Unruptured Arteriovenous Malformations of Brain: An overview

Arteriovenous malformations are congenital lesions that occur most commonly in the supratentorial region. These space-occupying vascular lesions consist of multiple arteries and veins, connecting as a fistula without an intervening normal capillary bed. Typically, AVM’s are single lesions, except when associated with hereditary hemorrhagic telangiectasia. The histology includes clusters of normal or dilated arteries and abnormal veins with calcification and occasionally some prior haemorrhage

Differences in the neural networks of thermal sensation with and without evaluation process

Several neuroimaging studies have analyzed the neural networks involved in thermal sensation. In some of these studies, participants were instructed to evaluate and report the thermal sensation using a point scale, visual analog scale, or other psychophysical rating tool while the imaging data were obtained. Therefore, the imaging data may reflect signals involved in the processes of both sensation and evaluation. The present study aimed to discriminate the neural networks involved in identifying different temperature stimuli and the two different processes by using functional magnetic resonance imaging (fMRI). We applied four different thermal stimuli (“hot,” 40C; “warm,” 36 °C, “cool,” 27 °C; and “cold,” 22 °C) to the left forearm using Peltier apparatus. During the stimuli, participants were instructed to either evaluate (evaluation task) or not evaluate (no-evaluation task) and report the thermal sensation. We found brain activation in the medial prefrontal cortex/anterior cingulate gyrus, inferior frontal gyrus, bilateral insula, and posterior parietal cortex during the four thermal stimuli both with and without the evaluation task. Additionally, the stimuli with the evaluation task induced stronger and broader activation, including the right fronto-parietal and anterior insula regions. These results indicate that thermal stimulation activates the common neural networks, independent of the thermal conditions and evaluation process. Moreover, the evaluation process may increase the attention to the thermal stimuli, resulting in the activation of the right lateralized ventral attentional network

Larger right posterior parietal volume in action video game experts: a behavioral and voxel-based morphometry (VBM) study.

Recent studies suggest that action video game players exhibit superior performance in visuospatial cognitive tasks compared with non-game players. However, the neural basis underlying this visuospatial cognitive performance advantage remains largely unknown. The present human behavioral and imaging study compared gray matter volume in action video game experts and non-experts using structural magnetic resonance imaging and voxel-based morphometry analysis. The results revealed significantly larger gray matter volume in the right posterior parietal cortex in experts compared with non-experts. Furthermore, the larger gray matter volume in the right posterior parietal cortex significantly correlated with individual performance in a visual working memory task in experts. These results suggest that differences in brain structure may be linked to extensive video game play, leading to superior visuospatial cognitive performance in action video game experts

Usefulness of a simplified management scheme for paraclinoid aneurysms based on a modified classification

Background: Our objective was to set up a management-oriented classification for paraclinoid aneurysms, and then design and apply a simplified management scheme according to each group defined by this classification. Methods: Paraclinoid aneurysms were classified as group I (supraophthalmic artery), group II (ophthalmic artery) and group III (infraophthalmic artery) aneurysms intradurally. Between January 2005 and December 2006, 86 cases with 89 paraclinoid aneurysms were treated. There were 35 (40.2%) aneurysms in group I (20 in group Ia, 15 in group Ib), 32 (36.8%) in group II and 20 (23%) in group III. Results: In group I aneurysms, 20 (57.1%) were treated by clipping or/and wrapping, while 15 (42.9%) were managed by coiling. In group II aneurysms, 20 (62.5%) were treated by clipping and 12 (37.5%) by coiling. The contralateral approach was performed for 4 (6%) aneurysms in groups I and II. All 20 group III aneurysms were treated by coiling. The overall rate of permanent complications was 4.6%. The rate of complete occlusion was 92.5% in surgical cases and 55.6% in endovascular ones. The overall outcomes in the treatment of paraclinoid aneurysms were excellent (GOS = 5, 95.4%). Conclusion: Based on our modified classification of paraclinoid aneurysms, a simplified management scheme was designed and applied. For group I (supraophthalmic artery) and group II (ophthalmic artery) aneurysms, surgical clipping or/and wrapping should be the first choice of treatment, while for group III (infraophthalmic artery) aneurysms, endovascular coiling should be the best modality. Additionally, individualizing the treatment planning might contribute to better results. Copyright (C) 2008 S. Karger AG, Basel

Visual working memory (WM) task.

<p>A: Experimental paradigms of the visual WM task. First, a sample array was presented for 100 ms on the computer display. Each sample array consisted of two, four, or six colored squares at randomized positions (in the present figure, the size of sample array is 6). After a 1,000-ms retention interval, the test stimulus was presented for 2,000ms at one of the sample array positions. Each test cue consisted of two colored rectangles that were half the width of the sample squares. Participates were asked to determine which test stimulus color was the same as the sample square that had been shown at that position. B: Behavioral results from the visual WM task. Data are presented as the group mean of percentage of correct responses, with bars indicating standard errors. The red and blue circles indicate data from AVG experts and non-experts, respectively. The horizontal axis represents sample array size. The percentage of correct responses in AVG experts is significantly greater than in the non-experts in the task with an array size of six. * indicates <i>p</i><0.05 after correction for multiple comparisons (Bonferroni correction).</p