Brain Tumours: Types, Symptoms and Causes
The brain is the command center of our entire body, responsible for our thoughts, emotions, movements, and memories. The diagnosis of a brain tumour—an abnormal growth of cells within the skull—is understandably one of the most frightening a person can receive. However, understanding the fundamentals of what a brain tumour is, how it presents, and its potential causes is the first step toward navigating the path to diagnosis and treatment.
This article provides a clear overview of the types of brain tumours, their common symptoms, and what science currently understands about their causes.
What Are the Different Types of Brain Tumours?
Not all brain tumours are the same. They are classified based on several key factors, including where they originate and whether they are cancerous.
1. Primary vs. Secondary Tumours
This is the most fundamental distinction:
- Primary Brain Tumours: These tumours originate within the brain tissue itself. They can develop from brain cells, the membranes surrounding the brain (meninges), nerves, or glands.
- Secondary (Metastatic) Brain Tumours: These are far more common. They occur when cancer cells from another part of the body—such as the lung, breast, kidney, or skin (melanoma)—spread (metastasize) to the brain.
2. Benign vs. Malignant Tumours
This classification refers to the behaviour of the tumour cells:
- Benign Tumours: These are non-cancerous. They tend to grow slowly, have clearly defined borders, and do not invade surrounding tissue or spread to other parts of the body. However, a benign tumour can still be life-threatening if it grows in a critical area and exerts pressure on sensitive brain structures.
- Malignant Tumours: These are cancerous. They are usually fast-growing, invade nearby healthy brain tissue, and can be very difficult to remove completely.
Common Types of Primary Brain Tumours:
- Gliomas: The most common type of malignant primary brain tumour, arising from the supportive glial cells of the brain. Subtypes include astrocytomas (the most famous being the aggressive glioblastoma), oligodendrogliomas, and ependymomas.
- Meningiomas: These tumours arise from the meninges, the protective layers that cover the brain and spinal cord. They are the most common type of primary brain tumour overall and are often benign.
- Pituitary Adenomas: These are typically benign tumours that develop in the pituitary gland at the base of the brain. They can cause problems by pressing on optic nerves or by overproducing hormones.
- Medulloblastomas: These are fast-growing, malignant tumours that are more common in children than in adults. They start in the cerebellum, the part of the brain that controls balance and coordination.
Recognizing the Symptoms: What to Watch For
The symptoms of a brain tumour are highly variable and depend on the tumour’s size, location, and rate of growth. The skull is a rigid box, so any abnormal growth inside it increases pressure, leading to a range of symptoms.
It’s crucial to remember that these symptoms are often non-specific and can be caused by many other less serious conditions. However, the persistence or sudden onset of these issues warrants a medical evaluation.
General Symptoms (Caused by Increased Pressure in the Skull):
- Headaches: Often described as being different from a typical tension or migraine headache. They may be worse in the morning, persistent, and may not respond to usual pain relievers.
- Seizures: A new onset of seizures, especially in an adult with no prior history, is a significant red flag.
- Nausea and Vomiting: Unexplained vomiting, particularly in the morning, can be a sign of increased intracranial pressure.
- Cognitive or Personality Changes: Difficulty with memory, confusion, trouble concentrating, or noticeable changes in mood, personality, or behaviour.
- Drowsiness: Feeling unusually sleepy, lethargic, or difficult to wake up.
Specific Symptoms (Related to the Tumour’s Location):
The brain is highly specialized, so where a tumour grows determines which functions are affected.
- Frontal Lobe: Problems with judgment, personality changes, weakness on one side of the body, and difficulty with speech.
- Temporal Lobe: Issues with memory, hearing, or understanding language.
- Parietal Lobe: Difficulty with sensation (touch, temperature, pain), spatial awareness, writing, or reading.
- Occipital Lobe: Vision problems, such as blurred vision, double vision, or loss of peripheral vision.
- Cerebellum: Problems with balance, coordination, and fine motor skills (e.g., trouble walking or buttoning a shirt).
- Brainstem: Difficulty with swallowing, facial weakness, double vision, and clumsiness. The brainstem controls essential functions like breathing and heartbeat.
What Causes Brain Tumours?
For the vast majority of primary brain tumours, the exact cause remains unknown. Researchers have not been able to pinpoint a specific environmental or lifestyle factor that directly causes them. However, several risk factors have been identified that can increase a person’s chances of developing a brain tumour.
Established Risk Factors:
- Exposure to Ionizing Radiation: This is the most significant and well-established environmental risk factor. High doses of radiation, particularly to the head (for instance, from radiation therapy to treat a previous cancer), increase the risk.
- Age: The risk of most brain tumours increases with age, with the incidence being highest in older adults. However, certain types of tumours are more common in children.
- Family History and Genetic Conditions: A small percentage (about 5-10%) of brain tumours are linked to inherited genetic syndromes. These include conditions like Neurofibromatosis (NF1 and NF2), Tuberous Sclerosis, Li-Fraumeni syndrome, and Turcot syndrome.
What About Cell Phones and Power Lines?
Public concern has often focused on whether exposure to radiofrequency (RF) energy from cell phones or electromagnetic fields from power lines can cause brain tumours. To date, the majority of large-scale scientific studies have not found a conclusive link. However, research in this area is ongoing.
When to See a Doctor
While a brain tumour is a rare diagnosis, it’s essential not to ignore persistent and unexplained neurological symptoms. If you or a loved one experience a new and persistent headache, a first-time seizure, or a noticeable change in personality, vision, or coordination, it is crucial to consult a doctor.
Early diagnosis often leads to more effective treatment options and a better prognosis. While the thought of a brain tumour is daunting, advances in surgery, radiation therapy, and chemotherapy have significantly improved outcomes for many patients.
Disclaimer: This article is for informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.