Transient cell depolarization after permanent middle cerebral artery occlusion: an observation by diffusion-weighted MRI and localized 1H-MRS.
Focal cerebral ischemia causes rapid intensity changes in diffusion-weighted images (DWI) and elevated lactate as detected by localized proton spectroscopy (1H-MRS). To investigate whether such changes can also be evoked by perischemic depolarizations, we combined DWI and 1H-MRS measurements with DC potential recordings. About 40 min after occlusion of the middle cerebral artery in a rat, a negative DC deflection was observed indicating transient cell depolarization. Coincidentally with the depolarization a transient increase of the DWI signal intensity and a partially reversible increase of lactate occurred in the periphery of the ischemic territory. These results show that peri-ischemic depolarization, known to contribute to the evolution of cerebral infarction, evokes disturbances that can be detected by DWI and 1H-MRS.
Gyngell
M L
ML
Max-Planck-Institut für neurologische Forschung, Abteilung für experimentelle Neurologie, Köln F. R. Germany.
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T
T
Hoehn-Berlage
M
M
Kohno
K
K
Hossmann
K A
KA
D000818:Animals; D002545:Brain Ischemia / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D007773:Lactates / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D051381:Rats
D007773:Lactates