Cushing's syndrome

Cushing's syndrome [ kʊʃɪŋ - ] is an excessive concentration of cortisol in the blood, among other things with elevated blood sugar levels and chronic form typical body shape changes. It was named after the neurologist Harvey Williams Cushing. Besides the described hereinafter Cushing's Syndrome I have other syndromes were found by Cushing, which are sometimes referred to as Cushing's syndrome II and III.

Cushing's Syndrome I

When Cushing's syndrome is physical changes that are caused by high levels of cortisol in the blood ( hypercortisolism ). This is characterized by elevated blood sugar levels and a partial suppression of the immune system. The disease may develop insidiously over many years, which is typically of the trunk increased accumulation of adipose tissue and limbs by muscle wasting be thinner.

A basic distinction is the endogenous and the exogenous Cushing's syndrome. The latter is far more common and is caused by external influences, particularly by long- term use of glucocorticoids.

The much rarer endogenous Cushing's syndrome affects women up to four times more often than men and can occur at all ages. The adrenal cortex produces without encouraged to be too much cortisol ( adrenal autonomy). If the adrenal cortex, however, stimulated by the hormone ACTH stimulation because of a tumor of the pituitary gland is present, the disease Cushing's syndrome is named.

Causes

The causes of Cushing's syndrome may include:

  • The central Cushing's syndrome ( hypothalamic-pituitary ): Increased production of adrenocorticotropic hormone (ACTH ) in the anterior pituitary ( Cushing's disease, Cushing disease ), rarely increased production of CRH in the hypothalamus with subsequently increased Kortikoidfreisetzung from the adrenal cortex.
  • Adrenal Cushing's syndrome: increased secretion of glucocorticoids and mineralocorticoids from the adrenal cortex in the course of neoplasms (adenomas or carcinomas of the adrenal cortex ) with subsequently suppressed ACTH secretion from the anterior pituitary.
  • Ectopic ( paraneoplastic ) Cushing's syndrome: formation of ACTH ( or very rarely CRH) in ectopic tissues, usually as part of a small cell lung cancer.
  • Iatrogenic ( caused by medical treatment ) Cushing's syndrome: onset of symptoms after a regular, systemic administration of ACTH or corticosteroids in the treatment of diseases, such as autoimmune diseases or allergies.
  • Pseudo- Cushing's syndrome ( Cushingoid ): Temporary Cushing's symptoms, for example, in the wake of severe head injuries.

Symptoms

The symptoms of Cushing's syndrome are due to the increased hormonal activity of the corticosteroids on the target tissue. A special form of Cushing's syndrome with similar symptoms is the Achard - Thiers syndrome.

  • " Moon face " (round and reddish)
  • Weight gain by truncal obesity
  • Called " buffalo hump " buffalo neck, caused by accumulation of fat between the shoulders
  • Metabolic condition such as diabetes mellitus with thirst and frequent urination
  • Increased blood pressure, especially arterial hypertension
  • Hypogonadism and power reduction in men
  • Menstrual disorders in women
  • Increased susceptibility to bone fractures due to bone loss, osteoporosis see
  • Rubrae formation of Gewebsstreifen by skin atrophy, striae so-called
  • Muscle weakness, and heart weakness and muscle atrophy
  • Acne and hirsutism
  • Water retention in the tissues (edema)
  • Formation of kidney stones
  • Back pain
  • Increased susceptibility to infection and slow healing of wounds
  • Growth reduction and obesity in children
  • Occasionally, mental changes such as anxiety disorder, or psychosis

Diagnostics

With suspected Cushing's syndrome must first be clarified whether cortisone- containing medications were taken. Through blood, urine and saliva samples corresponding hormone levels can be determined. Especially with the dexamethasone suppression test and the CRH test, a disturbance of the secretion of adrenal cortex hormones are detected. Moreover, searching for tumors, or adenomas, which can cause an endogenous Cushing's syndrome. With computer or magnetic resonance imaging to search for changes in the pituitary gland and the adrenal glands.

  • Physical examination: skin inspection
  • Blood pressure control
  • Kortisolausscheidung in 24- h urine
  • Insulin Hypoglykämietest
  • CRH test
  • Clarification of osteoporosis
  • Representation of the adrenal glands or the pituitary gland (sonography, CT, MRI)

Differentiation pituitary -adrenal - 1 ectopic CRH test: 100 ug corticotropin releasing hormone as an iv bolus; ACTH and cortisol before and after CRH 30, 60, 90 and 120 minutes measure 2 Liddle test: 2 days 0.5 mg dexamethasone po every 6 hours, two days after 2 mg dexamethasone every 6 hours. Daily Kortisolausscheidung in the urine as well as in Serumkortisol concentration on day 3 and 5 by 8 clock in the morning 3 petrosal sinus sampling: catheter in inferior petrosal sinus on both sides. ACTH, cortisol and prolactin may simultaneously ago from petrosal sinus left and right and from peripheral vein and 2, 5 and 10 minutes after CRH

Cushing - threshold dose

In the literature the Cushing threshold dose is given to the potency of 7.5 mg prednisone or 30-40 mg ( for men), 15-30 mg ( for women) cortisol per day.

In children, the Cushing threshold dose is 6 mg / m² body surface area / day Prednisonäquivalent (prednisone is approximately four times as potent as cortisol). This describes the daily maintenance dose, just not a Cushing's syndrome should be applied. However, this information is intended as a rough guide, there is considerable inter-individual differences. An absolute lower limit below which the glucocorticoid therapy is to be regarded as safe, does not exist. Topically applied ( on the skin) Glukokortikoidpräparate cause most likely no Cushing's syndrome because they penetrate only a very small part of the skin barrier. Nevertheless, it is recommended to limit the therapy to a maximum of 20% of body surface area and to be cautious in applying the face or eye.

Therapy

The treatment depends on the cause of Cushing's syndrome: Adenomas of the pituitary or the adrenal glands are surgically removed; the treatment of choice for a adrenocortical hyperplasia is the adrenalectomy and a subsequent lifelong hormone replacement to avoid the formation of Addison's disease.

In veterinary medicine, the treatment of the disease is usually made ​​only with drugs that reduce the activity of the adrenal cortex. Method of choice here is trilostane. Furthermore, a treatment by means of DDT descendant mitotane and also about the antifungal agent ketoconazole is possible.

Cushing's syndrome II

Cushing's syndrome II is a rare disease in which causes a tumor in the region of the pons or cerebellum ipsilateral lesions of the cranial nerves VI, VII and VIII. Deficits of the cerebellum and intracranial pressure are also described in this disease. The current name is the cerebellum bridges symptoms.

Allergy Achard–Thiers syndrome
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