Disappearing hyperdense middle cerebral artery sign in ischaemic stroke patients treated with intravenous thrombolysis: clinical course and prognostic significance

Abstract

Background and purpose: Hyperdense middle cerebral artery sign (HMCAS) on CT is a well known indication of thromboembolic arterial occlusion. Its disappearance after thrombolytic therapy is poorly described. Taking the rate of HMCAS disappearance as a surrogate for MCA recanalisation, its prognostic value after intravenous thrombolysis was examined. Methods: 1905 stroke patients with HMCAS on admission CT scan in the Safe Implementation of Treatment in Stroke-International Stroke Thrombolysis Register (SITS-ISTR) were studied. On follow-up CT scans 22-36 h after thrombolysis, HMCAS disappeared in 831 cases, persisted in 788 and was uncertain in 122; followup CT was not done in 164 cases. Results: Patients whose HMCAS disappeared were younger (median age 67 years vs 69 years for persistent; p = 0.03), with milder stroke (admission National Institute of Health Stroke Scale (NIHSS) score was 16 vs 17; p,0.005) and were less likely to have early infarct signs on admission CT (26% vs 33%; p,0.005). Patients with disappearing HMCAS were more likely to have early improvement in NIHSS score (median improvement 2 vs 0 at 2 h; 4 vs 1 at 24 h), be independent at 3 months (42% vs 19%), with fewer deaths (15% vs 30%) than those with persistent HMCAS. In multivariate analysis, HMCAS disappearance independently predicted functional independence and survival. Early NIHSS improvement independently predicted HMCAS disappearance. Conclusions: HMCAS disappeared after intravenous thrombolysis in about half of cases and these patients had twice as good outcomes compared with those with persistent HMCAS. The prognosis in patients with MCA occlusion that persists after intravenous thrombolysis is poor, which may indicate the need for an alternative treatment approach to this subgroup.In acute ischaemic stroke, hyperdense middle cerebral artery sign (HMCAS) on admission CT scan is a known indication of middle cerebral artery occlusion.

Is the Maximum Dose of 90 mg Alteplase Sufficient for Patients With Ischemic Stroke Weighing >100 kg?

“…[11][12][13][14] The threshold of Ն8-points improvement on the NIHSS score was chosen in accordance with the literature, suggesting that lower thresholds may be too insensitive to the effects of alteplase. 5,15,16 Reanalyzing data from the National Institute of Neurological Disorders and Stroke (NINDS) trial, Brown and colleagues investigated predictors for MNI within 24 hours, including weight Ͼ100 kg among other variables.…”

The Importance of Size

“…8,9 Loss of the hyperdense middle cerebral artery sign during follow-up was found to be an indicator of favorable outcome after IVT. 10 Two recent studies related the success of recanalization by IVT and patient outcome to scores that were derived from CTA studies. 1,8 These results compare to ours with respect to outcome.…”

Acute middle cerebral artery thrombus

“…Hyperdense middle cerebral artery sign disappeared on a repeat CT scan 22-36 hours after thrombolysis in 48% of the patients. The disappearance of the sign indicates vessel recanalization and better prognosis [7].…”