Functional and structural correlates of magnetic resonance patterns in a new in vitro model of cerebral ischemia by transient occlusion of the medial cerebral artery.
Magnetic resonance imaging (MRI) during the acute phase of a stroke contributes to recognize ischemic regions and is potentially useful to predict clinical outcome. Yet, the functional significance of early MRI alterations during brain ischemia is not clearly understood. We achieved an experimental study to interpret MRI signals in a novel model of focal ischemia in the in vitro isolated guinea pig brain. By combining neurophysiological and morphological analysis with MR-imaging, we evaluated the suitability of MR to identify ischemic and peri-ischemic regions. Extracellular recordings demonstrated depolarizations in the ischemic core, but not in adjacent areas, where evoked activity was preserved and brief peri-infarct depolarizations occurred. Diffusion-weighted MRI and immunostaining performed after neurophysiological characterization showed changes restricted to the core region. Diffusion-weighted MR alterations did not include the penumbra region characterized by peri-infarct depolarizations. Therefore, by comparing neurophysiological, imaging and anatomical data, we can conclude that DW-MRI underestimates the extension of the tissue damage involved in brain ischemia.
Breschi
Gian Luca
GL
Unit of Experimental Neurophysiology and Epileptology, Fondazione Istituto Neurologico Carlo Besta, via Celoria 11, 20133 Milano, Italy.
Librizzi
Laura
L
Pastori
Chiara
C
Zucca
Ileana
I
Mastropietro
Alfonso
A
Cattalini
Alessandro
A
de Curtis
Marco
M
D000818:Animals; D001921:Brain / Q000473:pathology* / Q000503:physiopathology*; D002545:Brain Ischemia / Q000209:etiology* / Q000473:pathology*; D004195:Disease Models, Animal; D004594:Electrophysiology; D005071:Evoked Potentials / Q000502:physiology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D020244:Infarction, Middle Cerebral Artery / Q000150:complications*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D010100:Oxygen / Q000097:blood
D008869:Microtubule-Associated Proteins; D010100:Oxygen