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Pituitary and hypothalamic diseases
Dr.Malith Kumarasinghe MBBS( Colombo)
Overview Anatomy and physiology Pituitary disorders Hypothalamic disorders
Pitutary gland
Location Sella turcica Floor of the brain
Parts of the Pituitary Gland
Anterior Pituitary Posterior Pituitary
Anterior Lobe Hormones
Growth Hormone Prolactin Thyroid Stimulating Hormone - TSH AdrenoCorticoTrophic Hormone - ACTH Follicle Stimulating Hormone Lutenizing Hormone
Posterior pituitary hormones Oxytocin
Milk ejection mechanism Uterine Contraction
Vasopressin or ADH
Hypothalamus
Lies superior to the pituitary at the base of the brain
Hypothalamic functions
homeostasis. controls the autonomic nervous system, regulates eating and drinking, controls
body temperature controls pituitary gland secretions.
Hypothalamic actions on the pituitary
Posterior pituitary
The hypothalamic nuclei produce ADH and oxytocin. These move down the axon and are stored in the posterior pituitary. Following stimulation of the hypothalamus these hormones are then released into the bloodstream.
Anterior pituitary
the hypothalamus is linked to the anterior pituitary by a network of microcapillaries - Control is maintained by release of hypothalamic hormones, some of which stimulate release and others inhibit release of pituitary hormones
Hypothamo pituitary axis
Pituitary disorders Tumorsprimary-benign -non functional
-adenomas-macroadenoma/microadenoma
-malignantsecondary
Infections Infiltrative diseases-TB Vascular disorders-Sheehans
syndrome
Pituitary tumors-features
Pituitary tumors-features Pituitary tumors may produce one
or more hormones causing endocrine dysfunction
Some pituitary tumors compress rest of the gland causing deficiency of hormones
Pituitary tumors-features
Symptoms caused by pressure from a larger pituitary tumor
Headache Visual changes
Double vision Visual field loss
Hypopituitarism-deficiency of pituitary hormones Causes
Pituitary tumour Sheehan’s syndrome TB,sarcoidosis
GH deficiency High body fat content fracture risk Fatigue, muscle weakness
Gonadotrophin deficiency Male
testicular volume Loss of facial & body hair sexual function and libido
Female Amenorrhoea Vaginal dryness
ACTH deficiency Weakness, tiredness Hypotension Vomiting Hypoglycaemia Hyponatraemia Myalgia
TSH deficiency Features of hypothyroidism
Investigation of hypopituitarism
Prolactin TSH Cortisol Testosterone/Estradiol LH, FSH IGF-1, GH Water deprivation test (assess ant
pituitary hormones first)
Treatment of hypopituitarism
Growth hormone defficiency-Recombinant GH S-C injections
ACTH Deficiency- Hydrocortisone-IV/oral TSH Deficiency-Thyroxin Gonadotrophin Deficiency
- Female estrogen /progesterone
-Male Testsosterone: injection
Diabetes insipidus Absence/defficincy of ADH 30-50% idiopathic Trauma, tumours Clinical features
Polyuria: urine output > 3 litres/day
Investigation, treatment
Water deprivation test Normal: urine osmolality rises in water
deprivation DI: Urine fails to concentrate ADH deficiency: urine osmolality with
desmopressin Nephrogenic DI: no response to desmopressin
Treatment Desmopressin
Nasal fluid/aerosol, tablet
Pituitary hormone excess
GH excess Causes
Pituitary tumour causing high growth hormone secretion
gigantism
Excessive GH Production during childhood causes increased height
acromegaly
When growth hormone excess occurs in adulthood
Clinical features Enlargement of hands, altered shoe and
ring size sweating Thyroid enlargement Sleep apnoea Diabetes, hypertension Colonic polyps, GI malignancies
Prior
Early Onset
Full Development
Treatment Surgery: Usually transsphenoidal Radiotherapy Somatostatin analogues
Octreotide/Lanreotide:
Hyperprolactinaemia Can occur due to-prolactin secreting pituitary
tumour(prolactinoma)-disconnection hyperperolactinemia-commonly
due to non functioning pituitary tumors
Hyperprolactinaemia: Reproductive function Nipple discharge
Treatment Dopamine agonists:
Bromocriptine
Surgery
Cushing’s disease Due to high ACTH Usually microadenoma
Central obesity Proximal weakness Osteopenia hypertension Purple striae
Treatment Pituitary surgery
Radiotherapy
Hypothalamic disorders Causes-trauma-malignancy-malnutrition-anorrexia nervosa
Features Endocrine dysfunction Eating disorders Problems related to autonomic
control
Questions ….