Posterior Reversible Encephalopathy Syndrome (PRES) Overview Clinico-Radiological Syndrome, characterized by: • Headache • Seizures • Altered mental status • Visual disturbance • White matter vasogenic edema affecting the posterior occipital and parietal lobes of the brain PRES Clinical Presentation: • Altered mental status • Headache • Seizures • Vision changes • Hypertensive crisis may precede the neurologic syndrome by 24 hours or longer/BP fluctuations PRES-Associated Clinical Conditions: • Preeclampsia, Eclampsia, Infection/Sepsis/Shock, Autoimmune disease, Cancer chemotherapy, Immunosuppressive agents, Renal failure, Transplantation including bone marrow or stem cell transplantation, Hypertension/Hypertensive emergency, Blood transfusion, Hypercalcemia Etiology: • Pathophysiology remains unclear, endothelial dysfunction is key, with hypertension being the most common precipitating factor PRES Diagnosis: 1. Neurological symptoms: Acute onset 2. Risk factors 3. Imaging Patterns in PRES: • Increased signal on T2-weighted images • Vasogenic edema visualized as a hypo- or isointense signal on DWI • White matter edema - both posterior cerebral hemispheres • (FLAIR) sequences improve sensitivity showing cortical lesions • Vascular narrowing on MRA/CTA • Anterior circulation: MCA ACA watershed territories signal changes 4. Reversible course Differential Diagnosis: • Infection, Electrolyte abnormality, Medication/Drug toxicity, Metabolic disturbance, External lines/devices, Constipation, Seizures, Stroke, Paraneoplastic syndrome, ADEM, Acute toxic leukoencephalopathy, Cerebral venous thrombosis Testing: • Imaging: White matter vasogenic edema affecting the posterior occipital and parietal lobes of the brain • CSF: Modestly elevated protein level (mean 58 mg/dL in one study) but no pleocytosis. An elevated white blood cell count in the CSF should prompt consideration of other diagnoses. • EEG: With persistent altered level of consciousness to exclude nonconvulsive status epilepticus Treatment: • Address the underlying cause • Treatment of HTN is the mainstay of therapy in patients - 10-25% BP reduction initially, Avoid overaggressive BP lowering - Lower the diastolic pressure to 100-105 mmHg within 2 to 6 hours - Use easily titratable parenteral agents: clevidipine, nicardipine, or labetalol. • Magnesium correction: Levels 2-3 mEq/L • Seizures: Treat with AEDs until cause identified #PRES #Posterior #Reversible #Encephalopathy #Syndrome #diagnosis #management #neurology
