title: Relationship between type 1 metabotropic glutamate receptors and cerebellar ataxia.
abstract: Imaging of type 1 metabotropic glutamate receptor (mGluR1) has recently become possible using positron emission tomography (PET). We aimed to examine the relationship between mGluR1 and cerebellar ataxia. Families with spinocerebellar ataxia type 19/22 (SCA19/22) and SCA6, six patients with sporadic SCA, and 26 healthy subjects underwent PET using an mGluR1 radiotracer. Volumes-of-interest were placed on the anterior and posterior lobes and vermis. The binding potential (BPND) was calculated to estimate mGluR1 availability. A partial volume correction was applied to the BPNDvalues. The Scale for the Assessment and Rating of Ataxia (SARA) score were measured. In each patient with SCA19/22 and SCA6, the anterior lobe showed the highest decrease rates in the BPNDvalues, compared with healthy subjects. In the families with SCA19/22 and SCA6, the disease durations and SARA scores were shorter and lower, respectively, in the offspring, compared with the parents. However, the offspring paradoxically showed lower BPNDvalues, especially in the anterior lobe, compared with the parents. The patients with sporadic SCA showed significantly lower BPNDvalues in all subregions than healthy subjects. The BPNDvalues significantly correlated with the SARA scores in all participants. In conclusion, these results showed a decrease in mGluR1 availability in patients with hereditary and sporadic SCA, a correlation between mGluR1 availability and degree of cerebellar ataxia, and paradoxical findings in two families. These results suggest the potential use of mGluR1 imaging as a specific biomarker of cerebellar ataxia.
authors: Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan. ishibashi@pet.tmig.or.jp.|Department of Neurology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, Japan. ishibashi@pet.tmig.or.jp.
authors: Kenji
authors: K
authors: Ishibashi
authors: Department of Neurology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, Japan.
authors: Yoshiharu
authors: Y
authors: Miura
authors: Department of Neurology and Neurological Science, and Predictive and Preventive Medicine, Tokyo Medical and Dental University, Tokyo, Japan.
authors: Kinya
authors: K
authors: Ishikawa
authors: Molucular Probe Program, Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan.
authors: Ming-Rong
authors: MR
authors: Zhang
authors: Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan.
authors: Jun
authors: J
authors: Toyohara
authors: Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan.|Institute of Cyclotron and Drug Discovery Research, Southern Tohoku Research Institute for Neuroscience, Koriyama, Japan.|Department of Biofunctional Imaging, Fukushima Medical University, Fukushima, Japan.
authors: Kiichi
authors: K
authors: Ishiwata
authors: Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan.
authors: Kenji
authors: K
authors: Ishii
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000000981:diagnostic imaging; D001931:Brain Mapping; D015220:Calcium Channels / Q000235:genetics / Q000378:metabolism; D002524:Cerebellar Ataxia / Q000000981:diagnostic imaging / Q000235:genetics / Q000378:metabolism*; D005192:Family Health; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D000072356:Parenchymal Tissue / Q000000981:diagnostic imaging; D049268:Positron-Emission Tomography; D018094:Receptors, Metabotropic Glutamate / Q000378:metabolism*; D013132:Spinocerebellar Degenerations / Q000235:genetics; D020864:Calcium Channels, N-Type
chemical_list: D015220:Calcium Channels; D018094:Receptors, Metabotropic Glutamate; C105656:CACNA1A protein, human; D020864:Calcium Channels, N-Type; C104077:metabotropic glutamate receptor type 1
keywords: 11C-ITMM; PET; Spinocerebellar ataxia type 19/22; Spinocerebellar ataxia type 6; Sporadic spinocerebellar ataxia; Type 1 metabotropic glutamate receptor