Hypothalamic Disease (Diseases of Hypothalamus) - Pituitary Disease

Hypothalamus – Pituitary Disease

Hypothalamic Disease (Diseases of Hypothalamus) – Pituitary Disease

 What is Pituitary Disease?

Pituitary Diseases: Hypothalamic disease is a group of diseases that cause hypothalamic dysfunction due to multiple reasons. The main features are hypoendocrine dysfunction and autonomic dysfunction.

The hypothalamus is both an advanced autonomic nerve center and an advanced endocrine center with complex functions. Hypothalamus is closely related to pituitary function, gonadal activity, body temperature regulation, appetite control and water metabolism. The hypothalamic nerve can be cholinergic, dopaminergic or adrenergic, and often shows chemical staining of different neurotransmitters at the same anatomical site. This suggests that different physiological functions overlap in the same area. The hormones that stimulate the anterior pituitary of the hypothalamus are thyroid growth hormone releasing hormone (TRH), luteinizing hormone releasing hormone (LHRH), follicle stimulating hormone releasing hormone (FSHRH), growth hormone releasing hormone (GHRH) and corticotropin Release hormone (CRH), prolactin release factor (PRF). Its inhibitory hormones are prolactin inhibitory factor (PIF), growth hormone inhibitory hormone (SST). The hormones that secrete in the posterior pituitary are vasopressin (VP) and antidiuretic hormone (ADH).

Causes of Pituitary Disease or Hypothalamus

I. Congenital

(A) Growth hormone deficiency (with or without other hormone deficiency)

(B) Luteinizing hormone (LH) and follicle stimulating hormone (FSH) deficiency.

(C) Sexual infancy-pigmented retinitis-sexual dysplasia syndrome (Laurence-Moon-BiedIesyndrome)

Cancer

(1) Hypothalamic craniopharyngioma, pineal tumor, meningioma, optic cross glioma and other internal tumors.

(2) Tumors on the pituitary sacral saddle.

(3) Infection with radon encephalitis, tuberculosis and syphilis.

(4) Granulomatous and sarcoidosis, Hand-Schuller-Christiandisease, eosinophilic granuloma, multisystemic granulomatosis.

(5)Vascular disease Postpartum hypophyseal hypofunction, carotid or intracranial aneurysm, subarachnoid hemorrhage, pituitary stroke, cerebral arteriosclerosis, cerebral embolism, cerebral hemorrhage.

(6) Mechanical oppression is caused by hydrocephalus for various reasons.

(7) Iatrogenic radon radiotherapy, neurosurgery.

(8) Trauma and craniocerebral trauma.

(9) Functional neurogenic vomiting, polyphagia, anorexia, amenorrhea, impotence, hypothyroidism and adrenal insufficiency.

 

Clinical Manifestations of Hypothalamus

I. Endocrine dysfunction

(A) Insufficient secretion of pituitary hormones: This is more common in pituitary stem injury in favor of various reasons. When the pituitary stalk is blocked, any pituitary hormones other than PRL can be deficient or inadequate. Common diabetes insipidus and hypogonadism with hyperprolactinemia are common. In addition, it can cause hypothyroidism and adrenal insufficiency. Growth hormone (GH) secretion is reduced. The basic measurement and kinetic tests of the corresponding pituitary hormones in this group of diseases showed low secretion, and given a proper amount of hormone release, they showed a good response.

(B) Excessive secretion of pituitary hormones: Excessive secretion of CRH is the cause of Cushing disease. GHRH is secreted too much, leading to acromegaly. The excessive secretion of GnRH earlier causes the premature release of pituitary gonadotropin (Gn), which can lead to true precocious puberty. Congenital cystic fibrous osteitis syndrome (AIbright syndrome) can be associated with precocious puberty. Increased TRH secretion can cause hypothalamic hyperthyroidism.

(C) Hormonal rhythmic secretion disorders: The daily rhythm of ACTH secretion may disappear due to the effects of certain hypothalamic diseases and Cushing syndrome. Other hormones GH and PRL secreted by the daily rhythm and LH and FSH secreted by the monthly rhythm. Both can lose the inherent rhythm of secretion due to hypothalamic disease or pituitary disease.

(D) Adolescent developmental abnormalities: The disease in the back of the hypothalamus can eliminate the inhibitory effect on the secretion of Gn by the pituitary gland, leading to adolescent precocious puberty. Conversely, hypothalamic disease can also cause delay in puberty.

 

Hypothalamic Symptoms

(A) Obesity Patients with obesity due to loss of function of the satiety center in the abdomen median nucleus, which leads to increased appetite. Obesity can be the prominent and only manifestation of this disease. Obese patients can often gain weight continuously. The cause of this phenomenon is not clear.

Prade-WiIIi syndrome is due to abnormal hypothalamic function, with significant obesity, overeating, diabetes, dull expression, hypogonadism, and small hands and feet. Obesity is also one of the prominent symptoms in sexual immature-pigmented retinitis-multi-finger deformity syndrome.

(B) Anorexia and weight loss When the ventral ventral nucleus is damaged, it can cause anorexia and weight loss. In severe cases, it has cachexia, muscle weakness, and hair loss. Severe disease can also be accompanied by anterior pituitary hypofunction.

 

(C) Sleep abnormalities:

i. Narcolepsy is the most common. Each attack lasts from several minutes to several hours. It is difficult to resist.

ii. Deep sleep can sleep for several days to several weeks. You can wake up to eat, urinate, and then fall asleep.

iii. Symptoms of bulimia bulimia, continuous sleep for hours to days, bulimia after waking up and more obesity in this pituitary disease.

iv. Stubborn insomnia at night in pituitary disease.

 

(D) Temperature regulation obstacles Low body temperature and high body temperature are more common. The degree of hypothalamic hypothermia depends on the humidity of the environment. Patients lack a party compensation mechanism for the cold. High body temperature is not effective for antipyretics.

 

(E) Impairment of regulation of water balance Disruption of the visual nucleus can cause diabetes insipidus. If the central thirst of hypothalamus is involved, it can cause a decrease in fluid intake which can lead to dehydration and an increase in serum sodium and chlorine. We can correct this by supplemental fluid and vasopressin.

 

Third

(1) headache and visual field defects are mostly related to the nature of hypothalamic disease. Hypothalamic diseases cause more headaches and visual field defects than pituitary diseases.

(2) Behavioral abnormalities: Behavioral and mental abnormalities can occur when the ventrolateral nucleus of the hypothalamus and the preoptic area are affected. Patients often have reduced behavioral movements and even sit still all day. It is often accompanied by disorientation, moodiness, hallucinations, etc.

(3) Symptoms of the autonomic nerves: Sweating or less sweating, cyanosis of the hands and feet, dilated or dilated pupils or unequal blood pressure on both sides.

 

Thesis on this Pituitary Disease

Hypothalamic disease has a variety of causes and various manifestations, and sometimes it is difficult to diagnose. The disease must be considered on the basis of a detailed medical history, combined with various examinations. The disease must be carefully considered before the cause can be considered.

Endocrine examinations should routinely measure the functions of the gonads, thyroid gland, adrenal glands, and pituitary gland. And if necessary, relevant kinetic tests should be performed to determine the pathological changes of abnormal hypothalamus-pituitary-endocrine gland function.

X-ray head radiography, pneumo-cerebral, cerebral angiography, skull CT, magnetic resonance, cerebrospinal fluid biochemical measurement, cytology, and EEG can be used as appropriate to clear the diagnosis and identify the cause.

 

Etiligo Treatment

First, etiology treatment: The tumor can be surgically removed or radiotherapy. The infection should be treated with appropriate antibiotics.

Second, special treatments such as diabetes insipidus can be treated with antidiabetes medication. If there is insufficient endocrine function, the corresponding hormone can be used instead of treating rickets. Breast cramps can be stopped with bromocriptine or galactorrhea. Amenorrhea can use bromocriptine or artificial cycle as appropriate. Patients with neuropsychiatric symptoms can use diazepam, rummina or phenytoin sodium.

 

Hypothalamic Disease (Diseases of HypothaIamus)

Anterior Pituitary Hypofunction (pituitary diseases)

Anterior pituitary hypofunction is a syndrome caused by insufficient secretion of hormones from the pituitary gland. The disease can be divided into two types, partial and complete. The former involves only 1 or 2 hormones. The latter is insufficient synthesis and secretion of all anterior pituitary hormones. The clinical manifestations mainly depend on the type and degree of anterior pituitary hormone deficiency. In addition, the age of onset also affects clinical manifestations.

Causes of Anterior Pituitary Hypofunction

Can be divided into primary pituitary lesions and secondary to the hypothalamus pituitary released hormone secretion. The specific cause is shown in Table.

Table showing Common causes of hypopituitar hypofunction
  • Primary & secondary
  • After treatment of pituitary tumors
  • Pituitary surgery craniopharyngioma
  • Radiation therapy meningioma
  • Pituitary tumor
  • Nonfunctional adenoma
  • Functional adenoma
  • Pituitary metastatic tumor radiotherapy / chemotherapy
  • Pituitary infarction
  • Pituitary tumors (functional or non-functional) Hypothalamic GRF deficiency
  • Postpartum necrosis (Sheehan syndrome) Hypothalamic GnRH deficiency
  • Chemotherapy (Kallman Syndrome)
  • Granulomatous brain ataxia and retinal pigmentation
  • Sarcoidosis and trauma
  • Trauma of tuberculosis
  • Syphilis granuloma
  • Histiocytosis X (same as primary)
  • Self-immune

Any damage that causes destruction of the anterior pituitary or hypothalamus can cause anterior pituitary hypofunction. Postpartum pituitary necrosis (Sheehan syndrome) is the most common cause of this disease. The pituitary gland is hypertrophic in the second trimester of pregnancy. When bleeding occurs during or after childbirth, it causes hypotension, spasm of the pituitary glandular arteries and ischemic necrosis of the anterior pituitary. Generally, when glandular necrosis is> 70%, clinical symptoms appear.

Another common cause is pituitary and tumors around the pituitary, especially chromocytoma and craniopharyngioma. Iatrogenic hypopituitar hypofunction is also common. Most of them are damaged by surgery or radiation treatment of the pituitary and hypothalamus. Caused by isolated individual pituitary hormone deficiency is often due to hypothalamic defects. This results in a lack of secretion of release hormones of which gonadotropin (Gn) or growth hormone (GH) are the most common.

 

Clinical Manifestations

The clinical manifestations of anterior pituitary hypofunction are related to the following factors:

i. The degree of pituitary failure

ii. The types of hormones involved

iii. The degree of increased pressure in the sphenoid saddle and the site of pituitary damage

iv. The age of onset and the sex of the patient.

Partial pituitary dysfunction is more common than all pituitary dysfunction. The secreted order of involvement is generally luteinizing hormone (LH) and GH, then follicle stimulating hormone (FSH), ACTH, thyroid stimulating hormone (TSH), and finally vasopressin (VP). Lack of prolactin (PRL) secretion is rare, except for pituitary necrosis after delivery. Hyperprolactinemia may originate from tumors (such as prolactin tumors), but it is more common because the hypothalamus functions abnormally, which increases PRL secretion from normal glands. Diabetes insipidus is more common in patients with hypothalamic lesions. When hypothalamic-pituitary lesions are sufficient to impair ACTH secretion, the polyuria symptoms of diabetes insipidus can be relieved and concealed.

Unhypophyseal hypothyroidism is very sensitive to various stresses such as infection, surgery, anesthesia, alcoholism, etc.

Due to the lack of pituitary hormones, the symptoms and signs of this disease are also different.

 

1. Lack of gonadotropins (Gn or LH and FSH): Those with prepubertal disease show delayed puberty, and those with postpubertal disease show secondary hypogonadism. Patients with delayed puberty tend to be taller. Finger distance> height, genitals are not developed, testicles are small and soft, long diameter <3cm, lack of beard, pubic hair and axillary hair, primary amenorrhea. After puberty, the axillary hair of the patient will fall off, and fine wrinkles will appear on the skin. Also, hyposexuality, atrophy of the testicles, less or no sperm.

2. Growth hormone (GH) deficiency: In children and adolescence often cause bone growth retardation, short stature. There are no obvious features in adults but the patient’s skin can become thinner and smaller, and occasionally fasting hypoglycemia.

3. Lack of prolactin (PRL) postpartum: No milk, breast atrophy, often the first symptom of postpartum pituitary necrosis.

4. TSH deficiency can lead to hypothyroidism without hyperthyroidism. Patients may have burnout, fear of coldness, dry skin and delayed Achilles tendon reflexes but myxedema may not be obvious. If it occurs in childhood, growth is retarded and epiphyseal closure is delayed. The secretion of GH may be suppressed by the lack of TSH.

5. Adrenocorticotropic hormone (ACTH) deficiency ACTH deficiency is often partial and often occurs after pituitary resection or pituitary radiotherapy. Onset is hidden, such as weakness, nausea, vomiting, hypotension, hypoglycemia, weakness and coma. The areola is pale, the skin is pale and the sun does not tan. The secretion of mineralocorticoids is more controlled by the renin-angiotensin system, so when the pituitary cortical function is low, electrolyte disorders are rarely caused.

6. Pituitary crisis due to anterior pituitary hypofunction in response to various stress factors is low, so infection, diarrhea, vomiting, dehydration, hunger, trauma, surgery, anesthesia, cold and sleep, sedatives, etc. Aggravating the original symptoms and the emergence of crisis, the clinical manifestations of pituitary crisis are the following types:

(A) Hypoglycemia coma is most common. It often occurs on an empty stomach, palpitations, sweating, dizziness and disturbance of consciousness. Sometimes it can be mental disorders and convulsions or epileptic seizures, and finally coma.

(B) Infectious coma has low resistance, is prone to infection and can be accompanied by high fever. It has unconsciousness and coma.

(C) hypothermia coma is more common in the cold winter and when patients are not warm well.

(D) Toxic coma in water Due to the lack of corticosteroids, the ability to regulate water metabolism is reduced. After too much infusion and drinking water, aquatic coma is prone to occur. Water poisoning manifests as nausea, vomiting, collapse, confusion, convulsions and coma.

(E) Unconsciousness after pituitary resection after coma, showing drowsiness and coma, which can last for several days to weeks, pulse rate and low, body temperature can be low or high or normal, blood sodium, blood sugar is normal or low .

(F) Pituitary stroke due to acute bleeding in the pituitary tumor. Sudden onset of illness, headache, dizziness, vomiting, decreased vision, blindness and even shock and coma.

(G) Sedation caused by sedation and anesthesia Patients with this disease are very sensitive to sedatives and anesthetics, and sometimes regular doses can cause drowsiness or coma. And the duration is extended.

 

Laboratory and other inspections

A. Peripheral gland function

(1) Adrenal cortical function:

i. 24-hour urine 17-ketosteroids (17-KS), 17-hydroxysteroids (17-OHCS) and urine free cortisol were lower than normal values.

ii. ACTH Excitation Test: ACTH 25μ was dissolved in 500ml of 5% glucosamine saline, and it was instilled for 8 hours. The patient showed a delayed response. After continuous intravenous infusion for 2 to 3 days, urine 17-KS and 17-OHCS gradually increased.

 

(B) Thyroid function:

i. The rates of serum T3, T4 and thyroid 131 were lower than those of political parties.

ii. TSH excitation test: TSh 10μ intramuscular injection, once a day for a total of 3 days. Patients with this disease may have increased thyroid gland 131 glandular rate and serum T3, T4 but not as significant as normal people, showing delayed response.

(C) Gonad function: male serum testosterone, urine 17-KS; female serum estradiol and urine estrogen (estrone, estradiol, estriol) levels are low. A vaginal cytology smear showed a significant decrease in estrogen activity.

 

Anterior pituitary function

(1) Serum TSH, LH, FSH, ACTH and GH can be lower than normal values.

 

(II) ACTH secretion test:

i.Mepyridone test: Mepyridone is an 11-β hydroxylase inhibitor, which can block the synthesis and secretion of cortisol and feedback stimulate the secretion of ACTH in the anterior pituitary gland. Methoprene 750mg, once every 4 hours, when the anterior pituitary dysfunction, plasma ACTH does not increase.

ii.Insulin hypoglycemia test: hypoglycemia caused by insulin can stimulate ACTH, GH and PRL secretion from the anterior pituitary. Intravenous injection of 0.1u / kg of insulin, 30 minutes after the blood was drawn for ACTH. Normal people’s ACTH should be> 200 pmol / L, with an average of 300 pmol / L. The ACTH of this disease shows a low response or lack. This test is dangerous and should be used with caution.

(iii) Growth hormone (GH) secretion test

a. The peak of normal response of insulin hypoglycemic excitement test occurs about 30 to 60 minutes after intravenous injection of insulin, which is about 35 ± 20 μg / L (35 ± 20 ng / ml). The response decreases when pituitary disease No reaction.

b. L-dopa excitement test: Oral levodopa 0.5g, 60 ~ 120 minutes after taking the drug, blood GH should be> 7 μg / L (7ng / ml).

c. Arginine excitation test: 5% arginine 500ml intravenous drip. The peak of normal GH is seen 60 minutes after the instillation, which can reach 3 times the basal value; the disease has a low or lacking response.

d. Glucagon test Glucagon 1mg, intramuscular injection. Normal people peak at 2 to 3 hours, and there is no obvious response to this disease when it is> 7 μg / L (7ng / ml).

 

(D) Prolactin (PRL) secretion test

i. Thyroid stimulating hormone releasing hormone (TRH) test: 15 minutes after the intravenous injection of TRH 500 μg, the peak of blood PRL appears, which can increase 3 to 5 times in men and 6 to 20 times in women. When the anterior pituitary function is low. Its basic value is low and it cannot rise after excitement.

ii. Metulin test Metulin 10mg was orally administered, and the results are the same as the TRH test.

iii. Insulin hypoglycemic excitement test: Normal blood PRL peaks at 1 hour after intravenous injection of insulin, and the highest value can reach 1.6-2.0nmol / L (40-50ng / ml), which is higher in women. The basic value of the disease is low and the response is poor.

(E) Gn secretion test 15 to 30 minutes after the intravenous injection of luteinizing hormone releasing hormone (LHRH) at 100 μg. The peak values ​​of LH and FSH are more than three times the base value for women and about two times for men. No response or low response indicates anterior pituitary hypofunction. The peak appears at 60 to 90 minutes for delayed response, suggesting hypothalamic lesions.

(F) Thyroid stimulating hormone (TSH) secretion test: 30 minutes after TRH injection at 500ng, the peak value of blood TSH was about 10-30 mu / L. There was no response during pituitary lesions.

 

Third

(I) Glucose metabolism Fasting blood glucose is often low. Most glucose tolerance tests are low-level curves.

(B) Electrolyte Metabolism Low blood sodium, low blood chlorine and normal potassium.

(3) Water metabolism: The water load test is positive and can be corrected with cortisone. Methods: After urination in the morning, drink 20ml / kg of water and urinate every 20 minutes after drinking water for a total of 8 times. If the urine output per minute is less than 10ml, repeat the water load test on the second day but take 50mg of cortisone 4 hours and 2 hours before the test. If the urine output of cortisone increases to 10ml / mln or more, Positive, indicating insufficient adrenal function.

(D) Lipid metabolism: The fasting rate of fatty acids is lower than normal, and blood cholesterol is generally normal or high.

(5) CT or X-ray photographs of the craniocerebral can show hypothalamus-pituitary related organic lesions, size of sphenoid saddle and bone destruction. Magnetic resonance examination is also of great diagnostic significance.

 

Diagnosis

According to the history, symptoms, signs and hormones of the pituitary and target glands, and the selection of appropriate functional tests, the diagnosis of this disease can be determined. The disease needs to be distinguished from diseases such as primary gonadal, thyroid, adrenal insufficiency, anorexia nervosa and malnutrition. Diagnosis of this disease should seek to find out the cause.

 

Treatment

The main treatment should depend on the cause of pituitary failure. If the anterior pituitary hypofunction caused by pituitary tumors, surgical treatment or radiation treatment should be considered according to the condition.

Hormone deficiency should be treated with long-term hormone replacement.

1. TSH deficiency: L-thyroxine can be used at 100-200 μg / day, starting at 50 μg / day, and gradually increasing, or with thyroid tablets 40-80 mg / day, starting at 20 mg / day. Or triodothyronine 10-20 μg / day, gradually increased to 50-75 μg / day. The gradual recovery of hypothyroidism after administration indicates that the treatment is effective. Attention should be paid to heart rate during treatment to avoid overdose.

2. ACTH deficiency Adrenocortical hormone replacement therapy should precede thyroid hormone therapy to avoid adrenal crisis due to increased metabolic rate. Hydrocortisone, 20 mg in the morning and 10 mg in the afternoon. Prednisone, 5mg in the morning, 2.5pm or cortisone, 25mg in the morning, 12.5mg in the afternoon. In severe cases you can increase the dose as appropriate, and then adjust the amount after the condition improves. In case of stress from infection, surgery, trauma, etc., the dose should be increased and gradually reduced as the condition improves. In general, mineralocorticoids are not used because aldosterone secretion may not be reduced in patients with this disease. Inappropriate application of mineralocorticoids can cause edema, hypertension, oliguria and heart failure.

3. GH deficiency: GH is usually used only before epiphyseal closure to ensure normal growth in prepubertal patients. At present, the most commonly used gene is recombinant GH, 5-19 mg, intramuscular injection 1 to 3 times a week, maintained for more than 2 years.

4. Gn deficiency Male patients can be replaced by testosterone preparations. Methyltestosterone, 10-30 mg daily, taken 2 or 3 times under the tongue. Or use testosterone propionate, 25mg each time, once or twice intramuscularly. Or testosterone enanthate 250mg, intramuscular injection once every 2 to 3 weeks, or testpsterone undeconoate 80mg, orally twice a day.

To promote spermatogenesis, a combination of PergonaI (containing 75IU of FSH and LH) and chorionic gonadotropin (HCG) is required. Pergonal 500-2000IU per injection 3 times a week, the course of treatment is at least 3 months (the spermatogenesis cycle is 3 months). HCG is 500 ~ 1000U each time, intramuscularly once or twice a week.

When the lesion is in the hypothalamus, LHRH pump can be used for intermittent infusion.

Female patients can use diethylstilbestrol 0.5 ~ 1.0mg once a day for 20 days a month, plus progesterone on the 16th day and 10mg intramuscular injection once a day for 5 days. Intramuscular injection of PergonaI and HCG.

 

5. The treatment of pituitary crisis

(1) Correction of hypoglycemia: First, intravenously inject 40% to 60ml of 50% glucose, followed by intravenous infusion of 10% glucose saline.

(2) Hydrocortisone tincture 100 mg hydrocortisone is added to a liquid for intravenous drip, 100 to 300 mg per day.

(3) fluid replacement If diarrhea, vomiting cause dehydration and low blood volume, balanced salt 5% glucose saline should be added, the amount depends on the condition.

(4) Anti-infection and anti-shock For those with infection, antibiotics should be selected as appropriate. Shock patients, appropriate use of booster drugs in pituitary disease.

(5) Sedatives and narcotics should be banned or used with caution. Central nervous system inhibitors such as barbiturates, morphine narcotics, chlorpromazine and various hypoglycemic agents should be banned to prevent coma.

 

Diabetes Insipidus (DiabetesInsipidus)

The lack of vasopressin (also known as antidiuretic hormone), or the failure of the renal tubules to respond to vasopressin can produce a large amount of diluted urine, causing diabetes insipidus. The former is caused by lesions in the hypothalamus-neurohypophysis. Patients with diabetes insipidus have symptoms of thirst, polydipsia and polyuria.

 

Etiology and pathogenesis

One third of central diabetes insipidus is caused by the destruction of the hypothalamus by primary or metastatic tumors. Primary tumors include craniopharyngioma, pituitary adenoma, meningiomas, and gliomas. Metastatic tumors are most common in breast cancer and lung cancer. Simple posterior pituitary lesions generally do not cause diabetes insipidus, but when the tumor spreads to the saddle, or surgery, or radiation therapy may cause central diabetes insipidus.

Other patients have unknown causes and are called “idiopathic diabetes insipidus.” The cause may be familial, either dominant or recessive. Viruses or “degenerative changes” can also cause this disease. But this can also be caused by autoimmune disorders that destroy hypothalamic cells that synthesize and secrete vasopressin. If idiopathic diabetes insipidus is accompanied by diabetes, optic nerve atrophy, neurological deafness, and low-tension bladder, that is, WoIfram syndrome.

Some patients have hypothalamic damage for a variety of other reasons, including trauma, histiocytosis X (Hand SchuIIr-Christian syndrome), Sarcoidosis, granulomas, meningitis, encephalitis, syphilis or rare brain Reticulocytosis. After a head injury, polyuria can occur several days later. Diabetes insipidus caused by a traumatic brain injury or neurosurgery may resolve on its own, usually a few weeks and a year.

Renal diabetes insipidus can be seen in hereditary defects in the renal tubules, which cannot respond to vasopressin, which leads to polyuria. The disease is associated with recessive inheritance (hereditary in females, onset in males). The mechanism may be due to the inability of the renal adenylate cyclase system to be stimulated by normally secreted vasopressin. Potassium loss, hypercalcemia, amyloidosis and other acquired kidney disease can also cause non-response to vasopressin and cause polyuria. Potassium salts and norcomycin can also cause reversible renal diabetes insipidus and pituitary disease.

 

Clinical Manifestations

Central diabetes insipidus can be seen at any age, but there are many young people. The incidence rate for both sexes is about 2: 1. The onset is irritable and solvable and it is gradually obvious in a few days or weeks. Patients with non-organic diseases often have more rapid onset.

Polyuria and irritability are the main symptoms. If drinking water is restricted, the patient may suffer from thirst and may cause dehydration. The amount of urination is usually about 5 liters per day, but occasionally it can reach 20 liters, which is related to the location of the lesion and the degree of damage. The specific gravity of urine is usually between 1.001 and 1.005. If the drinking water is restricted, the specific gravity of urine can exceed 1.010, and the osmotic pressure of urine can exceed 300 mmol / L, which is called partial diabetes insipidus.

If the pituitary or hypothalamic lesions of central diabetes insipidus continue to progress and cause anterior pituitary hypofunction, polyuria and thirst symptoms can be alleviated or even disappeared. Urine can be concentrated to varying degrees. If the lesion involves the hypothalamic thirst center, the patient’s thirst can also disappear, so that the patient cannot replenish water in time, and severe dehydration can occur. Plasma osmotic pressure and blood sodium concentration increase significantly. Water is lost inside and outside the cell, causing hyperosmosis.

Group: headaches, myalgias, increased heart rate, irritability, confusion, delirium, coma and high potential can cause death. People with mild dehydration may have dry skin, sweat, saliva reduction, chapped lips, decreased appetite and constipation.

If non-tumor mechanized diabetes insipidus can be replenished in time, the general health of the patient can be maintained in pituitary disease.

In addition to the above manifestations of secondary diabetes insipidus, there are still symptoms and signs of primary disease.

Congenital nephrogenic diabetes insipidus, which can develop from January to February after birth, often cry, irritable, dry mouth, quiet after feeding. If not diagnosed in time, or insufficient water supply, hypertonicity Dehydration, the mortality rate is 5 to 10%. This proves importance of this pituitary disease.

 

Laboratory inspection

1. Urine routine and renal function Understand urine protein, cast, pus cells, etc., and conduct bacterial culture to determine blood urea nitrogen, creatinine and electrolytes to determine kidney conditions.

2. The specific gravity of urine, urine osmotic pressure in chronic kidney disease, urine osmotic pressure is often fixed at about 285mmol / L. Most patients with diabetes insipidus have an osmotic pressure of less than 200mmol / L.

3. Blood potassium, calcium can detect polyuria caused by hypokalemia and hypercalcemia.

4. Plasma osmotic pressure: Normal people will feel thirsty if the plasma osmosis is greater than or equal to 290 mmol / L. Its threshold is significantly lower than this value, which can be <275 mmol / L.

 

Water test

Method

(A) Patient preparation

1. Antidiuretic drugs should be discontinued 24 hours before the test; chlorosulfuramide is discontinued three days before the test.

2. Drink water as usual on the test day and night.

3. Breakfast is available, but tea, coffee, tobacco and alcohol are forbidden.

 

(B) Water ban

1. Water is banned for 8 hours, generally starting at 8 am, with a small amount of dry food.

2. Urine is collected every hour, urine volume was recorded and osmotic pressure is measured.

3. The weight is measured every hour. If the weight loss is> 5%, or the weight loss is> 3%, but the plasma osmotic pressure is> 300mmol / L, the test shall be terminated.

If the patient’s urine output is reduced after hydration, urine specific gravity and osmotic pressure are both increased, diabetes insipidation can be excluded. Otherwise, the second phase of the test is continued.

 

 Vasopressin test

1. Intravenous injection of pituitary lutein 0.25 μ (vasopressin 0.1 μ), or 1-deamin-8 dextro-arginine vasopressin (DDAVP) 2 μ intramuscularly.

2. Patients are allowed to eat and drink, but the amount of water they drink must not exceed their urine output when water is forbidden.

3. Continue to record urine volume and measure specific gravity and osmotic pressure.

As a result, the explanation of the water-free test is shown:

This test can cause severe dehydration in severe diabetes insipidus, which is dangerous. Therefore, this test must be performed under close observation and can only be performed during the day. If the plasma osmotic pressure can be measured at the same time, it has good reference value.

 

Table for Explanation of the water ban test:

Urine osmolality (mmol / L) diagnosis

After water withdrawal After vasopressin injection

> 750 > 750 normal, primary polydipsia

< 300 > 750 central diabetes insipidus

< 300 < 300 nephrogenic diabetes insipidus

300 ~ 750 <750 partial diabetes insipidus or primary polydipsia

 

 Hypertonic saline test

Method:

1. Drink water as usual at night, ban water after midnight, and eat dry food.

Second, do not use coffee, tea, alcohol, do not smoke.

3. Drink 20ml / kg of water within 1 hour of the test day.

4. Empty the bladder 30 minutes after drinking, and then urinate once every 15 minutes. Calculate the urine output. If it exceeds 5ml / min, you can continue the test.

5. Intravenous infusion of 2.5% sodium chloride, input at a rate of 0.25ml / kg / min, for a total of 45 minutes. After the infusion was started, urine was collected every 15 minutes for a total of 3 times.

6. If the urine output does not decrease, use intravenous injection of posterior pituitary 0.25μ (vasopressin 0.1μ), and continue to observe the urine output, specific gravity and osmotic pressure.

Results: Central diabetes insipidus did not respond significantly to hypertonic water, but responded well to vasopressin. Renal diabetes insipidus did not respond to either. Normal people and psychiatric polydipsia respond well to hypertonic saline.

7. Plasma arginine vasopressin (AVP) determination can better diagnose diabetes insipidus. Normal human plasma AVP has a basal value of 1 to 5 pg / ml, which can be as high as 15 pg / ml or more after water banning. Renal diabetes insipidus has a significant increase in plasma AVP. Central diabetes insipidus has decreased significantly and it cannot rise after water abstinence.

8. 1-Deamin-8-D-VP-D-AVP treatment test: DDAVp 5 ~ 10μg, once a day nasal inhalation for 2 weeks. Central diabetes insipidus can improve thirst and drink more. Renal diabetes insipidus can’t be improved. Mentally drink more can appear progressive dilute hyponatremia, accompanied by weight gain and increased urine osmotic pressure. You should perform this test under the close observation of a doctor.

 

Diagnosis

According to the history, urine volume, urine specific gravity and osmotic pressure are not difficult to diagnose the disease. For some mild diabetes insipidus, when it is difficult to diagnose, you can choose to conduct a water test or a hypertonic saline test. If conditions permit, it can also be used for plasma AVP measurement and DDAVP treatment test. The cause of the disease should be diagnosed. Photos of the saddle, skull CT, magnetic resonance examination, fundus examination, visual acuity and visual field measurement and even anterior pituitary function measurement. The diagnosis of central diabetes insipidus needs to be differentiated from renal diabetes insipidus and psychotropic polydipsia.

 

Treatment

For light patients, those with less than 4 litres of urine per day may not need treatment and only need to drink enough water. Severe patients must be given the necessary medication.

I. 1-Deamin-8-D-V-Arginine vasopressin (DDAVP, desmopressin) has an anti-diuretic effect about 3 times stronger than natural vasopressin. Its blood pressure-raising effect is very weak. Its anti-diuretic effect is sustainable 12 hours. If the drug is administered nasally, 10 to 20 μg each time for adults, 5 μg each time for children, 1 to 2 times a day. For intramuscular or subcutaneous injection, 1 to 2 μg each time, 1 to 2 times a day. When the required dose is exceeded, dilute hyponatremia can occur.

II. Lysine vasopressin (lypressn) effect is maintained for about 4 hours. Spray 1 to 2 times into the nasal cavity each time, 3 to 5 times a day, 5 ml per bottle, containing 50 units per ml.

III. Pitressin tannate inoil intramuscular injection, every 0.2 ~ 0.3ml, can maintain the efficacy of 2 to 6 days. The initial dose starts at 0.1 ml and gradually increases to an effective amount. This medicine has the effect of raising blood pressure, which is contraindicated in patients with hypertension and coronary heart disease. Each bottle of 5ml contains 100mg.

The above vasopressin preparations are mostly used in critically ill patients. For partial diabetes insipidus, oral medications are mostly used, mainly including:

1. Chlorpropamide is a sulfonylurea preparation, a diabetic hypoglycemic agent, but the drug is also effective for mild central diabetes insipidus. It can increase the sensitivity of renal tubules to vasopressin, but may not be effective in severe cases. The dosage is once daily, 100-250mg each time. This medicine is often delayed after taking it, and it takes 3 days for the symptoms to improve. The use of this medicine must pay attention to blood glucose monitoring to prevent hypoglycemia.

2. Carbamazepine is a primary anticonvulsant, but it is also effective for partial diabetes insipidus. The dose is 400 to 600 mg per day, which can increase the secretion of vasopressin in some patients.

3. The pharmacological effects of clorfibrate are unknown, the dosage is 0.2-0.4g, 3 times a day.

4. The mechanism of action of thiazide diuretics is unclear. The commonly used drug is dihydrodiuretic, 25mg, three times a day, and potassium supplementation at the same time to prevent hypokalemia. Also belonging to this class of drugs are bendrofluazide and polythiazide. The former dose is 5mg, once a day. The latter is 1mg, once a day. Both need to pay attention to potassium supplementation. If necessary, can be added to amphotericin.

Renal diabetes insipidus cannot be treated with vasopressin preparations, sulfonylurea or amide imidazine. But it can be improved by thiazide diuretics.

Finally, the cause of diabetes insipidus should be identified as much as possible and necessary causative measures should be taken for the cause. So this was about pituitary disease or hypothalamus.

 

 

 

 

Refer also:

 

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