Patients with generalized anxiety disorder (GAD) experience psychological distress because of excessive and uncontrollable anxiety in everyday life. Only a few morphological studies have so far focused on specific brain regions of interest as well as the gray matter volume changes in GAD patients. This study evaluated gray matter volume alterations in whole-brain areas between GAD patients and healthy controls, and sex differences between the specific brain areas with significant volume changes in GAD patients using voxel-based morphometry. Twenty-two patients with GAD (13 men and nine women), who were diagnosed using the DSM-IV-TR, and 22 age-matched healthy controls (13 men and nine women) participated in this study. The high-resolution MRI data were processed using voxel-based morphometry analysis on the basis of diffeomorphic anatomical registration through an exponentiated Lie algebra algorithm in Statistical Parametric Mapping 8. There was no significant difference in the total intracranial volume between GAD patients and controls, but a significant difference was observed between sexes (P<0.05). Patients with GAD showed significant volume reductions in the hippocampus, midbrain, thalamus, insula, and superior temporal gyrus compared with the controls. As for the sex comparison, female patients showed a significant increase in the volume of the dorsolateral prefrontal cortex relative to male patients. Also, the volume of the dorsolateral prefrontal cortex in female patients was correlated positively with the Hamilton Anxiety Rating Scale score (γ=0.68, P=0.04). The specific morphological variations in patient with GAD will be helpful to understand the neural mechanism associated with a symptom of GAD. Furthermore, the findings would be valuable for the diagnostic accuracy of GAD using morphometric MRI analysis.
Aims: Patients with generalized anxiety disorder (GAD) suffer the symptoms of psychological distress, including excessive and uncontrollable anxiety. Until now, the functional neuroanatomy for working memory (WM) in conjunction with the major anxiety symptoms in GAD patients has not yet been clearly identified. This study investigated the neural activation patterns associated with the effect of neutral and anxiety-inducing distractors during the delayedresponse WM task in GAD patients.Methods: Eighteen patients with GAD and 18 agematched healthy controls participated in this study. The functional magnetic resonance images were obtained while the subjects performed a delayedresponse WM task with neutral and anxiety-inducing distractors.Results: During the neutral distractor, GAD patients compared to controls showed significantly lower activities in the fusiform gyrus, superior parietal gyrus, precuneus, superior occipital gyrus, lingual gyrus, cuneus, calcarine gyrus, parahippocampal gyrus and cerebellar cortex. During the anxietyinducing distractor, GAD patients showed significantly higher activity in the hippocampus, whereas they showed lower activities in the dorsolateral prefrontal cortex, fusiform gyrus, superior parietal gyrus, precuneus, superior occipital gyrus and cerebellar cortex. The blood-oxygen-level dependent signal changes in the dorsolateral prefrontal cortex in GAD patients during the anxiety-inducing distractor were negatively correlated with Anxiety Sensitivity IndexRevised scores.Conclusions: This study identified the specific brain areas associated with the interaction between emotional regulation and cognitive function associated with neutral and anxiety-inducing distractors during WM maintenance in GAD patients. These findings will be helpful for understanding the neural mechanism on the WM-related cognitive deficits and emotional dysfunction with typical anxiety symptoms in GAD.
Background & Aims
Despite a number of studies addressing the pathophysiology of hepatic IRI, a gold standard test for early diagnosis and evaluation of IRI remains elusive. This study investigated the metabolic alterations in a rat model of hepatic IRI using the in vivo hyperpolarized ¹³C MRS and metabolic imaging.
Methods
Hyperpolarized 13C MRS with IVIM‐DWI was performed on the liver of 7 sham‐operated control rats and 7 rats before and after hepatic IRI.
Results
The hepatic IRI‐induced rats showed significantly higher ratios of [1‐13C] alanine/pyruvate, [1‐13C] alanine/tC, [1‐13C] lactate/pyruvate and [1‐13C] lactate/tC compared with both sham‐operated controls and rats before IRI, whereas [1‐13C] pyruvate/tC ratio was decreased in IRI‐induced rats. In IVIM‐DWI study, apparent diffusion coefficient (ADC), f and D values in rats after hepatic IRI were significantly lower than those of rats before IRI and sham‐operated controls. The levels of [1‐13C] alanine and [1‐13C] lactate were negatively correlated with ADC, f and D values, whereas the level of [1‐13C] pyruvate was positively correlated with these values.
Conclusions
The levels of [1‐13C] alanine, [1‐13C] lactate and [1‐13C] pyruvate in conjunction with IVIM‐DWI will be helpful to evaluate the hepatic IRI as well as these findings can be useful in understanding the biochemical mechanism associated with hepatic damage.
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