Changes in central 5-HT(1A) receptor binding in mesial temporal epilepsy measured by positron emission tomography with [(11)C]WAY100635.
OBJECTIVE
The possible involvement of the brain 5-HT(1A) receptor in epilepsy has been indicated in animal seizure models. Recent in vivo neuroimaging studies demonstrated decreased 5-HT(1A) receptor binding in epilepsy. Using positron emission tomography (PET) with [(11)C]WAY100635, we investigated 5-HT(1A) receptor binding in patients with mesial temporal lobe epilepsy and aimed to clarify the involvement of the brain 5-HT(1A) receptor system in epilepsy.


METHODS
PET measurements with [(11)C]WAY100635 were performed on 23 healthy volunteers and 13 patients who were diagnosed with mesial temporal lobe epilepsy based on clinical symptoms and electroencephalogram (EEG) findings. They had non-lesional mesial temporal lobe epilepsy with unilateral EEG foci and no hippocampal atrophy on magnetic resonance imaging. The binding potential (BP) of [(11)C]WAY100635 was calculated by the reference tissue model method. Data were analyzed for each region of interest (ROI) and on a voxel-by-voxel basis by statistical parametric mapping (SPM) system.


RESULTS
ROI and voxel-based analyses consistently demonstrated that 5-HT(1A) receptor BP was significantly decreased in the temporal lobe, hippocampus and amygdala on the ipsilateral side of the EEG focus compared to controls. In addition, decreased 5-HT(1A) receptor BP was also observed on the contralateral side of the amygdala.


CONCLUSIONS
5-HT(1A) receptor binding in patients with mesial temporal lobe epilepsy decreased predominantly in the ipsilateral mesial temporal lobe structures but also in the contralateral side. The imaging of 5-HT(1A) receptor binding by PET detects functional changes of the limbic system in mesial temporal lobe epilepsy, proving to be a sensitive and useful method.
Ito
Shigeo
S
Section of Psychiatry and Behavioral Science, Graduate School of Tokyo Medical and Dental University, Tokyo, Japan.
Suhara
Tetsuya
T
Ito
Hiroshi
H
Yasuno
Fumihiko
F
Ichimiya
Tetsuya
T
Takano
Akihiro
A
Maehara
Taketoshi
T
Matsuura
Masato
M
Okubo
Yoshiro
Y
D000328:Adult; D002250:Carbon Radioisotopes / Q000378:metabolism; D004833:Epilepsy, Temporal Lobe / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D010879:Piperazines / Q000378:metabolism; D049268:Positron-Emission Tomography; D011725:Pyridines / Q000378:metabolism; D011985:Receptors, Serotonin / Q000378:metabolism*; D012702:Serotonin Antagonists / Q000378:metabolism
D002250:Carbon Radioisotopes; D010879:Piperazines; D011725:Pyridines; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; C078730:serotonin 5 receptor; C090413:N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridinyl)cyclohexanecarboxamide