Definition: When there is an occupying lesion in a subcavity of the cranial cavity, the pressure in that subcavity is higher than the pressure in the adjacent subcavity, and the brain tissue is displaced from the high-pressure area to the low-pressure area, which causes a series of clinical syndromes.
Classification: According to the location of cerebral herniation, there are five major categories: cerebellar herniation, foramen magnum herniation, pterygoid crest herniation, falx herniation, and central herniation.
Etiology.
1.Intracranial occupying lesion intracranial tumor, brain abscess, hematoma, parasitic disease, etc.
2, cerebrospinal fluid circulation disorders midline structural displacements and malformations and subcurtain occupying lesions, resulting in obstruction of cerebrospinal fluid circulation above the third ventricle, midbrain canal, and four ventricles, resulting in progressive high cranial pressure.
3, cerebral edema acute cranial injury or surgical trauma, intracranial inflammation, occupying lesions, subarachnoid hemorrhage.
4, Other causes poisoning, cerebral arteriovenous malformation and intracranial aneurysm after rupture, hypoxia, etc.
IV. Clinical manifestations.
1.Pupillary changes
2.Disorders of consciousness
3.Contralateral conus fasciculus sign and hemiparesis
4.Degenerative ankylosis
5.Alteration of vital signs
V. Auxiliary examination: Since brain herniation is an emergency, the examination time should be minimized. Most patients are allowed to have CT examination.
Emergency treatment of brain herniation.
1. If a patient with brain herniation is found in time, firstly, oxygen should be given, hypertonic dehydration (250~500 ml of 20% mannitol), tracheotomy or tracheotomy should be performed, changes in vital signs should be closely observed, preoperative preparations (blood routine, blood type, four items of coagulation, electrocardiogram, etc.) should be made quickly, fluids should be replenished, blood should be prepared if necessary, and the family should be informed of the critical condition and surgery should be recommended.
2.Surgical method:
Cerebellar curtain herniation
(1) Subtemporal muscle decompression: for obvious increased intracranial pressure with unknown etiology or cannot be ruled out for the time being (such as cerebral cysticercosis, cerebral arachnoid adhesions or sudden hemorrhage of deep brain tumor, liquefaction). Surgical attention: dura mater is completely incised without sutures, and the bone window should be large enough.
(2) Bilateral decompression with decompression of large bone flaps is mostly used for extensive cerebral contusion, and none of the designed bone flaps should be smaller than 8 cm (one on each side).
(3) Internal decompression: for obvious brain tissue edema, not only should the bone flap be removed for decompression, but also sub-temporal muscle decompression should be performed to remove part of the lifeless brain tissue to reduce brain pressure, brain edema, relieve intracranial pressure, and release brain herniation.
(4) Cerebellar curtain notch incision: Many scholars advocate that after brain herniation occurs, in addition to emergency removal of hematoma or excision of occupying lesions, the brain tissue embedded in the fissure of the curtain notch margin should be repositioned in order to release brain herniation.
(5) Ventricular puncture and drainage: It is more suitable for critically ill patients, especially for high cranial pressure crisis due to posterior cranial fossa or midline occupying lesions and inflammatory adhesive hydrocephalus.
Occipital foramen magnum herniation: This herniation is more urgent than cerebellar herniation, and rapid measures must be taken to save some patients. For on-the-spot first aid, drill a hole in the occipital horn under local anesthesia, perform external drainage of cerebrospinal fluid, rapidly reduce intracranial pressure, keep the airway open, perform tracheal intubation or tracheotomy in time, apply artificial ventilator for adequate oxygen supply, and monitor blood gas analysis. The application of hypertonic dehydrating agents, rapid identification of the cause of brain herniation, preoperative preparation, emergency surgical treatment, and release of the cause.