Laboratory InvestigationMidline-shift Corresponds to the Amount of Brain Edema Early After Hemispheric Stroke—An MRI Study in RatsWalberer, Maureen DVM* †; Blaes, Franz MD*; Stolz, Erwin MD*; Müller, Clemens PhD†; Schoenburg, Markus MD‡; Tschernatsch, Marlene MD*; Bachmann, Georg MD†; Gerriets, Tibo MD* †Author Information *Department of Neurology, University Giessen, Giessen †Department of Radiology, Experimental Neurology Research Group ‡Department of Cardiac Surgery, Kerckhoff Klinik, Bad Nauheim, Germany Supported by the Willy and Monika Pitzer Stiftung, Bad Nauheim, Germany. Reprints: Dr Tibo Gerriets, MD, Department of Neurology, University Giessen, Am Steg 20, 35390 Giessen, Germany (e-mail: [email protected]). Received for publication August 3, 2006; accepted October 20, 2006 Journal of Neurosurgical Anesthesiology: April 2007 - Volume 19 - Issue 2 - p 105-110 doi: 10.1097/ANA.0b013e31802c7e33 Buy Metrics Abstract Vasogenic brain edema formation is a serious complication in hemispheric stroke. Its space-occupying effect can lead to midline-shift (MLS), cerebral herniation, and death. Clinical studies indicate that quantification of MLS can predict cerebral herniation and subsequent death at early time-points, even before clinical deterioration becomes apparent. The present experimental study was designed to determine the relation between MLS, absolute edema volume, lesion size, and clinical findings in a rat stroke model. Middle cerebral artery-occlusion was performed in 24 rats using the suture technique. Clinical evaluation and magnetic resonance imaging (MRI) (Bruker PharmaScan 7.0T) was performed 24 hours later. Lesion volume, the volume-increase within the affected hemisphere (%HEV), and MLS were quantified on T2-weighted images. The absolute increase of hemispheric water content (ΔH2O) was determined in a subgroup using the wet-dry method (n=12). MLS correlated significantly with the total amount of brain edema (magnetic resonance imaging study: r=0.82; P<0.01; wet-dry analysis r=0.80; P<0.01). MLS correlated only moderately with T2-lesion volume (r=0.55; P<0.01). No significant correlation could be detected between MLS and clinical scores (r=0.26; P>0.05). MLS thus quantitatively reflects the amount of vasogenic brain edema within the affected hemisphere at early time-points. MLS quantification can be regarded as an easily assessable and valid global quantitative parameter for brain edema and thus might facilitate the surgical and nonsurgical management of edema in acute stroke patients. © 2007 Lippincott Williams & Wilkins, Inc.