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Objective To detect the neuronal network activity of specific brain areas in heroin addicts under craving state induced by heroin related cues with independent component analysis (ICA) of functional MRI (fMRI) data. Methods Fifteen heroin addicts,admitted to our hospital from February 2010 to December 2010, and 15 healthy controls were recruited in the case-control study; they were performed whole brain scan with 3.0Tesla MR scanner when being presented with heroin related cues.ICA was performed on these data and their neuronal network activities were compared. Results As compared with those in the controls,the bilateral prefrontal cortex,the left anterior cingulated cortex,the bilateral posterior cingulated cortex, the left inferior temporal gyrus and the left parietal lobe enjoyed obviously decreased activity, while bilateral nucleus accumbens, the right hippocampus, part of the temporal lobe and the occipital lobe enjoyed significantly increased activity (P＜0.05). Conclusion ICA is an advanced approach to identify fMRI data induced by related cues; the specific neuroanatomy mediated to cue-elicited heroin craving mostly locates in the learn-memory system and reward system,which involves the frontal cortex,the parietal lobe,the anterior eingulate,the posterior cingulate,the hippocampus and the nucleus accumbens.
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Objective To study the changes of amplitude of low-frequency fluctuation (ALFF) in blood oxygenation level dependent functional MRI (BOLD-fMPI) in non-lesional epilepsy (NLE),and discuss its underlying neurophysiological mechanism. Methods The BOLD-fMRI data of 16 patients with NLE and 15 normal volunteers were analyzed by ALFF. The amplitude of the blood oxygenation level dependent activation of the resting state brain was investigated. The brain structures showing increased and decreased ALFF in NLE patients were demonstrated by comparing to normal subjects with 2-sample t-test with threshold of P＜0.05. Results As compared with those in normal subjects,the regions showing increased ALFF in NLE patients were distributed in the right temporal lobe (Montreal Neurological Institute [MNI] coordinates:x=15,y=90,z=21),medial frontal lobe (MNI coordinates:0,24,-24),ventral anterior cingulated (MNI coordinates:-12,30,27) and right cerebellar hemisphere (MNI coordinates:-51,-57,-4); while the regions showing decreased ALFF covered the areas of the left cerebellar hemisphere (MNI coordinates:-48,-15,39),posterior cingulum gyrus (MNI coordinates:60,-21,33) and precuneus (MNI coordinates:-6,-54,66). Conclusion NLE patients show abnormal brain functional organization in resting state; the increased ALFF is considered to be the facilitation such as epileptic activity generation and propagation,while the decreased ALFF might be considered as the functional inhibition in these regions.
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Objective To explore the changes of functional connectivity of anterior cingulate cortex (ACC) in online game addicts during the resting state,and to analyze the function of ACC in the pathogenesis of online game addiction from a perspective of resting-state functional connectivity.Methods Seventeen online game addicts treated in our hospital from March 2011 to October 2011 were recruited as addiction group and 17 healthy controls at the same period were recruited as HC group.The baseline characteristics of all 34 subjects were investigated and compared between the addiction group and the HC group.All fMRI data were preprocessed after a resting-state fMRI scan,and then,the left and right anterior cingulate cortexes were selected as regions of interest (ROIs) to calculate the linear correlation between the ACC and the entire brain to compare the differences between the online game addicts and normal controls.Results Obvious differences between the addiction group and HC group were noted in hours and days of online game using and degree of thirst to play online games (P＜0.05);within the functional connectivity of ACC during the resting state,in contrast to the controls,the online game addicts showed increased connectivity with posterior cingulate,medium cingulate,midbrain,nucleus accumbens and supplementary motor area,but reduced connectivity with prefrontal cortex,temporal lobe and occipital lobe (P＜0.05).Conclusion Altered functional connectivity of the ACC reflects the dysfunction in ACC of online game addicts,which may be linked to the forming and maintaining of the online game addiction.
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Objective To explore the changes of functional connectivity of the prefrontal cortex in chronic heroin addicts under resting-state functional MRI (fMRI). Methods Resting fMRI examination was performed on 13 chronic heroin addicts and 14 healthy volunteers. After pre-processing the resting-state fMRI data, the prefrontal cortex was selected as the seed region, with which a whole-brain voxel temporal correlation in Iow frequency fMRI fluctuations was analyzed and the changes of functional connectivity of the prefrontal lobe in both chronic heroin addicts and healthy volunteers were calculated with SPM5 software. Results Compared with that in the control group, the functional connectivity between the left prefrontal cortex and the left hippocampus, right anterior cingulate, left middle frontal gyrus, right middle frontal gyrus, right precuneus in the heroin addiction group was significantly decreased. The functional connectivity between the right prefrontal cortex and the left orbital frontal cortex, left middle frontal gyrus in thc heroin addiction group was also significantly decreased as compared with that in the control group. Conclusion Functional connectivity of prefrontal cortex in chronic heroin addicts decreases, indicating that the prefrontal cortex may be involved in the maintenance of heroin addiction and relapse after withdrawal.
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Objective To explore the functional location of brain regions related to internet game addiction using clue-reaction model and functional magnetic resonance imaging (fMRI). Methods Twenty participants with internet game addiction and 20 control subjects without addiction were tested. They were presented with different internet game videos and the paired common life videos while undergoing fMRI. Questionnaire survey was employed to investigate their emotion changes after watching the game video; the activation data produced by the stimulations were collected through the measurement of blood-oxygen-level dependent signals in the brain. Subtraction algorithm was adopted to analyze the corresponding regions of interest. The activated brain areas stimulated by the internet game videos were determined. Results Compared with the common life video watching, the interact game video watching showed significantly different results of psychological assessments, including emotional states, degree of thirst, degree of liking and wishing to re-watch in the addiction group (P<0.05); while the interact game video watching only had a strong degree of re-watching as compared with the common life video watching in the control group. As compared with the common life videos, internet game videos could induce significantly high activation in the parietal lobe and visual cortex of the temporal lobe of the left brain region in the control group (P<0.05);while significantly activation of all the brain regions, except the nucleus accumbens and the caudate nucleus of the left brain region, was found in the internet game video watching as compared with those in the common life video watching in the addiction group (P<0.05). Conclusion The regions of brain activation of the internet game addiction can be determined by fMRI and these areas may be involved in the generation and maintenance of the internet game addiction.
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Objective To investigate the brain areas having functional connectivity with nucleus accumbens in heroin addicts with resting-state functional magnetic resonance imaging (fMRI), and explore the reward system of heroin addiction. Methods Fifteen participants with heroin addiction,voluntarily admitted to our drug rehabilitation center from June 2009 to March 2010, and 15 healthy controls at the same period were chosen in our study. Resting-state fMRI was performed on these patients; and then, the resting-state brain functional connectivity was also concluded by analyzing the left and right nucleus accumbens selected as regions of interests (ROIs). The corresponding brain areas having functional connections with ROIs were defined in the resting-state and the changes of functional connectivity were observed in heroin addicts. Results In the addiction group, the areas having functional connectivity with double nucleus accumbens included bilateral thalamus, the basal ganglia, the hippocampus, the midbrain and contralateral nucleus accumbens; and anterior cingulate cortex was also significantly correlated with left nucleus accumbens. However, in the control group, only the hippocampus and contralateral nucleus accumbens had these connection and their activity was much weaker than that in the addiction group. Conclusion In the resting-state, reward system of heroin addiction is constituted by the brain areas having functional connectivity with nucleus accumbens. And fMRI can be used to study the functional connections between the brain areas related to the heroin addiction from neuroimaging perspectives.
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Objective To explore the best target position and range of lesion for magnetic resonance image (MRI)-guided stereotactic cingulotomy. Methods We retrospectively analyzed the data of 71 patients underwent MRI-guided stereotactic cingulotomy, including 7 with chronic pain and 64 with psychiatric disorders. The cingulate gyrus target chose were 5 mm as X, 10-20 mm posterior tip of the lateral ventricle as Y, 2 mm above the roof of the lateral ventricle as Z. The target position and range of lesion were determined and revised by routine sagittal, axial and coronal stereotactic MRI scans. Radiofrequency thermocoagulation lesions were produced by inserting an electrode (1.6 mm diameter and 4 mm uninsulated tip) and heating them at a temperature of 75℃ for 100 seconds with a volume of lesion reaching 15 mm×10 mm×10 mm. Early postoperative MR or CT scans and long-term followed up examination were available for all cases. Results Postoperative images showed that the lesions were all in the anterior cingulate gyrus. Two patients reported transient urinary incontinence without permanent complications; significant pain relief appeared in all patients with chronic pain; In 64 with intractable psychiatric disorders, cure was showed in 3 obvious improvements in 35, improvement in 22, and no change in 4. Conclusion MRI-guided stereotactic cingulotomy offers substantial advantages by allowing direct visualization of the cingulate gyrus and surrounding structures and the best range of lesion is 10-25 mm from the anterior point of the corpus callosum, 10 mm above the bottle of cingulate gyrus and 10 mm in width.
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Objective To study the impairnlent of cognitive function and the change of P300 event-related potential(ERP)parameters in the patients with tumor in frontal lobe so as to investigate the role of the front lobe in cognitive function and the P300 production. Methods P300 examination and neuropsychological tests for cognition,including Stroop Test,Symbol Digit Modalities Test,and Verbal Fluency Test,et al,were performed in 31 patients with tumor in front lobe(left 15 and right 16)and 30 healthy controls. Results Compared with healthy controls, in the patients with front lobe tumor,cognitive function was degraded(P＜0.05),the latency of N3,P3 of P300 was significantly longer,and the amplitude of P3 was significantly lower(P＜0.05).Funhermore,the patients with tumor in right front lobe had signmcantly lower scores in cognitive tests compared with healthy controls (P＜0.05), but the ones with tumor in left front lobe were demonstrated obviously impaired only in Verbal Fluency Test(P＜0.05).Compared with healthy controls, the patients with tumor in eimer right or left flront lobe, the latency of N3,P3 of P300 was significantly longer,the amplitude of P3 was significantly lower(P＜0.05),while in the comparison of two sides, there was no statistically significantly difference in P300 (P＞0.05).Conclusions The cognitive function is obviously impaired in the patients with tumor in frontal lobe,and the impainnent is more serious in the ones with right frontal lobe tumor. Frontal lobe may be related to the generation and transmission of P300,and it is not significantly different in between left and right frontal lobes.
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Objective To explore the effect of Internet addiction on adolescent's attention.Methods Neuropsychological evaluations of attention function were done separately in 18 adolescents who met the diagnostic criterion for Internet addiction and in other 18 ones without Intemet addition tendency as a control group. With auditory and visual oddball paradigms, and stimulated by standard,target and novel stimuli, EEG was recorded and analyzed to get the event-related potential P300 and compare the latency and amplitude of P3a and P3b between the 2 groups. Results Compared with the controls, the attention of Internet addiction group was decreased significantly in neuropsychological evaluations. The latency of P3a potentials induced by novel stimulus was much shorter and the amplitude of it was higher in addiction group than in control group, but the latency of P3b potentials generated by target stimulus was prolonged and the amplitude decreased obviously. Conclusions Intemet addiction can cause damage to adolescent's attention function. There is a correlation between the attention impairment and the change of P300 potentials.
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Objective To evaluate the effect of surgical excision of the anterior temporal lobe and hippocampus on the cognitive function of patients with refractory temporal lobe epilepsy. Methods Nineteen patients with refractory temporal epilepsy received surgical excision of the anterior temporal lobe and hippocampus, and cognitive neuropsychologieal assessments were conducted, 3 and 6 months after the surgery, to evaluate the changes in the patinets' cognitive functions. Results Satisfactory effects were achieved in these patients after the operations. One patient showed temporary speech disorder, and two exhibited temporary euphoria. Patients with refractory temporal lobe epilepsy had severe cognitive dysfunctions involving especially in the intelligence, attention and memory, which were not aggravated after the operation, Conversely, the operation resulted in gradual improvement of some of the cognitive functions in these patients. Conclusion Patients with refractory temporal lobe epilepsy have cognitive dysfunction, and surgical excision of the anterior temporal lobe and hippocampus can cure or reduce seizure of temporal lobe epilepsy and improve the cognitive dysfunctions to some extent.