title: [11C]-(R)-PK11195 positron emission tomography in patients with complex regional pain syndrome: A pilot study.
abstract: Complex regional pain syndrome (CRPS) is characterized by severe and chronic pain, but the pathophysiology of this disease are not clearly understood. The primary aim of our case-control study was to explore neuroinflammation in patients with CRPS using positron emission tomography (PET), with an 18-kDa translocator protein specific radioligand [C]-(R)-PK11195. [C]-(R)-PK11195 PET scans were acquired for 11 patients with CRPS (30-55 years) and 12 control subjects (30-52 years). Parametric image of distribution volume ratio (DVR) for each participant was generated by applying a relative equilibrium-based graphical analysis. The DVR of [C]-(R)-PK11195 in the caudate nucleus (t(21) = -3.209, P = 0.004), putamen (t(21) = -2.492, P = 0.022), nucleus accumbens (t(21) = -2.218, P = 0.040), and thalamus (t(21) = -2.395, P = 0.026) were significantly higher in CRPS patients than in healthy controls. Those of globus pallidus (t(21) = -2.045, P = 0.054) tended to be higher in CRPS patients than in healthy controls. In patients with CRPS, there was a positive correlation between the DVR of [C]-(R)-PK11195 in the caudate nucleus and the pain score, the visual analog scale (r = 0.661, P = 0.026, R = 0.408) and affective subscales of McGill Pain Questionnaire (r = 0.604, P = 0.049, R = 0.364). We demonstrated that neuroinflammation of CRPS patients in basal ganglia. Our results suggest that microglial pathology can be an important pathophysiology of CRPS. Association between the level of caudate nucleus and pain severity indicated that neuroinflammation in this region might play a key role. These results may be essential for developing effective medical treatments.
authors.affiliation: Department of Neuropsychiatry, Seoul National University Hospital Department of Nuclear Medicine, Seoul National University College of Medicine Department of Brain and Cognitive Science, Seoul National University College of Natural Sciences Institute of Radiation Medicine, Medical Research Center Department of Psychiatry, Seoul National University College of Medicine Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Suwon, Republic of Korea.
authors.forename: So Yeon
authors.initials: SY
authors.lastname: Jeon
authors.forename: Seongho
authors.initials: S
authors.lastname: Seo
authors.forename: Jae Sung
authors.initials: JS
authors.lastname: Lee
authors.forename: Soo-Hee
authors.initials: SH
authors.lastname: Choi
authors.forename: Do-Hyeong
authors.initials: DH
authors.lastname: Lee
authors.forename: Ye-Ha
authors.initials: YH
authors.lastname: Jung
authors.forename: Man-Kyu
authors.initials: MK
authors.lastname: Song
authors.forename: Kyung-Jun
authors.initials: KJ
authors.lastname: Lee
authors.forename: Yong Chul
authors.initials: YC
authors.lastname: Kim
authors.forename: Hyun Woo
authors.initials: HW
authors.lastname: Kwon
authors.forename: Hyung-Jun
authors.initials: HJ
authors.lastname: Im
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Lee
authors.forename: Gi Jeong
authors.initials: GJ
authors.lastname: Cheon
authors.forename: Do-Hyung
authors.initials: DH
authors.lastname: Kang
mesh_terms: D000328:Adult; D000577:Amides / Q000493:pharmacokinetics; D001479:Basal Ganglia / Q000000981:diagnostic imaging* / Q000378:metabolism; D016022:Case-Control Studies; D002421:Caudate Nucleus / Q000000981:diagnostic imaging / Q000378:metabolism; D020918:Complex Regional Pain Syndromes / Q000000981:diagnostic imaging* / Q000378:metabolism*; D005260:Female; D005917:Globus Pallidus / Q000000981:diagnostic imaging / Q000378:metabolism; D006801:Humans; D007249:Inflammation / Q000000981:diagnostic imaging* / Q000378:metabolism; D007546:Isoquinolines / Q000493:pharmacokinetics; D008297:Male; D008875:Middle Aged; D009714:Nucleus Accumbens / Q000000981:diagnostic imaging / Q000378:metabolism; D010147:Pain Measurement; D010865:Pilot Projects; D049268:Positron-Emission Tomography / Q000379:methods*; D011699:Putamen / Q000000981:diagnostic imaging / Q000378:metabolism; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D013788:Thalamus / Q000000981:diagnostic imaging* / Q000378:metabolism
chemical_list: C504060:(R)-(11C)1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinolinecarboxamide; D000577:Amides; D007546:Isoquinolines; D019275:Radiopharmaceuticals