Spontaneous reperfusion after in situ thromboembolic stroke in mice

Area of Science:

• Neurology
• Medical Imaging
• Animal Models

Background:

• Thromboembolic stroke models are crucial for developing new treatments.
• The middle cerebral artery (MCA) is frequently affected in human stroke.
• Magnetic Resonance Imaging (MRI) offers non-invasive assessment of stroke pathophysiology.

Purpose of the Study:

• To evaluate a novel mouse model of thromboembolic stroke induced by middle cerebral artery (MCA) thrombin injection.
• To characterize MCA occlusion, perfusion deficits, and lesion development using multiparametric MRI.
• To assess the suitability of this model for preclinical evaluation of thrombolytic therapies.

Main Methods:

• Sequential multiparametric MRI, including Magnetic Resonance Angiography (MRA), Diffusion-Weighted Imaging (DWI), and Perfusion-Weighted Imaging (PWI).
• Induction of thromboembolic stroke via direct thrombin injection into the MCA of mice.
• Assessment of MCA occlusion, hypoperfusion, reperfusion, and lesion volume.

Main Results:

• Complete MCA occlusion and reproducible hypoperfusion were achieved in 85% of animals within the first hour.
• Partial to complete spontaneous reperfusion occurred in 80% of animals within three hours.
• Significant variability in ischemic volume was observed due to spontaneous reperfusion.

Conclusions:

• The thrombin-induced MCA occlusion model in mice is valuable for evaluating thrombolytic treatments.
• Spontaneous reperfusion introduces variability, necessitating careful consideration in study design.
• Extended MRI follow-up during the acute phase is recommended for therapeutic studies using this model.