The term cerebral edema refers to swelling (edema) of the brain that occurs when the brain increases in volume and pressure. There are many causes of cerebral edema. If it is not recognized and treated quickly enough, it can be life-threatening and lead to brain death.
What is cerebral edema?
The brain can swell as a result of injury, illness, or for other reasons. Cerebral edema refers to an increase in brain volume and, therefore, increased intracranial pressure, caused by retention of fluid in the tissue crevices or brain cells. This accumulation of fluid is serious in that the brain, which is embedded in the bony skull, can hardly expand. Swelling of the brain is usually difficult to treat and can quickly lead to serious problems, including death. Depending on the cause, swelling can occur in specific areas of the brain or throughout the brain. Wherever it occurs, the pressure in the skull increases. When swelling occurs, there is a risk that the brain will not receive enough blood supply and therefore not enough oxygen that it needs to function, which can lead to brain death. In addition, the swelling may block other fluids and prevent them from draining from the brain, further aggravating the swelling.
Causes
There are many causes of cerebral edema. In traumatic brain injury (SHT), a sudden event such as a fall, traffic accident, or blow to the head damages the brain. The brain tissue can swell from the injury itself and additionally from bone chips that injure blood vessels in the brain. An ischemic stroke is caused by a blood clot or blockage in or near the brain. Once this is no longer supplied with vital blood and oxygen, brain cells begin to die and the brain swells. A cerebral hemorrhage, in which a blood vessel in the brain bursts due to excessive blood pressure, for example, causes swelling due to blood leakage. Infections such as meningitis, encephalitis, and toxoplasmosis can also cause brain swelling. Brain tumors can put pressure on areas of the brain and block the drainage of fluid, causing swelling. Finally, brain swelling can occur at altitudes above 1500 meters (altitude sickness).
Symptoms, complaints, and signs
Depending on the cause and extent of cerebral edema, a number of symptoms may occur. The typical signs and symptoms usually begin suddenly and rapidly increase in intensity. Most characteristic are severe headache and neck pain, nausea and vomiting, and dizziness. In some sufferers, breathing stops or becomes irregular. This may be accompanied by visual disturbances or even complete loss of vision. In conjunction, eye muscle paralysis may develop. Memory loss and memory lapses are also signs of brain edema. At the beginning, the brain tumor symptoms resemble in many cases the symptoms of Alzheimer’s disease in the first stage. As the disease progresses, difficulty speaking also sets in relatively quickly. The characteristic restlessness increases and seizures or stupor develop. As a result of the increase in intracranial pressure, there is a risk of entrapment of areas of the brain, which can cause brain damage. If left untreated, cerebral edema can cause permanent damage, such as permanently limiting vision or speech or impairing motor skills. In the worst case, brain edema leads to circulatory arrest with brain death. To avoid this, a doctor should be consulted at the first sign of brain edema.
Diagnosis and course
The symptoms of cerebral edema vary depending on the cause and extent. Usually, they begin suddenly. Possible signs of cerebral edema include sudden headache, neck pain or stiffness, nausea and vomiting, dizziness, irregular breathing, vision loss or disturbance, memory loss, difficulty speaking, restlessness of movement, stupor (numbness), seizures, loss of consciousness, eye muscle paralysis, and fainting. As a result of the increase in intracranial pressure, there is a risk of entrapment of areas of the brain, which can lead to death. Therefore, prompt treatment is of utmost importance. Cerebral edema can be diagnosed by various examinations.This includes a neurological examination, CT scan as well as MRI of the head to see the extent and position of the swelling, and blood tests. The intracranial pressure itself can be measured via a catheter or probe.
Complications
Cerebral edema itself is a complication and may develop as a result of surgery, injury, or disease. Because of the increasing pressure in the brain, brain matter may be displaced. This impairs vital structures, so that in the worst case brain edema leads to circulatory arrest with brain death. Even if this can be prevented, the process causes permanent damage as brain cells die due to the lack of oxygen. The location of the brain edema and which regions are affected is crucial. Thus, both perception and speech or motor skills can be disturbed. Breathing problems are also possible. In any case, it is necessary that the brain edema is treated as soon as possible. This is the only way to prevent brain damage and save the affected person from brain death. Since medications are administered to promote elimination, hypersensitivity may result in side effects. While medication and a special type of positioning can often be sufficient for the swelling to go down and the load on the brain to be reduced, in certain cases surgical interventions are necessary. This involves removing part of the skull bone and exposing the brain. Such interventions also involve complications, of course, but often determine the survival of the affected person.
When should you see a doctor?
If symptoms such as headache, dizziness and high blood pressure occur at the same time, there may be underlying cerebral edema. A doctor should be consulted if symptoms persist for more than a week. If the symptoms increase in intensity and noticeably affect well-being, medical advice must be sought immediately. In the event of complications such as impaired consciousness or repeated vomiting, it is best to seek hospitalization. Cerebral edema occurs predominantly in connection with craniocerebral trauma or brain tumors. Edema also occurs repeatedly after infections such as encephalitis or meningitis. Anyone who belongs to these risk groups should consult their doctor promptly if they experience any of the symptoms mentioned above. Children, the elderly and pregnant women should also consult a physician in the event of non-specific symptoms that indicate a serious illness. In case of loss of consciousness or seizures, emergency medical treatment is required. First aiders must also administer first aid and place the victim in the recovery position. Subsequently, a longer hospital stay is usually indicated, during which the symptoms are clarified and any cerebral edema is surgically removed.
Treatment and therapy
Mild cerebral edema, due to moderate altitude sickness or mild concussion, for example, often resolves within a few days. In most cases, however, cerebral edema requires immediate treatment and intensive medical monitoring. It is important to ensure that the brain is supplied with sufficient blood and oxygen, that swelling is reduced, and that the causes triggering the cerebral edema are treated. Treatment may include multiple medical and surgical treatments. Patients are positioned with the upper body elevated and the head straight. Oxygen is supplied through a breathing mask, and blood pressure is kept low with medication or intravenously. Sedation may be useful to reduce blood flow and thus intracranial pressure. Hypothermia treatment, or lowering of body temperature, protects affected areas of the brain by reducing the brain’s energy needs. Diuretics, such as high-dose corticosteroids, are used to promote fluid excretion via the kidneys, thereby reducing cerebral edema. Possible surgical interventions include ventriculostomy, which uses a drain to remove fluid (cerebrospinal fluid) through a small opening in the skull and relieve cerebral edema. Also effective is a decompressive craniectomy, in which the bony skullcap over the area of swelling is surgically removed temporarily to give the brain edema more room until it is swollen down. In the case of a tumor, it is surgically removed as far as possible.
Outlook and prognosis
The prognosis for a patient with cerebral edema depends mainly on two factors: One is the trigger of the cerebral edema, and the other is the severity of the symptoms. The trigger depends on whether the cause is permanently reversible. For example, if it is a brain tumor that is very malignant, the prospect of recovery is unfavorable. This is because even if the brain edema temporarily resolves with certain medications, in many cases the swelling recurs due to the growth of the tumor and destroys additional areas of the brain. The severity of the edema is also a significant criterion for the patient’s prognosis. This is because the more extensive the edema has already spread to important brain areas, the more brain areas are destroyed and their functions are limited or completely abolished. This happens because the intracranial pressure increases progressively due to the edema, as there is a spread due to the natural limitation of the solid skull capsule. Therefore, the prognosis is often unfavorable in cases of severe edema. This is especially the case if the time between the appearance of the damaging edema and the initiation of necessary treatment measures is very long. If, as in the case of accidents or cerebral hemorrhage, there is an additional source of bleeding to the cerebral edema, this further worsens the prognosis.
Prevention
Prevention is problematic in cerebral edema, due to its usually sudden and unpredictable onset. With upper body elevation, blood pressure-lowering and blood sugar-lowering therapy, and administration of diuretic medications, swelling can be reduced but often cannot be prevented. If conservative treatment is ineffective, surgical opening of the skull may be necessary.
Follow-up care
The follow-up measures that must be taken after cerebral edema depend on the cause and consequences of the swelling and the type of treatment. If an injury is causative, it is checked during follow-up visits. Provided there are no complications or the injury is completely cured, the cause does not need to be further included in the follow-up. If the brain edema is due to poisoning, further blood tests may need to be performed to ensure that the toxin has been completely eliminated. Follow-up care for brain edema is provided by a neurologist. The medical professional will obtain a CT scan and also perform a physical exam. For permanent brain damage, follow-up care includes relearning lost skills. The therapy measures required in each case depend on the type and extent of the brain damage. In principle, the patient must visit the doctor regularly so that the progress of health can be checked. In addition, the medication must be regularly adjusted to the symptom picture. Medications typically used with the active ingredients clopidogrel or edoxaban reduce any pain, prevent blood clots and reduce the risk of a heart attack after brain swelling. The neurologist in charge must decide which measures are appropriate in detail.
What you can do yourself
Brain edema cannot be treated as part of self-help measures. Those affected are usually always dependent on medical treatment and, in many cases, surgical intervention. In some cases, the symptoms can be alleviated with the help of diuretics. However, this is only a temporary treatment. If the affected person has suffered an accident in which the head was also damaged, the brain should always be examined. Regular medical examinations are necessary even after successful treatment. If the affected person loses consciousness due to the brain edema, an emergency doctor must be called immediately or the nearest hospital must be visited. Early detection and treatment of the disease has a very positive effect on the further course of the disease. In most cases, the symptoms disappear completely after treatment, so that further measures are no longer necessary. If the symptoms of cerebral edema occur at a high altitude, this altitude must be left immediately. This can prevent further discomfort or bleeding. In the case of a stroke, the patient is often dependent on the help of other people in his daily life.The help of friends and family proves especially helpful.