Sheehan's syndrome overview
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Iqra Qamar M.D.[2]
Overview
Sheehan's syndrome is a life-threatening complication of severe postpartum hemorrhage (PPH) and results in mild to severe hypopituitarism. It is less prevalent in developed countries, but it is still one of the most common causes of hypopituitarism in underdeveloped and developing countries. During pregnancy, enlarged size of pituitary gland and decreased blood supply to it due to any causes can result in ischemic necrosis of pituitary gland. Severe PPH, glandular hypertrophy and hyperplasia, smaller sella size, autoimmunity, and disseminated vascular coagulation (DIC) are thought to play an important role in the pathogenesis of Sheehan's syndrome. The most common causes include massive hemorrhage during parturition, vascular compression, and vascular occlusion. Sheehan's syndrome needs to be differentiated from diseases causing hypopituitarism and other diseases like lymphocytic hypophysitis, pituitary apoplexy, hypothyroidism, addison's disease, empty sella syndrome, hypogonadotropic hypogonadism, simmond's disease, hypoprolactinemia, and menopause. Risk factors causing Sheehan's syndrome include pregnancy, severe/massive PPH, pituitary mass, pre-existing vascular diseases, smaller and rigid sella, traumatic delivery, multiple gestations, placental abnormalities, and type 1 Diabetes. Sheehan's syndrome, if left untreated lead to panhypopituitarism and empty sella syndrome. Common complications include adrenal crisis, hypotension, hypothyroidism, and hypopituitarism. Prognosis is generally excellent, providing early diagnosis and management may result in complete reversal of symptoms. Diagnosis of Sheehan's syndrome is made on clinical basis with a recent/remote history of traumatic delivery or delivery complicated by hypotension. The most common presentations are including postpartum lactation failure, amenorrhea, loss of sexual hair, fatigue, anorexia, and weight loss. Clinical features depend on the severity of hypopituitarism that results from Sheehan's syndrome. Almost all the patients have GH, prolactin, and gonadotropin deficiency; and the majority has ACTH and TSH deficiency. Laboratory evaluation gives a picture of partial or panhypopituitarism. Laboratory findings consistent with diagnosis of Sheehan's syndrome are including hyponatremia, hypokalemia, hypocalcemia, hypomagnesemia, hypophosphatemia, anemia, pancytopenia, eosinophilia, hypoalbuminemia, low fasting plasma glucose, and decreased levels of anterior pituitary hormones (free thyroxine, estradiol, and cortisol levels). The most sensitive test is inadequate prolactin and gonadotropin responses to stimulation. ECG findings associated with Sheehan's syndrome are including QT interval prolongation, Type-1 Brugada-like ECG pattern (due to adrenal crisis), findings suggestive of cardiac tamponade (sinus tachycardia, low voltage QRS, and electrical alternans), and dilated cardiomyopathy. CT scan findings in case of acute presentation of Sheehan's syndrome may show non-hemorrhagic pituitary gland enlargement, while chronic presentation may show an empty sella or decreased sellar volume. Findings on MRI suggestive of Sheehan's syndrome are including decreased sellar volume, empty sella, pituitary remnant tissue or CSF in the sella.Treatment involves appropriate hormone replacement therapy, which must be taken for the rest of your life, results in significant improvement and reversal of not only the physical symptoms, but also the psychological symptoms.
Historical Perspective
Sheehan's syndrome was first discovered by Leon Konrad Gliński about a century ago and it was named after Harold Sheehan (1900-1988).
Classification
There is no established system for the classification of Sheehan's syndrome.
Pathophysiology
It is thought that Sheehan's syndrome is the result of ischemic necrosis of pituitary gland, due to pituitary gland enlargement during parturition; precipitated by hypotension due to massive hemorrhage. Apart from pituitary gland enlargement during and before parturition, vasospasm, generalized Schwartzman phenomenon, thrombosis and compression of the hypophyseal arteries, autoimmunity, DIC, and smaller size of sella are thought to play a contributing role in pathogenesis of Sheehan syndrome.Occlusion and other vascular anomalies of the hypophyseal portal system can also cause complications in the exchange of hormones between the hypothalamus and the pituitary gland, leading to hypopituitarism. Sheehan's syndrome may result in mild to severe pituitary dysfunction (partial or panhypopituitarism), which is identified with growth hormone (GH), thyroid hormone, glucocorticoid, gonadotropins, and prolactin hormone deficiencies; manifests as a wide spectrum of presentation. Usually, GH is the earliest one to be lost.
Causes
Common causes of Sheehan's syndrome are including massive hemorrhage, hypotension during pregnancy, vascular compression, and vascular occlusion (thrombosis, DIC). Less common causes are including vascular insufficiency due to cronary artery bypass grafting (CABG) in older patients and snake bites (Russell's viper bites).
Differentiating Sheehan's syndrome from Other Diseases
Sheehan's syndrome must be differentiated from lymphocytic hypophysitis, pituitary apoplexy, hypothyroidism, Addison's disease, panhypopituitarism, empty sella syndrome, hypogonadotropic hypogonadism, Simmond's disease, hypoprolactinemia, and menopause.
Epidemiology and Demographics
The incidence of Sheehan's syndrome is difficult to assess. It was found to be the 6th most common cause of GH deficiency with an incidence of 3.1% of cases. In 2009, the prevalence of Sheehan's syndrome was estimated to be 5.1 per 100,000 women. It is less prevalent in developed countries due to better obstetrical care and maternal health awareness. It is still one of the most common causes of hypopituitarism in developing countries.
Risk Factors
Common risk factors in the development of Sheehan's syndrome include pregnancy, severe/massive PPH, pituitary mass, pre-existing vascular diseases, autoimmunity, type 1 diabetes, DIC, smaller and rigid sella, multiple gestations, placental abnormalities, and traumatic delivery.
Screening
There is insufficient evidence to recommend routine screening for Sheehan's syndrome.
Natural History, Complications, and Prognosis
Sheehan's syndrome, if left untreated lead to hypopituitarism and empty sella syndrome. Common complications are including adrenal crisis, hypotension, hypothyroidism, and hypopituitarism. Prognosis is generally excellent provided early diagnosis and management resulting in complete reversal of symptoms.
Diagnosis
Diagnosis is made on clinical basis with a recent/remote history of traumatic delivery or delivery complicated by hypotension. Diagnosis is mostly clinical but detailed medical history, measurement of pituitary hormone levels in blood, pituitary hormone stimulation tests and imaging (MRI preferred on CT) studies can help in making the diagnosis.
History and Symptoms
The most common symptoms of Sheehan's sydrome are including agalactorrhea and failure to resume menstruation after parturition. Common symptoms are including hot flushes, decreased pubic/axillary hair, hypotension, hypoglycemia, features of hypothyroidism, hypoadrenalism, and hypogonadism.
Physical Examination
Patients with this syndrome usually appear fatigued and lethargic. Physical examination is usually remarkable for bradycardia, hypotension, pallor, and signs suggestive of respective hormonal deficiency.
Laboratory Findings
Laboratory findings consistent with the diagnosis of Sheehan's syndrome include hyponatremia, hypokalemia, hypocalcemia, hypomagnesemia, hypophosphatemia, anemia, pancytopenia, eosinophilia, hypoalbuminemia, low fasting plasma glucose, and etc.
Electrocardiogram
ECG findings associated with Sheehan's syndrome can include QT interval prolongation,Type-1 Brugada-like ECG pattern (due to adrenal crisis), findings suggestive of cardiac tamponade, dilated cardiomyopathy (multifactorial).
X-ray
There are no X-ray findings associated with Sheehan's syndrome.
CT scan
Acute presentation shows non-hemorrhagic pituitary gland enlargement while chronic presentation shows an empty sella or decreased sellar volume.
MRI
Findings on MRI suggestive of Sheehan's syndrome are including decreased sellar volume, empty sella, pituitary remnant tissue, or CSF fluid in sella.
Ultrasound
Echocardiography findings associated with Sheehan's syndrome may include reversible dilated cardiomyopathy and pericardial effusion.
Other Imaging Findings
There are no other imaging findings associated with Sheehan's syndrome.
Other Diagnostic Studies
There are no additional diagnostic findings for Sheehan's syndrome.
Treatment
Medical Therapy
Treatment involves appropriate hormone replacement therapy that results in complete recovery and reversal of symptoms.
Surgery
Surgical intervention is not recommended for the management of Sheehan's syndrome.
Primary Prevention
Effective measures for the primary prevention of Sheehan's syndrome are including improved obstetrical care and perinatal monitoring, prevention of pregnancy related complications, maternal awareness about Sheehan's syndrome and risk factors causing it, and post-puerperal follow up.
Secondary Prevention
Effective measures for the secondary prevention are including early diagnosis and treatment to prevent life threatening complications.