How Brain Imaging Offers a Crucial Window to Identify, Assess and Treat Wake-Up Strokes, Pg II

Key Highlights:

• Wake-up strokes, occurring during sleep, account for 20% of all ischaemic strokes, posing a challenge due to unknown symptom onset time.
• Brain imaging, particularly MRI and CT angiogram, is crucial for identifying salvageable brain tissue in these cases.
• Imaging techniques like diffusion-weighted imaging and FLAIR help determine if brain tissue can still be saved, guiding treatment decisions.
• The Tamil Nadu Accident and Emergency Care Initiative and Stroke Care and Rapid Intervention with Plasminogen activator and Thrombectomy (SCRIPT) programme facilitate treatment for wake-up stroke patients.
• Prompt medical attention is vital, as timely intervention can significantly improve outcomes for stroke patients.

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Detailed Insights:

• The primary challenge with wake-up strokes is the inability to determine the exact time of symptom onset, which is critical for time-sensitive treatments like thrombolysis.
• Standard thrombolysis is typically effective if administered within 4.5 hours of stroke symptoms, but this window is often missed in wake-up strokes.
• For large vessel occlusions, mechanical thrombectomy can be performed up to 24 hours after symptom onset, depending on patient eligibility.
• Imaging studies, such as MRI perfusion or CT perfusion, help identify a "diffusion-perfusion mismatch," indicating brain tissue that is still viable and can be saved.
• The SCRIPT programme in Tamil Nadu ensures coordinated care, involving emergency, radiology, and neurology departments, to reduce "door-to-needle" time.
• Public awareness campaigns using acronyms like BE FAST (Balance, Eyes, Face, Arm, Speech, Time) are increasing recognition of stroke symptoms and improving referral systems.

Scientific/Technical Concepts Involved:

• Ischaemic Stroke: A type of stroke caused by a blood clot blocking an artery that supplies blood to the brain.
• Thrombolysis: A medical procedure using drugs to dissolve blood clots, typically administered within a narrow time window after stroke onset.
• Mechanical Thrombectomy: A surgical procedure to physically remove a blood clot from a large artery in the brain using a catheter.
• Diffusion-Perfusion Mismatch: An imaging finding where the area of brain tissue with reduced blood flow (perfusion deficit) is larger than the area of already damaged tissue (diffusion restriction), indicating salvageable brain.