hypopituitarism - is clinical and laboratory syndrome, reflecting the decline in the functional activity of the endocrine glands of the peripheral type, caused an imbalance of hormone anterior pituitary.
should distinguish between such concepts as panhypopituitarism (complete cessation of all production of hormones by the anterior pituitary), and partial hypopituitarism type which interferes with production of an isolated one of the six major anterior pituitary hormones.
Causes of hypopituitarism
disease "hypopituitarism" can occur under the influence of a wide variety of etiologic factors, but there are only three major pathogenetic mechanisms of this symptom.The extent of violations of the productive function of the pituitary gland depends on the extent and localization of the destructive focus in its structure.
first etiopathogenetic mechanism is to reduce the production of hormones of the hypothalamus that stimulate the production of pituitary hormones.Thus, all p
second mechanism of pathogenesis is caused by insufficient intake of pituitary hormones in the "tropic bodies" with the full preservation of the synthesis function of the pituitary gland.Typically, in this way development of hypopituitarism greatest role traumatic hypothalamic-pituitary axis.
third etiopathogenetic mechanism is caused by pituitary tumor lesions at the cellular level, resulting in most of the glandular tissue is replaced by the pituitary tumor substrate, thereby creating the conditions for a sharp inhibition of hormone production.
Transient hypopituitarism may occur after a viral infection in severe form, accompanied by a toxic lesion of the brain structures.
In women undergoing obstructed labor, accompanied by abundant thromboembolism and postpartum hemorrhage, postpartum hypopituitarism is often observed.
Among the etiological factors that are directly involved in the development of signs of secondary hypopituitarism should be considered:
- use of surgical interventions in the area of the hypothalamus and pituitary;
- exposure to high doses of ionizing radiation to the area of the pituitary gland;
- lesions of the glandular tissue of the pituitary gland in the form of the primary lesion and metastasis;
- acute circulatory disorders of the pituitary gland in the projection as a result of the loss of a large number of circulating blood during delivery (greatly reduced production of thyroid-stimulating hormone and adrenocorticotropic);
- traumatic impact on the area of the skull of varying severity (accompanied by dissociation of excessive production of prolactin in the background of a sharp decline in production of other hormones of the pituitary gland);
- «empty sella syndrome 'followed by an increase of prolactin;
- diseases of the pituitary gland, accompanied by massive infiltrative changes;
- violations of the hypothalamic-pituitary function such as the syndrome of malabsorption, severe course of diabetes, anorexia nervosa nature of renal failure (ischemic necrosis accompanied by the anterior pituitary gland).This reduction of tropic hormones is reversible and complete recovery of the patient in some cases, need to conduct a causal treatment;
- physiological dysfunction of the hypothalamic-pituitary axis in puberty and excessive physical activity in young adults (reduced levels of estradiol in the blood);
- long-term use of narcotic drugs is accompanied by a violation of secretion of testosterone;
- hyperprolactinemia as a factor inhibiting the development of hypopituitarism.
There are also types of congenital hypopituitarism due to genetic aberrations and anomalies of development structures hypothalamic-pituitary system.These predisposing factors provoke the development of signs of hypopituitarism immediately after birth.Fortunately, hypopituitarism in children is extremely rare.
In a situation where not possible to reliably establish a primary or secondary nature of the defeat of the pituitary gland, exhibiting conclusion "idiopathic hypopituitarism."
important fact is that the typical clinical syndrome of hypopituitarism is formed only when the percentage of normally functioning pituitary cells does not exceed 10%, and therefore, this pathology should be classified as slowprogressive diseases.
In situations where the affected products gonadotropins, diagnosis of hypopituitarism is straightforward from an experienced clinician.If these changes have an innate nature, the child from early childhood may experience symptoms of hypopituitarism, consisting of the backlog from the actual age of the bone, forming eunuchoid body type and in adolescence there is a significant backlog of sexual development.
secondary hypopituitarism associated with impaired production of gonadotropins in adulthood, reflected in a sudden and progressive decrease in potency, erasing secondary phenotypic traits (decrease until the complete lack of body hair in the projection of the armpits and pubic area, reducing the size of the scrotum, diffuse atrophy of muscle tissue in the bodyfollowed by its replacement by fat).Women of reproductive age with symptoms of hypopituitarism complained of decreased libido, dysmenorrhea, the occurrence of pain during sexual intercourse due to thinning of the tissues of the external genitalia.
specific and the most common symptom of hypopituitarism of any form is a violation of the olfactory function of varying severity.
The separate violation produce growth hormone by the pituitary gland, the adult a marked muscle weakness, even after minimal physical activity, accompanied by cardiac arrhythmias.In the children's period these violations are reflected in the backlog of forming skeleton.
imbalance in the production of thyroid stimulating hormone in the early childhood period, significantly affects the mental and physical development of the child, and in patients younger and mature these changes manifest symptom of hypothyroidism (unmotivated weakness, a tendency to bradycardia and hypotension, disruption of the functioning of the intestine).
hypopituitarism, pituitary tumor caused severe violation of different neurological status of the patient in the form of a constant headache with no clear localization of the visual function, various degrees of violation of the level of consciousness.
Despite the fact that the extent and specificity of clinical manifestations of both primary and secondary hypopituitarism, does not constitute a difficulty in the decision of the diagnosis, the pathology belongs to the category of laboratory violations, so each specific clinical case must be confirmed by a laboratoryand instrumentally.
diagnose tumor lesion even minimal dimensions allow available at the present time ray imaging techniques.During the beam diagnostics necessarily need to estimate the parameters of the tumor substrate, its location in relation to the bony structures of the pituitary fossa and signs of malignancy.
The list of diagnostic algorithm research postpartum women suspected of having postpartum hypopituitarism, must present the following activities: evaluation of estrogenic activity of the ovaries to study the reaction of vaginal smear, determination of serum concentrations of thyroid stimulating hormone, indirect signs of anemia in the study of the blood test.
greatest informative in determining the degree of violation of the pituitary gland are producing laboratory blood tests to determining the concentrations of various gonadotrophic hormones in the blood serum of both fasting and after use of stimulant pharmacological tests.
So, there are common diagnostic criteria for failure of a pituitary hormone.For example, for the establishment of gonadotropin deficiency in males is sufficient to define the low testosterone levels below the limit of 200 ng / dL.In order to reliably determine concentrations of corticotropin in the blood is not enough analysis on an empty stomach, and must be met with challenging samples Kozintropinom standard dose of 250 micrograms.Corticotropin index less than 18 mcg / dl after administration of the sample is an absolute criterion of hypopituitarism.
distinctive feature of the diagnosis of patients with hypopituitarism with suspected isolated deficiency of growth hormone, is required of its determination not only in blood but also in the urine.And as a child, you must radiography of hands and pelvis to determine bone age.
Treatment of hypopituitarism
To achieve good results treating patients with hypopituitarism in the form of a complete recovery and to prevent possible complications of the underlying disease, the initial phase of therapy should be to determine the etiopathogenesis and the pharmacological effects on all the links in the pathogenesis of this disease.
In a situation where hypopituitarism acts as the effects of tumor lesions of the hypothalamus or pituitary gland, the primary need to decide whether and acceptability of surgery followed by radiation therapy.
next stage of treatment is the use of hypopituitarism adequate "replacement therapy" with the use of drugs, the active ingredient of which is the hormone production is affected.For example, the gold standard of treatment failure corticotropin, cortisol replacement therapy is a daily dose of not less than 10 mg morning dose.Severe deficiency of gonadotropins leveled after prolonged use of drugs testosterone series (Sustanon 1 ml of 1 rub. / M. Intramuscular).Following laboratory confirmation of thyroid-stimulating hormone deficiency patient is expedient to appoint a L-thyroxine in the minimum daily dosage of 0.1 mg in combination with corticosteroids (prednisolone 25 mg) in order to prevent the emergence of signs of adrenal insufficiency.
In case of acute hypopituitarism, provoked a hemorrhage in the pituitary tissue, the patient is in critical condition and needs urgent application of resuscitation.As a first-aid products in this situation serves Hydrocortisone intravenous infusion at a dose of 100 mg in combination with parenteral administration of saline solutions.
peculiarity of treatment of postpartum hypopituitarism type is substitution treatment for life, since the pathogenesis of this disease are irreversible processes in the pituitary gland.