Bilateral Middle Frontal Gyrus Research Articles

Interhemispheric Connectivity in Drug-Naive Benign Childhood Epilepsy With Centrotemporal Spikes

Decreased intelligence quotients (IQ) have been consistently reported in drug-naive benign childhood epilepsy with centrotemporal spikes (BECTS). We aimed to identify the neurophysiological basis of IQ deficits by studying interhemispheric and anatomical functional connectivity in BECTS patients. Resting-state functional and structural magnetic resonance images were acquired in 32 children with BECTS and 25 healthy controls. The IQ was estimated using Wechsler Intelligence Scale for Children China-Revised. The functional connectivity between bilateral homotopic voxels was calculated and compared between groups. Homotopic regions showing abnormal functional connectivity in patients were adopted as regions of interest for analysis by diffusion-tensor imaging tractography. The fractional anisotropy, fiber length, and fiber number were compared between groups. Abnormal homotopic connectivities were correlated with IQ in BECTS patients. Compared with control subjects, patients showed decreased IQ, and decreased voxel-mirrored homotopic connectivity (VMHC) in the bilateral frontal lobule and cerebellum. The performance and full scale IQ significantly increased with the VMHC strength of the middle frontal gyrus (MFG) in controls but not in BECTS patients. A significant negative correlation was observed between VMHC in the premotor cortex and disease duration. Microstructural features within white matter tracts connecting functionally abnormal regions did not reveal any differences between groups. This study provides preliminary evidence for the disrupted functional cooperation between hemispheres in children with BECTS. The findings suggest that the hyposynchrony between the bilateral MFG may be involved in the decreased IQ of BECTS patients.

Diffusion tensor imaging study of brain structural integrity in patients with posttraumatic stress disorders

ABSTRACT Objective: To explore the changes of brain structural integrity in patients with posttraumatic stress disorders (PTSD) using diffusion tensor imaging (DTI). Patients and Methods: Twenty PTSD patients who underwent a traffic accident and 20 non-PTSD patients were selected from the Department of Rehabilitation, Southwest Hospital of the Third Military Medical University in Chongqing, China, between January 2007 and December 2013. Using voxel-based analysis, we investigated fractional anisotropy (FA) and mean diffusivity (MD) in PTSD patients. Linear correlation analysis was employed to detect the relationship between FA and MD in regions of interest, and to obtain PTSD Checklist-Civilian Version scores. Results: When compared with the non-PTSD group, the FA of PTSD patients significantly decreased in bilateral middle frontal gyrus, right superior frontal gyrus, and left putamen (P < 0.005). The MD of PTSD patients increased mainly in bilateral middle frontal gyrus, anterior cingulate cortex, left amygdala, left insula, and left globus pallidus (P <0.005). Pearson correlation analysis revealed that the FA value of right middle frontal cortex (MFC) had a significant negative correlation with the PTSD score (r = −0.628, P = 0.039), while the MD value of right MFC and left amygdala had a significant positive correlation with the PTSD score (r = 0.630, P = 0.047; r = 0.632, P = 0.041, respectively). Conclusion: The abnormalities of structural integrity in the amygdala and middle frontal gyrus may be the structural foundation of emotional and memory dysfunction in PTSD.

Disturbed spontaneous brain activity pattern in patients with primary angle-closure glaucoma using amplitude of low-frequency fluctuation: a fMRI study.

ObjectiveThe aim of this study is to use amplitude of low-frequency fluctuation (ALFF) as a method to explore the local features of spontaneous brain activity in patients with primary angle -closure glaucoma (PACG) and ALFFs relationship with the behavioral performances.MethodsA total of twenty one patients with PACG (eight males and 13 females), and twenty one healthy subjects (nine males and twelve females) closely matched in age, sex, and education, each underwent a resting-state functional magnetic resonance imaging scan. The ALFF method was used to assess the local features of spontaneous brain activity. The correlation analysis was used to explore the relationships between the observed mean ALFF signal values of the different areas in PACG patients and the thickness of the retinal nerve fiber layer (RNFL).ResultsCompared with the healthy subjects, patients with PACG had significant lower ALFF areas in the left precentral gyrus, bilateral middle frontal gyrus, bilateral superior frontal gyrus, right precuneus, and right angular gyrus, and higher areas in the right precentral gyrus. In the PACG group, there were significant negative correlations between the mean ALFF signal value of the right middle frontal gyrus and the left mean RNFL thickness (r=−0.487, P=0.033), and between the mean ALFF signal value of the left middle frontal gyrus and the right mean RNFL thickness (r=−0.504, P=0.020).ConclusionPACG mainly involved in the dysfunction in the frontal lobe, which may reflect the underlying pathologic mechanism of PACG.

Thalamic resting-state functional connectivity: disruption in patients with type 2 diabetes.

To explore the disrupted thalamic functional connectivity and its relationships with cognitive dysfunction in type 2 diabetes mellitus (T2DM) by using resting-state functional magnetic resonance imaging (fMRI). A total of 38 T2DM patients and 39 well-matched healthy controls participated in the resting-state fMRI and T1-weighted imaging scans. The thalamic functional connectivity was characterized by using a seed-based whole-brain correlation method and compared T2DM patients with healthy controls. Pearson correlation analysis was performed between thalamic functional connectivity and clinical data. When compared with healthy controls, T2DM showed significantly decreased functional connectivity of the thalamus mainly in the right middle temporal gyrus (MTG), right precentral gyrus and bilateral occipital cortex; Increased functional connectivity of the thalamus was detected in the left cerebellum, bilateral middle frontal gyrus and middle cingulate gyrus (p<0.05, corrected for AlphaSim). In T2DM patients, the decreased thalamic functional connectivity of the right MTG was positively associated with the Verbal Fluency Test score (r=0.438, p=0.006). Meanwhile, the decreased thalamic functional connectivity of the right cuneus was positively correlated with the Complex Figure Test-delayed score and negatively correlated with the Trail Making Test-B score, respectively (r=0.492, p=0.002; r=-0.504, p=0.001). Moreover, there was no structural damage in the thalamus of T2DM patients. T2DM patients develop disrupted thalamocortical functional connectivity, which is associated with cognitive impairment in selected brain regions. Resting-state thalamocortical connectivity disturbance may play a central role in the underlying neuropathological process of T2DM-related cognitive dysfunction.

Alterations in the functional connectivity of a verbal working memory-related brain network in patients with left temporal lobe epilepsy

The aim of this study was to investigate the alterations in a verbal working memory (VWM)-related network in left temporal lobe epilepsy (lTLE) at rest. We evaluated 14 patients with lTLE and 14 control subjects by resting-state functional connectivity (RSFC). The region of interest was defined by the voxel with the highest Z-score during a VWM task according to functional magnetic resonance imaging in 16 healthy volunteers. Our study revealed that the network of RSFC was similar to the task-induced network in the healthy volunteers. Moreover, the patients with lTLE exhibited significantly decreased RSFC in the bilateral middle frontal gyrus, the inferior frontal gyrus and the inferior parietal lobule at rest compared to the control subjects. We found no significant correlation between the mean reaction time of the accurate responses in a 2-back task and the mean z-values within the regions that exhibited significant differences in RSFC at the individual level. The alterations in FCs of VWM-related network in lTLE suggested that epileptiform discharges can damage the brain regions, both local focus and remote areas and that the alterations were not associated with VWM performance.

An fMRI study of the functional mechanisms of Stroop/reverse-Stroop effects

Many previous behavioral inhibition studies have employed the classic Stroop and reverse-Stroop paradigm. Although an experimental dissociation has been demonstrated between Stroop interference (SI) and reverse-Stroop interference (RI), the mechanisms that underlie these phenomena remain unclear. In this study, we used functional magnetic resonance imaging (fMRI) to compare the functional mechanisms of SI and RI. We identified the brain regions activated by the Stroop word-color matching task using four tests: the Stroop control test (Test 1), Stroop test (Test 2), reverse-Stroop control test (Test 3), and reverse-Stroop test (Test 4). Neuroimaging results revealed that SI elicited activation in the bilateral middle frontal gyrus (BA9). In contrast, a number of other regions, including the bilateral middle frontal gyrus (BA 9 and BA10), medial frontal gyrus (BA 8), and cingulate gyrus (BA6 and BA 32) exhibited significant activation during RI. Our results indicate that there is a dissociation between the types of interference and brain activation. These findings suggest that SI and RI interference can be attributable to different neural mechanisms. It also suggests that the prefrontal cortex and the cingulate cortex are differentially sensitive to various types of interference, and that the reverse-Stroop task may be more useful than the Stroop task for evaluating interference control in psychiatric patients with frontal dysfunction.

Resting-state functional MRI study on properties of emotional memory networks in late-life depression

Objective To explore properties of emotion memory circuits in late-life depression, and differences in functional connectivity of emotional memory network between late-life depression and healthy controls who were investigated by resting-state fMRI. Methods Eighteen late life depression patients and twenty four healthy controls were involved in our study. Resting-state functional MRI data were acquired via 3.0T MRI scanner. Functional MRI data were analyzed. Behavioral data were acquired during retrieval. The independent samples t-test of functional MRI data and ANOVA of behavioral performance were performed with AFNI and SPSS 13.0 statistical software, respectively. Results Decreased connectivities had been shown in depression, including amygdala-thalamus, amygdala-left inferior frontal gyrus, supramarginal gyrus-dorsomedial prefrontal cortex/anterior cingulate cortex (ACC), middle temporal gyrus-middle frontal gyrus and thalamus-inferior frontal gyrus/left frontal eye fields (FEF) connectivity; while increased connectivities included hippocampus-middle temporal gyrus, hippocampus-ventromedial prefrontal cortex/middle temporal gyrus/ACC/FEF, middle temporal gyrus- fusiform gyrus/FEF, insula-middle temporal gyrus/FEF and thalamus- caudate connectivity (P<0.05). For depression, global hubs included left amygdale, right hippocampus, right middle frontal gyrus, and right insula. For healthy group, global hubs included bilateral amygdale and middle frontal gyrus, right anterior inferior parietal lobe and right insula. Conclusion There are common and different characters in functional connectivity of emotional memory network between depression and healthy control. Global hub function decreases in the right amygdale and left inferior frontal gyrus, while right hippocampus shows compensatory increase. Key words: Depression; Emotional memory; Brain connectivity; Resting-state fMRI

A preliminary fMRI study of a novel self-paced written fluency task: observation of left-hemispheric activation, and increased frontal activation in late vs. early task phases.

Neuropsychological tests of verbal fluency are very widely used to characterize impaired cognitive function. For clinical neuroscience studies and potential medical applications, measuring the brain activity that underlies such tests with functional magnetic resonance imaging (fMRI) is of significant interest—but a challenging proposition because overt speech can cause signal artifacts, which tend to worsen as the duration of speech tasks becomes longer. In a novel approach, we present the group brain activity of 12 subjects who performed a self-paced written version of phonemic fluency using fMRI-compatible tablet technology that recorded responses and provided task-related feedback on a projection screen display, over long-duration task blocks (60 s). As predicted, we observed robust activation in the left anterior inferior and medial frontal gyri, consistent with previously reported results of verbal fluency tasks which established the role of these areas in strategic word retrieval. In addition, the number of words produced in the late phase (last 30 s) of written phonemic fluency was significantly less (p < 0.05) than the number produced in the early phase (first 30 s). Activation during the late phase vs. the early phase was also assessed from the first 20 s and last 20 s of task performance, which eliminated the possibility that the sluggish hemodynamic response from the early phase would affect the activation estimates of the late phase. The last 20 s produced greater activation maps covering extended areas in bilateral precuneus, cuneus, middle temporal gyrus, insula, middle frontal gyrus and cingulate gyrus. Among these areas, greater activation was observed in the bilateral middle frontal gyrus (Brodmann area BA 9) and cingulate gyrus (BA 24, 32) likely as part of the initiation, maintenance, and shifting of attentional resources. Consistent with previous pertinent fMRI literature involving overt and covert verbal responses, these findings highlight the promise and practicality of fMRI of written phonemic fluency.

Consistency of FDG uptake on 18F-FDG PET/CT and regional homogeneity on functional MRI in major depression disorder patients

Objective To investigate the changes of cerebral regional glucose metabolism and regional homogeneity (ReHo) and their relation in patients with major depression disorder (MDD) using 18F-FDG PET/CT and functional MRI (fMRI). Methods A total of 18 MDD patients (6 males, 12 females, age: (33.00±7.59) years) and 17 healthy controls (6 males, 11 females, age: (34.59±8.96) years) underwent 18F-FDG PET/CT and fMRI. The changes of glucose metabolism on PET and ReHo on fMRI were analyzed individually by SPM and ReHo fMRI 1.0 software. Pearson correlation analysis was used. Results Compared with the glucose metabolism of control subjects, those of MDD patients decreased in the bilateral superior, middle and inferior frontal gyri, bilateral superior and middle temporal gyri, bilateral anterior cingulate cortices, bilateral putamina and caudate nuclei and the left pallidum. Meanwhile the glucose metabolism increased in the bilateral hippocampi and the left thalamus. The ReHo in MDD patients decreased in bilateral superior and middle frontal gyri, left pallidum, bilateral putamina, left anterior cingulate cortex, whereas increased ReHo was found in right hippocampus and right thalamus. The SUV of bilateral superior, middle and inferior frontal gyri, bilateral superior and middle temporal gyri, bilateral putamina, left caudate, left pallidum, left anterior cingulate cortex, bilateral hippocampi and bilateral thalami were correlated with ReHo (r=0.51-0.83, all P 0.05). Conclusion There may be relative characteristic models of abnormal cerebral metabolism and cerebral dysfunction impairment in MDD patients, and the changes of cerebral regional glucose metabolism may be correlated with the changes of ReHo. Key words: Depressive disorder; Brain; Tomography, emission-computed; Tomography, X-ray computed; Magnetic resonance imaging; Deoxyglucose

Brain and behavioral evidence for altered social learning mechanisms among women with assault-related posttraumatic stress disorder

Current neurocircuitry models of PTSD focus on the neural mechanisms that mediate hypervigilance for threat and fear inhibition/extinction learning. Less focus has been directed towards explaining social deficits and heightened risk of revictimization observed among individuals with PTSD related to physical or sexual assault. The purpose of the present study was to foster more comprehensive theoretical models of PTSD by testing the hypothesis that assault-related PTSD is associated with behavioral impairments in a social trust and reciprocity task and corresponding alterations in the neural encoding of social learning mechanisms. Adult women with assault-related PTSD (n = 25) and control women (n = 15) completed a multi-trial trust game outside of the MRI scanner. A subset of these participants (15 with PTSD and 14 controls) also completed a social and non-social reinforcement learning task during 3T fMRI. Brain regions that encoded the computationally modeled parameters of value expectation, prediction error, and volatility (i.e., uncertainty) were defined and compared between groups. The PTSD group demonstrated slower learning rates during the trust game and social prediction errors had a lesser impact on subsequent investment decisions. PTSD was also associated with greater encoding of negative expected social outcomes in perigenual anterior cingulate cortex and bilateral middle frontal gyri, and greater encoding of social prediction errors in the left temporoparietal junction. These data suggest mechanisms of PTSD-related deficits in social functioning and heightened risk for re-victimization in assault victims; however, comorbidity in the PTSD group and the lack of a trauma-exposed control group temper conclusions about PTSD specifically.

Characterization of resting-state fMRI-derived functional connectivity in patients with deficiency versus excess patterns of major depression

Patients with major depression (MD) experience a variety of emotional and mental problems accompanied by characteristic clinical symptoms. Based on traditional Chinese medicine (TCM) notions, the clinical appearance of MD can be divided into two syndromes, namely a deficiency pattern (DP) and an excess pattern (EP), depending on the patient's clinical symptoms, pulse, and lingual signs. Brain functional neuroimaging has demonstrated cerebral activity abnormalities in MD patients. However, such abnormalities have not been linked to particular symptoms of MD. The objective of this work was to compare functional connectivity of the posterior cingulate cortex (PCC) across MD patients with DP, MD patients with EP, and normal control (NC) subjects in a resting-state functional magnetic resonance imaging (rs-fMRI) study. Participants (24 DP patients, 21 EP patients, and 20 NCs) underwent rs-fMRI scans. Whole-brain functional connectivity of a seed in the PCC was then mapped for each subject. Functional connectivity differences among the three studied groups were analyzed statistically. Compared to the NC group, DP patients had decreased functional connectivity of the PCC with the right middle temporal gyrus and bilateral precuneus, as well as increased functional connectivity of the PCC with the bilateral middle frontal gyrus. Meanwhile, compared to the NC group, the EP group had decreased functional connectivity of the PCC with both the middle temporal gyrus and bilateral precuneus, as well as increased functional connectivity of the PCC with the bilateral superior frontal gyrus. Relative to the DP group, the EP group had reduced functional connectivity of the PCC with the bilateral cerebellum and left superior frontal gyrus. Functional connectivity changes differ between MD patients with different TCM syndrome types, suggesting that the TCM clinical syndromes of MD are associated with correlates in cerebral functional activity.

Default mode network in childhood absence epilepsy by 3.0T magnetic resonance imaging

To explore the default mode network (DMN) in childhood absence epilepsy (CAE) patients and examine their correlations between functional connectivity (FC) and clinical characteristics. Fourteen CAE patients and 14 healthy volunteers were prospectively recruited from Henan Provincial People's Hospital from September 2012 to June 2014. FC in DMN of each group, between-group comparison of DMN FC and their relationships with clinical characteristics were respectively analyzed with 3.0T resting-state functional magnetic resonance imaging (fMRI) FC analysis seeding at bilateral precuneus/posterior cingulate cortex (PCC). Seeding at bilateral precuneus/posterior cingulate cortex (PCC), positive connection was found in bilateral angular gyrus, bilateral superior parietal gyrus, bilateral superior and middle frontal gyrus, bilateral superior medial frontal gyrus, bilateral middle temporal gyrus and bilateral superior and middle occipital gyrus in controls. However, positive connection in CAE patients was observed in bilateral superior parietal gyrus and bilateral superior occipital gyrus. Between-group analysis of DMN connectivity revealed a reduction of DMN FC in bilateral medial orbitofrontal cortex, bilateral anterior cingulate cortex, bilateral superior frontal gyrus, bilateral middle frontal gyrus and left caudate in CAE patients. Moreover, increased DMN FC was present in right paracentral lobule and right middle cingulate gyrus. FC between PCC and bilateral medial orbitofrontal cortex or bilateral superior/middle frontal gyrus correlated negatively with disease duration, but there was no correlation with seizure frequency or initial age. Brain's default mode network in childhood absence epilepsy is impaired, presumably, as a result of unconsciousness and cognitive impairment during absence seizure. Abnormal DMN activities may be a biomaker of disease progress in absence epilepsy.

Differential effects of androgenic and anti-androgenic progestins on fusiform and frontal gray matter volume and face recognition performance

Effects of oral hormonal contraceptives (OC) on human brain structure and behavior have only recently become a focus of research. Two explorative reports observed larger regional gray matter (GM) volumes in OC users within the prefrontal cortex, ACC and fusiform gyri, as well as parahippocampal gyri, hippocampus and cerebellum. These studies did however not control for the androgenicity of the progestin compound of OC, did not take into consideration how long OC users had been on their OC, and did not control for age differences between the OC group and the naturally cycling group. We compared 20 naturally cycling women during their early follicular cycle phase to 18 users of OC containing androgenic progestins and 22 users of OC containing anti-androgenic progestins. When controlling for age, we found that in users of anti-androgenic progestins relative GM volumes within the bilateral fusiform gyri, fusiform face area (FFA), parahippocampal place area (PPA) and cerebellum, were significantly larger than in naturally cycling women, while in users of androgenic progestins, relative as well as absolute volumes within the bilateral middle and superior frontal gyri were significantly smaller compared to naturally cycling women. These morphological changes were related to performance in a face recognition task. Face recognition performance was significantly better in users of anti-androgenic progestins compared to the other groups and significantly related to absolute as well as relative GM volumes in the FFA and PPA. Total GM volume, as well as absolute GM volumes within the bilateral fusiform gyri, FFA, hippocampus, parahippocampus, PPA, middle frontal gyri and ACC were significantly larger, the longer the duration of OC use, particularly in users of androgenic progestins. Morphological differences between active and inactive pill phase were observed in users of androgenic progestins. These findings suggest differential effects of androgenic and anti-androgenic progestins on human brain structure.

Using functional magnetic resonance imaging to explore the flashed face distortion effect.

The flashed face distortion (FFD) effect was coined by Tangen, Murphy, and Thompson (2011) in their second-place winner of the 2012 Best Illusion of the Year Contest. The FFD arises when people view various eye-aligned faces that are sequentially flashed in the visual periphery, and gradually the faces appear to be deformed and grotesque. In this functional magnetic resonance imaging (fMRI) study, participants were presented with four conditions: (a) one face pair changing only its illumination; (b) two and (c) three alternating face pairs; and (d) nonrepeated face pairs. Participants rated the magnitude of each illusion immediately after each block. Results showed that the receptive region of the early visual cortex (V1-V4), and category-selective areas such as the fusiform face area (FFA) and occipital face area (OFA), responded proportionally to the participants' rated FFD strength. A random-effects voxelwise analysis further revealed positively correlated areas (including the medial and superolateral frontal areas) and negatively correlated areas (including the precuneus, postcentral gyrus, right insula, and bilateral middle frontal gyri) with respect to participants' ratings. Time series correlations among these nine ROIs (four positive and five negative) indicated that most participants showed a clustering of the two separate ROI types. Exploratory factor analysis (EFA) also demonstrated the segregation of the positive and negative ROIs; additionally, two subsystems were identified within the negative ROIs. These results suggest that the FFD is mediated by at least two networks: one that is likely responsible for perception and another that is likely responsible for subjective feelings and engagement.

Multimodal magnetic resonance imaging study of treatment-naïve adults with attention-deficit/hyperactivity disorder.

BackgroundAttention-Deficit/Hiperactivity Disorder (ADHD) is a prevalent disorder, but its neuroanatomical circuitry is still relatively understudied, especially in the adult population. The few morphometric magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) studies available to date have found heterogeneous results. This may be at least partly attributable to some well-known technical limitations of the conventional voxel-based methods usually employed to analyze such neuroimaging data. Moreover, there is a great paucity of imaging studies of adult ADHD to date that have excluded patients with history of use of stimulant medication.MethodsA newly validated method named optimally-discriminative voxel-based analysis (ODVBA) was applied to multimodal (structural and DTI) MRI data acquired from 22 treatment-naïve ADHD adults and 19 age- and gender-matched healthy controls (HC).ResultsRegarding DTI data, we found higher fractional anisotropy in ADHD relative to HC encompassing the white matter (WM) of the bilateral superior frontal gyrus, right middle frontal left gyrus, left postcentral gyrus, bilateral cingulate gyrus, bilateral middle temporal gyrus and right superior temporal gyrus; reductions in trace (a measure of diffusivity) in ADHD relative to HC were also found in fronto-striatal-parieto-occipital circuits, including the right superior frontal gyrus and bilateral middle frontal gyrus, right precentral gyrus, left middle occipital gyrus and bilateral cingulate gyrus, as well as the left body and right splenium of the corpus callosum, right superior corona radiata, and right superior longitudinal and fronto-occipital fasciculi. Volumetric abnormalities in ADHD subjects were found only at a trend level of significance, including reduced gray matter (GM) in the right angular gyrus, and increased GM in the right supplementary motor area and superior frontal gyrus.ConclusionsOur results suggest that adult ADHD is associated with neuroanatomical abnormalities mainly affecting the WM microstructure in fronto-parieto-temporal circuits that have been implicated in cognitive, emotional and visuomotor processes.

Dissociation of functional and anatomical brain abnormalities in unaffected siblings of schizophrenia patients

ObjectiveSchizophrenia patients and their unaffected siblings share similar brain functional and structural abnormalities. However, no study is engaged to investigate whether and how functional abnormalities are related to structural abnormalities in unaffected siblings. This study was undertaken to examine the association between functional and anatomical abnormalities in unaffected siblings. MethodsForty-six unaffected siblings of schizophrenia patients and 46 age-, sex-, and education-matched healthy controls underwent structural and resting-state functional magnetic resonance imaging scanning. Voxel-based morphometry (VBM), amplitude of low-frequency fluctuation (ALFF) and fractional ALFF (fALFF) were utilized to analyze imaging data. ResultsThe VBM analysis showed gray matter volume decreases in the fronto-temporal regions (the left middle temporal gyrus and right inferior frontal gyrus, orbital part) and increases in basal ganglia system (the left putamen). Functional abnormalities measured by ALFF and fALFF mainly involved in the fronto-limbic-sensorimotor circuit (decreased ALFF in bilateral middle frontal gyrus and the right middle cingulate gyrus, and decreased fALFF in the right inferior frontal gyrus, orbital part; and increased ALFF in the left fusiform gyrus and left lingual gyrus, and increased fALFF in bilateral calcarine cortex). No significant correlation was found between functional and anatomical abnormalities in the sibling group. ConclusionsA dissociation pattern of brain regions with functional and anatomical abnormalities is observed in unaffected siblings. SignificanceOur findings suggest that brain functional and anatomical abnormalities might be present independently in unaffected siblings of schizophrenia patients.

Alterations of regional homogeneity in pediatric bipolar depression: a resting-state fMRI study.

BackgroundPediatric bipolar disorder (PBD) has attracted increasing attentions due to its high prevalence and great influence on social functions of children and adolescents. However, the pathophysiology underlying PBD remains unclear. In the present study, the resting-state functional magnetic resonance imaging (fMRI) was used to detect abnormalities of baseline brain functions in depressed PBD youth.MethodsSeventeen youth with PBD-depression aged 10 - 18 years old and 18 age- and sex-matched normal controls were recruited in this study. The fMRI data under resting state were obtained on a Siemens 3.0 Tesla scanner and were analyzed using the regional homogeneity (ReHo) method. Correlations between the ReHo values of each survived area and the severity of depression symptoms in patients were further analyzed.ResultsAs compared with the control group, PBD-depression patients showed decreased ReHo in the medial frontal gyrus, bilateral middle frontal gyrus and middle temporal gyrus, and the right putamen. Significant negative correlations of the mood and feelings questionnaire scores with mean ReHo values in the medial frontal gyrus and the right middle frontal gyrus in PBD-depression patients were observed.ConclusionOur results suggest that extensive regions with altered baseline brain activities are existed in PBD-depression and these brain regions mainly locate in the fronto-limbic circuit and associated striatal structures. Moreover, the present findings also add to our understanding that there could be unique neuropathophysiological mechanisms underlying PBD-depression.

Intensive cognitive training in schizophrenia enhances working memory and associated prefrontal cortical efficiency in a manner that drives long-term functional gains

We investigated whether intensive computerized cognitive training in schizophrenia could improve working memory performance and increase signal efficiency of associated middle frontal gyri (MFG) circuits in a functionally meaningful manner. Thirty schizophrenia participants and 13 healthy comparison participants underwent fMRI scanning during a letter N-back working memory task. Schizophrenia participants were then randomly assigned to either 80h (16weeks) of cognitive training or a computer games control condition. After this intervention, participants completed a second fMRI N-back scanning session. At baseline, during 2-back working memory trials, healthy participants showed the largest and most significant activation in bilateral MFG, which correlated with task performance. Schizophrenia participants showed impaired working memory, hypoactivation in left MFG, and no correlation between bilateral MFG signal and task performance. After training, schizophrenia participants improved their 2-back working memory performance and showed increased activation in left MFG. They also demonstrated a significant association between enhanced task performance and right MFG signal, similar to healthy participants. Both task performance and brain activity in right MFG after training predicted better generalized working memory at 6-month follow-up. Furthermore, task performance and brain activity within bilateral MFG predicted better occupational functioning at 6-month follow-up. No such findings were observed in the computer games control participants. Working memory impairments in schizophrenia and its underlying neural correlates in MFG can be improved by intensive computerized cognitive training; these improvements generalize beyond the trained task and are associated with enduring effects on cognition and functioning 6months after the intervention.

Unawareness of bipolar disorder: the role of the cingulate cortex

Reduced awareness of illness is a well-known phenomenon that has been understudied in remitted patients with bipolar disorder. In particular, the relationship between reduced awareness and executive dysfunction is an intriguing question that has yet to be resolved. The aim of the current study is to analyze the link between reduced awareness, brain dysfunction, and concomitant cognitive-behavioral disturbances from a neurocognitive perspective. In previous studies, we demonstrated the role of the anterior cingulate cortex (ACC) in the unawareness of distinct pathologies that exhibit overlapping symptoms in the context of overlapping circuit-specific dysfunction. Given the clinical importance of the results obtained, the present study considers six aware and four unaware remitted bipolar disorder patients. Cingulate functionality was assessed with functional magnetic resonance imaging while patients performed a go/no-go task. Patients were also studied on an overall cognitive task battery and with behavioral assessment of mood changes in terms of apathy and disinhibited behavior. Unaware patients showed frontoparietal hypo-perfusion, with a significant reduction of task-sensitive activity in the bilateral superior and middle frontal gyrus, putamen, insular, and ACCs.

Cocaine dependent individuals with attenuated striatal activation during reinforcement learning are more susceptible to relapse

Cocaine-dependent individuals show altered brain activation during decision making. It is unclear, however, whether these activation differences are related to relapse vulnerability. This study tested the hypothesis that brain-activation patterns during reinforcement learning are linked to relapse 1 year later in individuals entering treatment for cocaine dependence. Subjects performed a Paper-Scissors-Rock task during functional magnetic resonance imaging (fMRI). A year later, we examined whether subjects had remained abstinent (n=15) or relapsed (n=15). Although the groups did not differ on demographic characteristics, behavioral performance, or lifetime substance use, abstinent patients reported greater motivation to win than relapsed patients. The fMRI results indicated that compared with abstinent individuals, relapsed users exhibited lower activation in (1) bilateral inferior frontal gyrus and striatum during decision making more generally; and (2) bilateral middle frontal gyrus and anterior insula during reward contingency learning in particular. Moreover, whereas abstinent patients exhibited greater left middle frontal and striatal activation to wins than losses, relapsed users did not demonstrate modulation in these regions as a function of outcome valence. Thus, individuals at high risk for relapse relative to those who are able to abstain allocate fewer neural resources to action-outcome contingency formation and decision making, as well as having less motivation to win on a laboratory-based task.