Factors affecting the angiographic recanalization and early clinical improvement in middle cerebral artery territory infarction after thrombolysis.

BACKGROUND Factors affecting the angiographic recanalization (AR) and clinical improvement (CI) still remain unclear in patients receiving thrombolytic therapy. OBJECTIVES To elucidate factors related to AR and early CI in patients with middle cerebral artery (MCA) or internal carotid artery (ICA) occlusion. DESIGNS Retrospective study. SETTING Department of Neurology, Asan Medical Center, Seoul, South Korea. PATIENTS We studied 42 patients who (1) underwent diffusion-weighted magnetic resonance (MR) imaging and MR angiography within 6 hours after onset, (2) had MCA territory infarction, (3) had nonvisualization of the MCA or the ICA on initial MR angiography, (4) were treated with thrombolytics, and (5) underwent follow-up MR imaging and MR angiography at day 2 or 3. RESULTS Successful AR and CI were achieved in 31 and 16 patients, respectively. Angiographic recanalization was related to CI (P<.01), lower follow-up National Institutes of Health Stroke Scale scores (P<.05), the absence of a dominant ipsilateral posterior cerebral artery (P<.01) on initial MR angiography, and the sparing of the internal capsule on both initial (P<.05) and follow-up (P<.01) MR imaging. Clinical improvement was associated with the absence of ICA (vs MCA) flow signals (P<.05), the sparing of the internal capsule (P<.01), and marginally, with the infarct volume change (P = .06). CONCLUSIONS In patients with MCA or ICA occlusion, CI after thrombolysis is related to the AR and the sparing of the critical motor pathway. The presence of a dominant ipsilateral posterior cerebral artery may predict poor AR after thrombolysis.