tentorial meningioma
Introduction
Introduction to cerebellar meningioma The cerebellar meningioma refers to a meningioma with a tumor base attached to the cerebellum (including the incision and the sinus area), which can be developed in the direction of the cerebellum or in the lower part of the cerebellum. Some of the sub-theft type and the dumbbell type will be classified into the posterior fossa meningioma. basic knowledge The proportion of illness: 0.001% Susceptible people: no special people Mode of infection: non-infectious Complications: brain stem injury brain edema aphasia meningitis
Cause
Cause of cerebellar meningioma
Pathogenesis
Tumors are mostly fibrous, and blood supply is mainly from basilar artery and meningeal artery. Some scholars in China divide it into: supratentorial type, which can compress occipital lobe and midbrain; under the curtain type, can compress cerebellum and brainstem; It can compress the upper and lower adjacent structures. Considering the surgical approach, it can be divided into four types: the curtain type, and the tumor originates from the cerebellum itself (the upper and lower surfaces of the cerebellum). In the notch type, the tumor originates from the free edge of the cerebellum. At the curtain type, the tumor originates from the junction of the cerebral palsy and the cerebellum. In the circumflex type, the tumor originates around the sinus.
Prevention
Cerebellar meningioma prevention
No special, early detection and early treatment.
Complication
Cerebellar meningioma complications Complications brain stem injury cerebral edema aphasia meningitis
If surgery is performed, the following complications may occur:
1. Brain stem injury: occurs in the tumor at the free edge of the cerebellum, due to the large extent of the tumor, or due to adhesion to the brain stem, when the tumor is removed, the brain stem is pulled or compressed, or the blood supply artery of the brain stem is damaged. Caused by this, the key to this complication is prevention. For example, the tumor and the brain stem are closely adhered and cannot be separated. It is difficult to handle, and part of the envelope may remain.
2. Cranial nerve injury: caused by compression or pulling of nerves during operation.
3. Others: such as cerebral edema, postoperative intracerebral hematoma, limb hemiplegia, hemianopia, aphasia and other dysfunction and meningitis and other complications.
Symptom
Cerebellar meningioma symptoms Common symptoms Cerebellar signs edema, two-handed rotation, clumsy, intracranial pressure, increased nystagmus, fingertips, blindness, visual field defect
The cerebellar meningioma tends to grow in both the on-screen and off-screen directions. Therefore, there are two symptoms of the occipital occipital and cerebellum. The tumors that occur under the cerebellum are mostly cerebellar symptoms. Because the tumor is mostly biased to one side, the cerebellar sign is There are more than one side, or one side, such as large horizontal nystagmus, finger nose and rotation movements are not good, etc., often characterized by lesion side, because the tumor originates from the brain parenchyma, so the cerebellar sign appears later than Symptoms of increased intracranial pressure, tumor growth to the occipital, affecting the occipital lobe and temporal lobe of the cerebral hemisphere, can cause visual field changes, quadrant visual field defects or unilateral hemianopia, individual patients have visual hallucinations, due to the slow growth of cerebellar meningioma Early symptoms are not obvious. Many patients have increased intracranial pressure at the time of treatment. Among them, 10% of patients have medical treatment for secondary optic disc edema or hemianopia.
Examine
Examination of cerebellar meningiomas
1. Cranial plain film: Orthotopic tablets can be found in the scaly scaly localized bone hyperplasia or destruction; the lateral side of the skull can be seen in the inner plate of the skull or the outer plate hyperplasia, the tumor sometimes penetrates the skull to the scalp, and soft tissue can also appear. Tumor shadow.
2. Cerebral angiography: cerebral angiography is necessary for larger tumors or tumors located in the cerebellar stenosis. On the cerebral angiogram, it can be observed that the corresponding arteries are displaced due to tumor compression and tumor staining. The supply of arteries can come from the cerebellar incision artery (from the epidural segment of the internal carotid artery). The underside can have blood supply to the cerebellum and the posterior cerebral artery. The tumor can be invaded by the onset of the occipital occipital lesion. Arterial tip elevation and forward displacement, the important sign of tumor invasion of the cerebellum is the development of the cerebellar incision artery, which branches from the epidural segment of the internal carotid artery (C4~5). Under normal circumstances, the artery is not developed. However, when the tumor is supplied with blood, the diameter of the tube is thickened, and it can be developed. The tumor is connected to the tumor area and the tumor blood vessels are separated. The vertebral artery angiography reveals that the distal end of the superior cerebellar artery is curved inward and the posterior cerebral artery can also be moved. Position, there is pathological blood circulation, and in the venous phase, the tumor of the cerebellar incision should pay attention to whether the straight sinus is squeezed and displaced, and provide information for the isolation of the tumor during surgery.
3. CT and MRI examination: Meningiomas originating from the cerebellar incision along the cerebellar margin grow adjacent to each other. Due to the obstruction of growth across the cerebellum, often all traces are formed. Meningiomas near the vertebral bone can resemble cerebellopontine angles. At meningioma, meningiomas from the transverse sinus or sinus area grow to the suprate or under the curtain. Axon scanning is difficult to judge the relationship between the tumor and the cerebellum. Coronal scanning should be performed, while menisiomas in the transverse sinus and sinus area should be performed. Often cause local bone hyperplasia and even cause transverse sinus, sinus sink thrombosis, MRI can clearly show the relationship between tumor and adjacent blood vessels, sinusoids and brain stem, due to the "flow effect" of blood vessels, on T1 and T2 weighted images Both are low-signal and form a significant contrast with the surrounding tumor tissue. MRI can also show changes in the skull caused by meningioma, but not as clear as CT.
Diagnosis
Diagnosis and identification of cerebellar meningioma
Cerebellar meningioma is difficult to diagnose before CT and MRI. It relies mainly on X-ray film, cerebral angiography and ventriculography. It is currently diagnosed according to clinical manifestations and imaging features. It should be noted in CT and MRI diagnosis. The following points: 1 The tumor grows on the screen or under the curtain. 2 The relationship between tumor and transverse sinus. 3 The tumor in front of the cerebellar incision should carefully understand the relationship between the tumor and the brain stem. The sagittal position of CT and MRI is more valuable for the diagnosis of this disease.
There are no special diseases to identify.
