Brain activity for chronic knee osteoarthritis: dissociating evoked XXXX from spontaneous @entity158 .

@entity1 @entity571 @entity625 @entity17852 @entity615 @entity158 @entity3840 @entity1118 @entity9
@entity1118 is a hallmark of @entity571 ( @entity571 ), yet little is known about its properties and representation in the brain. Here we use fMRI combined with psychophysics to study knee @entity158 in fourteen @entity571 @entity1 and nine healthy controls. Mechanical painful pressure stimuli were applied to the knee in both groups and ratings of evoked @entity158 and related brain activity examined. We observe that psychophysical properties and brain activation patterns of evoked @entity158 are essentially the same between @entity571 @entity1 and healthy subjects, and between worse and better @entity571 knees. In @entity571 @entity1 , stimulus-related brain activity could be distinguished from brain activity associated with spontaneous @entity158 . The former activated brain regions commonly observed for acute painful stimuli in healthy subjects, while the spontaneous @entity158 of @entity571 engaged prefrontal-limbic regions closely corresponding to areas observed for spontaneous @entity158 in other @entity1118 conditions, such as @entity615 and @entity9 . @entity625 -related clinical characteristics of knee @entity571 also mapped to prefrontal-limbic regions. In a subgroup of @entity1 (n=6) we examined brain activity changes for a 2-week, repeat measure, @entity3840 inhibitor ( @entity17852 ) therapy. Treatment decreased spontaneous @entity158 for the worse knee and clinical characteristics of @entity571 , and increased blood and csf levels of the drug which correlated positively with prefrontal-limbic brain activity. These findings indicate dissociation between mechanically induced and spontaneous @entity158 , the latter engaging brain regions involved in emotional assessment of the self, and challenge the standard clinical view regarding the nature of @entity158 .
