Authors: Dimitri Renard Elodie Nerrant Catherine Lechiche
Publish Date: 2015/06/20
Volume: 262, Issue: 9, Pages: 2101-2105
Abstract
DWI has been described in some reports to be superior to FLAIR in early stage herpes simple virus encephalitis HSE Few data exist on detailed topographical MRI analysis in HSE Our aim was to study DWI and FLAIR and analyse topographically these sequences in nonneonatal HSE patients with MRI performed within 60 days Eleven HSE patients were analysed retrospectively For topographical analysis we developed a radiological 50point score 25 points for each hemisphere with each point corresponding to a brain area In patients with MRI performed within 2 weeks n = 9 DWI detected 11 more areas involved than FLAIR Thalamic involvement was frequent 67 in the early phase on FLAIR being the only brain substructure better visualized on FLAIR than on DWI In areas involved on both sequences DWI showed more extensive especially cortical abnormalities in 14 of the areas In patients with late MRI n = 2 FLAIR was superior to DWI with essentially white matter involvement From the mesial temporal area brain signal changes followed a centripetal ie towards anterior posterior and superior parts of the brain gradient The cutoff score before involving the contralateral hemisphere was 8–9/25 in the initially involved hemisphere DWI is slightly superior to FLAIR in acute–subacute HSE except for the thalamus with FLAIR signal changes more frequently seen than earlier reported Knowledge of typical topographical MRI involvement can help to differentiate from other conditions mimicking HSEOur study has been approved by the local ethics committee and performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments All persons gave their informed consent prior to their inclusion in the study
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