The diagnosis is usually made by brain scan (MRI) on which areas of swelling can be identified. High blood pressure is often present.  Computed tomography scanning may be performed in the first instance; this may show low density white matter areas in the posterior lobes. Posterior Reversible Encephalopathy Syndrome, Part 2: Controversies Surrounding Pathophysiology of Vasogenic Edema.  If lumbar puncture is performed this may show increased protein levels but no white blood cells. On magnetic resonance imaging (MRI) of the brain, areas of edema (swelling) are seen. Preventing Scarface: Pearls for Complicated Facial Lacerations – Lip Laceration, Preventing Scarface: Pearls for Complicated Facial Lacerations – Oral Mucosa Lacerations, Preventing Scarface: Pearls for Complicated Facial Lacerations – Tongue Lacerations, R.E.B.E.L. Fugate, J.E., et al., Posterior reversible encephalopathy syndrome: associated clinical and radiologic findings. Moratalla MB. This project is rolling and you can submit an idea or write-up at any time! Posterior reversible encephalopathy syndrome (PRES) is a clinical-neuroradiological entity characterized by headache, vomiting, altered mental status, blurred vision and seizures as well as images suggesting white-gray matter edema involving in most cases posterior regions of the central nervous system, as demonstrated by magnetic resonance image.  Non-resolution of MRI abnormalities has been linked with poorer outcomes. , After an episode of PRES, even when it was associated with seizure activity, only a small proportion of people remains at risk of ongoing seizures and the majority can eventually discontinue anticonvulsant treatment. , If there is a hypertensive emergency, the blood pressure is lowered by 20-30% using continuous infusion of a blood pressure lowering drug with close monitoring. , While the precise mechanism is PRES is not fully understood, it is considered to be related to a problem with the blood vessels of the brain. , The hyperperfusion theory posits that blood pressure elevations that exceed the autoregulatory mechanism of cerebral blood flow lead to increased vascular leakage. Similarly, the majority of people with PRES have an impaired kidney function, and 21% are receiving regular hemodialysis.  In PRES related to medications, there may be an interval of weeks to months between the initiation of the treatment and the development of PRES. If prior records are available, a comparison of prior blood pressure readings can provide helpful information in identifying an acute change from baseline values. 52(10): p. 855-863. If PRES is recognized and treated appropriately, a majority of patients recover without neurologic sequelae. Seizures occur in a majority of patients with PRES and are often the presenting symptom. , PRES was first described in 1996 in a group of 15 patients identified retrospectively in the records of the New England Medical Center in Boston and Hôpital Sainte Anne in Paris. 32(1): p. 25-35.  In PRES secondary to pre-eclampsia, magnesium sulfate may be administered. Liman, T.G., E. Siebert, and M. Endres, Posterior reversible encephalopathy syndrome.  The prevalence of PRES among patients with eclampsia is quite high, with the prevalence of PRES in this population reported to be 65-100%. with tacrolimus), severe infection and/or sepsis, chemotherapy, autoimmune disease, and pre-eclampsia. Computed tomography (CT) of the head without contrast reveals hypoattenuation in the subcortical white matter of the parietal and occipital lobes. J Clin Neurosci, 2019. In a 1996 case series , the entity most commonly known as PRES was first presented as a clinical syndrome. Garg, R.K., N. Kumar, and H.S. Click below to contact us or find us on Twitter, Facebook or Google+. 85(5): p. 427-432. , Factors that predict poorer prognosis are the person's age, the level of C-reactive protein in the blood (a marker of inflammation), altered mental state at the time of diagnosis, and altered markers of coagulation. Brewer, J., et al., Posterior reversible encephalopathy syndrome in 46 of 47 patients with eclampsia. , It has been suggested that PRES is identical or closely related with hypertensive encephalopathy, the presence of neurological symptoms in those with a hypertensive emergency. Authors: Aaron G. Matlock, MD (EM Attending Physician, Brooke Army Medical Center Department of Emergency Medicine, Assistant Professor, Uniformed Services University of Health Sciences) and Brit Long, MD (@long_brit) // Reviewed by: Alex Koyfman, MD (@EMHighAK). Neurocrit Care, 2018. , There is no direct treatment for PRES, other than removing or treating any underlying cause. Posterior reversible encephalopathy syndrome (PRES) is a syndrome characterized by headache, confusion, seizures and visual loss.It may occur due to a number of causes, predominantly malignant hypertension, eclampsia and some medical treatments.  In children this is more common still, at 90%. The "vasogenic" theory posits that extremely high blood pressure overcomes the normal capability of blood vessels in the brain to maintain a normal cerebral blood flow.  Computed tomography scanning may be performed in the first instance; this may show low density white matter areas in the posterior lobes. Her medications include tacrolimus, prednisone, mycophenolate, and lisinopril. The "vasogenic" theory posits that extremely high blood pressure overcomes the normal capability of blood vessels in the brain to maintain a normal cerebral blood flow. , Seizures occur in about two thirds of cases. Save my name, email, and website in this browser for the next time I comment. Someone with PRES may experience headache, changes in vision, and seizures, with some developing other neurological symptoms such as confusion or weakness of one or more limbs.  People with diabetes may have a worse outcome, and abnormalities in the corpus callosum on MRI have been linked with worse prognosis. with tacrolimus), severe infection and/or sepsis, chemotherapy, autoimmune disease, and pre-eclampsia. , Causes that may contribute to the development of PRES are: immunosuppression (especially for organ transplantation, e.g.  If the appearances are not typical, other causes for the symptoms and the imaging abnormalities need to considered before PRES can be diagnosed conclusively. Wagner, S.J., et al., Posterior reversible encephalopathy syndrome and eclampsia: pressing the case for more aggressive blood pressure control. Jun-Jul 2009. None of these names accurately reflects the complete spectrum of this disease, as its neurologic manifestations are not exclusively “posterior”, nor are the deficits always “reversible”.  A small proportion develops status epilepticus, where seizures are not controlled with simple measures.  This theory does not explain the edema in many other cases where the blood pressure has been normal or even low; in fact, the edema tends to be more severe in those without abnormally elevated blood pressure. 380: p. 11-15. Someone with PRES may experience headache, changes in vision, and seizures, with some developing other neurological symptoms such as confusion or weakness of one or more limbs. Visual fields are difficult to fully assess, but the patient did appear to have some degree of global visual impairment. 63(6): p. 983-9. We are actively recruiting both new topics and authors. , In 10–25% of cases of PRES there is evidence of hemorrhage on neuroimaging. Clinical features of PRES are summarized in Table 2.  Some consider the cytotoxic and immunogenic theories together as a single "toxic" theory. The excessive pressure damages the endothelial layer and the blood-brain barrier, leading to swelling (edema). Sharma, A., R.T. Whitesell, and K.J. There has been no recent trauma, toxic exposure, or infectious symptoms.