Abstract:
We used positron emission tomography to investigate local cerebral
metabolic rates for glucose (LCMRG1c) in patients with obsessive-
compulsive disorder before and after treatment with either fluoxetine
hydrochloride or behavior therapy. After treatment, LCMRG1c in the head
of the right caudate nucleus, divided by that in the ipsilateral
hemisphere (Cd/hem), was decreased significantly compared with
pretreatment values in responders to both drug and behavior therapy.
These decreases in responders were also significantly greater than right
Cd/hem changes in nonresponders and normal controls, in both of whom
values did not change from baseline. Percentage change in
obsessive-compulsive disorder symptom ratings correlated significantly
with the percent of right Cd/hem change with drug therapy and there was
a trend to significance for this same correlation with behavior therapy.
By lumping all responders to either treatment, right orbital cortex/hem
was significantly correlated with ipsilateral Cd/hem and thalamus/hem
before treatment but not after, and the differences before and after
treatment were significant. A similar pattern was noted in the left
hemisphere. A brain circuit involving these brain regions may mediate
obsessive-compulsive disorder symptoms