Global pituitary failure – Sheehan syndrome
Global pituitary failure (Sheehan’s and Simmond’s syndrome) is a severe condition, of complex etiology and with repercussions on the most endocrine glands. Affects most endocrine glands and is due to a disorder in pituitary trope hormones secretion (TSH, FSH, LH, ACTH).
The etiology of this disorder is complex including pituitary tumors, neuroinfections (encephalitis, meningitis), head trauma, immunological causes (autoimmune), iatrogenic causes (neurosurgical interventions, pituitary radiotherapy) and vascular causes (pituitary necrosis).
In the global pituitary failure have been described two forms: Sheehan’s syndrome and Simmonds disease (pituitary cachexia).
Pituitary necrosis which is installed as a result of dystocia deliveries with large blood loss is common feature in terms of the etiology of these diseases. In addition to pituitary necrosis, in Simmonds’s disease, extensive lesions appear in the hypothalamus.
The pituitary necrosis occurs because during pregnancy there is a hyperplasia (cell multiplication) of prolactin-secreting cells and a pituitary hypervascularization. Thus, if the birth will produce serious bleeding, this will lead to hypovolemic shock installation which will then determine a vasospam at pituitary level and pituitary necrosis later.
Symptoms and signs
Clinical manifestations appear when it is destroyed over 75% of the hypophysis.
Both conditions have the first clinical sign: no lactation followed by amenorrhea (absence of menstruation) and a series of desexualisation phenomena (axillary and pubic hair loss, genital tract involution, frigidity, sexual indifference, breast atrophy).
Sheehan syndrome, in the intermediate period has as clinical features, in addition desexualisation phenomena, anorexia, asthenia, weight loss, multiple trophic disorders (mild infiltration of the skin, thinning of the external edge of the eyebrow, depigmentation of skin and mammary areola). After a development more or less long, some cases may pass into the major form of pituitary cachexia.
Simmonds disease (pituitary cachexia) has about the same symptoms and clinical signs as Sheehan’s syndrome but much more pronounced.
Patients have anorexia with weight loss (1-5 kg / month) which during the terminal period is extreme (20 – 30 kg), giving the patient a skeletal appearance. The skin is dry, waxy pallor, hair falls everywhere, break nails, teeth fall. Pulse is bradycardic (decreased heart rate below normal 60 contacts / minute), the patient has hypotension and accuses cold.
All this symptoms are due to repercussions of pituitary necrosis on the activity of peripheral secretory glands, the intensity of symptoms depends on the degree of damage to these glands.
Investigations necessary to support the diagnosis of pituitary global failure are hormonal dosages (pituitary tropes, thyroid hormones, adrenal hormones, estrogen) that betrays a multiple glands failure and a series of investigations to demonstrate metabolic abnormalities (hypochromic anemia, hypoglycemia, low cholesterol, low Na, K increased).
If global pituitary failure etiology is thought to be of a tumor then is needed an X-ray of the Turkish saddle, which confirms the diagnosis.
Treatment is hormones replacement (cortisol or prednisone, thyroxine, pills for women and testosterone for men).