Meningiomas are tumors that arise from the coverings of the brain, known collectively as the meninges. As a rule, they are histologically (under the microscope) benign; often though they may act in a very harmful way, either by harming nearby brain structures or creating a disturbance in the brain that causes a seizure. Many are discovered after imaging the brain for unrelated reasons (incidental). Others create symptoms that lead to their discovery, such as headaches, seizures, lethargy, weakness, vision loss, loss of smell, or balance disturbance, to name a few.
Meningiomas may run in families and may be induced by remote (20+ years) radiation exposure. Their treatment greatly depends on several factors such as the severity of symptoms, the size of the tumor, the growth rate, and the location and extent of spread. For example, a small tumor found incidentally (without symptoms) will often simply be followed with serial MRI scans. On the contrary, a large tumor near the cerebellum that is causing fluid backup on the brain (hydrocephalus) may be an emergency requiring an immediate operation.
Surgery is usually the treatment of choice. First, though we must decide if surgery is needed and by which approach. Symptoms that are related to pressure from the tumor respond well to its removal. For example, pressure on the nerves to the eyes (optic nerves) from a meningioma may lead to loss of peripheral vision, and once the tumor is removed, the vision will return. Another example of an indication for surgery is for treatment of brain irritation: removal of a tumor that has caused a seizure will greatly reduce the chance of future seizures.
At Cerebrum MD, we have several methods we use in these surgeries gleaned over the years from working with accomplished meningiomas surgeons. These include methods for preventing post-operative seizures and methods for preventing certain strokes associated with removal of these tumors.
The cure rate for surgery is influenced by the characteristics of the tumor and by its location. Tumors over the brain surface have the highest cure rates (>90%), and those underneath the brain in the so-called “skull base” are hardest to fully eradicate with surgery. This is because tumors under the brain are more often wrapped around sensitive nerves and major arteries than those over the surface. Occasionally removal of a meningioma may be dangerous, such as one that is inside a major vein in the head (the sagittal sinus), and in those cases, we may choose to leave part of the tumor or choose radiation treatment instead of open surgery.
At the moment there is no good chemotherapy or pills for the treatment of meningiomas. If surgery cannot accomplish the goals of treatment, focused radiation, such as CyberKnife is effective.