Wake-Up Stroke with an M1 Occlusion: Time, Imaging and Reperfusion Decisions
A 68-year-old woman is brought to the emergency department at 07:10 after her husband found her at 06:30 unable to speak and with a weak right arm. She went to bed at 22:00 the previous night and was last seen well then. NIHSS 14 (global aphasia, right gaze preference, right hemianopia, dense right arm and leg weakness). BP 174/94 mmHg, capillary glucose 148 mg/dL, weight 70 kg. She takes amlodipine and atorvastatin only; no anticoagulant, INR 1.0, platelets 230 × 10⁹/L. Non-contrast CT at 07:25 shows no haemorrhage and early ischaemic change in the left insula and lentiform nucleus, ASPECTS 9. CT angiography shows occlusion of the left M1 segment. CT perfusion shows an ischaemic core of 22 mL and a penumbra of 95 mL.
1. Is she eligible for intravenous thrombolysis? Explain your reasoning using the time and imaging data.
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Her eligibility hinges on the fact that the time of onset is unknown.
She was last known well at 22:00 and found with symptoms at 06:30 - roughly 8.5 hours before arrival and 10.5 hours after last known well. On time criteria alone she is outside the 4.5-hour window and cannot be treated with alteplase.
However, this is a wake-up stroke, and she is within about 4.5 hours of symptom recognition. Two validated approaches exist:
- MRI DWI-FLAIR mismatch: if diffusion restriction is present but FLAIR is negative, thrombolysis is reasonable (WAKE-UP strategy).
- Perfusion mismatch with a small core on CT perfusion.
Her CT perfusion already shows a small core (22 mL) with a large penumbra, which supports reperfusion, but CT-based selection for thrombolysis is less well established than DWI-FLAIR. The pragmatic answer: do not delay thrombectomy while obtaining MRI. If MRI is immediately available and shows DWI-FLAIR mismatch and no contraindication, give alteplase; if it shows established FLAIR change, withhold it. Her blood pressure of 174/94 mmHg is acceptable for thrombolysis (<185/110).
2. What is your recommendation regarding mechanical thrombectomy, and how do you manage her blood pressure around the procedure?
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She is a thrombectomy candidate. She has a large-vessel occlusion of the left M1, a disabling deficit (NIHSS 14), a small ischaemic core (22 mL) and a large penumbra (95 mL) - a favourable target mismatch profile - and she is within the 6–24-hour window for imaging-selected thrombectomy. Age, baseline function and absence of a large established infarct all favour intervention. She should go directly to the angiography suite with the stroke team; do not wait for clinical improvement or for MRI.
Blood pressure:
- Before and during thrombolysis, keep BP <185/110 mmHg; her 174/94 mmHg currently qualifies. Treat higher readings with IV labetalol or a nicardipine infusion.
- After successful reperfusion, target <180/105 mmHg for the next 24 hours; avoid aggressive lowering below about 130/80 mmHg, which can worsen penumbral perfusion.
- If no reperfusion is achieved, permissive hypertension up to about 220/120 mmHg is acceptable unless there is another indication to lower it.
Also: no aspirin or heparin for 24 hours if thrombolysis is given, swallow screen before any oral intake, treat fever and maintain normoglycaemia, and admit to a stroke unit with early rehabilitation.
3. Suppose CT perfusion instead showed a core of 85 mL with a mismatch ratio of 1.2. How would your decision change, and what else matters in her care?
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A core of 85 mL with a mismatch ratio of 1.2 is a large core with minimal salvageable tissue. Recent randomised trials of thrombectomy in large-core infarction up to 24 hours have shown benefit on functional outcomes, so this does not automatically exclude her - but the balance shifts: the number needed to treat rises, and the risks of haemorrhagic transformation, malignant oedema and futile reperfusion increase. The decision should be made jointly with neurointervention, weighing her premorbid function, the M1 occlusion (which is accessible), the family's wishes and local protocol. If treated, she needs high-dependency care and an early discussion about decompressive hemicraniectomy should she deteriorate.
Supportive care that determines outcome either way:
- Dysphagia screening before oral intake, nil by mouth if failed.
- Avoid hypoxia, fever and hyperglycaemia; treat glucose >180 mg/dL with insulin.
- VTE prophylaxis with intermittent compression; early mobilisation and speech/physiotherapy.
- Antithrombotic plan: aspirin (or clopidogrel if allergic) after 24 hours if thrombolysis was given, then secondary prevention with high-intensity statin and control of vascular risk factors.
- Screen for atrial fibrillation with prolonged monitoring, since it would change anticoagulation.
- Structured goals-of-care conversation with her husband and documentation of her wishes.