In Vivo Detection of Postictal Perturbations of Cerebral Metabolism by Use of Proton MR Spectroscopy: Preliminary Results in a Canine Model of Prolonged Generalized Seizures
Ronald Neppla,
Canh M. Nguyena,
William Bowena,
Taoufik Al-Saadia,
Jeanne Pallagia,
George Morrisa,
Wade Muellera,
Roger Johnsona,
Robert Prosta and
Scott D. Randa
a From the Departments of Radiology, Neurology, and Neurosurgery, Medical College of Wisconsin, Milwaukee; and the Department of Biomedical Engineering, Marquette University, Milwaukee.
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FIG 1. A and B, T2-weighted fast spin-echo localizer images show reproducible locations for single-voxel proton MR spectra obtained in the same subject in control (A) and postictal (B) experiments conducted on different days.
C and D, T2-weighted fast spin-echo localizer images in another subject before (C) and 3 hours after (D) PTZ-induced generalized seizures show no evidence of head movement or cerebral edema at the conclusion of a postictal experiment.
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FIG 2. A, A control spectrum obtained from the frontal lobe cortex of an anesthetized, chemically paralyzed, mechanically ventilated mongrel dog with the PRESS (1500/41/256) technique at 0.5 T.
B, Lorentzian-fitted peaks for the NAA, glx, and Cr resonances in A.
C, Superimposition of the control spectrum in A and the lorentzian-fitted peaks in B.
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FIG 3. A control and a postictal spectrum obtained from the same subject were normalized by the area under the unsuppressed reference water peak and plotted on the same y-axis (arbitrary units). Note the postictal increase in glx amplitude and the emergence of lactate and free fatty acid peaks
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