Neuroscience 2004 Abstract
| Presentation Number: | 259.11 |
|---|---|
| Abstract Title: | Dissociation of T2-weighted MRI findings, tissue damage, and functional impairment in subcortical lesions after transient MCAO in rats. |
| Authors: |
Wegener, S.*1,2
; Weber, R.1
; Ramos-Cabrer, P.1
; Uhlenkueken, U.1
; Wiedermann, D.1
; Kandal, K.1
; Sprenger, C.1
; Villringer, A.2
; Hoehn, M.1
1in vivo NMR, MPI for Neurological Res., Cologne, Germany 2Germany, Gleueler Str. 50, 50931, |
| Primary Theme and Topics |
Neurological and Psychiatric Conditions - Ischemia -- Neuroprotection and tolerance |
| Secondary Theme and Topics | Neurological and Psychiatric Conditions<br />- Ischemia<br />-- Cellular and molecular mechanisms |
| Session: |
259. Neuroprotection I Slide |
| Presentation Time: | Sunday, October 24, 2004 3:30 PM-3:45 PM |
| Location: | San Diego Convention Center - Room 24A |
| Keywords: | ISCHEMIA, ANIMAL MODEL, NEUROIMAGING, NEURONAL DEATH |
Background: We investigated the connection between long term infarct evolution and functional consequences of subcortical lesions after transient middle cerebral artery occlusion (MCAO) in rats.
Methods: MCAO was induced in Wistar rats for 60min. Lesion volumes and absolute T2 times on MRI were assessed 1 and 14 days and up to 10 weeks after MCAO using a 4.7 T animal scanner, and combined with functional testing (adhesive tape removal, cylinder test, ledged beam walking).Tissue damage was analyzed histologically (HE, Luxol, and Nissl staining).
Results: Functional test scores were not distinguishable between sham operated (n=5) animals and those with exclusive subcortical infarct involvement (n=8, group A) at any time point, but were significantly worse in animals with cortico-subcortical infarctions (n=10, group B). Group A showed lower absolute T2 times and a more pronounced reduction in T2 infarct volume than the subcortical lesion component in group B. Ten weeks after MCAO, initial signal increments on T2 in group A had completely resolved, but structural damage was still detectable in histological analysis.
Conclusions: In exclusively subcortical ischemic lesions, positive T2-weighted (T2-w) MRI findings can occur in the absence of functional deficits and show complete resolution, while tissue damage persists. Therefore, T2-w MRI findings, tissue damage and loss of function can be “dissociated” depending on lesion location and time of analysis. When judged from functional tests alone, subcortical ischemic lesions may not be diagnosed reliably. This finding highlights the importance of combined in vivo MRI monitoring and functional testing for outcome assessment in experimental stroke studies.
Methods: MCAO was induced in Wistar rats for 60min. Lesion volumes and absolute T2 times on MRI were assessed 1 and 14 days and up to 10 weeks after MCAO using a 4.7 T animal scanner, and combined with functional testing (adhesive tape removal, cylinder test, ledged beam walking).Tissue damage was analyzed histologically (HE, Luxol, and Nissl staining).
Results: Functional test scores were not distinguishable between sham operated (n=5) animals and those with exclusive subcortical infarct involvement (n=8, group A) at any time point, but were significantly worse in animals with cortico-subcortical infarctions (n=10, group B). Group A showed lower absolute T2 times and a more pronounced reduction in T2 infarct volume than the subcortical lesion component in group B. Ten weeks after MCAO, initial signal increments on T2 in group A had completely resolved, but structural damage was still detectable in histological analysis.
Conclusions: In exclusively subcortical ischemic lesions, positive T2-weighted (T2-w) MRI findings can occur in the absence of functional deficits and show complete resolution, while tissue damage persists. Therefore, T2-w MRI findings, tissue damage and loss of function can be “dissociated” depending on lesion location and time of analysis. When judged from functional tests alone, subcortical ischemic lesions may not be diagnosed reliably. This finding highlights the importance of combined in vivo MRI monitoring and functional testing for outcome assessment in experimental stroke studies.
Supported by BMBF
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2004 Neuroscience Meeting Planner. San Diego, CA: Society for Neuroscience, 2004. Online.
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