TY - JOUR T1 - Neuroinflammation in Patients with Chronic Fatigue Syndrome/Myalgic Encephalomyelitis: An <sup>11</sup>C-(<em>R</em>)-PK11195 PET Study JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 945 LP - 950 DO - 10.2967/jnumed.113.131045 VL - 55 IS - 6 AU - Yasuhito Nakatomi AU - Kei Mizuno AU - Akira Ishii AU - Yasuhiro Wada AU - Masaaki Tanaka AU - Shusaku Tazawa AU - Kayo Onoe AU - Sanae Fukuda AU - Joji Kawabe AU - Kazuhiro Takahashi AU - Yosky Kataoka AU - Susumu Shiomi AU - Kouzi Yamaguti AU - Masaaki Inaba AU - Hirohiko Kuratsune AU - Yasuyoshi Watanabe Y1 - 2014/06/01 UR - http://jnm.snmjournals.org/content/55/6/945.abstract N2 - Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is a disease characterized by chronic, profound, disabling, and unexplained fatigue. Although it is hypothesized that brain inflammation is involved in the pathophysiology of CFS/ME, there is no direct evidence of neuroinflammation in patients with CFS/ME. Activation of microglia or astrocytes is related to neuroinflammation. 11C-(R)-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinoline-carboxamide (11C-(R)-PK11195) is a ligand of PET for a translocator protein that is expressed by activated microglia or astrocytes. We used 11C-(R)-PK11195 and PET to investigate the existence of neuroinflammation in CFS/ME patients. Methods: Nine CFS/ME patients and 10 healthy controls underwent 11C-(R)-PK11195 PET and completed questionnaires about fatigue, fatigue sensation, cognitive impairments, pain, and depression. To measure the density of translocator protein, nondisplaceable binding potential (BPND) values were determined using linear graphical analysis with the cerebellum as a reference region. Results: The BPND values of 11C-(R)-PK11195 in the cingulate cortex, hippocampus, amygdala, thalamus, midbrain, and pons were 45%–199% higher in CFS/ME patients than in healthy controls. In CFS/ME patients, the BPND values of 11C-(R)-PK11195 in the amygdala, thalamus, and midbrain positively correlated with cognitive impairment score, the BPND values in the cingulate cortex and thalamus positively correlated with pain score, and the BPND value in the hippocampus positively correlated with depression score. Conclusion: Neuroinflammation is present in widespread brain areas in CFS/ME patients and was associated with the severity of neuropsychologic symptoms. Evaluation of neuroinflammation in CFS/ME patients may be essential for understanding the core pathophysiology and for developing objective diagnostic criteria and effective medical treatments. ER -