Intimal thickening of meningeal arteries after serial corticectomies for Rasmussen encephalitis.

Rasmussen encephalitis is a rare cause of intractable epilepsy in children. Between 2008 and 2010, 4 patients had second cortical resections performed after a primary corticectomy for Rasmussen encephalitis. In each case, we observed some degree of vessel wall change in leptomeningeal arteries, consisting of moderate to moderately severe intimal hyperplasia. The intervals between original resection and second operation ranged from 8 months to 10 years. Ages of the patients ranged from 9 to 12 years at their first resection and from 10 to 19 years at the time of revision. Four other Rasmussen encephalitis cases operated upon in the years 2006 to 2010 and 2 surgical revisions for severe cortical dysplasia, 1 for mild cortical dysplasia and 1 for recurrent dysembryoplastic neuroepithelial tumor, did not show significant vascular abnormalities (with surgical intervals of 10 months to 16 years). Leptomeningeal intimal hyperplasia appears to develop in the interval between repeated cortical resections for Rasmussen encephalitis, an inflammatory disorder. The pathogenesis of this vascular change may be related to meningeal inflammation in Rasmussen encephalitis. This finding in children undergoing surgical resection for Rasmussen encephalitis may itself lead to "secondary" ischemic change that contributes to worsening of epilepsy.