyperplasia, parathyroid carcinoma previous history of ionising radiation |
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Workup once primary hyperparathyroidism has been confirmed
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Sestamibi scan- will show single adenoma in >70% of cases
neck ultrasound- provides additional info |
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Management of hyperparathyroidism
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Parathyroidectomy unless specific contraindications to surgery
Evidence that this provides neuropsychiatric benefit even in "asymptomatic" patients |
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Clinical features more likely to be found in secondary vs primary hyperparathyroidism
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painful osteodystrophy with deposits of calcium in the soft tissues resulting in skin itch, necrosis and severe conjunctivitis
Much more gross skeletal changes than in primary- irregular bone density loss and irregular deposition of bone with metastatic calcification |
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Cause of primary hyperparathyroidism
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single or multiple parathyroid adenoma in >90% if cases
Other causes: parathyroid hyperplasia, parathyroid carcinoma previous history of ionising radiation |
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Workup once primary hyperparathyroidism has been confirmed
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Sestamibi scan- will show single adenoma in >70% of cases
neck ultrasound- provides additional info |
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Management of hyperparathyroidism
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Parathyroidectomy unless specific contraindications to surgery
Evidence that this provides neuropsychiatric benefit even in "asymptomatic" patients |
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Clinical features more likely to be found in secondary vs primary hyperparathyroidism
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painful osteodystrophy with deposits of calcium in the soft tissues resulting in skin itch, necrosis and severe conjunctivitis
Much more gross skeletal changes than in primary- irregular bone density loss and irregular deposition of bone with metastatic calcification |
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What percent of patients will not adequately respond to optimal medical management of secondary hyperparathyroidism
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20%
Indications for surgery include the development of hypercalcaemua, and persistent elevations in ALP clinically: intractable itch and bone pain |
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Most common clinical scanario where tertiary hyperparathyroidism is observed?
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after successful renal transplant- calcium metabolism fails to return to normal within 6m
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Most common scenario of hypoparathyroidism and management
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Post thyroid surgery
Manage with oral Ca and Vit D Recovery may occur after several weeks |
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Indications for minimally invasive vs open parathyroidectomy
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minimally invasive: if localise to single site
open: with primary where localisation has not been sucessful, means that it is likely to be multifocal |
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In what percentage of patients is parathyroidectomy unsucessful?
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2% - usually means that parathyroid lies in ectopic position such as the pericardium or middle mediastinum. Will need localisation studies sich as CT/selective venous sampling prior to a 2nd operation.
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Concequences of damage to the external branch of the superior laryngeal nerve
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Patient may lose ability to shout, sing, project voice
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