What are brain metastases?
Brain metastases are brain tumours. Brain metastases occur when cancer from a different part of the body spreads to the brain. The most common cancers that spread to the brain are:
- Lung
- Breast
- Melanoma
- Colon
- Kidney
When cancer spreads to the brain, many different symptoms may develop such as:
- Vision changes
- Headache
- Problems with balance
What symptoms a person has depends on the exact location of the tumours. Cancer can also spread to places other than your brain. Cancer can spread to the thin coverings that line the brain (meninges).
When cancer spreads to the brain’s lining it is called Leptomeningeal disease. For more information about cancer of the meninges refer to the pamphlet: “Learn about Leptomeningeal Disease”.
Some people may never notice symptoms or have any vision changes. Lack of symptoms may be because the tumour is:
- Very small
- Far away from the part of the brain that controls vision
The only way to know how much your cancer has spread is by having imaging tests. For more about these tests, read the section below: “What can I expect at my doctor’s appointment?”.
What types of vision changes can I expect?
The vision changes you have will depend on where the tumour is in your brain. Different parts of the brain control different functions. For this reason, not all tumours affect vision. Most patients with brain metastases will never have vision changes.
There are two main types of possible vision changes from brain metastases:
1. Double Vision
Double vision is seeing two objects when you should only be seeing one. With normal vision, images from both eyes are joined to form one image.
Your eyes have many nerves. These nerves tell muscles to look in the direction you want. They also make sure both your eyes work together as a team.
Brain metastases can create problems in these nerves or muscles. Problems with nerves or muscles means that your eyes may not work well with each other. If your eyes do not work with each other, you might see two images instead of one.
Brain metastases might also increase the pressure inside your head. Increased pressure can lead to double vision. If you notice a headache and vision symptoms, see your doctor right away.
If cancer spreads to the lining of the brain (leptomeningeal disease), double vision might occur. You might also notice other symptoms with leptomeningeal disease like:
- Problems with moving your face
- Problems swallowing
- Decreased hearing
Double vision can also occur if cancer spreads to the brainstem (an area just below your brain). The brainstem is joined to nerves that control eye movement.
2. Vision Loss
Vision loss can be:
- Partial: affects only one eye or some parts of vision in both eyes
- Complete: affects both eyes
With partial vision loss, you may not see objects on one side of your body. For example, you might start bumping into objects a lot. With complete vision loss, you will not be able to see at all. This is very rare in patients with brain metastases.
What do I do if I have vision changes?
If you start having vision changes, here are some things you can do to keep yourself and others safe:
- Avoid driving
- Get help when climbing stairs
- Be careful when using sharp objects like knives
- Use good lighting at home
- Remove small rugs that may make you trip
- Use magnifying mirrors when shaving to avoid cutting yourself
When you start having vision changes, see your doctor.
What can I expect at my doctor’s appointment?
At your appointment, your doctor may do an eye exam. If the eye exam is not normal, your doctor might order some imaging tests like a CT scan or MRI scan.
These tests take pictures of your brain and will show where the metastases are in your brain. These tests will help find out how the brain metastases are affecting your vision.
What are my treatment options?
There are 3 treatment options for vision changes:
- Treatment for the brain metastases
- Symptom relief
- Mix of the two options above
1. Treatment for Brain Metastases
The goal of treating brain metastases is to remove or stop the growth of the tumours. Brain metastases might be pressing on the parts of your brain that control vision. By treating the tumours, your vision symptoms might improve.
| Type of treatment | What is it? | When is it used? |
|---|
| Surgery | Removing the tumour from the brain. | One large tumour that is easy to remove. |
| Stereotactic radiosurgery | Using X-ray radiation to kill cancer cells in exact parts of the brain. | Few small tumours. |
| Whole brain radiation | Using X-ray radiation to kill cancer cells in the whole brain. | Many tumours or if cancer has spread to the linings of the brain (leptomeningeal disease). |
| Medicines | Used with surgery, stereotactic radiation, or whole brain radiation. Help improve the side effects and symptoms from these treatments. | Dexamethasone decrease brain swelling. Anti-seizure drugs to prevent seizures. Anti-nausea drugs to treat the feeling of having to throw up. |
Symptom Relief: Double Vision
Medicine or surgery can improve double vision. Here are a few options that might help your double vision get better:
-
Wear an eyepatch: Sometimes double vision gets better by covering one eye. This means your brain will only see one image instead of two. Try covering one eye with your hand. If this helps your double vision, you can use an eyepatch.
-
Prisms in glasses: Double vision is mild if the images are seen very close together. If you have only a little double vision, you can try wearing glasses with special prisms. These can be put into your current glasses, or you can buy new glasses with prisms.
What can I expect after treatment?
Treating brain metastases takes time. Your vision changes may also take time to improve. There is also a chance your vision changes will not improve. Your doctor will support you, and can answer your questions.
Coping with vision problems from brain metastases can trigger many emotions. You may feel sad or anxious. Give yourself time to process these feelings. Ask your doctor to refer you to other team members if you are feeling sad or anxious.
