Posterior reversible encephalopathy syndrome (PRES): presentation, diagnosis and treatment

Abstract

Posterior reversible encephalopathy syndrome (PRES) is a neurological disorder which is characterised by variable symptoms, which include visual disturbances, headache, vomiting, seizures and altered consciousness. The exact pathophysiology of PRES has not been completely explained, but hypertension and endothelial injury seem to be almost always present. Vasoconstriction resulting in vasogenic and cytotoxic edema is suspected to be responsible for the clinical symptoms as well as the neuro-radiological presentation. On imaging studies, Symmetrical white matter abnormalities suggestive of edema are seen in the computer tomography (CT) and magnetic resonance imaging (MRI) scans, commonly but not exclusively in the posterior parieto-occipital regions of the cerebral hemispheres. The management is chiefly concerned with stabilization of the patient, adequate and prompt control of blood pressure, prevention of seizures and timely caesarean section in obstetric cases with pre-eclampsia/eclampsia. In conclusion, persistently elevated blood pressures remain the chief culprit for the clinical symptoms as well as the neurological deficits. Early diagnosis by diffusion weighted MRI scans, and differentiation from other causes of altered sensorium i.e. seizures, meningitis and psychosis, is extremely important to initiate treatment and prevent further complications. Although most cases resolve successfully and carry a favorable prognosis, patients with inadequate therapeutic support or delay in treatment may not project a positive outcome.

Childhood Posterior Reversible Encephalopathy Syndrome: Clinicoradiological Characteristics, Managements, and Outcome

“…Till now, the pathomechanism underlying PRES is yet to be thoroughly elucidated. Two competing theories have been proposed, both of which entail disruption of the blood-brain barrier and fluid leakage into the interstitial tissues, leading to the edematous change of cerebral parenchyma (9,15,16). However, more evidence indicates that vasogenic edema rather than cytotoxic edema plays a more critical role in the pathogenesis of PRES (17,18).…”

“…Nevertheless, patients with PRES always require management in the setting of intensive care units given that hypertensive crisis, status epilepticus, coma, or respiratory failure may complicate PRES, which require aggressive interventions (7,15,18). In adult medicine, it has been suggested that the management of PRES should be better delivered in a neurocritical care setting with meticulous neurological monitoring and interventions (9,16,46). However, besides neurological specialty, it usually requires frequent consultations with other specialties, including hematologist-oncologist, nephrologists, rheumatologists, or obstetricians, according to the diverse underlying comorbidities (31).…”

“…Generally, PRES is regarded to be both clinically and radiologically reversible and usually has a favorable prognosis while it is treated timely, with uneventful recovery within days or weeks (15,16,18,26,27). Clinical manifestations usually clear progressively within four days, but they may persist for over a few weeks.…”

“…However, the MRI diffusion sequence could be misleading, as both increased and decreased values may be incidental findings with no prognostic value (17,25,38). On the other hand, elevated serum lactate dehydrogenase levels (LDH) and C-reactive protein (CRP) have been proposed as potential biomarkers to predict the outcome in some patients with PRES; however, the most findings were based on a small group of patients (16,62,66,67). The role of clinical, biochemical, and radiological parameters in predicting the prognosis of patients with PRES warrants further verification.…”

The association of posterior reversible encephalopathy syndrome with COVID-19: A systematic review

“…The common presenting complaints include seizures, headache, visual disturbances, and altered sensorium [ 6 , 7 ]. Diffusion-weighted MRI is the imaging modality of choice for confirming the presence of typical or atypical radiographic features [ 8 , 9 ].…”