【Disease Science】 What is meningioma of lateral ventricle?

Menoma is one of the common intracranial tumors, and the most common sites are the frontal, apical, and occipital regions, the convex surface of the brain, the sinuses, the sphenoid crest, and the anterior cranial fossa. Lateral ventricle meningiomas are rare meningiomas with a low incidence, accounting for 0.15% -4.15% of intracranial meningiomas and 20% -30% of lateral ventricle tumors. Clinical features of lateral ventricle meningioma: lateral ventricle meningioma is derived from ectopic to choroid plexus, choroid tissue and arachnoid cells Ⅲ of lateral ventricle wall. It is a rare meningioma. Because of the rich triangular choroid plexus, 70% ~ 80% of the lateral ventricle meningiomas are located in the triangular area, and can also extend to the temporal angle, occipital angle and body. The blood supply mainly comes from the anterior choroidal arteries and / or posterior choroidal arteries. Adults are more common than children, and more women than men. More than on the right. Some scholars believe that the incidence of meningiomas in the lateral ventricle is more common in women, and the incidence of meningiomas in children is lower, but most of them are located in the lateral ventricle. Early diagnosis of lateral ventricle meningiomas is difficult. Because most of the tumors are benign, the growth is slow, and the lateral ventricle space is relatively large. It has a compensatory effect on the gradual growth of the tumor. There are few local symptoms. The early lack of localization signs, the general course of disease long. When the tumor grows larger, it will produce a space-occupying effect or affect the cerebrospinal fluid circulation, causing symptoms of high intracranial pressure and surrounding brain tissue compression. It is manifested as progressive headache and papilledema, because the tumor has a certain degree of activity in the brain chamber. It can produce flaps, especially near the interventricular foramen. Changing the head position can cause acute intracranial pressure to increase, which is characterized by the characteristic Brun sign. The typical headache is usually paroxysmal, accompanied by vomiting, sometimes exacerbated, sometimes relieved Therefore, it is easy to be misdiagnosed as neurological headache or vascular headache, etc., or because the symptoms are lighter at the time of onset and fail to attract attention, so it is impossible to obtain early diagnosis and delay treatment. When the tumor compresses the internal capsule, the adjacent internal capsule, basal ganglia, visual pathway and other structures cause hemiplegia, gait instability, sensory disturbance, aphasia, abducens nerve palsy, facial paralysis, vision loss, and isotropic hemianopia. Symptoms include memory loss, mental symptoms and even unconsciousness. Therefore, those who often have headaches and symptomatic treatments are not effective, with or without typical neurological signs, should also think of the possibility of this disease. The lateral meningeal meningioma mainly depends on CT and MRI examination to confirm the diagnosis. CT plain scan shows a round-shaped homogeneous high-density or slightly high-density shadow in the lateral ventricle. The border is clear, and some tumors have calcification, often accompanied by varying degrees of lateral ventricle enlargement. There is an edema zone around the brain parenchyma of the tumor, which is moderately enhanced Intensification, you can also see the connection between the tumor and the choroid plexus. Sometimes the center of the lesion is unevenly strengthened, and there may be cystic changes or necrosis. In MRIT1WI, most tumors are equal signals, and a few are low signals. T2WI shows slightly high signals, equal signals or low signals. After the enhancement, most of them appear to be evenly strengthened, and sometimes blood vessel emptying phenomenon can be seen, and some of the larger tumors can see white tumor edema around the tumor. MRI three-dimensional imaging can also understand the anatomical relationship between tumors and surrounding important structures. Whole brain angiography (DSA) or CTA, MRA can clarify the abnormal blood supply of the tumor, abnormalities of the anterior choroidal arteries or (and) posterior choroidal arteries, including thickening of blood vessels, tortuosity and tumor staining, and the main supply of meningiomas to arteries and veins The backflow situation, etc., provides a basis for the surgical approach. Choice of surgical approach for lateral meningioma: the ideal surgical approach should fully expose the tumor, easily handle the tumor blood supply artery, fully relax the brain tissue, and avoid the functional area is the basic principle of lateral ventricle tumor resection surgery. Therefore, it should be determined according to factors such as the location, nature, size and blood supply of the tumor, whether the tumor is located in the dominant hemisphere, the patient’s neurological dysfunction before surgery, and the possible neurological deficit after surgery. Temporal occipital valve approach is the safest and most reliable. Open 3 to 4 cm next to the longitudinal fissure of the brain, and cut the parietal lobe 4 to 5 cm long from 1 cm behind the central sulcus to the occipital sulcus, and reach the triangular area of ​​the lateral ventricle. The advantage of this human path is that the path is short, it is satisfactory, it is easy to access the tumor, and it can avoid excessively pulling or tearing the blood vessels and cortical blood vessels outside the brain; even if the tumor is too large and deep, it can also handle the tumor roots and blood vessels. The relationship with the choroid plexus makes the bleeding significantly reduced during the operation; the operation is in the posterior corner of the sensory area and the upper edge of the margin. It is suitable for the lateral ventricle triangle and the back of the body, extending to the occipital angle. Of the larger tumor. But the disadvantage of this approach is

[Disease Science] Surgical treatment of medullary ependymoma

The main function of the medulla oblongata is to regulate visceral activity. Many of the basic centers necessary to maintain life (such as breathing, circulation, digestion, etc.) are concentrated in the medulla oblongata. Once these parts are damaged, they often cause rapid death, so the medulla oblongata has a “center of life”. Said. If the medulla oblongata remains intact, even if the upper part is damaged, the functions of breathing and circulation can be temporarily maintained without immediate death. The brainstem, which controls almost everything in life, has long been called the “forbidden area” for brain surgery because of its special anatomical location and important physiological functions. The medulla oblongata is the center of breathing and circulation. This part of the damage can cause breathing, circulatory failure and other life risks, and the mortality rate is extremely high. Resection of tumors at the medulla oblongata of the brainstem was once considered a world problem and a contraindication to surgery. With current medical technology, intraoperative mortality is still as high as 60%. Associate Professor Zhao Tianzhi introduced: If the medullary ependymoma is operated, the biggest problem is that once the medulla oblongata is slightly inadvertently harassed, whether it directly damages or affects its blood supply, it will cause serious breathing, heartbeat, blood pressure and circulatory dysfunction. Complications, therefore, while removing the tumor, how to minimize the damage to the medulla oblongata, its supply artery and the drainage vein as much as possible is the key to this operation, so as to ensure a good prognosis for the patient. Ependymomas are mostly located in the ventricle of the brain, and the main body of a few tumors are located in the brain tissue. The posterior cranial cavity ependymoma mainly occurs in the depressions of the top, bottom and side walls of the fourth ventricle. The tumors located in the fourth ventricle mostly originate from the medulla of the ventricle floor. The growth of the tumor can occupy the fourth ventricle and cause obstructive hydrocephalus. Sometimes the tumor can extend through the middle hole to the occipital cistern. A few can compress or even surround the medulla oblongata or penetrate into the spinal canal to compress the upper cervical spinal cord. Some tumors originate from the top of the fourth ventricle, occupying the cerebellar hemisphere or the vermis, and occasionally the tumor occurs in the cerebellopontine angle. On-screen tumors are more common in the lateral ventricle, which can originate in various parts of the lateral ventricle and often infiltrate into the brain parenchyma. It is rare to occur in the third ventricle, and those located in the front of it can extend to the two ventricles through the interventricular foramen. Supraventricular ependymoma is thought to originate from the epithelial epithelium of the lateral ventricle or the third ventricle. The tumor can be completely in the ventricle, partly in the ventricle, and partly outside the ventricle. However, the tumor may also occur anywhere in the hemisphere of the brain and is completely located outside the brain. The tumor originates from the ependymal cell crest, which may be the result of a deformity when the neural tube is folded. , Parietal lobe, and third ventricle.