Brain perfusion following single seizures.
OBJECTIVE
The aim of this study was to assess the regional relative interictal and postictal perfusion changes in temporal and parietal lobe epilepsy.


METHODS
We investigated interictal and postictal magnet resonance perfusion changes in five patients with temporal lobe epilepsy either with hippocampal sclerosis (n = 3) or without (n = 2), and in one patient with extratemporal (parietal lobe) epilepsy. T(2)*-weighted single-shot echo-planar images were acquired after bolus application of 0.2 mmol/kg gadolinium-diethylene triamine pentaacetic acid (GD-DTPA) at baseline and after intervals of 2-12 min, 15-23 min, 28-50 min, 63-72 min, and 180-240 min. The bolus-peak ratio was calculated in regions of interest in the hippocampus (HIP), parahippocampal gyrus (PHG), thalamus (THA), cortex (COR), and white matter (WM), yielding relative perfusion changes.


RESULTS
Interictally, we found relative hyperperfusion of the ictogenic side in five of six patients in the HIP. Postictally, the perfusion decreased in the HIP by 25-39% as compared to baseline, whereas the PHG showed a reverse pattern. In the late postictal phase, perfusion increased in the HIP again and decreased in the PHG. In the THA, the inter- and postictal changes were small (5-19%). COR and WM showed equivocal results.


CONCLUSIONS
Postictal relative hypoperfusion in the HIP appears to be associated with the cessation of neuronal ictal discharge, whereas postictal hyperperfusion in the PHG lags behind and may reflect increased metabolism to restore the interictal state of neuronal excitability.
Leonhardt
Georg
G
Department of Neurology, University of Essen, Essen, Germany. georg.leonhardt@medizin.uni-halle.de
de Greiff
Armin
A
Weber
Johannes
J
Ludwig
Tanja
T
Wiedemayer
Helmut
H
Forsting
Michael
M
Hufnagel
Andreas
A
D000328:Adult; D001921:Brain / Q000098:blood supply* / Q000000981:diagnostic imaging; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000098:blood supply / Q000000981:diagnostic imaging / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D017352:Echo-Planar Imaging; D004827:Epilepsy / Q000000981:diagnostic imaging / Q000503:physiopathology*; D004833:Epilepsy, Temporal Lobe / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D019786:Gadolinium DTPA; D006624:Hippocampus / Q000098:blood supply / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D020534:Parahippocampal Gyrus / Q000098:blood supply / Q000000981:diagnostic imaging / Q000503:physiopathology; D010296:Parietal Lobe / Q000098:blood supply / Q000503:physiopathology; D012039:Regional Blood Flow / Q000502:physiology; D019690:Technetium Tc 99m Exametazime; D013702:Temporal Lobe / Q000098:blood supply / Q000000981:diagnostic imaging / Q000503:physiopathology; D015899:Tomography, Emission-Computed, Single-Photon
D019690:Technetium Tc 99m Exametazime; D019786:Gadolinium DTPA