NMDA-receptor activation measured with [18F]GE-179 PET lateralizes and localizes the epileptic focus.
Abstract number :
1.244
Submission category :
5. Neuro Imaging / 5B. Functional Imaging
Year :
2017
Submission ID :
344666
Source :
www.aesnet.org
Presentation date :
12/2/2017 5:02:24 PM
Published date :
Nov 20, 2017, 11:02 AM
Authors :
Marian Galovic, University College London; Kjell Erlandsson, University College London; Ben A. Thomas, University College London; Hasan Sari, University College London; Sarah McQuaid, University College London Hospital; Kris Thielemans, University College
Rationale: NMDA (N-methyl-D-asparate) receptors are involved in generating and sustaining seizures and play a role in epileptogenesis. We measured activation of NMDA receptors using [18F]GE-179 positron emission tomography (PET) in people with focal epilepsy and determined its value in lateralizing and localizing the epileptic focus for presurgical evaluation of epilepsy. Methods: Twenty-five consecutive people with focal epilepsy undergoing comprehensive presurgical evaluation and nine healthy controls matched for age and gender received a [18F]GE-179 PET scan. GE-179 is a novel ligand that selectively binds to the activated NMDA receptor, which is thought to be overactive in epilepsy. Subject-wise comparisons of standardized uptake value (SUV) images were calculated using statistical parametric mapping (SPM) and compared with (i) visual analysis without a fixed threshold and (i) a prespecified statistical threshold (p < 0.001). Results: Visual inspection of threshold-free statistical maps indicated correct lateralization of the epileptic focus in 92% (23/25 cases, p < 0.001) and correct localization in 84% (21/25 cases, p < 0.001). There was substantial agreement with the conclusions of pre-surgical investigations (Cohen’s kappa 0.85 and 0.83 respectively). Using a fixed statistical threshold (p < 0.001), significant signal-abnormalities co-localized with results of pre-surgical investigations in 68% (17/25) cases. Signal abnormalities within the hippocampus were detected in five out of six cases with hippocampal sclerosis. Additionally, 17 out of 22 (77%) cases with focal signal increases also showed increased uptake in areas known to be highly involved in epileptic seizures, i.e. bilateral thalamus, anterior cingulate cortex and contralateral temporal lobe. Conclusions: NMDA-receptor PET might help characterize the network involved in generating epileptic seizures. This instrument could be helpful for evaluating the lateralization and localization of the epileptogenic focus. Funding: UK Medical Research Council MR/L013215/1
Neuroimaging