Advanced

AJNR - American Journal of Neuroradiology

This Article Abstract Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Sämann, P. G. Articles by Auer, D. P. Search for Related Content PubMed PubMed Citation Articles by Sämann, P. G. Articles by Auer, D. P.

Serial Proton MR Spectroscopy and Diffusion Imaging Findings in HIV-Related Herpes Simplex Encephalitis

Philipp G. Sämann^a, Jürgen Schlegel^b,c, Georg Müller^d, Franz Prantl^e, Christoph Emminger^d and Dorothee P. Auer^a

^a Max-Planck-Institute of Psychiatry, NMR Study Group, Munich, Germany
^b Krankenhaus München-Schwabing, Teaching Hospital, Ludwig-Maximilians-Universität, Munich, Germany
^c Department of Neuropathology, Technical University of Munich, Munich, Germany
^d Department of Infectious Diseases, Technical University of Munich, Munich, Germany
^e Department of Pathology, Technical University of Munich, Munich, Germany

View larger version (98K): [in a new window]   FIG 1. A and B, Axial and coronal T2-weighted images (1.5 T, TR/TE = 3800/84 and 3500/75, respectively) show extensive areas of abnormally high signal intensity in the splenium and the perispenial, cingulate, and the bilateral perisplenial white matter. Note sparing of the hippocampi and the temporal and insular cortices. C–F, Diffusion-weighted images (upper row [C and E]) and corresponding apparent diffusion coefficient false-color maps (lower row) of week 8 (D) and week 26 (F) after disease onset. Note that the CSF signal intensity is nulled. C and D, Lesions on diffusion-weighted images 4 weeks after the first MR study (C) show hypointense central area with a hyperintense rim (arrows) and high regional mean diffusivity. E and F, Note resolution of diffusion-weighted hyperintensities and peripheral normalization of regional mean diffusivity, indicating irreversible necrosis and gliosis formation in areas with regional mean diffusivity exceeding about 1.4 x10-3 mm2/s, whereas initially hyperintense areas on diffusion-weighted images, mainly representing T2 shine-through, without corresponding reduction of regional mean diffusivity reflect potentially reversible inflammatory changes. (Image acquisition: TR/TE = 2200/120, tetrahedral gradient acquisition scheme [15] with b values of 330, 798, and 1320 s/mm2)

View larger version (28K): [in a new window]   FIG 2. A–C, 1H-MR spectra (automated stimulated-echo acquisition mode; TR/TM/TE = 3000/13.7/30, LCModel fit) of the right perisplenial lesion (voxel volume 7.2–8.0 mL; cf voxel position in 1A) in the 4th (A), 8th (B), and 26th (C) week after symptom onset. D, Note the time course indicating partial resolution of the acute inflammatory changes (decrease of Cho, Lac, and Lip), only incomplete recovery of NAA but evolving gliotic reaction (increase of mI). Mean ± SD of unaffected parietal white matter from 15 male HIV-positive subjects (mean age, 40.9; years; range, 28–63 years) are given on the left for comparison. Metabolite concentrations were estimated by using LCModel (Provencher S., http://s-provencher.com).

View larger version (136K): [in a new window]   FIG 3. Histopathologic examination of the biopsies of the left cingulate gyrus revealed the morphology of a hemorrhagic-necrotizing inflammation (A, [H&E staining]) with multiple cells containing Cowdry type A intranuclear inclusions (insert). Immunohistochemical detection of HSV antigen is depicted in B. By using an antibody directed against the glial fibrillary acid protein, a prominent gliosis with multiple reactive astrocytes (C and D) intermixed with macrophages (B and C) could be detected. Astrocytes and macrophages are marked by arrows and arrowheads, respectively.