Medulloblastoma is a neurological disease that occurs mainly in childhood. The malignant brain tumor occurs mainly in the back of the head, but has a good chance of cure. Research into its causes has not yet been adequately completed.
What is medulloblastoma?
Schematic diagram showing the location of a brain tumor in the brain. Click to enlarge. Medulloblastoma is considered the most common malignant brain tumor in children up to age 15. It develops as a malignant tumor in the cerebellum, usually growing from there to an adjacent cerebral ventricle and spreading further to healthy tissue. The brain stem is also frequently affected by medulloblastoma. Metastases form primarily at sites that are in contact with the cerebrospinal fluid. In addition to the cerebral ventricles themselves, these include areas around the brain, the meninges, and the spinal cord. On average, about 90 children are newly diagnosed with medulloblastoma each year. Boys are affected about one and a half times as often as girls. The age of onset of the disease is usually between five and eight years.
Causes
Medulloblastoma usually develops spontaneously, which means that heredity is unlikely to be a cause of the tumor. Nevertheless, the causes of the disease have not been adequately studied. However, it is known that medulloblastoma degenerates from immature embryonic cells, i.e. cells of the nervous tissue undergo malignant changes. In adult-onset disease, a correlation has repeatedly been found between radiation therapy in childhood, for example in the course of treatment for leukemia, and the development of the tumor later in life.
Symptoms, complaints, and signs
Medulloblastoma rapidly increases in size and produces its first symptoms relatively early. Initially, the tumor leads to increased pressure inside the skull. This results in a number of nonspecific complaints, for example, headache, nausea and vomiting, or dizziness. Typically, the signs of the disease appear in the morning after getting up and weaken during the course of the day. Nausea occurs predominantly in the morning and on an empty stomach. Sufferers also experience an increasing feeling of malaise and a gradual deterioration in their physical and mental condition. For example, exhaustion, difficulty concentrating and sleep problems set in. If the tumor is located in the area behind the eyes, visual disturbances may occur. The patient then perceives double images, squints or suffers from eye tremors. A medulloblastoma also displaces the cerebellar structures. This causes movement disorders and other neurological complaints. Possible accompanying symptoms are numbness or tingling. In the worst case, paralysis occurs in the arms and legs. As the tumor grows, the nature of the patient may change, often appearing irritable, restless or confused in the later stages of the disease. In addition, hydrocephalus forms as a result of nerve fluid drainage problems. Other external signs may include growths in the spinal canal and around the skull.
Diagnosis and course
Numerous symptoms associated with medulloblastoma are uncharacteristic, so they often occur in other conditions and may have a harmless cause. From headaches to nausea, dizziness and visual disturbances to numbness, the list of symptoms is long. Coordination difficulties can also occur in the course of the disease. All symptoms that are triggered by the increasing pressure in the brain or caused by metastases, especially in the area of the spinal cord, are conceivable. In particularly young patients, an increased increase in the circumference of the head and so-called hydrocephalus can often be observed in the advanced stage. The diagnosis is based on a detailed anamnesis. This is followed by imaging procedures. Computer tomography and magnetic resonance imaging are used to obtain initial examination results. If there is a reasonable suspicion of medulloblastoma, a tissue sample is surgically removed and subjected to fine tissue examination. A collection and examination of the cerebrospinal fluid is also necessary. Based on the results of the examination, the type of tumor, its location and size, and its spread are diagnosed.
Complications
Since medulloblastoma is a tumor in the brain, it leads to the usual symptoms of cancer. As a rule, in a very unfavorable case, the cancer can spread to other regions of the body and affect healthy tissue there as well. This reduces the life expectancy of the affected person. For this reason, further complications or chances of recovery depend very much on the time of diagnosis and the extent of the medulloblastoma. The affected person primarily suffers from severe headaches and dizziness. Furthermore, vomiting or squinting also occur. Patients experience disturbances in sensitivity or paralysis in various parts of the body. In many cases, there are also disturbances in coordination or concentration. Visual complaints may also occur, significantly reducing the patient’s quality of life. Medulloblastoma can be treated surgically and is not associated with complications. However, patients are still dependent on chemotherapy, which can lead to various side effects. Further control examinations are also necessary after the treatment. Whether there is a reduction in life expectancy due to medulloblastoma usually cannot be universally predicted.
When should you see a doctor?
In most cases, medulloblastoma occurs in childhood. Therefore, adolescents are particularly affected by the disease and should be examined at the first signs. If the child complains of dizziness, headache, or difficulty sleeping, a physician should be consulted. If concentration is impaired, there is an abnormality in learning or repeated vomiting, there is cause for concern. Characteristic of medulloblastoma is a strong symptomatology at the beginning of the day. In the following hours, the intensity of the symptoms usually decreases. Often by the end of the day there is a feeling of recovery until the following morning when all symptoms reappear. Children suffering from sudden disturbances of vision, unsteadiness of gait and increased risk of accidents as well as injuries should be presented to a doctor. In case of sensitivity disorders of the skin, numbness or a tingling sensation on the skin, a doctor is needed. Movement disorders, a decrease in well-being, and behavioral abnormalities should be evaluated by a physician. If the child shows unusual mood swings, academic performance declines, and withdrawal behavior occurs, a visit to the doctor should be made. Lumps on the back along the spine, swelling or other changes in skin appearance are signs of a present disorder that require medical consultation. A special warning sign that should be investigated immediately is an unnatural increase in the circumference of the head.
Treatment and therapy
The chances of treatment are favorable if medulloblastoma is detected early. Today, for example, more than 70 percent of patients can be cured if the tumor is detected and treated in time. First, the tumor is removed as completely as possible. To do this, the skullcap is surgically opened and the diseased tissue is cut out. If possible, this is performed using microsurgery or laser surgery to minimize subsequent physical discomfort. In addition, therapy with radioactive irradiation is performed, as the tumor cells are particularly sensitive to radiation. Alternatively, chemotherapy is performed. Depending on the age of the patient and his or her development, possible side effects of both forms of therapy must be weighed. In the case of particularly large tumors or if the medulloblastoma is located at a site that is very difficult to access, the diseased tissue can also first be only partially removed surgically and then reduced in size with radiation and chemotherapy. Thus, in a second surgical procedure, the remaining material can eventually be removed. In addition, it may be necessary to contain accompanying symptoms. Due to the medulloblastoma, the outflow of the nerve fluid can be blocked or rerouted. This malposition must then be corrected via a tube system. This often involves the placement of a so-called external drain, which is used to drain the nerve fluid to the outside.
Outlook and prognosis
The prognosis depends on the size of the tumor and the extent of tumor removal. Basically, there is a poor outlook if metastases have formed.After surgery, about half of all patients are tumor-free. They can continue to lead a normal life. However, it cannot be ruled out that the tumor will recur. For this reason, follow-up care is of great importance. Medulloblastoma occurs more frequently in children than in adults. A good one in five brain tumors in minors is due to this disease; in adults, the figure is only about one percent. Ten years after the start of treatment, 70 percent of all children with the disease are still alive. Children between the ages of four and nine and adults around age 30 are most commonly affected. Variants of the tumor have different expected outcomes. The majority of all patients survive desmoplastic medulloblastoma. Poorer chances of cure occur with anaplastic or large cell medulloblastoma. Without treatment, patients risk the medulloblastoma enlarging and invading further into the brain. Only consistent therapy can lead to freedom from symptoms. Life expectancy is significantly shortened without treatment.
Prevention
In principle, it is recommended to protect oneself and one’s children from exposure to radiation and pollutants. Contact with carcinogenic chemicals should also be avoided. In addition, a healthy, balanced diet and sufficient exercise will strengthen the immune system. Nevertheless, there are no general measures that prevent the development of medulloblastoma.
Aftercare
As with all tumorous diseases, after successful treatment of medulloblastoma, close follow-up care is initially required. This aims to detect any new tumors or metastases at a very early stage. In the case of a brain tumor, checks are therefore carried out several times a year at intervals of a few months. If no abnormalities are found, the intervals between the next check-ups are increased. Whether there are any new growths is usually checked via MRI or CT. Because malignant brain tumors often have a high risk of recurrence despite initially successful treatment, it is important that those affected keep their follow-up appointments regularly. The prognosis for new tumors is more favorable the earlier they are detected. New brain tumors do not always cause symptoms immediately, which should alert the patient. Often, findings that require treatment are discovered more by chance during follow-up. However, if unusual pain is noticed outside of the follow-up checks, this is always a reason to see the treating physician promptly. He or she can decide whether the next follow-up appointment should be brought forward in order to rule out the possibility that new tumors have formed.
What you can do yourself
If medulloblastoma has been diagnosed, surgical removal of the tumor is indicated in any case. The measures that affected individuals can take themselves depend on the severity of the tumor and any accompanying symptoms. In principle, the individual complaints can be treated by the patient. Cool compresses on the forehead and neck help against the typical headache. Gentle natural remedies such as belladonna or arnica can also help. Nausea and vomiting can usually be alleviated by a rich meal. If serious symptoms occur, such as visual disturbances or balance problems, the doctor should be consulted. It is then best to refrain from self-treatment using home remedies. After an operation, the patient should take it easy for a few weeks. Parallel to this, regular check-ups by the doctor are necessary in order to be able to detect any recurrences or other problems at an early stage. If physical complaints develop as a result of the radiation treatment, medical advice is also required. General measures such as exercise and a healthy and balanced diet help to counteract typical after-effects such as tiredness and fatigue. These measures can be accompanied by a therapist who supports the patient in dealing with the cancer.
