Overview of Meningioma
Parafalciparous meningiomas are a group of common meningiomas located in the longitudinal fissure of the brain and connected to the falx of the brain, often protruding into one cerebral hemisphere, and may sometimes develop bilaterally. Sometimes it may develop bilaterally. There are also a few tumors that are flat and grow infiltratively in the cerebral falx.
Etiology
Meningiomas of the falx cerebri are mostly of the endodermal and fibrous type, which begin in the falx cerebri and do not contact the inner plate of the skull, and therefore do not undergo local cranial changes. The tumor may be supplied by the cerebral falx meningeal artery or by the intracerebral artery, which may be anteriorly from a branch of the ophthalmic artery, posteriorly from the occipital artery, and centrally from the middle meningeal artery. There are multiple dilated veins within the cerebral falx at the base of the tumor and nearby.
Symptoms
Most of the parafalcine meningiomas are buried in the longitudinal fissure of the cerebral hemispheres, which is a deeper location. When the tumor is small, it usually does not cause obvious clinical symptoms, so the tumor tends to be large at the time of the onset of the disease. Since the central cortical area is lightly involved, the symptoms of limited brain damage are less common than those of sagittal sinus meningioma. Once the movement disorder appears, it manifests as starting from the foot, gradually affecting the whole lower limb, followed by upper limb muscular disorder, and finally spreading to the head and face. If the tumor grows to both sides of the cerebral falx, the patient may have bilateral limb weakness with dysuria.
Another important clinical symptom of the tumor in this area is epileptic seizures, which mostly start with limited seizures on the opposite side of the limbs or face, and then gradually form generalized grand mal seizures. In addition, anterior cerebral falciform tumors can cause psychiatric symptoms, whereas the incidence of epilepsy in the posterior cerebral falciform region is low. About 2/3 of patients present with increased intracranial pressure. Meningiomas in the posterior 1/3 of the falx of the brain are particularly common. Meningiomas in this part of the brain only cause visual field changes, which often do not attract the attention of the patients, and the tumors often grow to a huge size before they are detected.
A few parafalciparous meningiomas may develop bilaterally, and those occurring in the central cortical area may cause spastic paralysis of both lower limbs and urinary disorders. If the tumor occurs in the central cortex, it may cause spastic paralysis of both lower limbs and urinary disorders. If the tumor occurs in the posterior part of the brain, it may compress the talar fissure of the occipital lobe bilaterally and cause blindness.
Examination
1. Cerebral angiography
Cerebral angiography shows that the vascular pattern and circulation of the tumor are similar to that of other parts of the meningioma, but the tumor staining is not close to the top of the skull, and there is a gap between the tumor and the skull. If the tumor occurs in the posterior part of the falx, the posterior cerebral artery may be thickened and shifted to the opposite side. Falciform meningiomas may also have a dual blood supply, anteriorly from a branch of the ophthalmic artery, posteriorly from the occipital artery, and centrally from the middle meningeal artery. At this time, the thickened middle meningeal artery reaches upward to the inner parietal plate and then turns downward, showing a broom-like or radial shape to the midline cranial cavity, suggesting that the tumor is attached to the cerebral falx.
2. CT and MRI
CT shows unilateral or bilateral spherical or flat occupations next to the falx, with clear borders. On plain scanning, it is an isodense or slightly dense mass with punctate or irregular calcification, and the base of the cerebral falx is wide. One side of the lateral ventricle may be displaced or deformed by compression. The tumor shows obvious enhancement after injection of contrast medium. When the tumor is large, the cerebral veins are compressed and their reflux is impeded, and edema will appear around the tumor.MRI can better reflect the boundary of the tumor and the degree of edema of the surrounding brain tissue, and more accurately reflect the relationship between the tumor and the sagittal sinus and the important cerebral cortical structures, which is a guide to the choice of surgical access. The signal on MRI scan is the same as other parts of meningioma.
Diagnosis
The diagnosis can generally be made according to clinical manifestations and imaging examinations.
Treatment
Surgical resection is the mainstay. For those who cannot tolerate surgery, stereotactic radiotherapy can be considered, e.g., gamma knife, X-knife, etc.
Questions you may be interested in
What is the treatment for meningioma next to the falx cerebri?
Meningiomas can be treated by microscope-assisted surgical resection.
Surgery is the treatment of choice for parafalciparous meningiomas, which often grow from the base of the falx to the sides of the falx.
The disease has a long course and the clinical symptoms are not obvious, making early diagnosis difficult. Many patients are diagnosed with large tumors that have already formed a space-occupying effect, causing headaches and other neurological symptoms. As the tumor site is deep and surrounded by important blood vessels and brain functional areas, the space for surgical operation is narrow and the operation is difficult.
Microsurgery is the main surgery used in recent years, during which the structure and anatomical relationship of the tumor and surrounding tissues can be explored with the assistance of microscope to magnify the local fine structure and avoid accidental injury during the operation. Therefore, microscope-assisted surgical resection can be the preferred treatment method.
It is recommended that patients should consult the doctor as early as possible and receive timely treatment in order to prolong the survival period.