Cerebral blood flow is reduced in XXXX as assessed by arterial spin labeling.

@entity1 @entity5815
BACKGROUND: @entity5815 is diagnosed by a set of clinical criteria and therefore is probably heterogeneous. Earlier reports tested the hypothesis that the syndrome had a neurological substrate by doing studies of cerebral blood flow (CBF) but with discrepant results. One possible reason for the discrepancy was that relative CBF was assessed. We found reduced CBF in an earlier study of absolute CBF using xenon-CT. The purpose of this study was to use a second method of assessing CBF and to look within the study group for heterogeneity of responses. METHOD: Eleven CFS @entity1 and 10 age matched healthy controls underwent neuroimaging using arterial spin labeling to determine their regional and global absolute CBF. A template was constructed based on the control data, and individual @entity1 montages were compared on a case by case basis to determine if differences in regions of interest occurred. RESULTS: The @entity1 as a group had significantly lower global CBF than the controls. The reduction in CBF occurred across nearly every region assessed. Nine of the 11 @entity1 showed these reductions compared to the average control data, while two @entity1 showed actual increases relative to the controls. CONCLUSION: The data extend our earlier observation that CFS @entity1 as a group have broad decreases in CBF compared to healthy controls. However, as expected, the effect was not homogeneous in that 2 of the 11 @entity1 studied showed actual increases in CBF relative to controls.
