MRI volumetric analysis in rasmussen encephalitis: a longitudinal study.
OBJECTIVE
Rasmussen encephalitis is a progressive inflammatory process with difficult-to-control focal or lateralized seizure activity, leading to hemispheric dysfunction and atrophy in advanced stages. Anatomic changes of atrophy may be subtle in earlier phases of the disease, and progressive changes on serial scans may be difficult to detect. We report a case of early-stage Rasmussen encephalitis with a relatively stable clinical course in whom we performed magnetic resonance imaging (MRI)-based volumetric analysis over an interval of 1 year, to assess for volumetric changes.


METHODS
Volumetric analysis was performed on two successive MRI scans obtained at age 5 and 6 years, by using the CARDVIEWS program (J Cogn Neurosci, 1996). The images were segmented into gray- and white-matter structures according to signal intensity of their borders semiautomatically, with manual corrections. The cerebral cortex was further subdivided into smaller parcellation units according to anatomic landmarks identifiable on MRI.


RESULTS
Stable left cerebral hemispheric atrophy and progressive atrophy in the left precentral gyrus, left inferior frontal gyrus, and left cerebellar atrophy were detected over the 1-year interval.


CONCLUSIONS
Volumetric analysis enables early detection and quantification of anatomic changes, identification of focal involvement, and assists in determining the severity of disease and timing for surgical interventions such as hemispherectomy.
Takeoka
Masanori
M
Department of Neurology, Children's Hospital, Harvard Medical School, Boston, Massachusetts, U.S.A. maxtakeoka@aol.com
Kim
Francine
F
Caviness
Verne S
VS
Kennedy
David N
DN
Makris
Nikos
N
Holmes
Gregory L
GL
D001284:Atrophy; D002531:Cerebellum / Q000473:pathology*; D002540:Cerebral Cortex / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D018450:Disease Progression; D004292:Dominance, Cerebral / Q000502:physiology; D004660:Encephalitis / Q000175:diagnosis* / Q000473:pathology; D020938:Epilepsy, Partial, Motor / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008432:Mathematical Computing