5-HT1A Receptors Are Reduced in Temporal Lobe Epilepsy After Partial-Volume Correction

Journal of Nuclear Medicine

William H. Theodore¹  Maria T. Toczek¹  Peter Herscovitch¹  Giampiero Giovacchini¹  Charles Fraser¹  Lixin Lang¹  Pat Reeves-Tyer¹  Richard E. Carson¹  William C. Eckelman¹  Anto Bagic¹  Robert Bonwetsch¹ 

关键词: 5-HT_1A receptors;    temporal lobe epilepsy;    partial-volume correction;    PET;    depression;   

DOI  :  

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

Preclinical studies suggest that serotonin 1A receptors (5-HT1A) play a role in temporal lobe epilepsy (TLE). Previous PET studies reported decreased 5-HT1A binding ipsilateral to epileptic foci but did not correct for the partial-volume effect (PVE) due to structural atrophy. Methods: We used PET with 18F-trans-4-fluoro-N-2-[4-(2-methoxyphenyl)piperazin-1-yl]ethyl-N-(2-pyridyl)cyclohexanecarboxamide (18F-FCWAY), a 5-HT1A receptor antagonist, to study 22 patients with TLE and 10 control subjects. In patients, 18F-FDG scans also were performed. An automated MR-based partial-volume correction (PVC) algorithm was applied. Psychiatric symptoms were assessed with the Beck Depression Inventory Scale. Results: Before PVC, significant (uncorrected P < 0.05) reductions of 18F-FCWAY binding potential (BP) were detected in both mesial and lateral temporal structures, mainly ipsilateral to the seizure focus, in the insula, and in the raphe. Group differences were maximal in ipsilateral mesial temporal regions (corrected P < 0.05). After PVC, differences in mesial, but not lateral, temporal structures and in the insula remained highly significant (corrected P < 0.05). Significant (uncorrected P < 0.05) BP reductions were also detected in TLE patients with normal MR images (n = 6), in mesial temporal structures. After PVC, asymmetries in BP remained significantly greater than for glucose metabolism in hippocampus and parahippocampus. There was a significant inverse relation between the Beck Depression score and the ipsilateral hippocampal BP, both before and after PVC. Conclusion: Our study shows that in TLE patients, reductions of 5-HT1A receptor binding in mesial temporal structures and insula are still significant after PVC. In contrast, partial-volume effects may be an important contributor to 5-HT1A receptor-binding reductions in lateral temporal lobe. Reduction of 5-HT1A receptors in the ipsilateral hippocampus may contribute to depressive symptoms in TLE patients.

【 授权许可】

Unknown