The brain and spinal cord is covered by a thin membranous structure called meninges. Meningioma is a tumor arising from meninges. Meninges is comprised of three layers, dura mater, arachnoid and pia mater. Most of the meningioma develops from dura mater. Almost one fifth of brain tumors are meningiomas and 90% of them are benign, the remaining 10% are either atypical or malignant.
Even if meningioma is benign, the growing tumor may cause disability or sometime even life threatening, as it compresses the brain. Most benign meningiomas are slow growing tumors. Often small size tumors may go undetected as they are asymptomatic.
Larger size meningiomas produce symptoms and signs by their local effect on the brain. In most cases meningiomas are in one location; however there are instances where multiple tumors exist at the same time in brain as well as spinal cord.
Causes Of Meningioma Tumors
- The tumors usually arise in middle aged and elderly individuals. The average age for meningioma is between 40 to 70 years.
- Meningiomas are more common in women than in men. The ratio of female to male is almost 3:1.
- Meningiomas are rarely seen in children.
- Other predisposing factor is exposure to radiation.
- People suffering from genetic disorders such as neurofibromatosis are susceptible to meningioma.
- Previous head injury and virus infection may cause meningioma, however the etiology is not properly understood.
- The rate of growth increases in a pregnant women and hormones are suspected to play a role during pregnancy for their fast growth.
Symptoms Of Meningioma Brain Tumor
The signs and symptoms of meningioma are gradual in onset. The symptoms depend on the location of the tumor in the brain or in the spinal cord. The initial symptoms are subtle before the disease is diagnosed.
In most cases, the symptoms are caused by brain compression or displacement from the growing tumor.
- Headache is common but not an invariable manifestation of meningioma. When present it is localized to one area of the head, and its site gives rough idea of location of the tumor to the physician.
- Headache is caused due to raised intracranial pressure. Headache is intensified by bending, coughing and straining at stool.
- When the growth is around the cranial nerves, there may be loss of smell, changes in vision such as blurred vision or double vision, hearing loss, loss of taste etc.
- Weakness and paralysis of limbs.
- Clouding of consciousness in varying degree, from listlessness to drowsiness.
- Inattentive and irritable in the beginning with gradual loss of memory.
- Epileptic fits due to raised pressure.
- Vomiting and slow pulse rate.
- Backache and pain in the lower leg if the tumor is a spinal meningioma.
Prognosis Of Meningioma Patients
Several factors are responsible for the prognosis of the disease. The prognosis of meningioma is assessed in the light of its site, its pathological nature meaning whether it is benign or malignant, its blood supply and the degree of disability it causes.
- Even the age of the patient can influence the prognosis; a young patient may do well after the surgery as compared to older patient.
- The tumor that tends to invade the brain has poor prognosis as compared to tumor not invading the brain.
- Meningioma on the outer surface of the brain which are easily accessible and completely removable have better hopes of survival than those that are situated deeply and are not accessible.
- Survival rate are highest in benign meningiomas while malignant meningiomas have poor prognosis.