Description of Cushing’s syndrome
Cushing’s syndrome is an endocrine disorder characterized by increased production of cortisol, a steroid hormone produced by the adrenal glands. Its necessity is to regulate carbohydrate metabolism and also in improving glycemic control (blood glucose) in the morning and in stressful situations.
Among other things, cortisol used in the therapy of autoimmune diseases, namely the suppression of immune reactions.
An interesting feature is its cortisol diurnal cycle with highest levels in the early morning and the lowest levels at about midnight, which is also used in diagnosis.
Cushing’s disease is not entirely correct alternate name because it refers only to a subset of Cushing’s syndrome. While cortisolexcreted adrenal, as already mentioned, however adrenals are in turn controlled by another body – hypophysis (pituitary Czech) and one of its secreted hormones termed abbreviation ACTH.Pituitary receives impulses for the production of ACTH from thehypothalamus, which is also part of the brain and holds many autonomic and hormonal functions.
Creation of a stress hormone called is thus determined. Axis hypothalamic – pituitary gland – the adrenal gland. The disease can occur at the level of the brain (hypothalamus and pituitary), then this is the Cushing’s disease, ACTH is produced in excess and the more stimulated to adrenal production of cortisol.
Or may fail to occur at the level of the very adrenal glands,which are no longer dependent on the production of ACTH and cortisol you produce, how they want, when there is a surplus again. It also attenuates ACTH production, because even in a healthy organism when it has enough cortisol, ACTH production is suppressed and feedback system again restored when the body has a deficiency of cortisol. This form of the disease, when “to blame” the adrenal gland is considered as Cushing’s syndrome (not a disease) in the strict sense.
There are other forms of Cushing syndrome – e.g. called. Paraneoplastic syndrome – some tumors produce a hormone ACTH, which in turn raises the level of cortisol.
Risk factors and prevention of Cushing’s syndrome
Cushing’s syndrome can occur on the basis of several factors. Called. Iatrogenic Cushing’s syndrome develops excessive application of corticosteroids in the treatment of other diseases such as rheumatoid arthritis, systemic lupus erythematosis, hemolytic anemia, idiopathic thrombocytopenic purpura, asthma bronchiale (there are fortunately applied nowadays topical forms of medication – inhalers, that are not so defective) and chronic inflammatory bowel disease – Crohn’s disease and ulcerative colitis. Similarly, the corticosteroid used in the treatment of certain cancers (leukemia).
After discontinuation of corticosteroids (but must be discontinued gradually – gradually reducing the dose, otherwise worsening of the underlying disease for which the patient was taking steroids) usually disappear as symptoms of Cushing’s syndrome.
It can not however recommended not to take corticosteroids to prevent Cushing syndrome when the treatment of the patient’s disease necessary. The doctor certainly well consider whether you prescribe corticosteroids, it would certainly did not contemplate them unnecessarily. Sami can be avoided, for example, advertisements for cosmetic or dermatological preparations containing corticosteroids to certain dermatological companies.
The most common cause of Cushing’s disease is a tumor of the pituitary gland. Outside the pituitary tumor or enlargement may also affect the adrenal gland, which results in a direct increase in the formation of corticosteroids (Cushing’s syndrome has been mentioned in the strict sense).Tumors arise on the basis of DNA damage cells producing hormones either in the pituitary or adrenal glands (there may be a small percentage of cases, be a simple magnification – hyperplasia, which is not a tumor, but it is present in both adrenal glands). Their origin is generally applied genetic factors and environmental factors (radiation, chemical carcinogenic substances, etc.). Specific prevention of these tumors, however, is unknown.
Signs and symptoms of Cushing’s syndrome
The main symptoms of Cushing’s syndrome include weight gain due to persistently elevated blood sugar levels (hyperglycemia). Body fat is stored mainly in the abdomen, neck and face.
In the face creates a typical appearance měsíčkového face. Storage of fat around the cervical spine is formed hump (ie. Buffalo hump). On the abdomen and buttocks is greater fat reserves manifests as skin visible changes in the appearance of stretch marks (gray rose, surface cracking of the skin that bleed), caused by the growing belly. Some patients even belly hurts.
Further problems associated with a higher level of sugar is increased blood pressure, the possibility of developing diabetes and related symptoms associated therewith as unquenchable thirst and its upper bound need to urinate. Increased amounts of cortisol can enhance the activity of mineralocorticoid and thereby disrupt the management of minerals. Among them prevails potassium or calcium as an important structural element of bones.
Calcium loss can lead to osteoporosis.
To all become associated with psychological symptoms manifesting as depression, vague fears, fatigue. They also observed headache and loss of libido in both men and women. Women have tomenstrual cycle disorders, increased hair loss and sometimes hirsutism – increased growth of pigmented hairs (on the cheeks, upper lip, chin and other locations). Hirsutism is typical for adrenal involvement, ie not for Cushing’s syndrome caused by a pituitary tumor. Otherwise the symptoms of both are very similar.
For pituitary tumors, which applies pressure on the optic nerve can cause the loss of part of the visual field, resulting in a narrow space in the view (like looking in a tube).
Examination of Cushing’s syndrome
In suspected elevated cortisol levels in blood uses special endocrinological tests. One isdexamethazone test. Its principle consists in the administration of a glucocorticoid analogue (cortisol-like substances) – dexamethasone and subsequent measurement of the amount of cortisol in the blood (blood collection).
Other tests use urine cortisol excretion (urine test) or circadian variability of its production – removes blood midnight when to its very low levels, if they are higher, suggesting Cushing’s syndrome.
For pituitary tumors that threaten the patient’s vision is always necessary examinations by ophthalmologists (perimeter).
To distinguish between the two main forms of hypercortisolism, ie whether the pituitary or adrenal disease is used to determine the level of the hormone ACTH in the blood that increases in pituitary tumor is low and vice versa for adrenal disorders.
To confirm and refine further use of CT scans. For the loss of visual field and the associated pituitary tumor is indicated by MRI (magnetic resonance imaging). Pituitary tumors are benign (ie. Adenomas), they are not malignant – not growing too fast, metastasize, and their treatment is quite simple.
Treatment of Cushing’s syndrome
Treatment depends depending on the cause. For iatrogenic Cushing’s syndrome caused by the need to reduce corticosteroids.
In the case of tumors, elevated levels of cortisol is feasible only operation. After surgery, pituitary gland, which is now performed transnasal (ie. Through the nasal cavity, not open, therefore skull, as one might with a brain tumor just imagine), it is necessary to give some time replacement steroid therapy to restore normal function of the adrenal long were stimulated with high doses of ACTH.
In the event of failure of neurosurgery solutions to patients allowed to irradiate called. Leksell Gamma Knife, a radiation (no surgery that could give rise to the word “knife”, it is meant only figuratively) which operate only locally, not damaging the surrounding brain structures, it is therefore very safe and also effective.
In the case of tumor removal affected adrenal requiring continued substitution corticosteroid. If for any reason you can not perform the surgery (just as if you failed treatment of a pituitary adenoma that procedure) started drug therapy consisting of the administration of drugs that block steroidogenesis – the production of glucocorticoids (eg. Ketoconazole, metyrapone, adrenal carcinomas also mitotane).
Cushing’s syndrome is a serious disease especially for their cardiovascular risk factors(hypertension, diabetes, etc.). The prognosis of the disease depends on the timeliness of diagnosis and treatment on its method and result. The prognosis of tumors of the adrenal gland is often compared adenomům pituitary worse. Again, it depends on the timely diagnosis and the degree of malignancy (malignancy) of the specific tumor and its response to treatment.
Other names: hypercortisolism, Cushing’s disease, Cushing’s disease, morbus Cushing, iatrogenic Cushing’s syndrome
