Ishibashi Kenji, Miura Yoshiharu, Toyohara Jun, Ishii Kenji, Ishiwata Kiichi
Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan; Department of Neurology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komago2me Hospital, Tokyo, Japan.
Department of Neurology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komago2me Hospital, Tokyo, Japan.
J Neurol Sci. 2017 Apr 15;375:97-102. doi: 10.1016/j.jns.2017.01.036. Epub 2017 Jan 12.
Objective Newly developed methods for imaging type 1 metabotropic glutamate receptor (mGluR1) have the potential use for estimating cerebellar function. We aimed to compare mGluR1 imaging using N-[4-[6-(isopropylamino)pyrimidin-4-yl]-1,3-thiazol-2-yl]-4-C-methoxy-N-methylbenzamide (C-ITMM) with the existing marker, fluorine-18-labeled fluorodeoxyglucose (F-FDG) imaging, in the cerebellum.
Fourteen subjects consisting of 12 patients with cerebellar ataxia and two healthy subjects underwent C-ITMM and F-FDG positron emission tomography. The degree of ataxia was scored with the Scale for the Assessment and Rating of Ataxia (SARA). Volumes-of-interest were placed on the anterior and posterior lobes and vermis. The binding potential (BP) was calculated to estimate mGluR1 availability using the white matter as a reference region. F-FDG uptake was normalized using the white matter (FU).
There were significant positive correlations between the BP and FU values in the anterior lobe (r=0.83, P<0.001), posterior lobe (r=0.69, P=0.009), and vermis (r=0.58, P=0.042). Regarding the relationship of SARA scores with the BP and FU values, a significant negative correlation was found only in the anterior lobe between the SARA scores and BP values (r=-0.64, P=0.029).
This study showed that mGluR1 imaging was comparable to F-FDG imaging in the cerebellum. However, mGluR1 imaging was more strongly associated with the SARA scores than F-FDG imaging was, suggesting that mGluR1 imaging can be a more specific technique than F-FDG imaging for evaluating cerebellar ataxia.
目的 新开发的1型代谢型谷氨酸受体（mGluR1）成像方法有用于评估小脑功能的潜力。我们旨在比较使用N-[4-[6-(异丙基氨基)嘧啶-4-基]-1,3-噻唑-2-基]-4-C-甲氧基-N-甲基苯甲酰胺（C-ITMM）进行的mGluR1成像与现有标志物氟-18标记的氟脱氧葡萄糖（F-FDG）成像在小脑中的情况。
14名受试者，包括12名小脑共济失调患者和2名健康受试者，接受了C-ITMM和F-FDG正电子发射断层扫描。使用共济失调评估和评分量表（SARA）对共济失调程度进行评分。在小脑前叶、后叶和蚓部设置感兴趣区。以白质作为参考区域计算结合潜能（BP）以估计mGluR1的可用性。F-FDG摄取量使用白质进行标准化（FU）。
在前叶（r = 0.83，P < 0.001）、后叶（r = 0.69，P = 0.009）和蚓部（r = 0.58，P = 0.042），BP值与FU值之间存在显著正相关。关于SARA评分与BP值和FU值的关系，仅在前叶发现SARA评分与BP值之间存在显著负相关（r = -0.64，P = 0.029）。
本研究表明，mGluR1成像在小脑中与F-FDG成像相当。然而，mGluR1成像与SARA评分的相关性比F-FDG成像更强，这表明mGluR1成像在评估小脑共济失调方面可能是比F-FDG成像更具特异性的技术。
