Overview of Meningioma
Meningiomas originating in the convexity of the brain are second only to parasagittal sinus meningiomas in incidence, accounting for approximately 25% of intracranial meningiomas. The incidence is higher in the anterior half of the brain than in the posterior half. Most patients have symptoms of increased intracranial pressure such as headache and vomiting, and most cases have optic disc edema, leading to vision loss.
Etiology
The cause of meningioma remains unclear and may be related to the following factors.
1. Head trauma.
2. Type 2 neurofibroma.
Symptoms
Symptoms of meningioma of the convex side of the brain mainly depend on the location of the tumor and may range from psychiatric symptoms to motor disorders, sensory disorders and visual field defects. The incidence of epilepsy is high in this disease and is often the first symptom. Symptoms of increased intracranial pressure such as headache and vomiting are seen in the vast majority of patients, and in a significant number of cases optic disc edema leads to vision loss.
Examination
Tumor nodules can be seen in CT films, and MRI horizontal and coronal radiographs can clearly show the relationship between the tumor and adjacent structures. The tumor mostly shows long T1 and long T2 uniform signals, and after injection of contrast agent, the tumor mostly shows uniform and consistent enhancement, and its adjacent dura mater may also show enhancement effect, which manifests as the characteristic “meningeal tail sign”. In cerebral angiography, frontotemporal and central regions can see the characteristic displacement of blood supply arteries, the tumor vessels in the occipital region are not very obvious, and the vertebral artery angiography can see the thickening of the posterior cerebral artery. In addition, abnormal blood vessels and tumor shadows were seen.
Diagnosis
Usually when the volume of convex meningioma is very large, the diagnosis is relatively easy. Before 1970s, the diagnosis of this disease mainly relied on cranial plain film and cerebral angiography, and after the 1970s, CT was applied to the clinic, which could make a very clear diagnosis of this disease, and it is clearer than MRI, because in the latter image, sometimes the tumor is mixed with edema, which affects the qualitative diagnosis, such as the tumor is suspected to be related to sagittal sinus before operation. If the tumor is suspected to be related to the sagittal sinus before operation, it needs to be confirmed by cerebral angiography or MRI. Of course, cerebral angiography is not necessary for the diagnosis of convex meningioma.
Treatment
Surgery is the first choice. In addition to resection of the tumor, the dura mater and skull bone involved by the tumor should be removed as much as possible in order to reduce the recurrence rate after surgery. Stereotactic radiation therapy can also be considered depending on the needs of the disease.”