Rasmussen encephalitis associated with segmental vitiligo of the scalp: clinicopathologic report

A 3-year-old boy with segmental vitiligo, poliosis, and alopecia over the right side of the scalp developed epilepsia partialis continua involving the left side of the body and progressive atrophy of the right cerebral hemisphere. There was a right ear dysacusia and a perilimbal vitiligo associated with an area of iris depigmentation in the right eye. Pleocytosis and hypergammaglobulin were detected in cerebrospinal fluid. Because medical treatment that included phenobarbital, phenytoin, carbamazepine, oxcarbazepine, benzodiazepines, corticosteroids, gamma-globulin, and a ketogenic diet was ineffective, he underwent a right hemispherectomy. Neuropathologic examination showed a widespread scattered inflammatory process with numerous microglial nodules and perivascular lymphocytic cuffing associated with degenerative changes with severe neuronal loss, loosening of the neuropil, and microcystic changes with tissue collapse. The coexistence of vitiligo and possibly Vogt-Koyanagi-Harada syndrome in this child reinforces the autoimmune theory as the pathogenesis of Rasmussen syndrome.