Brain tumors are a common medical condition in children. Tumors can affect children of any age. However, understanding more about this problem and the available treatment options can often help parents to cope.

Basically, a brain tumor is a growth of abnormal cells or the uncontrolled growth of normal cells in the brain. Primary brain tumors involve a growth that starts in the brain, rather than spreading to the brain from another part of the body.

Brain tumors can directly destroy brain cells. They can also indirectly damage cells by pushing on other parts of the brain. This leads to swelling and increased pressure inside the skull, according to neurological surgeon experts.

How does a brain tumor present?

Experts say brain tumors may be benign (non-cancerous) or malignant (cancerous). They may destroy or damage brain cells by producing inflammation and pressing on other parts of the brain. This pressure causes cerebral edema (brain swelling) and increased intracranial pressure (the pressure within the skull).

Sometimes it may be difficult to remove a benign tumor, because of where it is and, in this situation, other treatments may be needed.

Causes

According to Dr David Hakizimana, a neurological surgeon at King Faisal Hospital, Kigali, the cause of primary brain tumors is unknown, although some tumors such as retinoblastoma tend to be hereditary. Other tumors are glalial tumors and embryonal, which means that they develop from the embryo and are present from birth of the child.

"Central nervous system tumors (tumors of the brain and spine) make up about 20 per cent of all childhood cancers. They are the second most common form of childhood cancers after leukemia. Brain tumors are the most common solid tumors in children,” he says.

Available data indicates that brain tumors in children in Rwanda account for 15.5 per cent of all tumors. Between 2006 and 2013, of the 383 people diagnosed with brain tumors, 71 of them were children.

Types of brain tumors

According to Hakizimana, there are over 120 different types of brain tumors grouped in 7 broad categories .The most common childhood brain tumors are astrocytoma, medulloblastoma, ependymoma and brain stem glioma. Brainstem gliomas are very rare tumors that occur almost only in children. The tumor may grow very large before causing symptoms.

He says gliomas account for 75 per cent of brain tumors in young children but less than 50 per cent in adults. Gliomas consist of glial cells, which form the supportive tissue of the brain. Astrocytomas are the most common type of childhood glioma and favor the nervous system.

"They typically occur in the cerebellum, a part of the brain that coordinates voluntary muscle movements and maintains posture, balance and equilibrium.

The majority are curable by surgery. Children may also suffer from gliomas in the brainstem, at the base of the brain,” says Hakizimana.

He adds that tumors containing a mix of glial cells (most commonly astrocytes) and neurons (ganglion cells) occur more often in children than in adults. They may develop anywhere in the nervous system but most typically appear in the cerebrum, an area of the brain involved in motor function and personality.

Signs and symptoms

Dr Steven Nshuti, a resident neurosurgeon operating at the University Teaching Hospital of Kigali (CHUK), says symptoms of a pediatric brain tumor vary according to the size, type and location of the tumor. Symptoms may occur when a tumor presses on a nerve or damages certain parts of the brain. They may also occur when the brain swells or there is fluid buildup in the skull.

"The most common symptoms include headaches (usually worse in the morning), nausea or projectile vomiting. Sometimes, the only symptoms of brain tumors are mental changes, which may include changes in speech, vision or hearing, balancing or walking problems, changes in mood, personality or ability to concentrate, seizures or convulsions, among others,” he says.

Nshuti advises that whenever a parent notices one or more of these symptoms mentioned above, they should immediately seek medical support to avoid further complications.

Diagnosis

According to neurological surgeons, knowing what a test for tumors involves can make things a bit easier.

After taking a complete medical history and doing a physical examination of the patient, a neurological exam is done to test reflexes, muscle strength, eye and mouth movement, coordination and alertness.

Nshuti notes that it is often necessary for doctors to remove a small part of the tumor (biopsy) to find out the exact type of the tumor.

"Most children will have a computerised tomography scan or an MRI scan, which looks in detail at the inside of the brain. A CT scan uses X-rays and computer technology to produce cross-sectional images (called ‘slices’) — both horizontal and vertical — of the bones, muscles, fat and organs. An MRI scan uses a combination of large magnets, radio frequencies and a computer to produce detailed images of organs and structures within the body,” he adds.

Treatment

Hakizimana says there are three common therapies used to treat the different types of brain tumors.

"The doctor will normally look at the type of brain tumor, its size and where it is in the brain before deciding on the best treatment option. A patient may have one form of treatment or a combination of treatments. Many tumors that are slow-growing are cured with surgery alone.

"Other types of tumors that are fast-growing might need additional treatment with radiation therapy (high –energy rays that kill or shrink cancer cells) or chemotherapy (drugs) or both,” he explains.

Dr Marie Aimee Muhimpundu, the division manager of non communicable diseases at Rwanda Biomedical Centre, says most of the treatment options can be provided locally.

"Surgery is usually the first step in treating brain tumors in children and it is offered at two referral hospitals (King Faisal and CHUK). Chemotherapy also is offered at Butaro Hospital,” she says.

Muhimpundu notes that currently patients whose tumors require radiation therapy are referred abroad but there is hope in the near future of getting it locally as a radiotherapy facility is under construction at the Rwanda Military Hospital.

Side effects of the treatment

Neurological surgeons say long-term brain and nervous system problems may result from the tumor itself or from treatment. Children may have problems with attention, concentration, or memory. Patients may also have problems processing information, planning, insight, or initiative or desire to do things. Parents are advised to make sure that children receive support services.

Follow-up care

Nshuti says continuous follow-up care is essential for a child diagnosed with a brain tumor because the side effects of radiation and chemotherapy — as well as second malignancies — can occur in survivors of brain tumors.

"After treatment is over, a child will be seen regularly by specialists. This is to check their progress and how well they’re recovering from treatment. It is also to check that they don’t have any long-term problems from treatment,” he says.

Nshuti adds that rehabilitation for lost motor skills and muscle strength may be required. Children’s speech, physical and occupational therapists may be undergoing this type of rehabilitation.