HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Correspondence: Submit a response Alert me when this article is cited Alert me when Correspondence are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Koepp, M. J. Articles by Duncan, J. S. Search for Related Content PubMed PubMed Citation Articles by Koepp, M. J. Articles by Duncan, J. S.

¹¹C-flumazenil PET in patients with refractory temporal lobe epilepsy and normal MRI

From the MRC Cyclotron Unit (Drs. Koepp, Hammers, Labbé, Brooks, and Duncan), Hammersmith Hospital, DuCane Road; and the National Society for Epilepsy (Drs. Koepp, Hammers, Woermann, and Duncan), Institute of Neurology, Queen Square, London, UK.

Address correspondence and reprint requests to Professor John S. Duncan, Epilepsy Research Group, Institute of Neurology, Queen Square, London WC1N 3BG, UK.

BACKGROUND: Using ¹¹C-flumazenil (FMZ) PET with correction for partial-volume effect, reductions of central benzodiazepine receptor (cBZR) binding can be detected reliably in vivo on remaining neurons in sclerotic hippocampi of patients with mesial temporal lobe epilepsy (TLE).

OBJECTIVE: To delineate abnormalities of ¹¹C-FMZ binding in patients with medically refractory TLE and normal quantitative MRI.

METHODS: Analysis of parametric images of FMZ volume of distribution (V_d) using two complementary approaches: 1) MRI-based volume of interest (VOI) approach with partial volume effect correction for multiple hippocampal and extrahippocampal VOIs; and 2) statistical parametric mapping (SPM) to localize significant ¹¹C-FMZ binding changes objectively on a voxel-by-voxel basis.

RESULTS: Significant abnormalities of absolute FMZ-V_d were found after partial volume effect correction in 5 of 10 patients: unilateral decrease in the amygdala ipsilateral to the EEG focus (1), unilateral hippocampal decreases and bilateral temporal and extratemporal neocortical decreases (2), unilateral increase in the temporal neocortex together with extratemporal neocortical increases (1), and bilateral posterior hippocampal increases together with temporal neocortical increases (1). In the three patients with extratemporal neocortical changes, the concomitant unilateral hippocampal or temporal neocortical changes were contralateral to the presumed epileptic focus. Significant asymmetries of FMZ-V_d between homologous regions were found in six patients. In four of those patients, absolute FMZ-V_d for the homologous regions were within normal limits, with two of the four patients showing relatively higher hippocampal values ipsilateral to the presumed epileptic focus. SPM analysis localized significant abnormalities of FMZ-V_d in similar locations in three of the seven patients in whom VOI analysis detected significant changes. In addition, SPM indicated significant unilateral contralateral hippocampal decreases in an eighth patient. However, both methods failed to localize epileptic foci in two patients identified by depth-EEG recordings.

CONCLUSIONS: ¹¹C-FMZ PET showed focal increases as well as decreases of FMZ binding in 80% of patients with refractory TLE and normal high-quality MRI but was not consistently helpful in localizing the epileptic foci.

Key words: ¹¹C-flumazenil PET—Temporal lobe epilepsy—Normal MRI

This article has been cited by other articles:

				S. Bouvard, N. Costes, F. Bonnefoi, F. Lavenne, F. Mauguiere, J. Delforge, and P. Ryvlin Seizure-related short-term plasticity of benzodiazepine receptors in partial epilepsy: a [11C]flumazenil-PET study Brain, June 1, 2005; 128(6): 1330 - 1343. [Abstract] [Full Text] [PDF]

				A. Hammers, M. J. Koepp, M. P. Richardson, R. Hurlemann, D. J. Brooks, and J. S. Duncan Grey and white matter flumazenil binding in neocortical epilepsy with normal MRI. A PET study of 44 patients Brain, June 1, 2003; 126(6): 1300 - 1318. [Abstract] [Full Text] [PDF]

				V. Frouin, C. Comtat, A. Reilhac, and M.-C. Gregoire Correction of Partial-Volume Effect for PET Striatal Imaging: Fast Implementation and Study of Robustness J. Nucl. Med., December 1, 2002; 43(12): 1715 - 1726. [Abstract] [Full Text] [PDF]

				A. Hammers, M. J. Koepp, R. Hurlemann, M. Thom, M. P. Richardson, D. J. Brooks, and J. S. Duncan Abnormalities of grey and white matter [11C]flumazenil binding in temporal lobe epilepsy with normal MRI Brain, October 1, 2002; 125(10): 2257 - 2271. [Abstract] [Full Text] [PDF]

				A. Hammers, M. J. Koepp, M. P. Richardson, C. Labbe, D. J. Brooks, V. J. Cunningham, and J. S. Duncan Central benzodiazepine receptors in malformations of cortical development: A quantitative study Brain, August 1, 2001; 124(8): 1555 - 1565. [Abstract] [Full Text] [PDF]

				A. Hammers, M.J. Koepp, C. Labbe, D.J. Brooks, M. Thom, V.J. Cunningham, and J.S. Duncan Neocortical abnormalities of [11C]-flumazenil PET in mesial temporal lobe epilepsy Neurology, April 10, 2001; 56(7): 897 - 906. [Abstract] [Full Text] [PDF]

				C. Juhasz, D. C. Chugani, O. Muzik, C. Watson, J. Shah, A. Shah, and H. T. Chugani Electroclinical correlates of flumazenil and fluorodeoxyglucose PET abnormalities in lesional epilepsy Neurology, September 26, 2000; 55(6): 825 - 835. [Abstract] [Full Text] [PDF]