Thrombolysis targeting MRI defined tissue at risk in minor stroke.

Background: Treatment with intravenous tissue plasminogen activator (IV-tPA) is usually not recommended in patients with minor stroke. Clinical and imaging outcome were studied after IV-tPA treatment based on MRI criteria in patients with minor stroke.

Methods: Data were analysed retrospectively of acute ischaemic stroke patients with minor stroke (National Institutes of Health Stroke Scale (NIHSS) score <4). All patients were studied by stroke MRI including perfusion and diffusion weighted imaging (PWI and DWI) and treated with IV-tPA for < or =6 h. Final infarct volume was delineated on follow-up MRI. Clinical outcome was assessed after 90 days using the modified Rankin Scale (mRS).

Results: Six patients with a median NIHSS on admission of 2 (range 0-3) were treated with IV-tPA based on MRI criteria. In all patients, occlusion of the middle cerebral artery (MCA) was detected (MCA branch n = 2, MCA trunk n = 3, MCA trifurcation n = 1), and the PWI lesion (41, 25-60 ml) exceeded the DWI lesion (4, 1-23 ml). Final infarct volume was 9 (2-29) ml. Favourable outcome (mRS 0-1) was seen in 5/6 patients and independent outcome (mRS = 2) in one patient. No intracerebral haemorrhages occurred.

Conclusion: Treatment with IV-tPA based on MRI criteria was safe and appeared to be effective in this small series of patients with minor stroke.