ABSTRACT
Objective To investigate the glucose metabolic pattern of brain functional loop in patients with refractory obsessive compulsive disorder (OCD) using 18 F-FDG PET.Methods Eight patients with refractory OCD and 8 age- and gender-matched healthy volunteers underwent 18F-FDG PET brain imaging.SPM software was used for image post-processing and quantitative analysis.Correlation analysis between 18F-FDG uptake and Yale-Brown obsessive compulsive scale(Y-BOCS) score was performed.Results Compared with the controls,the glucose metabolism of bilateral frontal cortices ( including the rectal gyrus,orbital gyrus and cingulate gyrus),left thalamus,right temporal lobe and bilateral cerebellum in refractory OCD patients increased significantly ( Zmax =3.45 - 5.80,all P ＜ 0.001 ).Bilateral motor cortices and bilateral parietal lobes (BA7),however,showed decreased glucose metabolism (Zmax =3.44 - 4.46,all P ＜0.001 ).Y-BOCS score was positively correlated with the glucose metabolism of the bilateral anterior cingulate cortex (Zmax =3.77,3.48 and 2.97,all P ＜ 0.01 ).Conclusions There is a characteristic metabolic pattern of increased glucose utilization in the fronto-striato-thalamic loop and decreased glucose utilization in bilateral motor cortices and parietal lobes in patients with OCD.The glucose metabolism in the anterior cingulate cortex might serve as a quantitative parameter for the assessment of the severity of OCD.
ABSTRACT
<p><b>BACKGROUND</b>The major neuropathological symptoms of Parkinson's disease (PD) consist of a loss of pigmented dopaminergic neurons in the substantia nigra and the presence of Lewy bodies. This study was to investigate the effects of bilateral subthalamic nucleus (STN) stimulation on resting-state cerebral glucose metabolism in advanced PD, and investigate the mechanism of deep brain stimulation (DBS).</p><p><b>METHODS</b>Seven consecutive advanced PD patients (4 men and 3 women, mean age 64 +/- 4 years, mean H-Y disability rating 4.4 +/- 0.65) receiving bilateral STN DBS underwent 18F-fluorodeoxyglucose (18F-FDG)/positron-emission tomography (PET) examinations at rest both preoperatively and one month postoperatively, with STN stimulation still on. The unified PD rating scale was used to evaluate the clinical state under each condition. Statistical parametric mapping (SPM) was used to investigate the regional cerebral metabolic rates of glucose (rCMRGlu) during STN stimulation, and to compare these values to rCMRGlu preoperation.</p><p><b>RESULTS</b>STN stimulation clearly improved clinical symptoms in all patients. A significant increase in rCMRGlu was found in the bilateral lentiform nucleus, brainstem (midbrain and pons), bilateral premotor area (BA6), parietal-occipital cortex, and anterior cingulated cortex, and a marked decrease in rCMRGlu was noted in the left limbic lobe and bilateral inferior frontal cortex (P < 0.05).</p><p><b>CONCLUSION</b>Bilateral STN stimulation may activate the projection axon from the STN, improving clinical symptoms in advanced PD patients by improving both ascending and descending pathways from the basal ganglia and increasing the metabolism of higher-order motor control in the frontal cortex.</p>