Pathology of pituitary failure

2021-01-27 12:00 AM

Lack of TSH in children will delay the development and manifest hypothyroidism in both children and adults. Lack of ACTH leads to adrenal insufficiency

Outline

The pituitary gland is an important gland that regulates the activity of other endocrine glands called the receptors, including the adrenal gland, thyroid, gonads, and mammary glands ...

The pituitary gland, on the other hand, is regulated by the hypothalamus.

An excess or deficiency of pituitary hormones will be clinically indicated by an increase or decrease in the activity of those glands, which is the Feed-Back phenomenon. The pituitary gland has two main lobes, the anterior and posterior lobes:

The anterior lobe has 3 duties

Regulates body growth: Due to STH (Soma hormone, Somatotropin, Somatotroph, or GH: Growth hormone) secreted from acid-loving cells. STH secretion is also regulated by an intermediate Somatomedin or IGF-1, which is secreted from the liver, intestines, and pancreas.

Adjust the operation of the target routes:

TSH: Regulates the activity of the thyroid gland (thyrotrope).

ACTH: secreted by basophils, regulating adrenal gland activity (corticotrope).

Sex hormones: LH, FSH (gonadotropin).

FSH: Follicule stimulating hormone, in men, is in charge of testicular growth, spermatogenesis and sperm production. In women, FSH stimulates follicle growth (De Graaf).

LH: Lutéotrophin Hormone, in men, has a nutritional effect on Leydig cells, stimulates the secretion of testostérone. In women, LH coordinates with FSH to ripen De Graaf follicles and secrete estrogen, LH has the effect of ovulating and forming luteum, secreting progesterone and estrogenic.

Lactation hormone: PRL (lactotrope): PRL is secreted increase during pregnancy, lactation, stress, PRL rate in women increases nearly 50% higher than in men. PRL regulation is mainly due to the inhibitory effects of Dopamine. Some commonly used dopaminergic antagonists such as psychiatric drugs, gastrointestinal bandages also cause an important increase in PRL secretion.

Normal: PRL <25 ng / ml in women, <18ng / ml in men.

The most basic metabolic effect is sugar metabolism.

Rear lobe

Contains ADH hormones (Vasopressin, Oxytocin), ADH is secreted from the lower region

hypothalamus.

Reason

Development / Structure

Transport factor injury.

Dysplasia/aplasia of the pituitary gland.

Congenital cranial nerve block, encephalocele.

Primary pituitary hollow.

Congenital hypothalamus disorder (visual septal dysplasia, Prader-Willi syndrome, h / c Laurence-Moon-Biedl, h / c Kalman).

Injury

Surgery and filtering.

Radiation irradiation.

Head injury.

Tumour

Adenoma of the pituitary gland.

Extra-pituitary tumours (meningioma, germinoma, ependymoma, glioma).

Nang Rathke.

Craniopharyngioma.

Hypothalamic hamartoma, gangliocytoma.

Lymphoma, leukaemia.

 Meningioma.

Infiltration / Inflammation

Hemochromatosis.

Lymphocyte pituitary inflammation.

Sarcoidosis.

Histiocytosis X.

Granular pituitary inflammation.

Damage to blood vessels

Pituitary anaemia.

Pregnancy-related: diabetic infarction, postpartum pituitary necrosis (Sheehan).

Sickle cell disease.

Arteritis.

Infection

Fungus: histoplasmosis.

Parasitology: Toxoplasmosis.

Tuberculosis.

Pneumocystis carinii

Clinical

Clinical anterior pituitary failure

In contrast to a primary dysfunction of the pituitary, usually one hormone enhancement, in premenostasis is usually a generalized failure. The predominant clinical manifestations are growth disorders, puberty, and sexual dysfunction. In general, the clinical manifestation of pituitary insufficiency depends on the type of pituitary hormone that is missing or absent.

Lack of GH is the cause of reduced body development.

Gonadotropin deficiency causes menstrual disorders and infertility in women and decreased sexual function and secondary sexual loss in men.

Lack of TSH and ACTH usually develops after a pituitary failure process. Lack of TSH in children will delay development and manifest hypothyroidism in both children and adults. Lack of ACTH leads to adrenal insufficiency.

Lack of PRL reduces lactation.

The following are the clinical manifestations of anterior pituitary failure

Paediatric patients:

In the elderly, the mental and sexual symptoms of children, the height of the patient depends on their age at the time of pituitary failure. If the patient develops as a child, the patient will be short, if the adult arises, the height is nearly normal or normal.

Genital Obesity Syndrome:

Obesity in the front of the neck, the nape of the neck is not affected.

Obesity in the chest, abdomen and extremities.

Skin is smooth and soft.

Genital: In children with little or no physical development, in adolescents without puberty, in adults, women have missed periods, hair loss, infertility. Men are impotent, child genitals, and female genitals are less developed.

Symptoms of tumour insertion.

Simonds Disease:

Causes: Due to failure of the entire pituitary gland, mainly due to anterior lobe failure. Poly-glandular failure syndrome caused by a decrease in the anterior pituitary hormone

Clinical:

Functional signs: Weakness, fatigue, often more tired in the afternoon than in the morning). Genital disorders. Lipothymie due to hypotension and hypoglycaemia

Entity mark: Green; atrophy of the skin and appendages; hypogonadism (impotence, amenorrhea, menopause without facial blisters); reduce HA. Signs of pituitary tumour insertion: headache, pain behind the eye socket, visual limitation

Subclinical:

CTM: anaemia; Reduced blood glucose; Na + health decreased, K + health increased.

Thyrotrope impairment: T3, T4 decreased, TSH is hypersensitive (or normal).

Gonadotroph impairment: Testosterone, Oestradiol decreased, FSH, LH decreased.

Corticotrope impairment: Cortisone, decreased ACTH, Synacthene test (ACTH) positive.

Distinguishing test for hypothalamic insufficiency (hypothalamus) or pituitary failure: Test TRH, Test LH-RH, LVP, positive if the cause is a hypothalamic failure, negative if the cause is pituitary.

Measurement of plasma PRL.

TRH test: inject TM 200 - 400 μg TRH, then measure PRL at 0 ', 30', 60 ', 120'.

Normal results: PRL increased by <60 ng / ml in women.

<80 ng / ml in men.

Sheehan:

Postpartum pituitary necrosis, the symptoms are much milder. The symptom onset is very rapid after birth, signs of no discharge, pubic hair growth (after shaving), or falling, no menstrual return, no blushing, no sweating. The full symptoms usually appear after a long time with skin atrophy, discolouration, weakness with all signs of premenstrual insufficiency.

Subclinical:

Biochemical diagnosis of pituitary failure showed that all hormones were low. For example, a low FT4 with low TSH suggests secondary hypothyroidism. Low testosterone analogy without an increase in gonadotropin suggests a decrease in gonadal function due to decreased pituitary gonadotrophin secretion.

Posterior lobe failure syndrome

Reason:

Due to lack of ADH (due to autoimmune pituitary inflammation) or damage to the hypothalamus-pituitary.

Clinical manifestations: Diabetes insipidus:

Clinical symptoms:

It usually happens suddenly.

Urinary volume: urine volume 8-10 litters / 24 hours. In some cases, a lot of urination can reach 15-20 litters or not very much, but the form of the urine is very specific: pale like la water.

Heavy drinking: Heavy drinking occurs after excessive urination, to compensate for the amount of water lost due to excessive urination. If you do not drink water, the patient is very uncomfortable, sometimes with acute dehydration: high fever, shortness of breath, nausea, vomiting, sometimes delirium, so drinking a lot during MSM has 3 specific characteristics: no, I can't stop drinking, I don't feel bored and drink continuously. Drink both day and night, patients must wake up from thirst.

If you try not to drink water, still urinate a lot, but are affected by the posterior lobe essence, injecting the posterior pituitary essence, will reduce the amount of urine (test treatment with ADH) or with dDAVP.

Usually does not affect your fitness much

Other symptoms: The pulse increased rapidly; the blood pressure decreased.

Subclinical:

Low urine osmolality <200mosm / l.

Increased plasma permeability.

Increased Na + blood (> 142mM / l).

Low plasma ADH.

Low urine density <1.005.

Proteinuria (-), Glucosuria (-).

DDAVP test: IV 4μp or 2μp dDAVP (p <50kg) every 2 hours, monitor pulse, BP, urine volume, urine osmolality. If urine volume decreases and urine osmolality increases, ECG or hypothalamus

Water restriction test:

If urine volume decreases and urine osmolality increases: primary drinking is. If urine volume and urinary osmolality do not change diabetes insipidus due to ADH, then injected with dDA.VP, if urinary volume and osmolality do not change, then TN due to kidney.

Subclinical addition

Cranial X-ray to see pituitary fossa: Jaw and forehead are wide open, skull thick, irregular, especially the outer part. The pit may be wider, or deeper, the wall lines are not clear, the muzzle is thinned, and the muzzle is shaped like a bird.

The scanner is not.

Measure STH (GH) for 24 hours or day or night every 20-60 minutes (because STH is secreted in a day-and-night rhythm.

Urinary STH measurement / 24 hours.

Somatomedin, or IGF plasma ..

STH measurement during the oral braking test (HGPO),

The baseline STH or GH is normally <5ng / ml, after the oral glucose tolerance test, STH <2ng / ml, if the disease is to the extreme extremes, then the weakened braking test is ≥2 ng / ml.

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