Oligodendroglioma is a brain tumor that forms from cells called oligodendrocytes, primarily in the cerebrum. Oligodendrocytes produce the fatty covering of nerve cells. The average age at diagnosis of oligodendroglioma is 35 years.
What is oligodendroglioma?
Schematic diagram showing the location of a brain tumor in the brain. Click to enlarge. Tumors that affect the central nervous system (CNS) tend to be rare. Oligodendroglioma is diagnosed in about 5 percent of these cases. This type of brain tumor is more common in adults (9.4% of all primary brain tumors) than in children (4%). Oligodendroglioma forms particularly in the frontal or temporal lobes, i.e., frontal lobe, parietal lobe, and occipital lobe. Referring to the observation of the tumor under the microscope, the disease is divided into two types: a well-differentiated oligodendroglioma that grows slowly (class II) and an anaplastic, faster-growing oligodendroglioma (class III). Oligodendroglioma in the frontal lobe of the brain can cause gradual changes in mood and personality, as well as hemiparesis. Problems with coordination and language or memory may be due to oligodendroglioma in the temporal lobes of the brain.
Causes
As with most brain tumors, the cause of oligodendroglioma is largely unknown. The central nervous system (CNS) consists of the brain and spinal cord. Cells in the CNS normally grow in an orderly, controlled manner. If for some reason this order is disrupted, the cells begin to divide and form a clump or tumor. In the brain there are nerve cells and cells serving to protect the nerve cells. These supporting cells are called glial cells. A tumor that forms there is called a glioma. Like other tumors, an oligodendroglioma is either benign or malignant. Benign tumors can continue to grow without interfering with normal cell growth. A malignant oligodendroglioma will invade cells, destroy surrounding tissue, and spread to other areas of the brain.
Symptoms, complaints, and signs
Symptoms of oligodendroglioma are primarily characterized by displacement and compression of adjacent brain structures due to tumor growth. Typically, there are general signs of intracranial pressure and focal deficits. Nausea, vomiting, loss of appetite, fatigue, headache, attention deficit or restlessness occur as part of the intracranial pressure signs. In pronounced cases, the symptom triad of hypertension, decreased heart rate, and dyspnea is observed. Very typical for oligodendroglioma is also the occurrence of epileptic seizures or strokes. The strokes are due to the fact that there is a tendency to bleed in the tumors. Edema (perifocal edema) may form around the tumor, which in turn leads to additional space-occupying lesions. In some circumstances, obstruction of the cerebrospinal fluid outflow also occurs. The resulting accumulation of cerebrospinal fluid also leads to displacement of brain tissue. This can exacerbate signs of intracranial pressure, headache, vomiting and seizures. Without treatment, the development of life-threatening brainstem entrapment is then possible. However, not every affected person develops the same set of symptoms. Symptoms depend on which areas of the brain are affected and how the tumor behaves. For example, the rate of growth, infiltration capacity, and risk of metastasis may differ among tumors. While in many tumors, symptoms due to compression processes are the primary concern and are critical for survival, other symptoms may predominate if metastasis occurs early.
Diagnosis and progression
Affected individuals with slow-growing oligodendroglioma may develop mild symptoms for several years before the tumor is detected. Initial symptoms of any type of brain tumor develop mostly because of increased pressure inside the skull (increased intracranial pressure), which may be caused by the oligodendroglioma. This leads to headaches, nausea (vomiting) and visual disturbances. Further progression of the disease may lead to convulsive seizures, and in up to 80% of cases, mainly to personality changes.Diagnosis is aimed at obtaining the most comprehensive information possible about the oligodendroglioma. Simple reflex tests as well as anophthalmoscopy (examination of the back of the eye) initiate further examinations by computer tomography or magnetic resonance imaging. Oligodendroglioma can only be diagnosed beyond doubt by histopathologic examination (biopsy).
Complications
Since oligodendroglioma is a tumor in the brain, the usual symptoms and complications of cancer occur. The further course of the disease thus also depends very much on the time of diagnosis. In most cases, those affected suffer from severe headaches and epileptic seizures. Visual disturbances or nausea can also occur and are not infrequently associated with vomiting. Due to the oligodendroglioma, the affected persons also suffer from disorders of consciousness and, in many cases, personality changes. Furthermore, forgetfulness and general memory disorders occur. Most patients feel unwell in everyday life and suffer from a general feeling of illness. The quality of life of the affected person is significantly limited and also reduced by the oligodendroglioma. In many cases, depression or other psychological upsets also occur. Oligodendroglioma can be partially treated by surgery and other methods. However, a complete cure does not occur, so in most cases those affected also have a significantly reduced life expectancy.
When should you see a doctor?
As a brain tumor, oligodendroglioma belongs in medical diagnosis and treatment. There are a lot of reasons that make it necessary to see a doctor in this context. These include the suspicion of a brain tumor as well as side effects of therapies or the consistent adherence to follow-up appointments. Suspicion of brain tumor activity can result from sensory disturbances, paralysis or headaches. However, these symptoms are so unspecific that they cannot be clearly assigned to a brain tumor such as oligodendroglioma, but may have many other causes. The first contact person in this context is therefore the family doctor. If necessary, he or she will refer the patient to physicians in other specialties, such as radiologists or neurologists. During the therapy of an oligodendroglioma or even afterwards, side effects may occur that require a visit to the doctor. Surgery, chemotherapy and radiation therapy put a strain on the body, and complications such as post-operative bleeding must be ruled out, as must blood count changes that can lead to serious consequences. The psyche is also a reason to see a doctor if a patient cannot cope with the stressful diagnosis. In this case, a referral to a psychologist or psychooncologist can be useful. Follow-up care is also important and linked to appropriate appointments with the doctor. Here, it is important not only to follow up on follow-up appointments consistently, but also to always see the doctor if unusual, severe or long-lasting symptoms occur.
Treatment and therapy
Oligodendroglioma is considered incurable by current medical standards. Studies have shown that with aggressive treatment and close monitoring, it is possible to increase life expectancy. How oligodendroglioma is treated depends on the patient’s overall health, the anatomy of the tumor and the spread of the cancer cells. Treatment is usually provided by a multidisciplinary team of specialists. Before oligodendroglioma is treated surgically, medication is often initiated to lower intracranial pressure. The goal of surgical intervention is to remove the tumor without damaging the surrounding brain tissue. Due to its diffuse infiltrating nature, oligodendroglioma cannot be completely eliminated and is not curable by surgery alone. Therefore, other treatment methods are used. Radiation therapy uses high-energy beams to destroy the cancer cells. It is usually an external method of treatment, and in some circumstances a small radioactive implant may be used. Oligodendroglioma may also be treated with chemotherapy, i.e., use of cytotoxic drugs, concomitant with surgery or radiation.
Outlook and prognosis
Compared with other brain tumors, the prognosis for oligodendroglioma is better.A part of oligodendrogliomas grows slowly. Therefore, the prognosis is significantly better than for fast-growing and malignant oligodendrogliomas. The prognosis depends, among other things, on the nature of the tumor cells. If there is a well-differentiated low grade oligodendroglioma, the outlook is much better than if there is an anaplastic and higher grade oligodendroglioma with severely degenerated cells. A cure is not possible for oligodendroglioma. The prognosis is about estimating the survival time. With the help of appropriate therapeutic measures, patients can survive a slow-growing oligodendroglioma for ten years or more. In the case of a higher grade, anaplastic oligodendroglioma, it is only a few months. These prognoses should be viewed with caution because other parameters influence survival time. These include general health, age, the exact location of the tumor or its size. The therapy and how it responds also influence the prognosis. Metastases can form postoperatively, or in the case of higher-grade oligodendrogliomas. On average, cancer specialists expect 74 percent of low-grade oligodendrogliomas to survive five years. Forty-six percent of those affected survive longer. Survival rates are significantly lower for high-grade malignant oligodendrogliomas.
Prevention
Because the causes of brain tumors such as oligodendroglioma are largely unknown, no preventive measures can be taken. Dealing with a cancer also affects the entire personal environment of those with oligodendroglioma and often requires significant lifestyle changes.
Aftercare
Oligodendroglioma is a brain tumor that requires consistent aftercare following therapy. This also depends on where the tumor was located and what size it had possessed, whether it had caused any deficits, and how it was treated. What all tumors have in common, however, is that the patient needs close monitoring so that any new tumor growth can be detected early and adequately treated. Physical aftercare focuses, on the one hand, on regeneration after a strenuous treatment phase and, on the other hand, on symptoms of failure or other problems as a result of the tumor. Often, the affected person learns individually suitable exercises within the framework of speech therapy, occupational therapy or physiotherapy, which can then be consistently practiced at home. The consequences of radiation and chemotherapy can often be managed well by a healthy lifestyle. Excessive alcohol consumption and especially nicotine should be avoided at all costs. Psychological aftercare is also important in order to be able to come to terms with the diagnosis of a brain tumor and the fear of a relapse. Talking to family and friends can be just as helpful in this context as attending an oncological support group. Relaxation techniques can also be helpful. Progressive muscle relaxation according to Jacobsen is also gentle motor training. Yoga also calms through a combination of physical, breathing and relaxation exercises.
Here’s what you can do yourself
As a brain tumor, oligodendroglioma basically belongs in specialist treatment, but there are nevertheless also some things that the patient can do in everyday life as part of self-help. This everyday help can be differentiated into the physical and the mental-emotional area. In the physical area, motor skills are often restricted by the tumor itself or by an operation. Here, physiotherapists or occupational therapists often teach exercises that the patient can also perform at home on his or her own. In addition to exercises for these local limitations, there are also ways to improve the patient’s overall condition, especially after radiation or chemotherapy. These include a healthy diet and adequate drinking, as well as dosed exercise, which can be done either at home or a sports club, but also in special rehabilitation courses. Shortened and tense muscles can be loosened with the help of massages. The mental and emotional state can also be positively influenced by self-help. On the one hand, this concerns cognitive abilities: Perception and memory, like speech, can be trained through suitable exercises. In the mental sphere, the thought of the brain tumor often makes life difficult for those affected.Talking to relatives, friends or in self-group sessions can help here. Methods such as progressive muscle relaxation according to Jacobsen, autogenic training or yoga provide relaxation.