Increased binding potential of brain adenosine A 1 receptor in chronic stages of patients with diffuse axonal injury measured with [1-methyl- 11 C] 8-dicyclopropylmethyl-1-methyl-3-propylxanthine PET imaging.

The positron emission tomography (PET) radioligand for adenosine A 1 receptor (A1R) [1-methyl- 11 C] 8-dicyclopropylmethyl-1-methyl-3-propylxanthine (MPDX) has recently been developed for human brain imaging. In the present study, we evaluated the alteration of the A1R in patients with diffuse axonal injury (DAI) in chronic stage in vivo . Ten patients with DAI (7 men and 3 women) were included in this study. Three PET examinations were sequentially performed to measure A1R binding with 11 C-MPDX, glucose metabolism with 18 F-fluorodeoxyglucose (FDG), and central benzodiazepine receptor binding with 11 C-flumazenil (FMZ), decreases of 11 C-FMZ uptake indicate neuronal loss. 11 C- MPDX did not depict any lesion with significantly decreased nondisplaceable binding potential ( BP ND ) in comparison to healthy controls (14 men) in ROI analysis. Instead, it showed a significant increase of BP ND in the ...