Facing the Time Window in Acute Ischemic Stroke: The Infarct Core.

Area of Science:

• Neurology
• Stroke Medicine
• Neuroimaging

Background:

• Brain tissue viability decreases rapidly after ischemic stroke onset, necessitating timely treatment.
• Current endovascular stroke treatment trials may not fully reflect this critical time dependency.
• This study investigates the time dependency in embolic carotid T or M1 occlusions within the first 6 hours post-stroke.

Purpose of the Study:

• To evaluate the existence and extent of time dependency on brain tissue viability.
• To analyze the relationship between time from stroke onset and infarct volume.
• To assess factors influencing early infarct development in specific stroke types.

Main Methods:

• Retrieved patient data from the Freiburg stroke data bank.
• Analyzed diffusion-weighted images (DWIs) acquired between 49 and 357 minutes post-onset.
• Segmented ischemic lesions and assessed occlusion location, thrombus length, and collateral status (hyperintense vessel sign).

Main Results:

• Included 155 patients with carotid T or M1 middle cerebral artery occlusions.
• Infarct volumes ranged from 0.3 to 180.2 mL.
• No correlation found between infarct size and time to DWI, occlusion location, thrombus length, or collateral status.

Conclusions:

• No significant time dependency of brain tissue viability was observed for embolic carotid T or M1 occlusions within 1-6 hours post-stroke.
• Early infarct volume is likely determined by leptomeningeal collateral quality in the hyperacute phase.
• Infarct size appears relatively stable within this 1-6 hour time window.