Pituitary apoplexy

Introduction to pituitary apoplexy The term pituitaryapoplexy is quite confusing in the literature. Some scholars believe that as long as there is infarction or hemorrhagic necrosis in the pituitary, whether it is clinically symptomatic, it should be classified as pituitary apoplexy; other scholars argue that Acute infarction or hemorrhagic necrosis occurs on the basis of pituitary adenomas, and pituitary dysfunction accompanied by headache and neuro-ophthalmologic symptoms can be called pituitary apoplexy. basic knowledge The proportion of illness: 0.08% Susceptible people: no specific people Mode of infection: non-infectious Complications: Diabetes insipidus

Cause of pituitary apoplexy

Pituitary adenoma (35%):

Pituitary adenoma is the most common cause of pituitary apoplexy. Pituitary adenoma can cause spontaneous bleeding, infarction, necrosis, and cause pituitary apoplexy, but some incentives also play a role. Trauma (including minor trauma) can induce pituitary apoplexy; cerebrospinal fluid pressure Changes such as decreased cerebrospinal fluid pressure caused by lumbar puncture, coughing, Valsava movements, and increased cerebrospinal fluid pressure caused by diving (over 18m) can induce pituitary apoplexy; changes in arterial blood pressure such as angiography and emotional arousal It can induce pituitary apoplexy; application of anticoagulant, elevated estrogen levels, bromocriptine treatment, radiotherapy of pituitary adenoma and pituitary function test can induce pituitary apoplexy.

Postpartum hemorrhage, diabetes and other diseases (20%):

Non-adenomatous pituitary apoplexy for many reasons, postpartum or postpartum hemorrhage, diabetes, arteriosclerosis, hypertension, tuberculosis, hypoparathyroidism, tetanus, heart failure, acute hemolysis, meningitis, temporal arteritis, high Skull pressure can cause pituitary apoplexy.

Pregnancy (25%):

Non-pituitary adenoma pituitary stroke pregnancy can cause hypertrophy of the pituitary gland, the pituitary suddenly loses the excitatory effect of placental hormone (mainly estrogen) after delivery, and the blood supply of the pituitary gland decreases, at this time, if there is major bleeding or other complications Systemic vasospasm, less blood flow in the pituitary gland, is prone to pituitary necrosis, the pituitary changes during pregnancy play a crucial role in the above process, because bleeding during childbirth or postpartum does not cause necrosis of other organs, Major bleeding caused by other causes, even if the amount of bleeding is large, pituitary necrosis is rare.

Arteriosclerosis can cause degenerative lesions in the blood vessels of the pituitary, and the resistance of the blood vessels to the injury is weakened. In some cases, bleeding in the pituitary can occur. In patients with arteriosclerosis, blood flow is slow and blood viscosity is increased, so that thrombus is easily formed in the pituitary. Cause pituitary infarction, such as hypertension, patients are more prone to pituitary apoplexy, diabetes can also cause pituitary apoplexy due to degenerative lesions of pituitary blood vessels, and some scholars have reported that acute myocardial infarction patients with heparin treatment induced pituitary apoplexy.

Pathogenesis

The incidence of intratumoral hemorrhage in pituitary adenoma pituitary adenoid pituitary adenoma is much higher than other intracranial tumors. The incidence of pituitary adenoma in the literature is about 5 times that of other intracranial tumors (pituitary adenoma is 9.6% to 17). %, other intracranial tumors were 2.9% to 3.7%). This characteristic seems to be independent of the location of the tumor. Because other non-adenomatous saddle tumors rarely bleed, a large number of studies have shown that the first change of adenoma pituitary apoplexy is a tumor. Internal ischemia, followed by edema, necrosis, and finally bleeding, pituitary adenomas may be associated with the following factors: some pituitary adenomas grow rapidly, exceeding the limit of tumor blood supply, causing ischemic necrosis, followed by Bleeding, some pituitary adenomas are not large, but strokes have also occurred. The reason may be that the growth of the tumor causes the upper pituitary artery of the nutritional tumor to be compressed. However, some people hold the opposite view, suggesting that the blood vessels of the pituitary adenoma are mostly derived. The inferior pituitary artery, such that compression of the superior pituitary artery will cause normal pituitary ischemia without necrosis, hemorrhage, and in addition, internal defects of the intravascular blood vessels (such as blood Tube hardening, increased fragility, etc.) are also associated with pituitary apoplexy.

Bromocriptine treatment can induce pituitary apoplexy. It has been reported in the literature that patients with PRL tumors and GH tumors have pituitary apoplexy within 2 hours after the first administration of bromocriptine. The mechanism of bromocriptine-induced pituitary apoplexy is still unclear. It is believed that bromocriptine causes tumor shrinkage and intratumoral vasoconstriction. It is also believed that bromocriptine can directly inhibit the division of tumor cells and reduce the organelles of tumor cells, thereby causing tumor cell necrosis, leading to intratumoral hemorrhage, pituitary adenoma. Radiation therapy can make the tumor vascular hyperplasia, thickening, hyaline degeneration, and then hemorrhagic necrosis. It should be emphasized that bromocriptine and radiation therapy can induce pituitary apoplexy, but it is rare after all (pituitary stroke itself is a rare disease). ), can not therefore deny the value of the two treatment methods.

Certain pituitary function tests (such as TRH test, GnRH test, insulin hypoglycemia test, etc.) can also induce pituitary apoplexy, the mechanism of which is unknown, may be related to the frequent rise of blood pressure during these tests.

The incidence of pituitary apoplexy in pituitary adenomas is related to the histological classification of adenomas. Early studies have revealed that eosinophilic and chromophobic adenomas are more prone to pituitary apoplexy, while basophilic adenomas and malignant pituitary tumors rarely occur. Subsequent studies have shown that GH tumors are prone to pituitary apoplexy. The reason may be that GH tumors are prone to hypertension and the intravascular blood vessels often have hyperplasia and hypertrophy.

Pituitary stroke prevention

Radiation therapy is not recommended in the acute phase, and antibiotics can be used in critically ill patients to prevent infection.

Pituitary stroke complications Complications diabetes insipidus

Pituitary apoplexy can aggravate the existing function of the pituitary gland. Some 70 patients with pituitary apoplexy were found. About 2/3 of the patients had acute adrenal insufficiency; 88% had GH deficiency; 42% of patients There is hypothyroidism; almost all patients have hypogonadism, and PRL levels are elevated (about 2/3 patients), the reason may be bleeding caused by pituitary stalk compression, reducing PIF to the pituitary gland, pathological examination confirmed The pituitary gland is common, but the occurrence of diabetes insipidus is rare. The reason may be that the posterior lobe is less involved, which is not enough to reduce the vasopressin. According to the literature, the incidence of transient diabetes insipidus is about 4%. The incidence of permanent diabetes insipidus is about 2%, and a small number of patients develop antidiuretic hormone secretion syndrome (SIADH) due to hypothalamic involvement.

Pituitary stroke symptoms common symptoms coma visual field defect high fever nausea sensory disorder dizziness diplopia hypotension

The onset is mostly acute, and a few are subacute and chronic.

1. Severe headache may be the expansion of the sella wall, the dura mater stimulation, the hemorrhagic stimulation of the subarachnoid space, the headache is mostly persistent, the part is on the side of the forehead, sputum, posterior or apical, occipital, and then expand To the full head.

2. Vision cross oppression can be sharply reduced within a few hours, even black sputum, blind, visual field examination of bilateral hemianopia, and double vision, extraocular muscle paralysis, pupillary abnormalities, drooping eyelids and facial dysfunction, these symptoms And the signs of the saddle-side compression of the cranial nerve involvement of the III, IV, V, VI may be bilateral or unilateral.

3. Meningeal stimulation of intratumoral hemorrhage such as escape to the subarachnoid space caused by hypothalamic dysfunction, increased intracranial pressure, headache, nausea, vomiting, neck stiffness, cerebrospinal fluid is bloody, the number of cells increased, about half of patients.

4. Hemorrhagic necrosis in the disturbance of consciousness disorder causes acute failure of pituitary function and compression of the hypothalamus, which can cause disturbance of consciousness. One third of cases may have lethargy, confusion, and coma.

5. Others may have high fever, shock, arrhythmia, gastrointestinal bleeding, hypotension, electrolyte imbalance, temporary diabetes insipidus and endocrine, hypothalamic dysfunction and other clinical manifestations, its impact on pituitary function depends on the stroke The location and extent, stroke can affect the release of hormones from the hypothalamus, block the blood flow of the pituitary portal vein or destroy the pituitary gland cells, or both. In addition, the internal carotid cavernous sinus can be cerebral ischemic signs, such as Hemiplegia, partial hemiplegia, quadriplegia, seizures, etc.

In fact, many patients do not have a history of pituitary adenoma at the time of treatment. At this time, it is easy to cause misdiagnosis. If the patient is conscious at the time of the visit, he can detect neurological ophthalmologic symptoms such as visual field defects, which is beneficial to the diagnosis, such as the patient has been comatose, or Although awake but no neuro-ophthalmological symptoms, the diagnosis is extremely difficult. Fortunately, CT has become popular in recent years. Timely CT examination can show existing pituitary adenomas and intratumoral hemorrhage, thus avoiding misdiagnosis.

Pituitary stroke examination

Pituitary CT, MRI has a rapid and accurate diagnostic value, can show pituitary tumors and hemorrhage and necrosis in the tumor, and can show whether the tumor grows on the saddle and the saddle, the saddle X-ray can show the expansion of the saddle , destruction, help diagnose.

If the tumor is hemorrhage or necrotic tissue leaks into the subarachnoid space, the cerebrospinal fluid is bloody, leukocytosis, the total number of white blood cells and neutrophils in the peripheral blood, such as the presence of pituitary dysfunction, blood thyroid hormone, thyroid stimulating hormone, Cortisol, adrenocorticotropic hormone, gonadotropin, testosterone, estradiol are reduced, such as pituitary tumors are prolactinoma, blood prolactin levels are elevated, such as adenoma secreting growth hormone, blood growth hormone ( Elevated levels of GH), such as adenoma secreting ACTH, elevated levels of ACTH and cortisol in the blood.

The performance of adenoma pituitary apoplexy on the flat film: saddle enlargement, saddle bottom thinning, destruction, saddle bottom fracture, saddle enlargement, saddle bottom thinning also seen in non-stroke pituitary adenoma, so no specificity, Only with the recent cranial plain film is valuable, saddle-bottom fracture is specific for the diagnosis of pituitary apoplexy, but its incidence is too low, in the acute phase of pituitary adenoma, CT shows clear high-density circular lesions After a few days, the density of the lesion gradually decreases. CT can also show the amount of bleeding. Whether the bleeding breaks into the subarachnoid space and the structural involvement around the pituitary gland, MRI can not show acute bleeding, so it is not preferred as a diagnosis, along with red blood cells. Destruction, deoxyhemoglobin is converted to methemoglobin, and methemoglobin can enhance the signal of T1 and T2 weighted images, so the signal density of hematoma gradually increases with time. Generally, hematomas within 7 days are in T1 and T2 weighted images were low or equal signal lesions (compared to surrounding brain tissue); 7 to 14 days of hematoma, the boundary signal increased, but the center of the hematoma remained low signal area; 14 days Later, the entire hematoma was a high-signal lesion on both the T1 and T2-weighted images.

Pituitary stroke caused by postpartum hemorrhage is characterized by pituitary ischemia, necrosis, and no hemorrhage. In imaging, the pituitary gland is reduced, and pituitary apoplexy caused by other diseases has corresponding performance.

Diagnosis and diagnosis of pituitary apoplexy

Patients with pituitary adenoma suddenly have severe headache and vomiting. The possibility of pituitary apoplexy should be considered. If the patient has vision loss, visual field defect and eye movement dysfunction, the pituitary apoplexy should be highly suspected. At this time, CT examination should be performed immediately. If a hemorrhagic foci is found in the pituitary, the diagnosis is established.

Differential diagnosis

1. Pituitary apoplexy should be differentiated from subarachnoid hemorrhage, bacterial meningitis, cerebral hemorrhage, cerebral infarction, pituitary metastatic tumor, ocular cross-stroke, retrobulbar optic neuritis and other diseases.

(1) Subarachnoid hemorrhage: Subarachnoid hemorrhage is caused by rupture of intracranial aneurysm or arteriovenous malformation, which is characterized by sudden and severe headache, accompanied by vomiting, disturbance of consciousness and meningeal irritation, and extreme pituitary apoplexy. Similar, but the development of this disease is faster than pituitary apoplexy, the time from headache to disturbance of consciousness is very short, lumbar puncture shows bloody cerebrospinal fluid, CT scan shows cerebral pool, blood in brain rupture but no saddle occupying position, however, pituitary apoplexy The blood can also enter the subarachnoid space, but it is rare, and the amount of blood entering is much less than the primary subarachnoid hemorrhage.

(2) bacterial meningitis and viral encephalitis: headache, meningeal irritation and fever associated with patients should be differentiated from bacterial meningitis and viral encephalitis, bacterial meningitis and viral encephalitis The height is more obvious, the white blood cell count is increased, the white blood cells and protein of the cerebrospinal fluid are increased, there is no neuro-ophthalmological symptoms, and the CT scan has no performance of the sphenoid saddle. According to this, it can be distinguished from the pituitary apoplexy. It is worth noting that some pituitary apoplexy has been reported. It can be expressed as aseptic meningitis, which is difficult to distinguish from bacterial meningitis. It is characterized by the ineffective treatment of antibiotics in such patients.

(3) cerebral hemorrhage and cerebral infarction: headache, vomiting, visual field defect, ocular motor nerve palsy, meningeal irritation, disturbance of consciousness, so it must be differentiated from pituitary apoplexy, cerebral hemorrhage and cerebral infarction have so-called "three-biased" performance, CT scans can show intracerebral hemorrhage or ischemic lesions, which can be differentiated from pituitary apoplexy.

(4) pituitary metastatic tumors: pituitary metastatic tumors are generally malignant, fast growth, can cause severe headache, visual field defects, ocular motor nerve paralysis, but these symptoms are gradually appearing, which is different from pituitary apoplexy, CT and MRI examination Helps identify.

(5) Optometry stroke: chiasmal apoplexy is caused by vascular malformation in the optic chiasm. The clinical manifestations are similar to pituitary apoplexy, such as sudden headache, visual field defect, vision loss, nausea, vomiting, The disease generally has no meningeal irritation, and CT shows no enlargement of the sella, but high-density space-occupying lesions may appear on the saddle.

(6) Posterior optic neuritis: posterior optic neuritis may have forehead or post-ocular pain, with vision loss, visual field defect and pupillary changes, similar to pituitary apoplexy, but the fundus of the second disease is very different, the optic disc of the posterior optic neuritis patient Congestion, blurred edges and mild elevation, edema, hemorrhage and exudation of the retina; normal fundus of pituitary apoplexy, in addition, CT examination of pituitary apoplexy can show the performance of the sella, while posterior optic neuritis normal.

2. The headache caused by pituitary apoplexy can be differentiated from the following diseases

(1) Aneurysm rupture: aneurysms develop more rapidly from the onset of headache to loss of consciousness, and are easy to rebleed. The optic nerve and oculomotor nerve paralysis are often unilateral, with no endocrine symptoms, and the amount of subarachnoid hemorrhage is also lower than that of the pituitary. There are many strokes, and arteriography can help identify.

(2) Intracranial infection: encephalitis, meningitis, etc. may have meningeal irritation, fever, no endocrine symptoms, increased white blood cells in the cerebrospinal fluid.

(3) cerebral hemorrhage: CT scan of the head, MRI examination can help identify, cerebral hemorrhage without endocrine changes of pituitary dysfunction.

(4) Posterior optic neuritis: headache, decreased vision, no visual field defect and increased saddle, normal pituitary function.

(5) Meningioma: headache, optic nerve compression, no pituitary function changes and abnormality of the saddle.

(6) Craniopharyngioma: In the case of hemorrhagic necrosis of the craniopharyngioma in the sella, the performance of pituitary apoplexy is difficult to distinguish from pituitary adenoma. It is necessary to rely on pathological diagnosis. Children with craniopharyngioma often have calcification.

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