(18)F-fluorodeoxyglucose positron emission tomography and MR imaging findings in Rasmussen encephalitis.

Published

Journal Article

BACKGROUND AND PURPOSE: Rasmussen encephalitis is a chronic, progressive encephalitis that manifests as an abrupt-onset, intractable seizure disorder in previously developmentally normal children. The objectives of the current study were to characterize the (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) and MR imaging findings in Rasmussen encephalitis and to test the hypotheses that data from both imaging techniques are required to establish the diagnosis and identify the affected cerebral hemisphere in some cases. METHODS: Eleven patients with Rasmussen encephalitis were identified from a review of a computer database. The MR (n = 10) and PET (n = 11) imaging data were reviewed retrospectively and conjointly. RESULTS: On MR images, nine of 10 patients manifested bilateral cerebral atrophy that predominantly involved one hemisphere. One patient had purely unilateral cerebral atrophy. We observed foci of abnormally increased T2 signal intensity in nine of 10 patients. On FDG PET images, all patients showed extensive regions of hypometabolism within the cerebral hemisphere that showed the greatest atrophy. Discrete foci of hypermetabolism, indicative of seizure activity, were observed in six patients. The FDG PET and MR imaging findings were either stable or gradually progressive in patients with multiple imaging studies (MR, n = 5; FDG PET, n = 5). CONCLUSION: Rasmussen encephalitis is characterized by diffuse, unilateral cerebral hypometabolism on FDG PET images, with corresponding regions of cerebral atrophy on MR images. Although MR imaging data alone are sufficient to suggest a diagnosis of Rasmussen encephalitis in many cases, correlation with FDG PET data increases diagnostic confidence and allows the unequivocal identification of the affected cerebral hemisphere in patients whose MR imaging findings are subtle or distributed bilaterally.

Full Text

Duke Authors

Cited Authors

  • Fiorella, DJ; Provenzale, JM; Coleman, RE; Crain, BJ; Al-Sugair, AA

Published Date

  • August 2001

Published In

Volume / Issue

  • 22 / 7

Start / End Page

  • 1291 - 1299

PubMed ID

  • 11498416

Pubmed Central ID

  • 11498416

Electronic International Standard Serial Number (EISSN)

  • 1936-959X

International Standard Serial Number (ISSN)

  • 0195-6108

Language

  • eng