From the Guidelines
PRES syndrome is a neurological condition characterized by temporary swelling in the posterior regions of the brain, typically triggered by severe hypertension, and is fully reversible with timely recognition and management.
Key Characteristics of PRES Syndrome
- It is characterized by white matter lesions in the posterior regions of the brain 1
- Symptoms include headache, visual disturbances, and focal or general neurological symptoms 1
- It occurs when blood pressure rises beyond what the brain's self-regulatory mechanisms can handle, causing fluid leakage into brain tissues
- Diagnosis involves brain imaging, typically MRI, which shows characteristic white matter edema in posterior brain regions 1 ### Diagnosis and Treatment
- Magnetic resonance imaging (MRI) demonstrating increased signal intensity on T2-weighted or fluid attenuated inversion recovery (FLAIR)-imaging may be of additional value to confirm the diagnosis 1
- Computerized tomography (CT) is useful to exclude intra-cerebral haemorrhage 1
- Treatment focuses on addressing the underlying cause, such as controlling blood pressure with medications, discontinuing triggering medications, or managing eclampsia
- Most patients recover completely within days to weeks with prompt treatment, though delayed diagnosis can lead to permanent brain damage 1 ### Importance of Timely Management
- The rate of BP increase appears to be more important than the absolute BP value in the development of hypertensive emergencies 1
- Regular blood pressure monitoring is essential during recovery to prevent recurrence
- Prompt recognition and management of PRES syndrome are crucial to prevent permanent brain damage and ensure full recovery.
From the Research
Definition and Characteristics of PRES
- Posterior Reversible Encephalopathy Syndrome (PRES) is an acute neurotoxic syndrome characterized by a spectrum of neurological and radiological features from various risk factors 2.
- It is a clinical-radiological syndrome, usually reversible, characterized by vasogenic edema in cerebral posterior regions in patients with autoimmune diseases, nephropathies, hypertensive crisis, eclampsia, and exposure to cytotoxic drugs 3.
- PRES is characterized by neuroimaging findings of reversible vasogenic subcortical edema without infarction 4.
Clinical Symptoms
- Common neurological symptoms include headache, impairment in level of consciousness, seizures, visual disturbances, and focal neurological deficits 2.
- The clinical syndrome of PRES typically involves headache, encephalopathy, visual symptoms, and seizures 4.
- Clinical symptoms and neuroradiological findings are typically indistinguishable among the cases of PRES, regardless of underlying cause 5.
Radiographic Findings
- The classic radiographic findings include bilateral subcortical vasogenic edema predominantly affecting the parieto-occipital regions 2.
- Magnetic resonance imaging (MRI) typically shows edema involving the white matter of cerebral posterior regions, especially parieto-occipital lobes but frontal and temporal lobes, and other encephalic structures may be involved 5.
- Findings are characterized by hyperintensity on fluid-attenuated inversion recovery images and apparent diffusion coefficient mapping, and isointensity on diffusion-weighted images involving the parieto-occipital or posterior frontal cortical-subcortical regions 6.
Triggering Factors
- Common triggering factors include blood pressure fluctuations, renal failure, eclampsia, exposure to immunosuppressive or cytotoxic agents, and autoimmune disorders 2.
- PRES is associated with a number of different causes, most commonly acute hypertension, preeclampsia/eclampsia, and immunosuppressive agents 5.
- Underlying conditions such as hypertensive encephalopathy, eclampsia, collagen disease, and severe infection can also cause PRES 6.