5 years ago

Long-term sequelae of hippocampal lesions in patients with transient global amnesia: A multiparametric MRI study

Haibo Jiang, Jiaxing Zhang, Wenping Wei, Zhongming Gao, Xiaochuan Wang, Jianzhong Lin, Ran Zhang
BACKGROUND MRI signal diffusion-weighted imaging (DWI) hyperintensity in the hippocampus in patients with transient global amnesia (TGA) are resolved within several days after the onset of TGA. PURPOSE To use multiparametric MRI to unravel the sequelae of TGA. STUDY TYPE A prospective longitudinal study. POPULATION Eight TGA patients. FIELD STRENGTH/SEQUENCE A 3.0T Siemens Tim Trio MRI scanner with T1-weighted MPRAGE, diffusion-weighted echo planar imaging, and multiecho gradient-recalled echo sequences. ASSESSMENT Brain MRI scanned within 72 hours, 2 weeks, and 3 months after onset of TGA, respectively. T1 image hippocampus was first segmented into 12 subregions using FreeSurfer and registered to DWI to locate DWI lesion. Then a T1 image with segmented hippocampus was registered to its corresponding apparent diffusion coefficient (ADC) map, fractional anisotropy (FA) map, and quantitative susceptibility map, respectively. Finally, the volume, water diffusion and anisotropy, and magnetic susceptibility of DWI lesion were analyzed. STATISTICAL TESTS A paired samples t-test was performed to detect measurement differences between three tests. Pearson correlation was used to assess the correlations between all measurements. RESULTS Hyperintensity was detected in the head, body, and caudate of CA1 and hippocampal tail. No significant changes existed in CA1/unit volume across the three timepoint measurements (all, P > 0.480). In Test 1, ratio ADC (DWI lesion / adjacent healthy, rADC) and ratio FA (rFA) decreased below, while ratio susceptibility increased above 1.0. In Test 2, all the episodes normalized around 1.0. In Test 3, rADC remained normalization, but rFA decreased and ratio susceptibility increased again. In Test 1 and Test 3 (vs. Test 2), decreased FA values were accompanied with lower axial diffusivity and/or higher radial diffusivity (all, P < 0.001). Moreover, rFA significantly correlated with ratio susceptibility in Test 3 (r = −0.665, P = 0.039). DATA CONCLUSION Microstructural sequelae in hippocampus were demonstrated, which indicates that ischemic lesions may be associated with TGA. Level of Evidence: 2 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2017.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/jmri.25844

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.