He Panhypopituitarism Is a condition characterized by inadequate or absent production of hormones from the anterior pituitary.
The anterior pituitary or adenohypophysis is a part of the Pituitary gland . It is responsible for segregating hormones essential for the functioning of the organism. Mainly the following: growth hormone (GH), gonadotropins, thyroid stimulating hormones (TSH), pituitary hormone corticotropin and prolactin.
Due to the anatomical relationship that the pituitary has with the Hypothalamus , There may also be defects in the synthesis or secretion of hypothalamic hormones.
Panhypopituitarism may have different manifestations depending on the age at which it appears. Some of them are short stature, low blood pressure, dizziness, muscle weakness, micropenis, optic atrophy, hypoglycemia, dry skin, fatigue, constipation, etc.
However, these symptoms depend on the hormones that are affected and will vary if the condition is congenital or acquired.
Panhypopituitarism can have multiple causes. It may appear as a problem during the embryonic period. Or, by some lesion, inflammation or tumors in more advanced ages.
This disease is chronic and requires permanent treatment to replace missing hormones. Depending on the deficient hormones, the indicated treatment will be different. This is based on pharmacological support.
The terms hypopituitarism and panhypopituitarism are sometimes used interchangeably, although the latter concept usually refers to a total deficit of certain hormones produced by the anterior lobe of the pituitary.
Both hypopituitarism and panhypopituitarism are very rare conditions. There are really few studies that examine the prevalence of this condition. Most are focused on hypopituitarism in general.
According to Bajo Arenas (2009), the prevalence of hypopituitarism is 45.5 out of 100 000. Presenting 4.2 new cases per 100 0000 inhabitants.
Pituitary gland and panhypopituitarism
To understand panhypopituitarism, it is important to know the mission of the pituitary gland.
The pituitary gland, also called pituitary, is the one that is affected in panhypopituitarism. This gland is the"endocrine master of the body"because it controls the functions of other endocrine organs.
Thus, it secretes hormones that regulate other important glands maintaining the homeostasis (equilibrium) of the organism. It seeks the adequate administration of nutrients and proteins that we capture from the diet.
Through the hormonal levels, the pituitary controls functions such as: growth of the body, hair and nails, body mucous membranes, breast milk, etc.
This gland is located on a bone called the"Turkish chair"that is found in the bone efenoides of the skull. Thanks to its location, it connects with the hypothalamus more easily, through a structure called a pituitary stem. The hypothalamus forms control the anterior pituitary.
The hypophysis Or pituitary is divided into anterior and posterior lobe. The former produces thyroid stimulating hormone (TSH), corticotropin, luteinizing hormone (LH), follicle stimulating hormone (FSH), growth hormone (GH) and prolactin. While the latter secretes vasopressin (antidiuretic hormone) and oxytocin.
As mentioned, in panhypopituitarism there is an absence of these hormones for various causes. Therefore, patients who suffer from it may have problems in the functioning of their body.
Panhypopituitarism can originate from acquired causes or, less frequently, from genetic causes. When the pituitary gland does not work as it should, but the causes have not yet been identified, it is called"idiopathic panhypopituitarism."
It appears that the most common acquired causes are tumors that affect the pituitary gland. The second most common cause is Sheehan's syndrome, which occurs in women after childbirth. It is characterized by an infarct in the pituitary gland as a result of a hemorrhage during or after childbirth.
The following are the most possible causes of panhypopituitarism:
- Defects during the embryonic development of the cells that make up the anterior pituitary, or the hypothalamus.
- Acquired infundibular lesions (in the posterior part of the pituitary gland) following a stroke, for example.
- Both hypothalamic and pituitary tumors. In adults, the most common are pituitary adenomas and account for between 10% and 15% of intracranial tumors. They tend to grow slowly and affect women more. However, they do not normally metastasize.
Craniopharyngiomas may be present in children. They are tumors that appear by embryonic remains of the bag of Rathke (a structure that during embryonic development gives rise to the pituitary gland). They are manifested by an increase in intracranial pressure, headaches, vomiting, low stature and slow growth.
- Metastasis of other tumors, such as breast, prostate, colon or lung.
- Treatments with radiotherapy.
- Granulomatosis (inflammation of the blood vessels) that involve the area of the pituitary or hypothalamus.
- It can arise as a result of hemochromatosis. This is a hereditary disease that affects the metabolism of iron producing too high levels of iron.
- Autoimmune diseases in which the immune system fails and attacks healthy tissues of the body. An example is the lymphocytic autoimmune pituitary, in which the system destroys the lymphocytes of the pituitary.
- Pituitary apoplexy: this is an ischemia or a hemorrhage that affects the pituitary gland. It produces symptoms such as headache, vomiting and visual deficit.
- Sequelae after surgery that affects the pituitary or involved areas.
- Vascular problems in this gland such as the Sheehan syndrome mentioned above, or aneurysm in the internal carotid (which irrigates the gland).
- Cranial injuries.
- Syndrome of the empty Turkish chair. It occurs when the pituitary gland shrinks, pressured by an increase in filtered cerebrospinal fluid.
- Genetic causes, such as genetic mutations in PIT1 or PROP1. A genetic syndrome that is associated with panhypopituitarism is the Kallmann's syndrome . It is characterized by the lack of development of the sexual characters and olfactory alterations.
The symptoms of panhypopituitarism vary greatly depending on the causes, age, how quickly it appears, the hormones involved and the level of severity.
In this way, there may be patients who present with severe hypothyroidism (deficient functioning of the thyroid gland). While others only feel general malaise or excessive tiredness.
Obviously, the consequences are worse when panhypopituitarism appears earlier.
The absence of hormones produces different symptoms according to what they are. Thus, a lack of growth hormone (GH) causes low stature in children. While in adults it results in changes in body shape, problems in the metabolism of glucose and lipids, and general feeling of malaise.
The deficit of gonadotrophins, on the other hand, would cause women to delay menstruation or lack of menstruation and low libido. In men it produces sexual dysfunction and micropenis (if the problem appears in childhood).
On the other hand, if there is an absence of thyroid stimulating hormones (TSH) hypothyroidism would appear that is characterized by weight gain, fatigue, cold intolerance, muscle aches, constipation, depression , etc.
The lack of adrenocorticotropic hormone or corticotrophin (ACTH), has more negative consequences and could endanger the life of the patient. Above all, if the deficit occurs abruptly. In that case, it is manifested by low blood pressure, hypoglycemia, nausea, vomiting, extreme tiredness and low blood sodium concentration.
If ACTH levels go down slowly, the symptoms are weight loss, weakness, fatigue and nausea.
On the other hand, the lack of prolactin is a very revealing symptom of panhypopituitarism. It can prevent women from producing milk after pregnancy. It also causes the Sheehan syndrome described above.
Other general symptoms of panhypopituitarism are hypersensitivity to cold, decreased appetite, anemia, infertility, loss of pubic hair, lack of body hair, facial swelling, inhibited sexual desire, etc.
Excessive thirst and exaggerated increase in urine secretion may also occur, which come from diabetes insipidus. The latter condition arises from a deficit of vasopressin, a hormone that is produced in the hypothalamus and is stored in the pituitary gland.
Treatment of panhypopituitarism
The main treatment of panhypopituitarism is to replace those hormones that are absent or deficient. At the same time the underlying cause that caused this condition is treated.
Exact hormone doses should be prescribed to an endocrine after having performed the appropriate tests. They must be the quantities that the organism would naturally make if there were no panhypopituitarism. This hormone replacement can last a lifetime.
Corticosteroids such as hydrocortisone or prednisone are usually prescribed to replace those hormones that are missing due to corticotropin deficiency (ACTH). They are drugs that are taken orally two to three times a day.
To replace thyroid-stimulating hormone (TSH) deficiency, a medication called Levothyroxine .
There may be a deficit of sex hormones. To reach normal levels, in men, testosterone is given through different forms. For example, through the skin with a patch, with a gel for daily use or by injections.
In women, estrogen and progesterone are added to the body with gels, patches, or pills. Oral contraceptives are the most used in young women, while women close to menopause are recommended valerate estradiol.
When there is a deficit in growth hormone, it is necessary to inject somatropin under the skin. Those who receive this treatment in adulthood, will notice obvious improvements, although they will not increase their height.
On the other hand, if there are fertility problems caused by panhypopituitarism, it is possible to inject gonadotropins to stimulate ovulation in women. As well as the generation of spermatozoa in men.
Strict adherence to treatment is important to improve. Like a follow-up over time by an endocrine specialist. This will check that the treatment is being effective, and that the hormone levels remain within the normal range.
In cases in which there are tumors that have produced panhypopituitarism, surgery is necessary to remove them. While, if the pituitary is under pressure, it can be opted for a decompression of the latter through transsphenoidal surgery (bypassing the Sphenoid bone ). This last treatment is the most appropriate to treat pituitary apoplexy.
Apparently, rapid decompression has been shown to restore pituitary function partially or completely. In addition to reducing the need for chronic hormone therapy (Onesti, Wisniewski & Post, 1990).
Patients with panhypopituitarism appear to be twice as likely to die. Mainly due to respiratory and cardiovascular affections. However, if it is detected early and treatment is met, the patient can make a normal life.
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