Pituitary apoplexy is an acute condition that occurs due to a sharp increase in the size of a pituitary tumor due to its rupture, hemorrhage or necrosis. The disease is accompanied by severe headaches, visual impairment, nausea, vomiting. The defeat of the pituitary gland causes hypopituitrism. Compression of the cerebral vessels leads to the development of local ischemia. Diagnosis is based on brain tomography, determination of the level of tropic hormones. Treatment depends on the severity and prevalence of the pathological process. With extensive lesions, hormonal therapy and surgical intervention are performed to decompress brain structures.
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Pituitary apoplexy is an urgent condition in neurosurgery characterized by hemorrhage into the cavity of the Turkish saddle and compression of the structures of the parasellar region. The disease is rare, but it always poses a threat to the patient’s life. Apoplexy develops mainly in patients with actively growing pituitary tumors and neoplasms of large or giant sizes. Hemorrhages into neoplasms are more common, less often – ischemic infarcts, necrosis.
The acute condition occurs in patients with corticotropic and somatotropic adenomas, gliomas, metastases to the pituitary tissue. The following factors can lead to apoplexy:
- Long-term anticoagulant therapy. The use of high doses of blood-thinning drugs with an increase in blood pressure can provoke the occurrence of bleeding from a brain vessel.
- Tumors of the pituitary gland. The rapid growth of neoplasms causes compression of nearby brain structures, violation of the trophism of the pituitary gland.
- Radiation therapy. Radiotherapy of brain tumors causes a violation of the integrity and nutrition of the vascular network up to the formation of trophic ulcers, bleeding.
- Traumatic brain injuries. Bruises, concussions of the brain, fractures of the skull bones lead to mechanical damage to brain structures or neoplasms.
- Conducting studies of the pituitary gland. Invasive methods of assessing pituitary function can lead to a violation of the integrity of the neoplasm tissues and cause bleeding.
- Idiopathic hemorrhage. There are cases of spontaneous apoplexy without previous physical or chemical influences.
The pathogenesis of apoplexy is associated with the formation and active growth of a pituitary tumor. This condition is accompanied by an increase in the vascular network, an increase in local microcirculation. Physical or chemical effects on the tumor provoke a violation of the integrity of the capillaries and the outflow of blood into the subarachnoid space. The active growth of the neoplasm causes compression of the medulla, cranial nerves, vessels feeding the brain. This explains the rapid development of neurological symptoms in pituitary apoplexy. Compression of nerves leads to disruption of the function of other systems (visual, respiratory, cardiovascular). Most often there is a lesion of the adenohypophysis, the neurohypophysis remains intact and functions normally.
The clinic of the disease depends on the size of the neoplasm, the type of damaging factor, can vary from insignificant symptoms to impaired consciousness and coma. About 25% of pituitary apoplexy occur without clinical manifestations. Massive bleeding in the parenchyma of the brain is characterized by a rapid increase in neurological symptoms. There is an intense headache in the frontal or paraorbital zone, nausea, vomiting. In the absence of treatment, cerebral edema develops, clouding of consciousness up to coma.
With the rapid growth of the tumor and dislocation of brain structures, visual acuity decreases up to blindness, ptosis occurs, visual field defects. Compression of the internal carotid artery leads to an ischemic stroke, compression of the middle cerebral artery leads to disruption of the olfactory tracts, the development of anosmia.
The defeat of the pituitary gland causes various endocrine disorders. With a small tumor size, minor hemorrhage, the level of tropic hormones remains normal. Extensive bleeding is accompanied by dysfunction of the anterior pituitary lobe and the development of hypopituitarism. This condition causes a decrease in the secretion of adrenocorticotropic (ACTH), somatotropic (STH), thyroid-stimulating (TSH), follicle-stimulating (FSH), luteinizing (LH) hormones, prolactin. 5-10% of patients with pituitary apoplexy develop diabetes insipidus, accompanied by polyuria, polydipsia.
Extensive hemorrhages, penetration of blood into the cerebrospinal fluid cause the development of meningeal symptoms, impaired motor function, the development of stupor, sopor, coma. With parenchymal hemorrhage in the median structures of the brain, epileptic seizures, loss of consciousness, paralysis occur. The defeat of the cardiovascular and respiratory center of the medulla oblongata causes sudden death. Generalized damage to the adenohypophysis leads to a deficiency of all tropic hormones (pangypopituitarism) and hypofunction of the peripheral endocrine glands. There is a sharp weight loss, pronounced asthenization, signs of hypothyroidism and hypocorticism, neuropsychiatric disorders, pituitary coma.
The variability of symptoms and laboratory analysis data make the diagnosis of pituitary apoplexy difficult. It is mandatory to consult an endocrinologist, neurosurgeon, ophthalmologist, neurologist. If apoplexy is suspected , the following examinations are carried out:
- Radiation diagnostics. CT brain with contrast is the main diagnostic method that allows you to identify areas of hemorrhage, necrotic tissue, bulky formations of any size. Brain MRI or skull x-ray in the lateral projection is performed in the absence of the possibility of CT. Radiography allows you to detect a volumetric formation in the pituitary fossa. MRI reveals necrotic areas, tumors of small size.
- Analysis of the hormonal background. Blood sampling is performed to determine the level of cortisol, prolactin, thyroid hormones, gonadotropic and somatotropic hormones.
- Monitoring of the general condition of the body. It is carried out using a blood test, urine analysis, cerebrospinal fluid analysis, biochemical blood analysis with a mandatory study of the level of urea, creatinine and electrolytes (Na, K) in dynamics.
Differential diagnosis of pituitary apoplexy is performed with rupture of a cerebral aneurysm, other intracranial neoplasms, occlusion of the carotid artery. In this case, angiography of intracranial vessels is additionally performed. With impaired consciousness, the disease is differentiated from other acute conditions: viral and bacterial meningitis, meningoencephalitis, extensive stroke. For diagnosis, cerebrospinal fluid is taken to determine protein, blood, leukocytes, glucose.
The treatment tactics depend on the severity of the pathological process, the clinic of the disease. In case of endocrine insufficiency, hormone replacement therapy is carried out until the condition stabilizes. With the increase in symptoms of intracranial hypertension, a sharp decrease in vision, the threat of brain edema, loss of consciousness, surgical decompression of the brain is performed.
The operation is performed urgently by transsphenoidal or transcranial accesses. During the intervention, the material is taken for histological examination, the pressure on the vital structures of the brain is relieved, the tumor, necrotic masses and hemorrhagic clots are completely removed. At the end of the operation, ventricular drainage is installed in order to prevent intracranial hypertension and cerebral edema. In the postoperative period, acid-base, electrolyte balance is restored, endocrine disorders are corrected with the help of glucocorticoids, thyroxine, sex hormones. If necessary, artificial lung ventilation is continued.
Prognosis and prevention
The prognosis for apoplexy depends on the type and volume of damage to brain structures. In case of local hemorrhage with preservation of normal brain function, provision of emergency specialized care, the prognosis is favorable. In most cases, it is possible to stabilize the condition, return the normal level of hormones and electrolytes. Massive hemorrhage, rapid tumor growth with compression of brain structures rarely occurs, leading to rapid disruption of consciousness, coma and death. Prevention of the occurrence of pituitary apoplexy consists in the dispensary observation of a neurologist and an endocrinologist, annual computed tomography of brain tumors.