Posterior reversible leukoencephalopathy syndrome presenting with global cerebral edema and herniation

Background: We report a case of global cerebral edema and herniation due to Posterior Reversible Leukoencephalopathy Syndrome (PRES). Methods: Case report. Results: A 37-year-old healthy female developed persistent severe occipital headache, and after 1 month of persistent headache, developed an episode of loss of consciousness. CT brain showed diffuse cerebral edema and effacement of the sulci and basal cisterns. Her initial neurological examination was nonfocal but with severe headache. Overnight, she acutely became unresponsive with fixed dilated pupils, tachycardia, and hypertension. She was intubated and treated with hypertonic saline and mannitol with improvement in her clinical status. Intracranial Pressure (ICP) monitor showed elevated ICPs to 37 mmHg which responded to mannitol. MRI brain showed diffuse vasogenic edema predominantly in the white matter without enhancement. Cerebral angiogram was unremarkable. Cerebrospinal fluid including infectious work-up was negative. With supportive care, her mental status improved. On her 3 month follow-up visit, she was asymptomatic and had returned to work. Repeat MRI brain at 3 months showed persistent white matter changes that subsequently resolved at 9 months. Conclusions: Although PRES is typically considered to have a benign clinical course, clinician should be aware that severe cases can present with global cerebral edema and associated complications including intracranial hypertension and herniation.