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The brain is the body’s most powerful organ, and when a mass of abnormal cells develops in the brain, it can severely impact a person’s well-being and threaten one’s life. Brain tumours can begin from any part of the brain and be cancerous (malignant) or non-cancerous (benign). Cancer can sometimes start in another body part and eventually spread to the brain. When cancer spreads from another organ to the brain, it is called a ‘metastatic brain tumour’, where 40 per cent of all malignancies spread to the brain. Studies have shown that there are over 120 types of brain tumours, which depend on where they originate.
The occurrence of brain tumours in India is steadily rising. The International Association of Cancer Registries (IARC) has reported that brain-related tumours are 5-10 per 100,000 people, and an increasing number of cases of brain tumours each year are among people of varied age groups. Recently, IARC has ranked brain tumours as the tenth most common kind of tumour among Indians. The organisation has reported more than 28,000 brain tumour cases, and over 24,000 people die from brain tumours annually.
Causes of Brain Tumour
At a neurologist consultation, you will learn that primary brain tumours originate in the brain or surrounding tissues, such as in the meninges or brain-covering membranes, cranial nerves, and pituitary or pineal glands. In adults, primary brain tumours are less common than secondary brain tumours, in which cancer begins in other areas and spreads to the brain. They form when normal cells develop and mutate in their DNA. The cell’s DNA contains instructions for the cell, and the mutations tell a cell what to do. Eventually, the mutations tell the cells to grow and multiply rapidly and to out-survive the healthy cells. As a result, the mass of abnormal cells becomes a brain tumour.
Research by medical experts has been unable to confirm definitive primary brain tumour causes. Although some risk factors have been identified, scientists can still not determine why a brain tumour has appeared. At a neurologist consultation, you will learn whether you are born with changes in your genes. The mutations in a cell’s DNA lead to abnormal growth (uncontrolled division), but due to the complexities in individual cases, what causes these mutations is likely to vary between individuals.
Environmental factors like exposure to X-ray radiation or previous cancer treatment may trigger damage in other cases. A few rare, inherited genetic conditions are also associated with brain tumours.
Brain Tumour Versus Lesion
A brain tumour is a brain lesion describing any area of damaged tissue. All tumours are lesions, but not all lesions are tumours. Stroke, injury, and other conditions can trigger other brain lesions.
Brain Tumour Versus Brain Cancer
All brain cancers are tumours, but not all brain tumours are cancerous. Non-cancerous brain tumours are called benign brain tumours.
At times, those with a brain tumour may not experience the typical signs and symptoms usually observed in patients. Sometimes, the brain tumour symptom may be a different medical condition that is not a brain tumour.
Brain tumour symptoms can be general or specific. A general manifestation can be due to the tumour’s pressure on the brain or spinal cord. Specific symptoms are typically when a particular part of the brain is not functioning adequately because of the tumour. Many people with brain tumours were diagnosed when they booked an appointment for a neurologist consultation and were put through a series of tests. The signs of a brain tumour vary and depend on the brain tumour’s size, location, and growth rate.
Patients may experience the following general brain tumour symptoms:
• Different types of seizures, like single or multiple muscle twitches, jerks, spasms
• Loss of consciousness, followed by twitching and body contractions
• Loss of control of body functions like bladder control
• Personality or memory changes
• Changes in ability to walk or perform regular or daily routines
Brain tumour symptoms specific to the tumour location include:
• Pressure or headache near the tumour.
• Cerebellum: There will be a loss of balance and difficulty with motor skills, which is linked to a tumour in the frontal and temporal lobes of the cerebrum. The brain tumour also affects speech, hearing, and memory or shows problems understanding or retrieving words. It can also affect your emotional state and trigger aggressiveness.
• Frontal or parietal lobe of the cerebrum: Patients experience altered perception of touch or pressure, weakness on one side of the body or in the arm or leg, or there may be confusion with the left or right sides of the body
• Brain stem: Difficulty swallowing, facial weakness or numbness, or double vision
There are several types of primary brain tumours. They usually get their names from the type of cells involved. Examples include:
• Glioma: The type of brain tumour is composed of glial cells. It originates in the brain or spinal cord and includes cancers like astrocytoma, ependymoma, glioblastoma, oligoastrocytoma and oligodendrogliomas.
• Meningioma: The tumour can start from the brain membranes and spinal cord, although most meningiomas are non-cancerous.
• Acoustic neuroma (schwannoma): It is a benign brain tumour that develops from the nerves that control your balance and hearing from your inner ear to your brain.
• Pituitary adenoma: The brain tumour develops in the pituitary gland and can impede the pituitary hormones with other effects throughout the body.
• Medulloblastoma: It is a cancerous brain tumour observed in children, though it can occur at any age. It starts in the lower back part of the brain and spreads through the spinal fluid.
• Germ cell tumour: The brain tumour may develop where the testicles or ovaries will form during childhood, and at times, germ cell tumours also affect the brain.
• Craniopharyngioma: It is a rare brain tumour that starts near the pituitary gland in the brain, which secretes hormones that control many body functions. Slowly, as the tumour grows, it can impede the pituitary gland and, eventually, other structures near the brain.
Brain Tumour With No Symptoms & Misdiagnosis
Brain tumours do not always show symptoms. For instance, the most common brain tumour in adults, meningioma, often grows slowly and goes unnoticed. Tumours may not show signs until they grow large enough and start interfering with the healthy tissues inside the brain. A brain tumour can be misdiagnosed as Alzheimer’s disease, encephalitis, headaches, or migraines because of the similarity across brain tumour symptoms.
Diagnosing a brain tumour can be a complex process and can involve several specialists. In some cases, doctors may discover a brain tumour when performing imaging tests for another medical issue.
For those experiencing symptoms of a brain tumour, a neurologist consultation will include a physical exam. The specialists will take down your medical history and ask questions about the following:
• Your symptoms
• Past and current health conditions
• Current medications
• Surgeries and medical treatments
• Family medical history
During a neurologist consultation, they may also perform a neurological exam and determine changes that can indicate the location of your brain that is affected by the brain tumour. The specialists will put you through tests that involve looking for changes in your:
• Balance and coordination
• Mental status
Brain MRI or CT scan
Magnetic resonance imaging (MRI) is the best method of identifying brain tumours. Another suitable alternative is Computed tomography (CT). Before these scans, during a neurologist consultation, a contrast agent is injected into a vein to help the doctors see the tumours during the imaging tests. These tests can show the brain tumour’s size and exact position in detail.
Biopsy: Doctors need to do a brain tumour biopsy to identify the type of brain tumour and if it is cancerous. A neurosurgeon may perform a biopsy during which they remove all or part of the tumour. There are specialised biopsies to extract a tissue sample from the tumour.
Spinal tap: The doctor extracts cerebrospinal fluid around your spine with a small needle. A laboratory examines this fluid for cancer. Doctors perform this procedure when they suspect that the brain tumour has invaded the tissue layers that cover your brain, i.e., meninges.
Specialised tests: Certain tests can help with the diagnosis. For example, your doctor may ask for tests to check your blood and cerebrospinal fluid for tumour markers, which are substances that certain brain tumours release. Your specialists may also examine the rest of your body during a basic full body check up to see if the tumour has spread.
Brain tumour treatment depends on factors, including (a) The tumour’s location, (b) size and type, (c) The number of tumours, (d) Your age and (e) Your overall health. Benign brain tumours can usually be removed successfully with surgery and typically do not grow back. Also, it depends on whether your neurosurgeon can safely remove all parts of the brain tumour.
During your neurologist consultation, your specialist may use a combination of therapies to treat your brain tumour. Your treatment options might include the following:
• Brain surgery (craniotomy): Neurosurgeons remove the brain tumour, if possible and work very carefully, sometimes performing surgery when you are awake to minimise damage to the functional areas of your brain.
• Radiation therapy: The test comprises high doses of X-rays to destroy brain tumour cells or shrink the tumour in this treatment.
• Radiosurgery: It is not surgery, as no incision was made. It is a radiation therapy that uses focused radiation beams to destroy a brain tumour.
• Brachytherapy: It is a radiation therapy involving placing radioactive seeds in or near the cancerous tumour with surgery.
• Chemotherapy: The therapy entails anti-cancer drugs destroying cancer cells in your brain and body. You might receive chemotherapy via an injection or take it as a pill. Your specialist may recommend chemotherapy after surgery to destroy any leftover cancer cells and prevent remaining brain tumour cells from growing back.
• Immunotherapy: It is also called biological therapy that stimulates your immune system to fight the brain tumour.
• Targeted therapy: Drugs target specific features in brain tumour cells without harming your healthy cells. The doctor may recommend targeted therapy if you cannot tolerate the side effects of chemotherapy, like fatigue and nausea.
Treatments like radiation therapy can be tolerated by adult brains but can prevent the brain’s normal development in children younger than five.
Other treatments that help with brain tumour symptoms include the following:
• Shunts: When the brain tumour triggers pressure within your skull to increase, the doctor may have a shunt, a thin tubing placed in your brain, after drilling a hole to drain excess cerebrospinal fluid.
• Drugs: Medications like mannitol and corticosteroids can help reduce the swelling around the brain tumour.
• Palliative care: A specialised form of care that relieves discomfort and supports people living with such an illness.
Benign brain tumours grow slowly, have distinct borders, rarely spread, and can be risky. They can compress and impede parts of the brain, causing severe dysfunction. Finally, benign brain tumours in vital brain areas can be fatal. Very rarely, a benign tumour can become malignant. Typically, benign brain tumours include meningioma, vestibular schwannoma, and pituitary adenoma.
Malignant brain tumours are cancerous. They multiply and invade surrounding healthy brain structures. Brain cancer can be fatal when it changes vital structures of the brain.
Is Prevention Possible?
Although you cannot prevent a brain tumour, you can reduce your risk of a brain tumour by avoiding environmental hazards like smoking and excessive radiation exposure.
In case you have an immediate relative, like a sibling or parent, who has been diagnosed with a brain tumour, it is crucial to inform your doctor. He may recommend genetic counselling to determine if you have an inherited genetic syndrome associated with a brain tumour.
Those diagnosed with a brain tumour must partner with a medical team to determine the next steps–observation, surgery, radiation therapy, or other treatment.
The success of your outcome will depend on many factors, including:
• The brain tumour type, size, grade, and location
• The degree of spread in the brain or elsewhere
• How long you had brain tumour symptoms before being diagnosed
• How has the brain tumour affected your ability to function
• The expertise of your treatment team
• Age and overall health
Although there is no projected survival rate for brain tumour patients, some malignant tumours can be controlled by radiation therapy. Other brain tumours may be life-threatening, even if they are benign, primarily due to their location. Individual circumstances play a significant role, and doctors must examine many patients with similar case histories to identify tumour behaviour.
Finally, a brain tumour means you can re-look at your overall health and condition and be positive. Your prognosis will likely change as you undergo various treatments, which will help determine future steps.