PET and SPECT findings in anxiety disorders [Anksiyete bozukluklarinda PET ve SPECT bulgulari]

Abstract

In most of the cases of psychiatric disorders, since there has been no structural changes detected in the brain, the researchers directed themselves to the functional changes in these disorders. By using functional brain imaging techniques such as Positron Emission Tomography (PET) and Single Photon Emission Computerized Tomography (SPECT) some increases have been found in cortical, frontal and temporal cortex metabolism in generalized anxiety disorders and it has been impressed on that cortical structures, limbic system, basal ganglions, parietal cortex and cerebellum might have an etiological importance. Especially being localized to the parahippocampal region, it has been also found that regional cerebral blood flow (rCBF) was decreased in frontal, occipital and temporal cortex in cases of panic disorders, while in obssessive compulsive disorders, rCBF and metabolism uses decreased mostly in orbitofrontal cortex, caudate nucleus and anterior cingulate gyrus, talamus, parietal cortex and pallidum/putamen complex. Also in phobic disorders while given some phobic stimulators rCBF has been detected to be decreased in some areas in the brain (hypocampus, frontal and temporal cortex and primary and secondary visual cortex, cingulate cortex and striatum) some significant changes in cortical/subcortical and right caudate nucleus, limbic, paralimbic and visual areas rCBF ratios have been found during the 'Flashback' experience in posttraumatic stress disorders associated with substance use decrease in right/left ratios and an increase in orbital frontal cortex rCBF has been detected.