Metabolic Patterns in Temporal Dysembryoplastic Neuroepithelial Tumors.
Abstract number :
1.213
Submission category :
Year :
2001
Submission ID :
192
Source :
www.aesnet.org
Presentation date :
12/1/2001 12:00:00 AM
Published date :
Dec 1, 2001, 06:00 AM
Authors :
F. Chassoux, MD, Neurosurgery, CHSA, Paris, France; V. Bouilleret, MD, Nuclear Medicine, SHFJ/CEA, Orsay, France; B. Devaux, MD, Neurosurgery, CHSA, Paris, France; E. Landre, MD, Neurosurgery, CHSA, Paris, France; B. Turak, MD, Neurosurgery, CHSA, Paris,
RATIONALE: Dysembryoplastic neuroepithelial tumors (DNET) are known to be associated with intractable partial epilepsy that can be cured by surgery. However, cerebral metabolism studies in DNET are few. The aim of this study was to analyze metabolic patterns in temporal DNET and to compare them to the location of the lesion and epileptogenic zone (EZ). Our second goal was to compare these metabolic patterns to those observed in mesiotemporal lobe epilepsy (MTLE) associated with hippocampal sclerosis (HS).
METHODS: 18Fluoro-deoxyglucose positron emission tomography (PET) study was realized in 12 adult patients investigated for drug resistant partial epilepsy associated with histologically proved temporal DNET. PET scans were performed on a head-dedicaced PET-camera (Siemens 953B). EZ was defined by electroclinical correlations obtained by ictal recording (video-EEG: all patients, stereo-electroencephalography: 4 patients). Group 1 (6 patients) corresponded to lesions located into the mesial structures and group 2 (6 patients) to DNET located in the anterior part of the temporal lobe (pole, antero-lateral or antero-basal cortex). The metabolism study was done using group analysis with statistical parametric mapping (SPM96) comparing the patient population to 10 healthy volunteers (p=0,005). The same analysis was performed in a group of patients with MTLE (n=33).
RESULTS: Group 1 analysis showed hypometabolism in the parahippocampal gyrus, pole and inferior frontal gyrus. In group 2, hypometabolism was found in the pole, inferior temporal gyrus, insula, orbitofrontal cortex, inferior frontal and precentral gyri. These two types of pattern were concordant with the EZ and ictal spread patterns. The hypometabolic areas were larger than lesional areas but more restricted that those observed in HS, particularly in terms of insular and perisylvian involvement which was more severe in the latter case.
CONCLUSIONS: Hypometabolic areas in temporal DNET are 1) larger than lesional areas 2) related to the location of the lesion 3) concordant with EZ and spead pathways and 4) more limited that in HS.