Glioma is the medical term for a primary brain tumour that originates in the glial cells of the brain. The glial cells are specialized cells that outnumber neurons as the most common types of cells present in the brain. One of the most important functions of these cells is the formation of myelin sheaths around neurons, which helps in the faster conduction of nerve impulses.
A glioma occurs when the glial cells multiply rapidly out of control.
There are three main types of glial cells: astrocytes, oligodendrocytes, and ependymal cells. Gliomas are named after the type of glial cells from which they are derived. For example, a glioma that develops from abnormal astrocytes is an astrocytoma. Similarly, gliomas evolved from oligodendrocytes and ependymal cells are known as oligodendrogliomas and ependymomas, respectively. Of the three types of gliomas, the most commonly seen are astrocytomas.
Symptoms of a glioma develop gradually and are therefore, likely to go unnoticed in the initial stages of the disease. Some of the common symptoms include headache, seizures, problems with speech and language, visual disturbances, and visibly reduced cognitive and functional capabilities.
Scans form the foundation of a glioma diagnosis. These include a CT scan or an MRI scan. The scans create detailed images of the brain to diagnose tumours. In cases where the scan indicates a tumour, the doctor may order a biopsy (removal of a small sample of the tumour for microscopic examination) to confirm the diagnosis.
Treatment of a glioma involves a multi-disciplinary approach and often includes valuable inputs from neuro-surgeons, oncology specialists, pathologists, and radiation therapists. A standard treatment plan considers factors that include location of the tumour, general symptoms, age, overall health of the patient, and stage of the disease. Surgery (craniotomy) is the most commonly adopted treatment method. The aim of this surgery is to remove the maximum possible amount of tumour. Other treatment options include radiotherapy (destroying tumour cells using high dose radiation) and chemotherapy (use of cancer-killing drugs).