Posterior Reversible Encephalopathy Syndrome (PRES) is a neurological condition characterized by reversible brain edema, primarily affecting the posterior regions of the cerebral hemispheres, such as the occipital and parietal lobes. It is often associated with acute changes in blood pressure, though it can occur in normotensive individuals as well.

Key Features:

• Symptoms: Headache, seizures, altered mental status, visual disturbances (e.g., cortical blindness), and occasionally focal neurological deficits.
• Causes/Risk Factors:
  • Hypertensive crisis (e.g., eclampsia, pheochromocytoma)
  • Immunosuppressive or cytotoxic drugs (e.g., cyclosporine, tacrolimus)
  • Renal failure
  • Autoimmune disorders
  • Sepsis or systemic inflammatory states
• Pathophysiology: Likely involves impaired cerebral autoregulation leading to vasogenic edema, often due to endothelial dysfunction or abrupt blood pressure changes.
• Diagnosis:
  • Imaging: MRI or CT showing bilateral, symmetric vasogenic edema, typically in posterior brain regions. Hyperintensities on T2/FLAIR MRI sequences are classic.
  • Clinical correlation with risk factors and symptoms.
• Treatment:
  • Address underlying cause (e.g., control blood pressure, discontinue offending drugs).
  • Anticonvulsants for seizures (e.g., levetiracetam).
  • Supportive care.
• Prognosis: Typically reversible with prompt treatment, but delayed management can lead to permanent neurological damage or death.

Notes:

• PRES is not always posterior or fully reversible, especially if untreated.
• Early recognition is critical to prevent complications.

Disclaimer: owerl is not a doctor; please consult one.