Asymmetric posterior reversible encephalopathy syndrome complicating hemodynamic augmentation for subarachnoid hemorrhage-associated cerebral vasospasm.

BACKGROUND: Posterior reversible encephalopathy syndrome (PRES) is a rare complication of hemodynamic augmentation for subarachnoid hemorrhage (SAH)-associated vasospasm. The roles of hyperperfusion and hypoperfusion in the genesis of PRES remain uncertain. METHODS: Case report. RESULTS: We admitted a 35-year-old woman with Hunt & Hess grade II SAH secondary to rupture of a right middle cerebral artery (MCA) aneurysm. This was surgically clipped. Beginning on hospital day 3, she developed recurrent symptomatic vasospasm of the right MCA despite hemodynamic augmentation to a MAP as high as 130 mmHg and endovascular therapy. On hospital day 7, after 36 h of sustained MAP 120-130 mmHg, her level of arousal progressively declined, culminating in stupor and two generalized tonic-clonic seizures. MRI showed widespread, yet markedly asymmetric changes consistent with PRES largely sparing the right MCA territory. After the MAP was decreased to 85-100 mmHg, she had no further seizures. 2 days later she was fully alert with mild left hemiparesis. CONCLUSIONS: PRES is a rare complication of hemodynamic augmentation that should be considered in the differential diagnosis of delayed neurological decline in patients with aneurysmal SAH-associated cerebral vasospasm. The markedly asymmetric distribution of PRES lesions with sparing of the territory affected by vasospasm supports the hypothesis that hyperperfusion underlies the pathophysiology of this disorder.