Introduction

Meningiomas are "brain tumors" although they do not grow from brain tissue. They arise from the meninges - the thin tissue covering the brain and spinal cord. They usually grow inward causing pressure on the brain or spinal cord, although occasionally they also grow outward and cause the skull to thicken.

They are usually benign i.e., non-cancerous, and slowly growing, and often grow to a large size before showing symptoms.

Incidence

They are the very common tumor in people between 40-60 years of age. Benign meningiomas occur in both men and women.

Causes

Like other brain tumors, the cause of meningiomas is unknown. In some cases, an abnormal chromosome #22 has been found, but what causes this chromosome abnormality is uncertain.

Symptoms

The first symptoms are usually due to increased intracranial pressure caused by the growing tumor. Seizures and headaches are common symptoms. Other symptoms depend on the size and location of the tumor.

Diagnosis

The diagnosis may be suspected from symptoms and the neurological examination, but CT and / or MRI scans are required to determine the location, size and probable type of tumor.

MRI Scan Showing Meningiomas

Treatment

Surgery

Surgery is the primary treatment for meningiomas in the brain or spinal cord. Surgery often involves removal of the tumor, part of the meninges and abnormal bone. Some tumors can only be partially removed because of their location or adherence to vital brain structures. Partial removal will relieve symptoms, and because tumor growth is slow, it could be many years before further treatment, if any, is necessary.

Several surgical "tools" are available to help the neurosurgeon during surgery. High-powered operation microscopes allow the surgeon to see the tumor and vital structures clearly. UltrasoRic aspirators may be used to break up and suck out the tumor. In some cases where the tumor has a rich blood supply, cerebral angiography (X-ray of the blood vessels of the brain) may be required to allow embolization (blockage) of the tumor blood supply.

Surgical removal of benign meningiomas usually provides a cure. The length of recovery after surgery varies according with the age and general health of the patient, the location and size of the meningioma. Steroids are often given to reduce brain swelling around the. tumor before and after the operation. Anti-convulsants may be used to control seizures before surgery or prevent their occurrence after surgery. Weakness, co-ordination or speech problems may occur after surgery. Physical, occupational and speech therapy may help reduce these impairments which are often temporary in duration.

In the elderly, small meningiomas may be monitored frequently and brain scans done during the period of observation to see whether the tumor is enlarging in size. Surgery can be avoided if the tumor does not increase in size. New symptoms or signs must be reported to the attending doctor so that he can reassess the situation.

Radiosurgery

Radiosurgery may be used for meningiomas that cannot be operated on for medical reasons, when total removal was not possible or for small recurrences. Radiosurgery directs beams of radiation at the tumor, and allows the tumor to receive a single massive dose of radiation in 1 -2 hours, and is most suitable for small tumors. The radiation does not kill the tumor but stops it from growing. It involves fixing a special frame (stereotactic frame) on the head under local anaesthesia followed by a MRI scan before treatment on the radio surgery machine. It is usually done as an outpatient procedure.

Recurrence

Recurrence can however occurs when the entire or meningeal orgin cannot be removed by surgery or killed by other treatment, or when it is of malignant nature. The recurrence rate is also higher when the tumour has typical features. It is the therefore important that the patients comes for regular follow –up and CT or MRI scans that may be ordered by the neurosurgeon from time to time. Treatment for a recurrent meningoma may be a second surgery, radiation therapy or chemotherapy may be used.