Unilateral papilledema caused by a fronto-temporo-parietal arachnoid cyst

PURPOSE: To report a case of unilateral papilledema caused by an arachnoid cyst. METHODS: Interventional case report. RESULTS: A 36-year-old woman presented with unilateral papilledema in the l eft eye. Magnetic resonance imaging (MRI) of the brain demonstrated a large fronto-temporoparietal arachnoid cyst in the left hemisphere. The papilled ema resolved after placement of a cysto-peritoneal shunt that drained the c erebrospinal fluid directly from the arachoid cyst into the peritoneum. CONCLUSION: Papilledema caused by increased intracranial pressure is usuall y bilateral; unilateral papilledema is possible under special anatomical ci rcumstances. (C) 2001 by Elsevier Science Inc. All rights reserved.