Correlation of MRI and histopathology in epileptogenic parietal and occipital lobe lesions.
BACKGROUND
To analyze the diagnostic accuracy of MRI in patients undergoing parietal and occipital lobe epilepsy surgery.


METHODS
In a retrospective study, we analyzed MRI scans and neuropathology reports of 42 patients who had undergone resective epilepsy surgery in the parietal and occipital lobe between 1998 and 2003. We evaluated, whether lesions were precisely characterized by MRI and whether lesion characterization allowed to estimate postsurgical seizure outcome.


RESULTS
Within the categories epilepsy associated tumors, focal cortical dysplasias, vascular malformations, scarring, and others, MRI was concordant with histopathology in 36 of 42 (86%) lesions. Among the discordant lesions, one lesion was re-classified following MRI-histopathology synopsis, another two lesions represented new tumor entities (angiocentric neuroepithelial tumor, isomorphic astrocytoma) which have been described recently. Seizure freedom (Engel class I) one year following surgery was achieved in 25 patients (60%). Seizure outcome was different for lesion categories (Engel class I: epilepsy associated tumors, 62%; focal cortical dysplasias, 71%; vascular malformations, 75%; scarring, 40%), and was unchanged if no lesion was found on preoperative MRI.


CONCLUSIONS
If MRI and histopathology are discordant, not only the MRI findings may be debatable. MRI lesion detection is important, since chance of seizure freedom is low if no lesion is detected.
Urbach
Horst
H
Department of Radiology, University of Bonn Medical Center, Bonn, Germany. urbach@uni-bonn.de
Binder
Devin
D
von Lehe
Marec
M
Podlogar
Martin
M
Bien
Christian G
CG
Becker
Albert
A
Schramm
Johannes
J
Kral
Thomas
T
Clusmann
Hans
H
D000293:Adolescent; D000328:Adult; D001932:Brain Neoplasms / Q000150:complications / Q000473:pathology; D004569:Electroencephalography; D004827:Epilepsy / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D002538:Intracranial Arteriovenous Malformations / Q000150:complications / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures; D009778:Occipital Lobe / Q000473:pathology* / Q000601:surgery; D010296:Parietal Lobe / Q000473:pathology* / Q000601:surgery; D011446:Prospective Studies; D015899:Tomography, Emission-Computed, Single-Photon; D016896:Treatment Outcome