Thrombolysis targeting MRI defined tissue at risk in minor stroke

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.

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).

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.

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