Medulloblastoma – Symptoms and Causes
Overview
Medulloblastoma is a type of brain tumor that starts in the cerebellum, the part of the brain that controls balance and coordination. This cancer occurs most often in children but can affect adults too.
In babies, a rapidly growing head size may be noticed. Symptoms typically worsen over weeks rather than months as the tumor grows.
Scientists don’t fully understand what causes medulloblastoma. Unlike some cancers, medulloblastoma isn’t linked to lifestyle factors or environmental exposures.
Signs and Symptoms
Medulloblastoma symptoms typically develop gradually and worsen over time. The signs vary based on the tumor’s size, location, and how fast it grows. Common symptoms include:
- Morning headaches that may improve during the day
- Nausea and vomiting, especially in the morning
- Balance problems or trouble walking
- Unusual clumsiness or coordination difficulties
- Unusual eye movements, double vision, or blurred vision
- Tilting the head to one side
- Increased head size (in infants)
- Increased irritability
- Fatigue and drowsiness
Symptoms often result from increased pressure inside the skull or from the tumor pressing on brain structures.
When Medical Care Is Needed
Contact a healthcare provider right away if you or your child experiences:
- Persistent headaches, especially in the morning
- Unexplained, recurring vomiting
- Vision changes or eye movement problems
- New balance problems or coordination issues
- Personality changes or unusual behavior
- Seizures with no prior history
Your doctor will perform tests, including imaging studies, to determine if symptoms are caused by medulloblastoma or another condition.
What Causes Medulloblastoma?
While researchers continue to study this condition, they have identified several factors that may contribute to its development.
Genetic factors play an important role in many cases. About 5-10% of medulloblastomas are linked to specific genetic conditions, including:
- Gorlin syndrome (also called nevoid basal cell carcinoma syndrome)
- Turcot syndrome
- Li-Fraumeni syndrome
Most medulloblastomas happen due to changes in genes that control how brain cells grow and divide. These changes are usually not inherited but occur randomly during a person’s lifetime.
Scientists have identified four main molecular subgroups of medulloblastoma, each with different causes:
| Subgroup | Genetic Features | Age Group |
|---|---|---|
| WNT | Mutations in WNT signaling pathway | Children and adults |
| SHH | Mutations in Sonic Hedgehog pathway | Infants and adults |
| Group 3 | MYC gene amplification | Mainly young children |
| Group 4 | Various genetic changes | Children and adolescents |
Research suggests that most cases develop from primitive embryonic cells that remain in the cerebellum after birth.
Risk Factors
Several factors might increase the chance of developing medulloblastoma. Age plays a significant role, as this brain tumor occurs most often in children between ages 4 and 9, though it can develop at any age.
Boys are more frequently affected than girls, with a slightly higher occurrence rate.
People with these inherited conditions have a higher risk of developing this type of brain tumor compared to the general population.
Additionally, family history may also influence risk. Some research suggests that having a family member who had medulloblastoma might slightly increase risk, though most cases occur in people with no family history of the disease.
Another risk factor is radiation exposure to the head area, particularly at a young age. This may increase the risk of developing brain tumors later in life. This is an important consideration for patients who received radiation therapy for other conditions.
