Association of hyperdense middle cerebral artery sign with clinical outcome in patients treated with tissue plasminogen activator.

The hyperdense middle cerebral artery sign (HMCAS) is a marker of thrombus in the middle cerebral artery. The aim of our study was to find out the frequency of the HMCAS, its association with initial neurological severity and early parenchymal ischemic changes on CT, its relevance to clinical outcome, and the efficacy of intravenous recombinant tissue plasminogen activator (rtPA) in patients with the HMCAS.Secondary analysis of the data from 620 patients who received either rtPA or placebo in the European Cooperative Acute Stroke Study I (ECASS I), a double-blind, randomized, multicenter trial. The baseline CT scans were obtained within 6 hours from the onset of symptoms. Functional and neurological outcomes were assessed using the modified Rankin Scale and the Scandinavian Stroke Scale at day 90.We found an HMCAS in 107 patients(17.7\%). The initial neurological deficit was more severe in patients with the HMCAS than in those lacking this sign (P<0.0001). Early cerebral edema and mass effect were also more common in patients with the HMCAS (P<0.0001). The HMCAS was related to the risk of poor functional outcome (grade of 3 to 6 on the modified Rankin Scale) on univariate analysis: 90 patients (84\%) with the HMCAS and 310 patients (62\%) lacking this sign were dependent or dead at day 90 (P