Journal of the Neurological Sciences 173 (2000) 10–17 www.elsevier.com / locate / jns Computed tomography findings in the first few hours of ischemic stroke: implications for the clinician * Marco Fiorelli , Danilo Toni, Stefano Bastianello, Maria Luisa Sacchetti, Giuliano Sette, Anne Falcou, Corrado Argentino, Svetlana Lorenzano, Emanuele Di Angelantonio, Luigi Bozzao Department of Neurological Sciences, University ‘ La Sapienza’, Rome, Italy Received 2 July 1999; received in revised form 28 September 1999; accepted 30 September 1999 Abstract In order to evaluate the clinical usefulness of emergency computed tomography (CT) in acute ischemic stroke, we assessed whether CT findings within the first few hours of stroke onset reliably predict type, site and size of the index infarction, and risk of death or disability. For this reason we reviewed clinical and CT findings in a cohort of unselected consecutive patients referred to the stroke unit of a large urban hospital because of a presumed ischemic stroke in the anterior circulation (AC), and submitted to CT within 5 h from onset. Out of 158 total patients, emergency CT revealed parenchymal changes compatible with AC focal ischemia in 77 (49%) and a hyperdense middle cerebral artery (MCA) in 41 (26%). Parenchymal changes and hyperdense MCA predicted an AC territorial infarction respectively in 97% of cases (95% C.I. 93% to 100%) and in 95% of cases (95% C.I. 88% to 100%). Site and size of early changes coincided with those of final lesions in 79% of patients with cortical changes and in 95% of patients with cortico-subcortical changes, but only in 37% of patients with initial subcortical changes, the remainder of whom developed a cortico-subcortical infarction. At logistic regression parenchymal changes were the only independent predictor of an AC territorial infarction. Negative predictive power, however, was only 40% (95% C.I. 29% to 51%) for parenchymal changes, and 35% for hyperdense MCA (95% C.I. 26% to 44%). The odds for death or disability at 1 month associated with parenchymal changes were thrice as high as with negative CT, even after adjustment for clinical severity on admission. These results indicate that CT scan adds significantly to the prediction of outcome made on clinical grounds. The frequent development of a territorial infarction in patients with initially negative CT and the subsequent recruitment of the cortex in those initially exhibiting only subcortical changes suggest that the transition from ischemia to infarction often occurs after the first five h following stroke.  2000 Elsevier Science B.V. All rights reserved. Keywords: Ischemic Stroke; Computed Tomography; Prognosis; Cerebral Infarction 1. Introduction performed within three months from onset is an indepen- dent predictor of poor outcome after adjustment on age or X-ray computed tomography (CT) has an invaluable severity of the neurological deficit [1]. Early signs of place in the work-up of acute stroke patients, since it is infarction also appear to influence the response to throm- easily available, it can exclude stroke-mimicking con- bolysis [2,3]. ditions, and can differentiate ischemia from hemorrhage. In Clinicians do not yet know: (1) how frequent CT patients with ischemic stroke, a visible infarction on a CT positivity is in unselected patients whose clinical picture suggests an acute ischemic stroke; (2) whether or not CT positivity is a reliable predictor of the development of an infarction; and (3) if so, how accurately the topography and the extent of the final lesion can be predicted from *Corresponding author. Tel.: 139-06-499104720; fax: 139-06- admission CT. Moreover, it is unclear, although it may be 490259. E-mail address: fiorelli@uniroma1.it (M. Fiorelli) of practical importance, whether early changes at CT can 0022-510X / 00 / $ – see front matter  2000 Elsevier Science B.V. All rights reserved. PII: S0022-510X(99)00294-4