Pharmacotherapy and Regional Cerebral Blood Flow in Children with Obsessive Compulsive Disorder

While regional cerebral blood flow (rCBF) studies on adults involving the caudate, prefrontal, orbitofrontal, and cingulated areas have been reported, no such published data on children exist. In this study, we aimed to determine the significance of pre- and post-treatment regional cerebral blood flow (rCBF) differences in children with obsessive compulsive disorder (OCD) and compared them with healthy controls. Eighteen drug-free obsessive compulsive children, aged 11 to 15, without comorbid states except for anxiety disorders - participated in this study. The control group consisted of 12 children, aged 11 to 15, with no medical or psychiatric illnesses. Using SPECT (Single Photon Emission Computerized Tomography) scans with Technetium-99m-HMPAO-hexamethly propyleneamine oxime (Tc99mHMPAO), the rCBF was calculated in 15 regions of the control group according to a standard protocol, while in the study group, it was measured at baseline and after 12 weeks of treatment with a fixed dose of paroxetine (20 mg qd). We compared the resulting pre- and post-treatment CBF values for the control group and study group. The right and left caudates, right and left dorsolateral prefrontals, and cingulate had significantly higher rCBF in children with obsessive compulsive disorder than in the control group. These areas, in addition to the right anteromedial temporal, showed significant rCBF reduction after treatment with paroxetine. The mean percentage of change in obsession scores during the treatment correlated significantly with the baseline and post- treatment rCBF level of the right caudate, post-treatment left caudate, and baseline left caudate. Our findings on children are consistent with adult studies and support the theory of a cortical-striatal-thalamic-cortical loop disturbance in OCD.

Tc-99m-ECD SPECT Brain Imaging in Children with Tourette's Syndrome

We undertook this study to assess the patterns of regional cerebral perfusion (RCP) with SPECT using Technetium-99m-ethyl cysteinate dimer (Tc-99m-ECD) in children with Tourette's Syndrome (TS), and to compare these with the patterns in a group of normal controls. The study sample consisted of 38 children (7 to 14 years) who met the ICD-10 and DSM/IV criteria for Tourette's Syndrome, and a control group of 18 children (9 to 14 years). The Children's Depression Inventory and Maudsley Obsessional-Compulsive Questionnaire were used for assessment, and the severity of motor and vocal tics were assessed using the Goetz Rating Scale. The RCP values were significantly lower in the TS group in left caudate, cingulum, right cerebellum, left dorsolateral prefrontal, and the left orbital frontal region. A positive correlation was found between the severity of vocal tics and blood flow of mid-cerebellum, right dorsolateral prefrontal and left dorsolateral prefrontal regions. Although no depressive or obsessive patients were included in the study, the depression and obsession scores were found to be negatively correlated with all RCP values, especially in the temporal regions. Further studies are needed to explore the relationship between the hypoperfusion of certain brain areas and the underlying neurophysiology and neurobiology of patients with TS. Additional disturbances such as obsessive- compulsive symptoms and depressive symptoms should also be assessed.