Isolated insular infarction following successful intravenous thrombolysis of middle cerebral artery strokes.

Considering the 39 thrombolysed patients with an imaging control, 34 patients (87%) had cortico-subcortical infarcts with insular involvement (entire insula in 26, posterior in 6 and anterior in 2). Four patients (10%) had subcortical infarcts. In a single case, there was a cortico-subcortical infarction of the posterior MCA territory without insular involvement. In those cases where the insula was involved, the insular lesion was never distinct from adjacent lesions. In 2 patients – a 72-year-old man ( fig. 1 ) and a 77-year-old woman ( fig. 2 ) – we observed in the imaging control (both with a post-treatment MRI) a particular pattern consistent with an isolated insular infarct. This finding was not observed in the 542 patients whose MRI scans were available on the stroke registry. This isolated insular infarction was visible on DWI, FLAIR and/or T 2 sequences. MRA (TOF) images of the MCA showed a normal, patent artery in each case. Both patients were thrombolysed between 2 and 3 h after onset of symptoms, and both had complete resolution of symptoms at a 3-month review. Before thrombolysis, a CT angiogram showed normal intracranial and cervical vessels for the man and an occlusion of the MCA at the bifurcation with patent leptomeningeal collaterals for the woman. Dear Sir, Insular involvement in middle cerebral artery (MCA) territory stroke is common, whereas an isolated insular stroke is very rare. We noticed isolated insular ischaemia after intravenous thrombolysis in 2 cases and here suggest that this may reflect successful intravenous thrombolysis.