Hyperdense Middle Cerebral Artery Sign: Can It Be Used to Select Intra-Arterial versus Intravenous Thrombolysis in Acute Ischemic Stroke?

Abstract

Background: Stroke patients with a hyperdense middle cerebral artery sign (HMCAS) may respond less favorably to intravenous (IV) thrombolysis. Objective: To compare outcomes of patients with and without early CT findings treated with IV versus intra-arterial (IA) recombinant tissue plasminogen activator (rtPA). Methods: Initial and 24-hour CT scans of the head were evaluated in 83 consecutive stroke patients (66 on IV rtPA, 17 on IA rtPA). Time permitting, a CT angiogram was performed immediately after the initial CT scan to ascertain major cerebral artery occlusion. Demographics and etiological stroke subtype, times to thrombolysis and CT scan, baseline (prethrombolysis) and 24-hour National Institutes of Health stroke scale (NIHSS) score, discharge NIHSS score and 90-day modified Rankin scale (mRS) were recorded. The initial CT of these patients was examined for early signs of stroke. The 24-hour scan was reviewed for the presence of infarct, hemorrhage and persistence of HCMAS. Results: A favorable outcome, indicated by a significant improvement in the discharge NIHSS score, was noted with IA rtPA, irrespective of the presence (p = 0.001) or absence (p = 0.01) of HCMAS. A less favorable outcome in discharge NIHSS score was noted with IV rtPA in patients with HCMAS (p = not significant) than those without the sign (p < 0.001). A similar proportion of patients with HCMAS exhibited a neurological improvement at 24 h as those without the sign in the IA rtPA group (p = 0.9). However, a smaller proportion of patients with HCMAS exhibited a neurological improvement at 24 h than those without the sign in the IV rtPA group (p = 0.005). The results were similar using 90-day mRS ≤1 as an indicator of significant persistent improvement (p = 1.0 for IA rtPA and 0.04 for IV rtPA group). Conclusions: In a small sample, patients with HMCAS appeared to respond better to IA than IV rtPA.