Posterior Reversible Encephalopathy Syndrome

A posterior reversible encephalopathy syndrome (PRES) presents itself as a combination of sudden headaches, clouding of consciousness, epileptic seizures and visual disturbances. The causes can be very diverse. While the disease can even lead to death in individual cases if left untreated, it usually resolves completely if therapy is started quickly.

Posterior Reversible Encephalopathy Syndrome

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 formation are suspected. A vasogenic cerebral edema is always diagnosed. See howsmb for Liver Cyst Definition and Meaning.

The vasogenic cerebral edema develops as a result of a disruption in the blood-brain barrier, with fluid from the cytoplasm getting into the intercellular space of the brain marrow. The syndrome is usually associated with a rapidly increasing arterial hypertension. However, cases of posterior reversible encephalopathy syndrome without an increase in blood pressure have also been observed.

Furthermore, there is no direct connection between the level of blood pressure and the severity of the symptoms. So far, the complete development process of this syndrome is not 100 percent clear. 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 is discussed that it represents a reaction to the vasogenic cerebral edema. As the name suggests, posterior reversible encephalopathy syndrome is a reversible disorder of brain function that usually resolves completely with prompt treatment. However, there are also cases where structural changes develop in the brain due to cerebral hemorrhage or other pathological processes. Occasionally there are even deaths.


Posterior reversible encephalopathy syndrome can be triggered by several causes. However, what is then discussed is a joint process that leads to the collapse of the blood-brain barrier. The syndrome is actually a complication that can occur with various diseases, drug treatments, other medical treatments or alcohol and drug abuse.

It has now been established that the common feature of the syndrome is vasogenic cerebral edema. The vasogenic cerebral edema is probably caused by a malfunction of the endothelium. The consequence of this malfunction is a disruption of the blood-brain barrier with liquid transfer from the cell plasma into the intercellular space in the marrow area of ​​the brain.

This disorder can occur as a result of such diseases as acute and chronic renal failure, hemolytic and uremic syndromes, various blood diseases, eclampsia or various autoimmune diseases of connective tissue of vessels and skin. As for drugs, chemotherapeutic agents 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 goes for drugs like LSD or cocaine. In rare cases, the symptom complex of the posterior reversible encephalopathy syndrome can also develop after blood transfusions or exposure to contrast media.

It is not yet clear what role high arterial high blood pressure (hypertension) plays. It was previously considered to be the cause of posterior reversible encephalopathy syndrome. However, current assumptions are based on the fact that it is a reaction to the vasogenic cerebral edema.

The blood flow to the brain is endangered by the transfer of liquid into the intercellular space. As a result, the organism reacts with a sharp increase in arterial blood pressure in order to ensure normal cerebral blood flow. This rise in blood pressure increases the risk of cerebral hemorrhage and stroke.

Symptoms, Ailments & Signs

The posterior reversible encephalopathy syndrome is characterized by the symptom complex of acute headaches, epileptic seizures, visual disturbances, states of confusion and clouding of consciousness. The symptoms rarely occur at the same time. Multiple epileptic seizures often occur within the first 24 hours of the illness.

Epilepsy can also become a permanent condition during this period, which can lead to coma. After 24 hours, epileptic seizures usually no longer occur. In most cases, hypertension (arterial hypertension) is also observed. However, this does not apply to all cases of illness. Very rarely, neurological disorders with symptoms of paralysis can develop.

Diagnosis & course of disease

The combination of symptoms alone suggests a posterior reversible encephalopathy syndrome. Diagnosis can be confirmed by imaging tests such as MRI, CT, diffusion-weighted imaging (DWI), or Flair technique. During these examinations, a vasogenic cerebral edema is discovered.


People with this syndrome suffer from a number of different symptoms. In most cases, this leads to very severe headaches, which can also spread to other regions of the body. Loss of consciousness or epileptic seizures can also occur with this syndrome and have a very negative effect 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 depends heavily on the time of diagnosis. Those affected are very confused with this disease and can no longer correctly assign things and actions. A coma can also occur. In many cases, the patients suffer from symptoms of paralysis due to illness, which, however, only occur for a short time.

However, if the symptoms of the disease occur more frequently, irreversible damage to the patient’s nerves can occur. As a rule, the treatment is carried out without complications and always depends on the underlying disease. This is usually treated with medication. If treatment is initiated early, the disease progresses positively in most cases.

When should you go to the doctor?

If vision problems, headaches or epileptic seizures occur, there is probably a serious underlying condition. A doctor should be consulted if the symptoms appear suddenly and get worse quickly. If there is a loss of consciousness, the emergency services must be called. Posterior reversible leukoencephalopathy syndrome occurs predominantly in people who already have a serious neurological disorder. Cancer patients and people with an unhealthy lifestyle also belong to the risk groups. You should consult a doctor if the above symptoms become acute and persist for more than a few minutes.

The syndrome can first be clarified by the family doctor or an emergency doctor. The posterior reversible leukoencephalopathy syndrome is then treated by a neurologist. Depending on the symptoms, cardiologists, ophthalmologists and internists can also be involved in the treatment of the syndrome. If the course is severe with subcortical cerebral edema, the patient needs physiotherapeutic support. If necessary, the lifestyle must also be changed, for which nutritionists, therapists and a number of other experts are responsible.

Treatment & Therapy

Since the onset of posterior reversible encephalopathy syndrome is sudden and often violent, therapy must begin very quickly. This is the only way to avoid long-term damage or even death. As a rule, the symptoms disappear completely after treatment. However, treatment depends on the underlying disease or disorder.

If severe hypertension is present, it should be treated as soon as possible in order not to risk a stroke or cerebral hemorrhage. The diastolic blood pressure should be reduced to around 100 to 105 mm Hg. However, the mean arterial pressure must not be lowered by more than 25 percent from the initial value in order to ensure normal cerebral blood flow.

This can be achieved by administering certain blood pressure-lowering drugs intravenously. Suspected toxic substances and drugs must be discontinued quickly. In the case of chronic diseases, a change in medication must be considered.


To prevent posterior reversible encephalopathy syndrome, the underlying cause must be eliminated. A healthy lifestyle with a balanced diet, plenty of exercise and avoiding stimulants and drugs can already reduce the risk of various underlying diseases.


After treatment of posterior reversible encephalopathy syndrome in the intensive care unit, comprehensive follow-up begins. This is to monitor, among other things, the normalization of blood pressure. At the same time, it is about treating the original triggers of the disease in a targeted manner. The risk of epileptic seizures can also be controlled to a certain extent in this context.

It is essential for patients to follow the doctor’s recommendations exactly. Depending on the individual case, they need to take magnesium regularly. The majority of sick people can recover completely, so that no more symptoms occur. In order to ensure that the condition improves, those affected can have a medical examination carried out at regular intervals.

If complications should arise, rapid action is required. So some introspection is necessary. The patient’s family should learn about the symptoms such as vascular occlusion and call a doctor quickly in an emergency. In this way, long-term consequences such as neurological disorders may be avoided.

A healthy lifestyle to lower blood pressure is not a guarantee, but it does help reduce the risk of it coming back. With this background knowledge, those affected can strengthen their own health and improve their condition through more exercise and a healthy diet.

You can do that yourself

Posterior Reversible Encephalopathy Syndrome requires rapid action, so those at risk should be closely monitored. In order to avoid accidents due to sudden seizures, blurred vision or loss of consciousness, regular check-ups are necessary.

Direct treatment is with antihypertensive drugs administered intravenously. Chronically ill people need to change their medications to reduce the risk of seizures. The basic aim is to eliminate the actual cause of the attack. This is achieved through a balanced and nutritious diet, through enough exercise and by not drinking alcohol, cigarettes and other stimulants. A low stress level also has a positive effect on the overall well-being and thus reduces the risk of life-threatening seizures.

However, high blood pressure is not causally related to the disease. Patients should do their own research and ask their doctor for advice. The medical recommendations not only relate to acute cases, but also to everyday things. With a reasonable lifestyle and an early examination date, targeted treatment with medication is possible. Regular intake according to medical prescription supports the positive course of therapy.