Overview of the Hypothalamus
The hypothalamus is an important organ for reproduction. The hypothalamus regulates the function of the pituitary gland through nerve conduction and the pituitary-portal system, causing the pituitary gland to secrete the appropriate hormones, which act on the ovaries to produce steroid hormones to ensure the normal maintenance of reproductive function.
Etiology
Amenorrhea due to deficiency or dysregulation of the secreted form of the hypothalamic hormone GnRH. This includes amenorrhea due to improper feedback regulation of the hypothalamus caused by abnormal function of the hypothalamic-pituitary unit, abnormal central nervous system-hypothalamic function, and other endocrine abnormalities.
Symptoms
1. Psychogenic amenorrhea
These patients often have a history of mental stimulation, only scanty menstruation and amenorrhea, and may have infertility and weight loss. Relevant tests show high blood cortisol level, but there are no relevant clinical symptoms; gonadotropin-releasing hormone stimulation test shows that the pituitary gland is responsive or unresponsive to exogenous GnRH.
2. Pseudo-pregnancy
The patient desires to have children and develops depression, amenorrhea, lactation, and may have nausea and vomiting, loss of appetite and other early pregnancy-like reactions, which is a typical neuroendocrine disease. When the patient thinks that she is pregnant, the examination shows that the BBT continues to be in the high temperature phase, the pulse amplitude of PRL and LH secretion in the blood increases, and the level of E2 and P is maintained in the luteal phase. However, when the patient learns that she is not pregnant, her level of the above mentioned hormones may drop sharply, and then menstruation may come.
3. Anorexia nervosa
Anorexia nervosa is commonly seen in adolescent or young women, who are obsessed with thinness and excessive dietary restriction, which induces vomiting and even almost no eating. The patient is progressively emaciated and loses more and more weight. Amenorrhea is the most important manifestation (primary or secondary), accompanied by different degrees of hypogonadism.
4. Athletic amenorrhea
This disease is common in female athletes, due to long time participation in strenuous sports training or competition activities, so that the hypothalamus – pituitary gland function is abnormal, causing delayed menarche or normal menstruation temporary menstrual disorders and even amenorrhea. The incidence of amenorrhea is higher in long-distance runners and ballet dancers.
Tests
Ovarian function tests:
1. Vaginal exfoliative cell examination
It is the more common method to know the level of estrogen. The higher the percentage of superficial cells, the higher the estrogen level.
2. Cervical mucus
If the cervical mucus of amenorrheic patients is found to be transparent and thin mucus with good tension, which can be seen as amniotic crystals under the microscope after applying on a glass slide and drying, it indicates that the ovaries of the patient have the function of secreting estrogen.
3. Drug test
This is a commonly used diagnostic test for amenorrhea, especially in the absence of laboratory equipment for hormone measurement, the drug test is important for the evaluation of ovarian function and endometrial function. Progesterone test and estrogen test can be performed.
4. Measurement of sex hormone levels
Measurement of pituitary hormones is particularly important in diagnosing the cause of amenorrhea. Patients with amenorrhea and low estrogen should have their blood levels of FSH, LH and prolactin (PRL) measured. If FSH and LH are elevated, ovarian amenorrhea is suggested; if FSH and LH are low, the cause may be in the pituitary gland or the hypothalamus; FSH and LH are equivalent to normal follicular phase levels, and amenorrhea is due to hypothalamic secretion dysfunction; if LH is elevated and FSH is relatively deficient, the diagnosis of polycystic ovary syndrome should be taken into account; if PRL is abnormally elevated, and the amenorrhea is due to hyperprolactinemia, further testing for hyperprolactinemia should be performed. further investigate the cause of hyperprolactinemia, with special attention to the possibility of pituitary tumors. When FSH and LH levels are low, pituitary excitability test can further distinguish whether the lesion is in the pituitary gland or in the hypothalamus.
5. Basal body temperature measurement
It can indirectly understand the function of ovulation. After ovulation, the corpus luteum secretes progesterone, which has the effect of raising body temperature. Pelvic ultrasound can assist in the diagnosis of congenital uterine agenesis or malformation. Imaging of the saddle region can diagnose the presence of a pituitary tumor. Diagnostic curettage, uterine iodine-oil contrast and endoscopy may be performed to visualize the uterine cavity and endometrium. In addition, if other endocrine abnormalities or developmental malformations are excluded, hormone levels of other relevant glands such as thyroid and adrenal glands, biochemical and pathophysiological tests, and chromosomal tests should also be performed.
Diagnosis
Diagnosis is the process of finding the cause of amenorrhea, i.e., determining where amenorrhea occurs.
1. Medical history
Mainly menstrual history, age at menarche, menstrual cycle, etc. Determining whether it is primary or secondary amenorrhea is helpful in analyzing the cause of amenorrhea. It is important to know whether there are any congenital defects or other disease conditions, history of medication use and response to medication. It is also important to ask whether there were any triggers that led to amenorrhea before the onset of the disease, such as mental factors, environmental changes or other diseases.
2. Physical examination
Attention should be paid to the general condition, whether the development is normal or not, and whether there is any deformity. Whether the height and weight are in the normal range, the proportion of limbs and trunk, intelligence, nutrition and health status, check the development of the second sex characteristics, such as breast development, hair distribution, milk secretion, etc. The gynecological examination should pay attention to the development of internal and external genitals, with or without defects, malformations and tumors.
3. Ovarian function examination.
4. Pelvic ultrasound uterine iodine oil imaging and endoscopy.
5. Imaging examination of saddle area, pathologic examination and chromosome examination.
Treatment
In addition to treating the corresponding primary causes, the following principles should be adopted according to the estrogen level in the patient’s body and whether or not the patient has reproductive requirements.
1. Ovulation should be actively induced in patients with fertility requirements.
There are several methods to induce ovulation:
(1) Clomiphene is often used in polycystic ovary syndrome and certain hypothalamic amenorrhea with a certain level of estrogen in the body. Because of its cheapness and simplicity of use, it is by far the most used in clinical practice.
(2) Urotropin (HMG) It can be used for almost all hypothalamic amenorrhea.
(3) LHRH This method is only applicable to patients with amenorrhea who have abnormal hypothalamic GnRH secretion and normal pituitary and ovarian response. The administration of LHRH must simulate the physiological form of GnRH pulse secretion and release, and the intermittent pulsatile intravenous or subcutaneous, intramuscular administration of LHRH is also available through the nasal mucous membrane, anus, or vaginal route, and it is most ideal to be administered intravenously, and ovulation is monitored during the period of administration of LHRH.
(4) Bromocriptine For the treatment of amenorrhea caused by hyperprolactinemia, this drug is a dopamine agonist, which acts on the hypothalamus, activates the prolactin inhibiting factor, inhibits the pituitary gland from secreting prolactin, and decreases the level of blood PRL. Measure the basal body temperature to monitor ovulation during the period of taking the medicine.
2. For those who have no requirement for childbearing
For hypothalamic amenorrhea with low estrogen level, the treatment is still based on sex hormone supplementation; unmarried patients should choose the above ovulation induction treatment when they need to have children after marriage.
Prognosis
Hypothalamic amenorrhea is the most complicated type of amenorrhea, but generally speaking, it is the one with the best prognosis.