Because meningiomas tend to grow inward, they commonly cause pressure on the brain or spinal cord. Although less common, meningiomas can grow outward, causing the skull to thicken. Meningiomas grow very slowly, and it is oftentimes many years before they become symptomatic. Neuroscientists are not certain of the cause of meningioma, although several theories are being investigated. Most agree that a malformed chromosome is the most common abnormality in meningiomas, but the cause of this abnormality is unknown.
Symptoms vary by location and size of the tumor.
They often first appear as headaches and seizures, primarily due to increased pressure of the growing tumor. Weakness in the arms or legs, or loss of sensation, may occur with spinal cord meningiomas. This will help determine the size, location, and type of tumor, if one exists. Skull x-rays may be obtained if the tumor is believed to involve the bone. For spinal cord tumors, a myelogram may be done, and in some cases, arteriograms, or x-rays of the blood vessels, are necessary.