The image below reveals the most common locations for brain tumors in children. The peak incidence occurs in the early years of childhood and dips to a minimum in the teen years. The most commonly found brain tumours in childhood include infratentorial (70-80%) such as Medulloblastoma and Glial tumors and are followed by Germ cell tumors and Craniopharyngioma. Children have a greater chance of responding better to curative treatment than adults.
Incidence Of Brain Tumors in Children
Benign and malignant tumors of the brain and CNS account for roughly a quarter of all cancer cases seen in children. The rate of incidence witnessed in United Kingdom is approximately 5 per 100,000 of kids aged between 0-9 years. Out of all CNS and brain tumor cases in young children, 43% consist of Astrocytomas, which are frequently ‘low grade’ tumors and rarely exhibit signs and symptoms of high (fast growing) grade tumors. Tumors of the Ependyoma and Choroid plexus are seen in children less than one year of age.
The exact underlying reason for initiation of brain tumors has not been found out. A definite correlation between certain inherited illnesses and brain tumor has been noticed. For example- The frequency of incidence of Astrocytomas elevates in young patients suffering from Neurofibromatosis. Similarly, those having Von Hippel-Lindau disease have greater chances of being afflicted by a tumor known as haemangioblastoma. Genetic mutations in those genes that function as tumor suppressants such as retinoblastoma gene are suspected. The majority of brain tumors seem to be sporadic in origin.
A medical history of certain conditions such as removal of adenoids or tonsils predisposes your child to solid tumors. No definite conclusion has been reached and research continues. The incidence rate and frequency of some common childhood brain tumors are as follows-
Tumors located in the hemispheres: Gliomas
Tumors located in the midline: Chiasmal Gliomas, craniopharyngiomas and tumors in pineal region.
Tumors developing in the posterior fossa: Brainstem Gliomas, Medulloblastoma, ependymomas and cerebellar astrocytoma. (In descending order of incidence rate)
The symptoms described below are commonly experienced by most patients, though they will vary with each child. Other factors that determine the extent or intensity of symptoms experienced include the size of the tumor and its location as well as the increased pressure in the limited space. The presence of extra fluid or tissue in the delicate structure of the brain and blockage of one or a few ventricles that normally drain out the fluid poses another problem. It pushes the intracranial pressure to beyond normal limits.
This pressure gives rise to episodes of headache which cause the most pain in the morning, vomiting, changes in personality and feelings of drowsiness. The patient may experience depression too. The respiratory and heart functions get impacted. Tumors in the front portion (cerebrum) of the brain cause the following symptoms: changes in vision, speech, seizures, confusion and a decline in strength or paralysis of one half of the entire body. If the middle portion (brainstem) is where the tumor is situated, some of the features are:
Double vision, fits, intense headaches, changes in respiration plus endocrinal disturbances in the form of diabetes. Cerebellum tumors cause a gradual loss of co-ordination over muscular movements, vomiting but without nausea (frequently in the morning time), ataxia (disturbance in function of walking) and headache. Impaired concentration, loss of weight, excessive sleeping are some of the other symptoms to note. If your little one has recently been complaining of any of the above, make sure you consult a child physician for examination and diagnosis of the underlying cause.
Signs Of Brain Tumors in Children
Get a physical examination if you notice a few important changes in your child’s health. For example, an outward curving of your infant’s fontalle (a soft spot) that looks like a prominent bulge, larger than normal eyes, etc. If the health care provider notices a lack of reflex in your child’s eye, Babinski’s reflex or sutures that are separated, he will ask for a few tests to be done such as CT scan and an MRI of the head.
If diagnosed with a brain tumor, go in for treatment as early treatment dramatically improves chances of complete recovery. Proper management includes treatment of cancer plus complications and moral support to the child. Specific treatment of brain tumors is based on: Your child’s health status, previous and current medical history, the extent of damage caused to your child’s level of tolerance towards medical and surgical procedures, medications etc and your personal opinion.
Surgical resection is the main mode of treatment, which involves removal of the tumor mass. There are certain cases for which surgery is not a possibility due to the risky location of the tumor, such as brainstem gliomas. Other modalities of treatment combined with surgery include chemotherapy and radiotherapy. Removal of the abnormal collection of tumour cells while preserving neurological function is the ultimate goal of surgeons. Partial removal is sometimes the only option. To control the mounting intracerebral pressure, neurosurgeons will install a shunt.
Chemotherapy– Many chemotherapy regimens are in use nowadays and involve Vincristine. In cases where partial excision has been carried out, the residual tumor cells are destroyed via chemotherapy. Drugs like Cyclophosphamide and 5- Fluorouracil are new and effective.
Radiotherapy– This treatment is provided in comparatively low doses to localized areas of the brain to prevent damage to normal tissues. In a few slow growing brain tumors, interstitial seeds are incorporated in the site of operation during the operation.
Medications– These include corticosteroids such as Dexamethasone to relieve the pressure caused by brain swelling. Mannitol and urea act as effective diuretics to decrease both, the elevated pressure and swelling. Seizures need to be treated with via anti-convulsants such as phenytoin etc.
The overall prognosis depends to a great degree on the type of tumor, its location and size. Other factors include presence of metastasis and responsiveness of the brain tumor to surgery. Prompt treatment and aggressive medical therapy is a must for a favorable prognosis. Periodic follow up care must not be overlooked.