Dynamic susceptibility contrast (DSC) MRI and interictal epileptiform activity in cryptogenic partial epilepsy.
OBJECTIVE
To study the possible correlation between interictal EEG patterns and neuroradiologic data obtained by dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI) in patients with partial epilepsy.


METHODS
Seventeen subjects with cryptogenic partial epilepsy underwent long-term video-EEG monitoring and DSC-MRI in the same session. Ten patients had temporal lobe epilepsy (TLE) and seven, epilepsy of extratemporal origin (ExTE). MRI data were compared with EEG findings, and the accuracy of DSC-MRI was analyzed considering spiking rate (number of interictal epileptiform abnormalities, IEA/min) and type of epilepsy.


RESULTS
DSC-MRI showed a relevant asymmetry in the frontal, temporal, and occipital regions in eight (47%) of 17 patients, consisting of a relative regional cerebral blood volume (rCBV) increase in these areas. Because this region corresponded to the interictal EEG focus (IEF) or to the hemisphere involved in the genesis of epileptic discharges in most patients showing a higher spiking rate, patients were classified in two groups: patients with high spiking rate (HSR, n = 9) and with low spiking rate (LSR, n = 8); the cutoff corresponded to the median value of IEA/min. The rCBV increase corresponded to the IEF or to the hemisphere involved in the genesis of epileptic discharges in seven (77.7%) of nine HSR patients. No patients with LSR showed significant asymmetries in rCBV pattern. In five of six patients with TLE-HSR (83.3%), DSC-MRI showed a relative rCBV increase concordant with IEF or hemisphere involved in the genesis of epileptic discharges; in patients with ExTE-HSR, the concordance was 66%.


CONCLUSIONS
DSC-MRI is a noninvasive procedure that may provide useful additional information to lateralize and/or localize the IEF when interictal epileptiform activity is sufficiently elevated.
Placidi
Fabio
F
Neurofisiopatologia, Università di Roma Tor Vergata, Roma, Italy. fbplacidi@libero.it
Floris
Roberto
R
Bozzao
Alessandro
A
Romigi
Andrea
A
Tombini
Mario
M
Baviera
Maria Elena
ME
Sperli
Francesca
F
Izzi
Francesca
F
Mattia
Donatella
D
Marciani
Maria Grazia
MG
D000293:Adolescent; D000328:Adult; D000368:Aged; D001810:Blood Volume / Q000502:physiology; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000098:blood supply / Q000503:physiopathology; D002648:Child; D004292:Dominance, Cerebral / Q000502:physiology; D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000175:diagnosis* / Q000503:physiopathology; D017029:Epilepsy, Complex Partial / Q000175:diagnosis / Q000503:physiopathology; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow / Q000502:physiology; D012680:Sensitivity and Specificity