Brain diffusion after single seizures.
OBJECTIVE
Diffusion-weighted magnetic resonance imaging (DWI) after focal status epilepticus has demonstrated focal alterations of the apparent diffusion coefficient (ADC) in the epileptogenic zone. We hypothesized that localized dynamic alterations of brain diffusion during the immediate postictal state will be detectable by serial DWI and correlate with the epileptogenic zone.


METHODS
Nine adult patients (four men, five women) with medically intractable epilepsy were prospectively examined with a total of 25 DWI scans taken 2-210 min after a seizure.


RESULTS
The interictal ADC was significantly (p < 0.05) elevated in the ictogenic hippocampus in all patients with temporal lobe epilepsy. The following postictal changes of the ADC were seen: (a) decreases by maximally 25-31%, which were most pronounced in the epileptogenic zone (n = 2); (b) generalized ADC changes after generalized seizures (n = 1) or prolonged complex partial seizures (n = 2); (c) no major changes after short-lived seizures or if the time to first DWI scan was >15 min or both (n = 3); and (d) widespread bilateral ADC increases after a flumazenil-induced seizure (n = 1).


CONCLUSIONS
ADC changes seen during serial postictal DWI are complex and appear to reflect origin and spread of the preceding seizure. A delineation of the epileptogenic zone appears to be possible only in complex-partial seizures of >60 s duration that do not secondarily generalize.
Hufnagel
Andreas
A
Department of Neurology, University of Essen, Essen, Germany. aa.hufnagel@uni-essen.de
Weber
Johannes
J
Marks
Sonja
S
Ludwig
Tanja
T
De Greiff
Armin
A
Leonhardt
Georg
G
Widmann
Guido
G
Stolke
Dietmar
D
Forsting
Michael
M
D000328:Adult; D016477:Artifacts; D001812:Blood-Brain Barrier / Q000502:physiology; D002463:Cell Membrane Permeability / Q000502:physiology; D002540:Cerebral Cortex / Q000473:pathology / Q000503:physiopathology; D038524:Diffusion Magnetic Resonance Imaging; D004292:Dominance, Cerebral / Q000502:physiology; D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000175:diagnosis / Q000503:physiopathology*; D017029:Epilepsy, Complex Partial / Q000175:diagnosis / Q000503:physiopathology*; D004829:Epilepsy, Generalized / Q000175:diagnosis / Q000503:physiopathology*; D005260:Female; D006624:Hippocampus / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D008297:Male; D008432:Mathematical Computing; D008875:Middle Aged; D020534:Parahippocampal Gyrus / Q000473:pathology / Q000503:physiopathology; D012598:Sclerosis; D013788:Thalamus / Q000473:pathology / Q000503:physiopathology