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Panhypopituitarism
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Dr. D.S. Merchant is a Gold Medalist in (Anatomy & Histology), For more articles on Panhypopituitarism or Pituitary Tumor visit www.articlesbridge.com is a popular website that offers information on Pulmonary Disease, Mesothelioma Symptoms, VHF Solutions, and VHF Medications. Please leave the links intact if you wish to reprint this article.

• Hypopituitarism can present with complete or partial deficiency of anterior and/or posterior pituitary hormones.

• Panhypopituitarism refers to the situation in which more than 80% of the anterior pituitary is lost.

Aetiology
• neoplasms in the suprasellar region:
– pituitary adenoma in adults
– craniopharyngioma in children
– glioma
– meningioma
– metastatic cancer


• infiltration:
– sarcoid
– histiocytosis X
– haemochromatosis
• infection:
– tuberculous meningitis
– syphilis
– encephalitis


• vascular:
– Sheehan's syndrome (post-partum infarction)
– pituitary apoplexy
– carotid artery aneurysms
• autoimmune
• iatrogenic:
– surgery
– radiotherapy
– chemotherapy


• miscellaneous:
– head injury
– empty sella syndrome
– emotional deprivation
– starvation & anorexia nervosa
Clinical Features
• loss of anterior or posterior pituitary hormones
• local effects in the region of the pituitary fossa



• headache
• visual field defects:
– most commonly a superior bi-temporal quadrantanopia
– progressing to a bitemporal hemianopia

• cerebrospinal fluid rhinorrhoea d/t inferior extension of the tumour

• III, IV and VI nerve palsies due to lateral extension of the tumour



• loss of anterior pituitary hormones is usually partial and occurs in the order:

• Growth Hormone Deficiency:
– pituitary dwarfism in children - diminished skeletal growth, retarded sexual development, normal intelligence, hypoglycaemic episodes
– wrinkling of skin, tendency to hypoglycaemia in adults


• Gonadotrophin Deficiency:
– delay in puberty in children
– amenorrhoea, impotency, loss of libido in adults

• TSH Deficiency:
– isolated TSH deficiency is very rare
– secondary hypothyroidism - sensitivity to cold, dry skin, physical and mental sluggishness, coarseness of hair


• ACTH Deficiency:
– decreased skin pigmentation
– poor appetite, nausea, vomiting, fatigue, muscle weakness, loss of axillary and pubic hair in females

• Prolactin Deficiency:
– failure of lactation in post-partum patients


• Loss of posterior pituitary hormones:

• ADH Deficiency:
– polyuria, thirst

Investigations:
• basal levels of T4, T3, TSH, prolactin, gonadotrophins, testosterone, cortisol,

• U+Es (dilutional hyponatraemia),

• FBC (normochromic normocytic anaemia).

• assessment of visual fields
• skull radiology
• CXR may show signs of a primary tumour that has produced metastases, sarcoidosis or tuberculosis
• MRI/CT scan

[combined pituitary test]
• absence of the normal rises in gonadotrophins, TSH and cortisol after GnRH, TRH and insulin injection.

• a basal cortisol measurement MUST be made before undertaking a C.P.T. in patients suspected of hypopituitarism

• If cortisol is already low, insulin could be dangerous and ACTH should be measured to differentiate between primary and secondary hypocortisolaemia

• alternatives testing agents include metyrapone, glucagon or depot synacthen.

Treatment
• Sex Hormones:
– cyclical oestrogen with low-dose progesterone if uterus intact in women; if premenopausal, consider an oral oestrogen contraceptive since ovulation and conception may occur in hypopituitarism
– testosterone in men - depot or subcutaneous
• Thyroxine - 100-200 mcg daily in a single dose
• Hydrocortisone - 10-20 mg in the morning, 10 mg in late afternoon - mineralocorticoids not needed

• Growth hormone replacement therapy in adults
• Intranasal desmopressin if diabetes insipidus - 10 mcg once or twice daily

• Note that if there is combined adrenal and thyroid failure, an adrenal crisis may be precipitated by starting thyroxine replacement before corticosteroids

Follow-up
• Review should be every 6-12 months or more frequently if there is progressive pituitary damage.

• measure sex hormone levels and ask about:
– libido
– potency
– secondary sexual characteristics
• corticosteroids
• thyroxine
• measure growth hormone levels and check:
– growth velocity
– skeletal radiographs, for epiphyseal closure
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