Posterior reversible encephalopathy syndrome (PRES) presents as a combination of sudden-onset headache, clouding of consciousness, epileptic seizures, and visual disturbances. The causes can be very diverse. While the condition can even lead to death in isolated cases if left untreated, it usually resolves completely with rapid onset of therapy.
What is posterior reversible encephalopathy syndrome?
Posterior reversible encephalopathy syndrome is a sudden-onset symptom complex of acute headache, visual disturbances, and epileptic seizures. Despite completely different causes, similar processes leading to its development are suspected. Diagnostically, vasogenic cerebral edema is always diagnosed. Vasogenic cerebral edema forms due to disruption of the blood–brain barrier, with fluid from the cytoplasm entering the intercellular space of the cerebral medulla. In most cases, the syndrome is associated with a sharp increase in arterial hypertension. However, cases of posterior reversible encephalopathy syndrome without a rise in blood pressure have also been observed. Furthermore, there is also no direct correlation between the level of blood pressure and the severity of symptoms. To date, the complete process of development of this syndrome has not been 100% elucidated. In particular, the role of hypertension is not yet clearly understood. In the past, hypertension was considered to be the cause of posterior reversible encephalopathy syndrome. Today, the possibility that it represents a response to vasogenic cerebral edema is discussed. As suggested by its name, posterior reversible encephalopathy syndrome is a reversible disorder of brain function that usually resolves completely with prompt treatment. However, there are cases where structural changes develop in the brain due to cerebral hemorrhage or other pathological processes. Occasionally, deaths even occur.
Causes
Posterior reversible encephalopathy syndrome can be caused by multiple etiologies. However, a common process leading to breakdown of the blood-brain barrier is then discussed. The syndrome is actually a complication that can occur with various diseases, drug treatments, other medical treatments or alcohol as well as drug abuse. Meanwhile, it has been found that the common feature of the syndrome is vasogenic brain edema. Presumably, vasogenic cerebral edema is caused by endothelial dysfunction. The consequence of this dysfunction is a disruption of the blood-brain barrier with fluid transfer from the cytoplasm to the intercellular space in the medullary region of the brain. This disorder may occur as a result of such diseases as acute and chronic renal failure, hemolytic and uremic syndrome, various blood diseases, eclampsia, or various autoimmune diseases of the connective tissue of the vessels as well as the skin. In the case of medications, chemotherapeutics and immunosuppressants play a special role in the development of the syndrome. This complication can also occur after hormone treatments with estrogen preparations. The same applies to drugs such as LSD or cocaine. The symptom complex of posterior reversible encephalopathy syndrome can also develop in rare cases after blood transfusions or exposure to contrast media. The role of high arterial blood pressure (hypertension) is not yet clear. It was previously thought to be the cause of posterior reversible encephalopathy syndrome. However, current conjecture rather assumes that it is a response to vasogenic cerebral edema. Due to the transfer of fluid into the intercellular space, blood flow to the brain is compromised. As a result, the organism responds with a sharp increase in arterial blood pressure to ensure normal cerebral perfusion. This rise in blood pressure increases the risk of cerebral hemorrhage and stroke.
Symptoms, complaints, and signs
Posterior reversible encephalopathy syndrome is characterized by the symptom complex of acute headache, epileptic seizures, visual disturbances, confusional states, and clouding of consciousness. Rarely, the symptoms occur simultaneously. Multiple epileptic seizures often occur within the first 24 hours of illness.Epilepsy can also become a permanent condition during this period, which can lead to coma. After the 24 hours have elapsed, epileptic seizures usually no longer occur. In most cases, hypertension (arterial hypertension) is also observed. However, this is not true for all cases of the disease. Very rarely, neurologic disorders with paralysis may develop.
Diagnosis and course of the disease
The compilation of symptoms alone suggests a posterior reversible encephalopathy syndrome. The diagnosis can be confirmed by imaging techniques such as MRI, CT, diffusion-weighted imaging (DWI), or flair technique. Vasogenic cerebral edema is detected during these studies.
Complications
In this syndrome, affected individuals suffer from a number of different complaints. In most cases, this involves very severe headaches that may spread to other regions of the body. Disturbances of consciousness or epileptic seizures can also occur in this syndrome and have a very negative impact on the patient’s quality of life. In the worst case, the epileptic seizures can lead to death. However, the further course of the disease strongly depends on the time of diagnosis. Patients with this disease are very confused and can no longer correctly assign things and actions. A coma can also occur. In many cases, patients suffer from symptoms of paralysis due to the disease, but these only occur for short periods of time. However, if the symptoms of the disease occur more often, irreversible damage to the patient’s nerves may result. As a rule, treatment is carried out without complications and always depends on the underlying disease. This is usually treated with the help of medication. If treatment is initiated early, a positive course of the disease occurs in most cases.
When should you go to the doctor?
If visual complaints, headaches, or epileptic seizures occur, there is probably a serious underlying condition. A doctor should be consulted if the symptoms appear suddenly and quickly become more severe. If disturbances of consciousness develop, emergency medical services must be called. Posterior reversible leukencephalopathy syndrome occurs predominantly in people who already have a serious neurological condition. Tumor patients as well as people with an unhealthy lifestyle also belong to the risk groups. You should consult a doctor if the above symptoms occur acutely and persist for more than a few minutes. The syndrome can first be clarified by the family doctor or an emergency physician. Posterior reversible leukencephalopathy syndrome is then treated by a neurologist. Depending on the symptom picture, cardiologists, ophthalmologists and internists may also be involved in the treatment of the syndrome. In a severe course with subcortical cerebral edema, the patient requires physiotherapeutic support. Lifestyle changes may also be needed, and nutritionists, therapists, and a number of other experts are responsible for this.
Treatment and therapy
Because posterior reversible encephalopathy syndrome has a sudden and often violent onset, therapy must begin very quickly. This is the only way to avoid long-term damage or even a fatal course. As a rule, the symptoms regress completely after therapy. However, treatment depends on the underlying disease or disorder. If severe hypertension is present, it should be treated as soon as possible to avoid the risk of stroke or cerebral hemorrhage. Thus, diastolic blood pressure should be lowered to approximately 100 to 105 mm Hg. However, mean arterial pressure should not be reduced more than 25 percent from baseline to ensure normal cerebral perfusion. This can be achieved by intravenous administration of certain antihypertensive drugs. Suspected toxic substances and medications must be discontinued quickly. In cases of chronic disease, medication changes must be considered.
Prevention
To prevent posterior reversible encephalopathy syndrome, the underlying cause must be eliminated. A healthy lifestyle with a balanced diet, plenty of exercise, and abstinence from stimulants and drugs can already reduce the risk of various precipitating underlying diseases.
Aftercare
After treatment of posterior reversible encephalopathy syndrome in the intensive care unit, comprehensive follow-up begins. Among other things, this is to monitor the normalization of blood pressure. At the same time, the aim is to target the original triggers of the disease. The risk of epileptic seizures can also be controlled to a certain extent within this framework. It is essential for patients to follow the doctor’s recommendations exactly. Depending on the individual case, they may need to take magnesium regularly. A large proportion of people with the disease are able to recover completely, so that they no longer experience any symptoms. In order to ensure the improvement of the condition, those affected can have a medical examination at regular intervals. If complications should arise, quick action is necessary. That is why some self-monitoring is necessary. The patient’s family should be aware of symptoms such as vascular occlusion and call a doctor quickly in case of emergency. This may prevent long-term consequences such as neurological disorders. A healthy lifestyle to lower blood pressure is not a guarantee, but it helps reduce the risk of recurrence. With this background knowledge, those affected can strengthen their own health and improve their condition by exercising more and eating a healthy diet.
Here’s what you can do yourself
Posterior reversible encephalopathy syndrome requires rapid action, which is why people at risk should be watched closely. To avoid accidents due to sudden seizures, visual disturbances, or loss of consciousness, regular monitoring is necessary. Direct treatment is provided by antihypertensive drugs administered intravenously. In chronically ill persons, a change in the medication previously taken is necessary to reduce the risk of seizures. Basically, the aim is to eliminate the actual cause of the attack. This can be achieved by eating a balanced diet rich in nutrients, by getting enough exercise and by avoiding alcohol, cigarettes and other stimulants. A low stress level also has a positive effect on the overall condition and thus reduces the risk of life-threatening attacks. However, high blood pressure is not causally related to the disease. Patients should obtain accurate information and ask their doctor for advice. Medical recommendations refer not only to acute cases, but also to everyday matters. With a reasonable lifestyle and the early examination appointment, a targeted treatment with medication is possible. Regular intake according to the doctor’s prescription supports the positive course of therapy.
