What Is Panhypopituitarism?

The hypothalamus-pituitary system plays a very important role in maintaining the stability of the human environment and neuro-endocrine function. This system is closely related to the body's water and electrolyte metabolism balance, feeding, reproduction, immunity, behavior, psychology and aging and other life activities, and its regulation is quite complicated. When hypothalamic-pituitary lesions occur, a variety of clinical manifestations often occur, such as water and electrolyte disturbances, food intake disorders, temperature regulation disorders, decreased reproductive function, abnormal growth and development, etc., which affect the quality of life and survival of patients. Hypothalamic-pituitary system diseases are one of the doubts and difficulties in clinical diagnosis and treatment.

Basic Information

Visiting department: Department of Neurology, Endocrinology
Common locations: Hypothalamus, pituitary
Common causes: Bacterial or viral infections, congenital abnormalities, intracranial space occupying lesions, autoimmune diseases, traumatic brain injury, tumors, vascular injuries, pituitary resection, etc.

Common symptoms: Water and electrolyte disorders, food intake disorders, temperature regulation disorders, decreased reproductive function, abnormal growth and development, altered consciousness, lethargy, and reduced motor function

Causes of hypothalamic-pituitary lesions

Bacterial or viral infections, congenital developmental abnormalities, intracranial space-occupying lesions, autoimmune diseases, traumatic brain injury, tumors, vascular injuries, pituitary resection or pituitary stem rupture, radiotherapy injury, etc. The pathological basis of hypothalamic-pituitary system diseases is that both the hypothalamus and the pituitary can secrete a variety of hormones that act on multiple target glands in the body, thereby participating in the body's water-electrolyte metabolism balance, feeding, reproduction, immunity, behavior, psychology and aging, etc. Related to various life activities.

1. The hypothalamus can secrete a variety of pituitary hormone releasing hormone, pituitary hormone releasing inhibitor, antidiuretic hormone, oxytocin and other polypeptides, such as the hypothalamus hormone thyroid stimulating hormone releasing hormone, gonadotropin releasing hormone, growth hormone releasing inhibitor, Corticotrophin-releasing hormone, growth hormone, melanin-releasing factor (MRF) and melanin-releasing factor (MRIF), prolactin-releasing factor (PRF) and prolactin-inhibiting factor (PIF), antidiuretic hormone (ADH) , Also called vasopressin) and oxytocin.

2. The pituitary gland is divided into neural pituitary gland and adenoid pituitary gland. The anterior and middle lobe of the pituitary gland are collectively called the pituitary gland, which can secrete a series of protein and peptide hormones, such as thyroid stimulating hormone (TSH), adrenocorticotropic hormone (ACTH), and luteinizing hormone. (LH), follicle stimulating hormone (FSH), prolactin (PRL), growth hormone (GH), melatonin (MSH), lipolytic hormone (LPH), endorphin, etc.

Classification of Hypothalamic-Pituitary Diseases

Cause classification

Inflammation, craniocerebral trauma, tumor, vascular injury, pituitary resection or pituitary stem dissection, radiotherapy injury, etc.

2. Types of abnormal hormones

Disease groups that cause pituitary hormone deficiency, disease groups that cause abnormal secretion of gonadotropin-releasing hormone (GnRH), disease groups that cause abnormal secretion of prolactin, and disease groups that cause abnormal secretion of corticotropin-releasing hormone (CRH).

3. Classified by age

Premature and neonatal diseases (intraventricular hemorrhage, bacterial meningitis, gangliomas, hemangiomas, or trauma, etc.); adult diseases (nutritive diseases, tumors, inflammation, etc.).

Clinical manifestations of hypothalamic-pituitary lesions

Both the hypothalamus and the pituitary gland can secrete a variety of hormones that act on multiple target glands throughout the body and participate in various life activities such as the body's water-electrolyte metabolism balance, feeding, reproduction, immunity, behavior, psychology and aging. There are various clinical manifestations depending on the location of the lesion and the endocrine function affected, such as water and electrolyte disorders (hypernatremia, diabetes insipidus), abnormal food intake (anorexia or weight loss), and temperature regulation disorders (high or low body temperature). ), Reduced reproductive function, abnormal growth and development, altered consciousness, lethargy, decreased motor function, and even mental disorders and severe memory disorders.

Hypothalamic-pituitary examination

Hormone determination

Indirect measurement of pituitary hormone, antidiuretic hormone measurement, vasopressin (AVP) detection, etc.

2. Pituitary function reserve test

Can assist in qualitative diagnosis.

3. Imaging examination

(1) MRI is an important basis for the localization and diagnosis of hypothalamic-pituitary lesions.

(2) CT showed better intracranial calcification or saddle base bone lesions than MRI.

(3) Octreotide scanning can assist in the localization diagnosis of pituitary space.

(4) PET examination is helpful for early diagnosis of pituitary injury and hypofunction.

Diagnosis of hypothalamic-pituitary lesions

Due to the wide variety of this disease and its diverse clinical manifestations, the diagnosis must follow the qualitative, localization and etiology diagnosis process.

Qualitative diagnosis

It is necessary to determine whether the hormone is secreted abnormally, and it must be combined with clinical manifestations and laboratory tests.

Most cases need to be qualitatively diagnosed by indirect determination of pituitary hormones and pituitary function reserve test based on clinical manifestations, and antidiuretic hormone determination (normal plasma antidiuretic hormone is 1 5mU / L, urine antidiuretic hormone is 10 60mU / L) is of certain value in clarifying the diagnosis of central diabetes insipidus, and it is of reference significance to dynamically observe the level of AVP in the water-free test.

2. Positioning diagnosis

It needs to be determined through clinical manifestations, hormone level analysis and imaging examination.

(1) Clinical manifestations The hypothalamic preoptic area is damaged with autonomic nerve dysfunction, and the anterior preoptic area has high fever. When the anterior part of the hypothalamus is damaged, there is a manifestation of feeding disorder. Anterior hypothalamus, supraoptic nucleus, and paraoptic nucleus are damaged with central idiopathic hypernatremia, diabetes insipidus, or inappropriate AVP secretion syndrome. Sexual dysfunction when the median eminence of the ventromedial hypothalamus is damaged, and the symptoms of adrenocorticotropic hormone (ACTH), growth hormone (GH), abnormal PRL secretion or diabetes insipidus. Anorexia or weight loss occurs when the medial lateral area of the hypothalamus is damaged. Damage to the ventromedial region of the hypothalamus is accompanied by bulimia, obesity, and personality changes. Damage to the posterior hypothalamus is often accompanied by altered consciousness, lethargy, decreased motor function, and hypothermia. Involvement of the papillary body and third ventricle is often accompanied by insanity and severe memory disorders. About 10% of women and 60% of men have precocious puberty lesions at the base of the third ventricle in the posterior superior hypothalamus or in the median bulge.

(2) Hormone level analysis Generally, it is not possible to determine the location of the lesion in the hypothalamus or pituitary by a single measurement of pituitary hormone level. The biosynthetic pituitary hormone-releasing hormone stimulation test can be used to analyze indirectly. If the pituitary hormone secretion level is significantly increased after stimulation, more It is suggested that the lesion is located in the hypothalamus. There is no peak of pituitary hormone secretion after stimulation, and the possibility of pituitary involvement is greater.

(3) Imaging inspection

1) MRI can show the pituitary gland and its surrounding soft tissue structure, can distinguish the optic cross and the saddle diaphragm, show whether the cerebrovascular and pituitary space invasion of the cavernous sinus, and whether the pituitary stem is interrupted or compressed. Occupy an important position. For example, some patients with central diabetes insipidus may find the pituitary handle thickened.

2) CT is better than MRI for calcification or saddle base osteopathy, and intracranial ectopic calcification can be found, such as calcification of craniopharyngioma.

3) Octreotide scanning has some value in the localization diagnosis of pituitary space.

4) PET examination can provide pituitary blood flow perfusion and ammonia metabolism, which is helpful for early monitoring of pituitary injury and early diagnosis of hypophyseal function.

5) Precautions Due to the small size of the hypothalamus and the absence of obvious morphological abnormalities in some diseases, it is difficult to find or confirm the lesions by current imaging studies, which leads to missed diagnosis or misdiagnosis, such as germ cell tumors and early pineal glands. Tumors require long-term follow-up to detect abnormalities.

3. Etiology diagnosis

Common causes include tumors, inflammation, congenital developmental abnormalities, and gene mutations, which are usually diagnosed by combining clinical manifestations and auxiliary examinations.

(1) Bacterial or viral infections often have symptoms of infection. In addition to routine examinations, cerebrospinal fluid analysis may increase the diagnosis rate. For example, routine examination of cerebrospinal fluid may increase the number of white blood cells and cerebrospinal fluid biochemical abnormalities may have certain diagnostic value for inflammatory lesions.

(2) Congenital developmental abnormalities occur in newborns, children, and adolescence. For example, pituitary stem interruption syndrome is manifested as growth retardation, Kallmann syndrome is manifested as hyposmia and adolescent asexual development.

(3) Intracranial space-occupying lesions may have increased intracranial pressure. Human chorionic gonadotropin (-HCG) and alpha-fetoprotein (AFP) in cerebrospinal fluid of patients with pineal gland hormone-secreting germ cell tumors were elevated. Pineal gland blastoma cells are prone to detachment, and CSF implantation occurs. If cerebrospinal fluid exfoliated cells are found, pathological cells can be diagnosed.

(4) Anti-pituitary cell antibodies have certain reference significance for the diagnosis of autoimmune diseases.

(5) Pituitary abnormalities For patients whose imaging examination only shows thickening of the pituitary stem, a pituitary biopsy can be taken through the sphenoid sinus to determine the etiology, but for pathological diagnosis of hypothalamus, it is difficult to obtain pathology.

(6) Genetic testing is an effective means for diagnosing the etiology of congenital or hereditary genetic mutation diseases. For example, Kallmann syndrome is caused by a mutation in the KAL gene, and pituitary stalk interruption syndrome can find genetic mutations such as HESXl, LHX4, OTX2, SOX3, and PROKR2.

Treatment of hypothalamic-pituitary lesions

The treatment of hypothalamic-pituitary lesions requires a treatment plan based on the cause.

1. Hypothalamic-pituitary hypofunction due to genetic mutation or genetic disease

Target gland hormone replacement or supplement of hypothalamic-pituitary hormone is the only effective symptomatic treatment. Most of the hypothalamic hormones are difficult to extract and synthesize, but there are also some clinical applications, such as GnRH analogs, desmopressin and so on. However, in hormone replacement or replacement therapy, how to make the replacement scheme closer to the physiological state and improve the treatment effect is still a problem in clinical treatment.

Tumor

Such as germ cell tumor, pineal tumor, radiotherapy has a very good effect. There is still a lack of large-scale clinical studies on whether a combination of chemotherapy and radiotherapy can achieve good results.

3. Notes

The lack of long-term follow-up during treatment is a problem that needs attention in the diagnosis and treatment of hypothalamic-pituitary disease.