Hypopituitarism is a pathological condition that is caused by a decrease in the production of several or all pituitary hormones. Cider occurs when the pituitary gland is directly affected by necrosis, tumor or inflammatory process, in addition, it can be a consequence of violations of hypothalamic-pituitary regulation. Disease is manifested by symptoms of hypocorticism, hypogonadism, hypothyroidism, metabolic disorders. Diagnosis of the disease includes tests for pituitary hormones, neuroimaging methods, and examination of peripheral endocrine glands. The basis of treatment is hormone replacement therapy.
ICD 10
E23.0 Hypopituitarism
Meaning
Hypopituitarism is a syndrome that is diverse in etiopathogenesis and clinical signs, which occurs in patients of different profiles, proceeds under the “mask” of other diseases. The true frequency of hypopituitarism has not been established, information about the prevalence exists only for individual forms. Hypopituitarism is one of the most difficult conditions to diagnose, its detection and proper treatment requires high professional training from an endocrinologist.
Causes
The etiological structure of hypopituitarism is diverse, since it reflects not only specific organic processes in the pituitary gland, but also a variety of somatic diseases that provoke its development. In clinical endocrinology , all possible causes of hypopituitarism are grouped into the following groups:
- Pituitary necrosis. The death of pituitary tissue occurs due to ischemia of the organ with inflammation of the temporal arteries, atherosclerosis, sickle cell anemia. Hypopituitarism is rarely found in pregnant women with severe eclampsia, with massive bleeding after childbirth (Sheehan syndrome).
- Tumors of the pituitary gland. The primary neoplasms of the central endocrine organ include chromophobic adenoma, craniopharyngioma. Parasellar tumors are also observed: meningioma, optic nerve glioma.
- Vascular diseases. The cause of hypopituitarism may be an intracranial aneurysm of the carotid artery, thrombosis of the cavernous sinus, hemorrhage into the pituitary gland.
- Neuroinfections. Involvement of the pituitary gland in the inflammatory process is observed in bacterial pathologies: tuberculosis, meningococcal meningitis, syphilis. A deficiency condition can be diagnosed with systemic mycoses.
- Metabolic disorders. Hypopituitarism often results from systemic health disorders and the accumulation of toxins, which is possible with renal and hepatic insufficiency.
- Iatrogenic factors. Hormone deficiency is often detected in patients who have undergone a course of irradiation of the nasopharynx or Turkish saddle, with accidental surgical destruction of the organ.
All of the above factors are the causes of the primary form of hypopituitarism. Secondary insufficiency is mainly noted when the hypothalamus is affected due to inflammatory, traumatic or toxic effects. It is also possible to have tumors of the hypothalamus: primary neuroendocrine neoplasms, metastatic lymphomas. In rare cases, secondary hypopituitarism develops against the background of forced starvation, anorexia nervosa.
Pathogenesis
The pituitary gland is the central gland of internal secretion, which consists of the anterior lobe (adenohypophysis), which occupies 70-80% of the mass of the organ, the posterior lobe (neurohypophysis), the intermediate lobe, which by origin belongs to the adenohypophysis. Regulatory hormones are produced in the adenohypophysis: thyroid-stimulating (TSH), adrenocorticotropic (ACTH) follicle-stimulating (FSH), luteinizing (LH), somatotropic (STH) and luteotropic.
Hypopituitarism has many mechanisms of development that are caused by a specific cause of the disease. It is possible both direct destruction of cells or infectious-toxic damage to them, and the indirect influence of hypothalamic pathologies on the activity of the adenohypophysis. With a decrease in the production of regulatory hormones, the work of the corresponding peripheral glands is disrupted, which is manifested by characteristic symptoms.
Classification
Taking into account the mechanism of development, hypopituitarism is divided into primary with direct damage to secreting cells, and secondary, when insufficient hormone synthesis is associated with the absence of stimulating influences from higher neuroendocrine centers. In practical endocrinology, the division of hypopituitarism into clinical forms is widely used according to the degree of violation of hormone secretion:
1 Total hypopituitarism is the most severe variant of pathology, when the production of all pituitary hormones decreases or completely stops. This includes pituitary cachexia (Simons disease), postpartum hypopituitarism (Sheehan syndrome), hypothalamic-pituitary insufficiency.
2 Partial hypopituitarism is a partial lesion of the pituitary gland, in which the synthesis of one or more hormones is disrupted. The partial form has the following subspecies:
- pituitary hypogonadism — underdevelopment of external sexual characteristics and violation of reproductive function resulting from a deficiency of LH and FSH;
- pituitary dwarfism (nanism) – stunting due to insufficient synthesis of somatotropin in childhood;
- pituitary hypocorticism — hypofunction of the adrenal cortex, which is caused by the absence of the stimulating effect of ACTH;
- adiposogenital dystrophy — progressive obesity and underdevelopment of the genitals;
- pituitary hypothyroidism is a decrease in the production of thyroid hormones against the background of TSH synthesis disorders in the anterior pituitary lobe.
Hypopituitarism symptoms
Given the variety of clinical forms of the disease, it is impossible to distinguish typical symptoms of hypopituitarism. The manifestations of the disease will depend on the severity of the pituitary gland malfunction, the causes of damage to the endocrine organ, the presence of concomitant pathologies in the patient. Hypopituitary syndromes in most cases combine three groups of signs: polyhormonal insufficiency, neurosomatic disorders, mental disorders.
Total hypopituitarism
With pituitary cachexia, a sharp weight loss and muscle atrophy and lack of appetite come to the fore. The condition occurs more often in women aged 30-40 years. Patients complain of constant drowsiness, loss of strength, their sexual desire decreases. Sheehan’s syndrome has a similar clinical picture, but its pathognomonic sign is the development of symptoms in women in the postpartum period.
Patients with hypothalamic-pituitary insufficiency have symptoms of hypocorticism, hypothyroidism, hypogonadism. Due to the deficiency of antidiuretic hormone, the clinical picture is supplemented with signs of diabetes insipidus. The volume of urine excreted reaches 10-15 liters per day, against which constant agonizing thirst worries.
Partial hypopituitarism
With a lack of STH, dwarfism occurs in children with the correct body proportions. In adults, somatotropin deficiency affects the basic metabolism: it inhibits metabolic reactions, increases cholesterol levels in the blood, promotes the breakdown of muscle tissue proteins. As a result of a decrease in bone density, fractures are not uncommon. The skin looks dry, sweating decreases. A person experiences constant fatigue, apathy, decreased performance.
Deficiency of gonadotropins (FSH, LH) in women of reproductive age causes cycle disorders up to the absence of menstruation, decreased libido, vaginal dryness. Urination disorders and discomfort during sexual intercourse often occur. Men experience erectile dysfunction, decreased libido, inability to ejaculate. Often, the hair cover in hormone-dependent areas (armpits, perineum) decreases.
For hypothyroidism, the appearance of drowsiness, lethargy, and a decrease in mental and physical performance is typical. The skin becomes pale, dry, cool to the touch. The defeat of the gastrointestinal tract is characterized by constipation. Against the background of edema and metabolic disorders, patients gain weight even if the standard caloric content of the diet is observed. With hypocorticism, on the contrary, there is a decrease in body weight in combination with gastrointestinal disorders.
Complications
The main negative consequence of hypopituitarism is a pituitary crisis, which is an extremely severe degree of hormonal insufficiency. Its onset is facilitated by acute stress, physical trauma, absence or abrupt termination of hormone replacement therapy. Crises often occur when hypopituitarism is complicated by infectious and inflammatory processes.
Pathology develops gradually over several days, but with hemorrhage in the pituitary gland, symptoms appear in a matter of hours. Pituitary crisis is manifested by adynamia, a decrease in body temperature, suppression of tendon and abdominal reflexes. In patients, blood pressure decreases, pulse slows down, all metabolic processes are disrupted. Without timely help, the condition leads to multiple organ failure, coma, and death of the patient.
Diagnostics
The initial examination of the patient takes place in the office of an endocrinologist. Given the diversity of hypopituitary syndrome, it is required to conduct a full physical examination, find out all the complaints and collect a detailed history of the disease in order to suspect hypopituitarism. The following diagnostic methods help to confirm the presence of hypopituitarism:
- Neuroimaging. To detect organic lesions of the hypothalamic-pituitary zone, radiography of the Turkish saddle, MRI or CT of the brain is performed. If necessary, the examination is supplemented by cerebral angiography, electroencephalography.
- Ultrasound of the endocrine organs. Ultrasound diagnostics is informative for assessing the condition of target organs, the work of which is determined by the level of tropic hormones. To detail the data, it is possible to perform CT scans of the thyroid gland, adrenal glands, and pelvic organs.
- Biochemical analyses. The assessment of the general state of health is based on the proteinogram, lipidogram, acute phase indicators. The levels of the main blood electrolytes are important. If diabetes insipidus is suspected, a urine test is prescribed.
- Hormonal studies. The basic diagnostic method is the measurement of hormone levels in the blood. As a rule, to clarify the cause and form of hypopituitarism, samples are made with the introduction of GnRH, clofelin, tyroliberin.
- Consultations of specialized specialists. To clarify the root cause of hypopituitarism, patients are recommended to undergo a comprehensive examination by a neurologist, cardiologist, ophthalmologist, infectious disease specialist, and other doctors.
Hypopituitarism treatment
Planned therapy
With hypopituitarism, differentiated treatment is indicated, which is carried out taking into account the etiological factor of the disease, the severity, clinical symptoms, and the presence of complications. Most hypopituitic syndromes are successfully treated with the help of drug therapy, for which the following therapeutic scheme has been developed:
- Hormone replacement drugs. Analogues of corticotropic, thyroid-stimulating, somatotropic hormones are effective for correcting the work of the endocrine system. Combined oral contraceptives are recommended for women to eliminate hypogonadism, and drugs with an androgenic effect are selected for men.
- Glucocorticosteroids. Medications are used for pituitary necrosis to prevent cerebral complications of this condition, relief of cerebral edema. Also, medications are used for active immune inflammation that damages the organs of the hypothalamic-pituitary system.
- Antimicrobial drugs. Medications are necessary for proven infectious etiology of hypopituitarism in order to quickly eliminate the provoking factor, eliminate inflammation in the brain.
- Cytostatics. Chemotherapy drugs are prescribed for primary malignant neoplasms of the pituitary gland or for metastatic tumors. Cytostatics are combined with other methods of treatment in neuro-oncology.
Emergency care
Relief of the pituitary crisis is carried out in the intensive care unit. Treatment begins with the introduction of high doses of corticosteroids, with persistent arterial hypotension, a DOXA solution is additionally administered. After 12-24 hours, therapy is supplemented with thyroid medications. To improve water-salt metabolism, normalize glycemic indices, infusion solutions are introduced: saline solution, glucose solution, hypertonic solutions with sodium.
To improve metabolism, the administration of coenzyme preparations of thiamine, the active form of vitamin B6, cytochrome C, adenosine monophosphate is indicated. To eliminate the signs of heart failure, it is necessary to use cardiotropic drugs from the group of beta-adrenomimetics, analeptics, cardiac glycosides. Respiratory support includes inhalation of moistened oxygen, artificial ventilation of the lungs.
Surgical treatment
With pituitary adenomas, Ratke pocket tumors and other neoplasms of the Turkish saddle area, the possibility of neurosurgical removal of pathological tissue is being considered. For the complex treatment of tumor processes, surgical intervention is often supplemented with radiation therapy. In the first days after a hemorrhagic stroke, surgery is also possible if conservative treatment does not give the expected effect.
Prognosis and prevention
The prognosis is assessed taking into account the cause, severity of the condition, largely depends on the timeliness of the diagnosis of the problem, the patient’s compliance with medical recommendations. With constant use of substitution therapy, it is possible to maintain a high quality of life and normalize the functions of the peripheral endocrine glands. A doubtful prognosis for patients with total hypopituitarism, which often ends in a coma. Preventive measures have not been developed.
Literature
- Endocrinology: National guidelines/ edited by I. I. Dedov — 2016.
- Clinical pathophysiology/ P.F. Litvitsky. — 2015.
- Hypopituitarism: causes and epidemiology / A.V. Dreval// Algorithms for diagnosis and treatment of pituitary insufficiency. — 2014. — №5-6.