Reversal of acute apparent diffusion coefficient abnormalities and delayed neuronal death following transient focal cerebral ischemia in rats

Li, Fuhai; Han, Sam; Tatlısumak, Turgut; Liu, Kai-Feng; García, Julio Herrero; Sotak, Christopher H.; Fisher, Marc

doi:10.1002/1531-8249(199909)46:3<333::aid-ana9>3.0.co;2-x

Cited by 126 publications

(114 citation statements)

References 43 publications

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“…The first time point follow-up after t-PA was realized at day 1 in our study. The early changes in diffusion intensity incoming in the cerebral hypoperfused territory as early normalization reported in some studies (7,34,35) could not be revealed.…”

Section: Discussionmentioning

confidence: 67%

“…Most of the normalization previously reported concerned ADC values (7,9,10); many studies have focused on the ADC time course with quantitative values of diffusion modifications and pixel-by-pixel analyses were developed. Shen et al (32) found a bimodal distribution of ADC values, which seemed to indicate some viability threshold in the acute stage.…”

Section: Discussionmentioning

confidence: 99%

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Evolution of lesion volume in acute stroke treated by intravenous t‐PA

Pialat

Wiart

Nighoghossian

et al. 2005

Magnetic Resonance Imaging

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Purpose:To determine the evolution of the ischemic lesion volumes in a population treated with tissue plasminogen activator (t-PA), MRIs were performed before treatment and 24 hours later; final infarct size was evaluated 60 days later. Materials and Methods:A total of 42 patients with hemispheric stroke were recruited for a thrombolytic study. Intravenous t-PA was given after MRI within the first seven hours after stroke onset. Volumes were evaluated on day 0 and day 1 with diffusion-weighted imaging (DWI), on day 60 with T2-weighted imaging (T2WI), and recanalization was assessed based on day 1 MR angiography (MRA).Results: Lesion volume increased between day 0 and day 1, and decreased between day 1 and day 60. It was lower in the group of patients with recanalization on day 1 MRA. Conclusion:Volume analysis emphasizes the effectiveness of recanalization as a predictive factor for better outcome, based on final infarct size. The decrease in lesion volumes between day 1 and day 60 suggests that other factors leads to overestimation of day 1 abnormal diffusion volume. This could explain the delayed partial reversibility of the DWI abnormality.

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Section: Discussionmentioning

confidence: 67%

Section: Discussionmentioning

confidence: 99%

Evolution of lesion volume in acute stroke treated by intravenous t‐PA

Pialat

Wiart

Nighoghossian

et al. 2005

Magnetic Resonance Imaging

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“…The latter is preferred because with the former cortical ischemia is not only less severe but also less consistent. 39,48 Using proximal MCAo in rats, scattered patches of cortical SNL but virtually no infarction is observed following p30 minutes of proximal MCAo, 10,11,[35][36][37]40,42,49 the only exception being Zhan et al, 38 but see caveats above. However, cortical SNL was found not to affect every subject, being for instance observed in 40% of rats subjected to 10-to 25-minute tMCAo.…”

Section: Animal Modelsmentioning

confidence: 99%

Selective Neuronal Loss in Ischemic Stroke and Cerebrovascular Disease

Baron

Yamauchi

Fujioka

et al. 2013

J Cereb Blood Flow Metab

192

208

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As a sequel of brain ischemia, selective neuronal loss (SNL)-as opposed to pannecrosis (i.e. infarction)-is attracting growing interest, particularly because it is now detectable in vivo. In acute stroke, SNL may affect the salvaged penumbra and hamper functional recovery following reperfusion. Rodent occlusion models can generate SNL predominantly in the striatum or cortex, showing that it can affect behavior for weeks despite normal magnetic resonance imaging. In humans, SNL in the salvaged penumbra has been documented in vivo mainly using positron emission tomography and 11 C-flumazenil, a neuronal tracer validated against immunohistochemistry in rodent stroke models. Cortical SNL has also been documented using this approach in chronic carotid disease in association with misery perfusion and behavioral deficits, suggesting that it can result from chronic or unstable hemodynamic compromise. Given these consequences, SNL may constitute a novel therapeutic target. Selective neuronal loss may also develop at sites remote from infarcts, representing secondary 'exofocal' phenomena akin to degeneration, potentially related to poststroke behavioral or mood impairments again amenable to therapy. Further work should aim to better characterize the time course, behavioral consequences-including the impact on neurological recovery and contribution to vascular cognitive impairment-association with possible causal processes such as microglial activation, and preventability of SNL.

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“…(I/C)ADC av As suggested previously (23,24) hemispheric averaged ADC ratios (ipsilateral/contralateral [I/C]), i.e., (I/ C)ADC av , were calculated by dividing the average ADC value in the lesion area by the average ADC value of its respective contralateral region of interest (ROI):…”

Section: Lesion Volumementioning

confidence: 99%

“…In the chronic stage of ischemic stroke, high ADC values (compared with the contralateral regions) are observed for the infarct area as a result of the necrotic process that includes cells death and membrane loss (22). Therefore, computed ADC values in the ischemic hemisphere normalized to averaged ADC values of the contralateral hemisphere values, i.e., (I/C)ADC av , may predict tissue condition (23,24). Simultaneously to the changes in the diffusion characteristics of water within the ischemic region, changes in levels of different brain metabolites can be detected by different MRS methodologies (25,26).…”

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confidence: 99%

Late stimulation of the sphenopalatine‐ganglion in ischemic rats: Improvement in N‐acetyl‐aspartate levels and diffusion weighted imaging characteristics as seen by MR

Bar‐Shir

Shemesh

Nossin-Manor

et al. 2010

Magnetic Resonance Imaging

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Purpose: To assess, by MR spectroscopy (MRS) and diffusion weighted imaging (DWI), the ability of electrical stimulation of the sphenopalatine ganglion (SPG) to augment stroke recovery in transient middle cerebral artery occluded (t-MCAO) rats, when treatment is started 18 6 2 h post-occlusion. Materials and Methods: 1 H-MRS imaging ( 1 H-MRSI) and DWI were used to evaluate ischemic brain tissue after SPG stimulation in rats subjected to 2 h of t-MCAO. Rats were examined by 1 H-MRSI, DWI, and behavioral tests at 16 6 2 h, 8 days, and 28 days post-MCAO.Results: N-Acetyl-aspartate (NAA) levels of the stimulated and control rats were the same 16 6 2 h post-MCAO (0.52 6 0.03, 0.54 6 0.03). At 28 days post-occlusion, NAA levels were significantly higher in the treated group (0.60 6 0.04) compared with those of the untreated animals (0.50 6 0.04; P < 0.05). This effect was more pronounced for regions with low NAA values (0.16 6 0.03) that changed to 0.32 6 0.03 (P ¼ 0.04) for the treated group and to 0.10 6 0.03 (P ¼ 0.20) for the controls. DWI data showed better ischemic tissue condition for the treated rats, but the measured parameters showed only a trend of improvement. The MR results were corroborated by behavioral examinations. Conclusion:Our findings suggest that SPG stimulation may ameliorate MR tissue characteristics following t-MCAO even if treatment is started 18 h post-occlusion.Key Words: Sphenopalatine ganglion (SPG); middle cerebral artery occlusion (MCAO); N-acetyl aspartate (NAA); MRI; MR spectroscopy (MRS)

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Reversal of acute apparent diffusion coefficient abnormalities and delayed neuronal death following transient focal cerebral ischemia in rats

Cited by 126 publications

References 43 publications

Evolution of lesion volume in acute stroke treated by intravenous t‐PA

Evolution of lesion volume in acute stroke treated by intravenous t‐PA

Selective Neuronal Loss in Ischemic Stroke and Cerebrovascular Disease

Late stimulation of the sphenopalatine‐ganglion in ischemic rats: Improvement in N‐acetyl‐aspartate levels and diffusion weighted imaging characteristics as seen by MR

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