Low grade glioma

A glioma is a type of brain tumour made up from supportive tissue of the brain, known as GLIAL cells. These cells support the nerve cells and help them perform their functions.

Gliomas are classified in four grades: I, II, III and IV. The treatment and prognosis of each tumour depends on its grade. Grade I or II are low grade gliomas, or LGG.

A tumour just means a lump that would not be there normally. It is a descriptive word and does not necessarily mean how serious it is. For example, a tumour describes benign conditions like warts as well as malignant cancers.

Pilocytic astrocytomas These tumours occur almost exclusively in people who are younger than 25 years of age. It is important to distinguish pilocytic astrocytomas from other low grade gliomas because these tumours tend to progress very slowly.

Diffuse astrocytomas are the most common low grade glioma. They are usually diagnosed in persons in their late thirties.

 Oligodendrogliomas have two genetic changes that separate them from other low grade gliomas. Oligodendrogliomas are usually slow-growing tumours.

Gangliogliomas These tumours have features of both gliomas and of tumours arising from neurons, the other type of cell within the brain. These tumours tend to grow very slowly

Most LGG grow by 1—2% a year. Some people may have them for many years without being aware of them. The cause for a tumour is often unknown.

You will usually have a CT (Computed Tomography) scan, or an MRI (Magnetic Resonance Imaging) scan, when you first show symptoms of a LGG. This gives information such as the location of the tumour.

You may have an electroencephalogram [EEG]. This is a test that measures the electrical activity coming from the brain.

To find out what type of tumour it is, you may have a biopsy. A biopsy is a procedure where a small amount of the tumour is removed so it can be looked at under a microscope.

All of these tests are done to find out more about the tumour, and what treatments can be safely offered.

When an image is taken of your tumour, we will have a snapshot of what it looks like at a particular point in time, but we need to monitor how it progresses. We do this by repeating the scans every two to three months and then extending that to six and twelve month intervals.

To get a better understanding of what part of the brain the tumour is affecting, you may require additional MRI scans (fMRI). These scans map the functional areas of the brain, for example the parts that control your movement, your speech or your memory. This is to see where they are in relation to your tumour.

We can also arrange for you to have a neuropsychology review. This helps to assess your cognitive (brain) strengths and weaknesses. If you are having difficulties such as remembering things, reading, or problem solving, you can be referred for an assessment by a member of the team looking after you.

Your assessment will be completed by a Neuropsychologist or Clinical Psychologist.

A neuropsychological assessment helps you to understand more about how your brain functions and how we can support you. It is not an invasive test (you won’t have things done to you).

The assessment will involve paper and pencil tasks like completing puzzles, copying drawings, remembering things and solving problems. These will help to build a picture of your brain functions including: concentration, language, memory and mood.

The neuropsychologist may also ask for information from your close friends and family, as you may not be aware of some of the things you are having difficulty with. The aim of the test is to highlight your strengths but also to identify areas where you might be weaker and provide you with strategies to help you on a daily basis.

Surgery: The first treatment option for low grade gliomas is surgery. Evidence shows that surgery completed within six months of when you are first diagnosed will give you the best outcome. Many, but not all, tumours are suitable for surgery. This depends on the size, shape and position of the tumour within the brain.

The aim of the surgery is to remove as much of the tumour as is safe, causing as little damage to the brain as possible. This is called debulking.

In certain circumstances, it may be an option for the surgery to be preformed while you are awake so that your speech and movement can be tested. This is not a painful procedure. If this is the case then the procedure will be discussed in full with you.

Active monitoring or watchful waiting: Your Consultant may decide that surgery is not the right option for you at the moment as these tumours are typically slow growing and may not cause symptoms for many years. Or it may be in an area that is difficult to operate on. You may also decide you do not want any treatment for the time being. If this plan is agreed with the multidisciplinary team (MDT) you will have regular MRI scans, usually every six months, to monitor the tumour, and watch for changes.