Postcarotid Endarterectomy Hyperperfusion or Reperfusion Syndrome

Abstract

The authors studied the pathophysiology of hyperfusion syndrome with diffusion-weighted and perfusion-weighted magnetic resonance imaging. They identified vasogenic or cytotoxic edema by diffusion-weighted imaging, assessed cerebral artery mean flow velocities by transcranial Doppler, and assessed the relative nterhemispher c difference of cerebral blood flow by perfusion-weighted imaging. No patient presented with pathologic diffusion-weighted imaging hyperintensitities, 2 patients exhibited an MRI pattern of reversible vasogenic edema. Mean flow velocities in the middle cerebral artery were not abnormally increased. They concluded that hyperfusion syndrome can occur in the presence of moderate relative hyperfusion of the ipsilateral hemisphere and that mean fiow velocities may not accurately reflect relative interhemispheric differences.