Left Superior Parietal Lobule Research Articles

Dynamic functional connectivity patterns predict early antidepressant treatment response in drug-naïve, first-episode adolescent MDD

ObjectiveAdolescents with major depressive disorder (MDD) exhibit abnormal dynamic functional connectivity (dFC) patterns, but it remains unclear whether these aberrant dFC patterns are linked to antidepressant treatment. The aim of this study is to investigate whether dFC patterns will be changed by antidepressant treatment, as well as whether baseline dFC pattern could predict treatment response in adolescent MDD patients.MethodWe included 35 drug-naïve, first-episode MDD adolescents (age 14.40 ± 1.24; 8 males and 27 females) and 24 healthy controls (HCs, age 14.21 ± 1.41; 11 males and 13 females). All MDD adolescents received 6 weeks of antidepressant treatment. Resting state and T1 MRI data were collected in MDD adolescents before and after treatment and in HCs. Independent component analysis (ICA) was used to compare the different dFC pattern between MDD adolescents and HCs at baseline, as well as which between before and after treatment in MDD adolescents. Finally, Pearson correlation and multivariate linear regression analyses were used to explore the associations between dFC pattern and changed score of BDI in MDD adolescents.ResultsThe mean dFC value between right inferior frontal gyrus (IFG) and bilateral insular cortex (IC; right, r = −0.461, p-FDR = 0.012; left, r = −0.518, p-FDR = 0.007) at baseline were negatively correlated with BDI score reduction. The mean dFC value between left frontal pole (FP) and right superior parietal lobule (SPL) after treatment was positively correlated with BDI score reduction (r = 0.442, p-FDR = 0.014). And the mean dFC values between right IFG and bilateral IC (right, β = −1.563, p-FDR = 0.021; left, β = −1.868, p-FDR = 0.012) at baseline could predict antidepressant treatment response.ConclusionThese findings demonstrate that dFC patterns between some brain areas could be a prospective factor for predicting antidepressant treatment response.

Voxel-Based Morphometry and Subfield Volumetry Analysis Reveal Limbic System Involvement in Tinnitus.

Tinnitus is a condition in which individuals perceive sounds, such as ringing or buzzing, without any external source. Although the exact cause is not fully understood, recent studies have indicated the involvement of nonauditory brain structures, including the limbic system. We aimed to compare the volumes of specific brain structures between patients with tinnitus and controls. Voxel-based morphometry and subfield volumetry were applied to analyze the brain structures of 53 patients with tinnitus and 52 age- and sex-matched controls. The volumes of the amygdala, hippocampus, and thalamus were measured and compared between the groups. Patients with tinnitus had larger volumes in the whole amygdala, basal nucleus, right lateral nucleus, and left paralaminar nucleus compared with controls. In addition, the subiculum head, left fimbria, and left presubiculum head in the hippocampus were larger in patients with tinnitus. No differences were found in the total thalamic volume or thalamic subnuclei between groups. The gray matter volumes in the thalamus, amygdala, and hippocampus were significantly high in the tinnitus group. The cortical thicknesses of both of the marginal branches of the cingulate sulcus, the left superior parietal lobule, and the left subparietal sulcus were also high in the tinnitus group. These findings indicate the involvement of the limbic system in tinnitus, and enhance our understanding of the condition. The subfield volumetry technique used in this study may aid in identifying the structural differences associated with specific neurological and psychiatric conditions.

Сhanges in the brain connectome in patients with multiple sclerosis after complex neurorehabilitation: a prospective study

INTRODUCTION: The presence of steadily progressive neurological deficit in patients with multiple sclerosis (MS) is the main indication for complex rehabilitation with the involvement of a multidisciplinary team of specialists. A detailed analysis of changes in brain connectivity may provide a better understanding of which compensatory brain mechanisms contribute to productive rehabilitation. MRI markers of neurorehabilitation, on the other hand, can facilitate the standardization of rehabilitation measures, help ensure an individual approach and objectify the results of the treatment process. It should be noted that the possibility of using functional resting state MRI (rs-fMRI) as a technique for assessing the results of neurorehabilitation has still not been sufficiently studied.OBJECTIVE: To evaluate early and delayed changes in the brain connectome in patients with multiple sclerosis before and after complex neurorehabilitation by using resting state functional MRI.MATERIALS AND METHODS: The study involved 15 patients with multiple sclerosis (EDSS 1.5–6). A comprehensive neurological examination was performed before and after comprehensive inpatient neurorehabilitation. Resting state functional MRI was performed at three control points: before admission, within 3–5 days after completion of neurorehabilitation, and within 25–30 days after discharge.Statistics: Statistical processing and evaluation of fMRI data results was carried out using the CONN v.22 software package (p-FDR<0,05).RESULTS: A decrease in connectivity between the regions of the default mode network of the brain (DMN), the subcallosal and occipital cortex (T= –8,34, Т= –9,12), and an increase in connectivity between the regions of the DMN and the left superior parietal lobule were revealed (T=11,72). There was also increased connectivity between the left superior parietal lobule and elements of the salience network (Т=8,38). Connectivity between visual network components and the right frontal lobe increased (Т=7,04), while connectivity with the left frontal and temporal lobes decreased (Т= –8,69, T= –17,68).DISCUSSION: A decrease in connectivity in the elements of the DMN in patients indicates the stabilization of its functioning and the restoration of the connection between it and the subcallosal cortex, which belongs to the limbic system. A decrease in connectivity between the lingual gyrus and the DMN regions and a simultaneous increase in connectivity with elements of the right frontal lobe may indicate an increase in the functioning of the directed action system. The identified increase in connectivity between elements of the salience network and the left superior parietal lobule may indicate an improvement in the functioning of the sensorimotor system, incl. its conscious components. Increased connectivity between elements of the medial visual network and the right frontal lobe may also indicate an increase in the quality of directed sensorimotor actions, incl. in the «vision-hand» system. Reduced connectivity between elements of the right occipital lobe and the right sections of the somatosensory network, responsible for the perception of space, the location of the limbs, as well as with the left frontal visual field, precuneus and left inferior temporal gyrus, more probably associated with a reorganization of the structures of directional eye movement and attention.CONCLUSION: The identified early and late changes in the functional networks of the brain indicate a decrease in the pathological activity of the network of the default mode of the brain, an increase in the activity of structures involved in sensory processing of space (including visual and auditory), as well as an increase in the activity of the salience network and elements of information processing from analyzers of proprioceptive sensitivity.

Instruction-induced modulation of the visual stream during gesture observation.

Although gesture observation tasks are believed to invariably activate the action-observation network (AON), we investigated whether the activation of different cognitive mechanisms when processing identical stimuli with different explicit instructions modulates AON activations. Accordingly, 24 healthy right-handed individuals observed gestures and they processed both the actor's moved hand (hand laterality judgment task, HT) and the meaning of the actor's gesture (meaning task, MT). The main brain-level result was that the HT (vs MT) differentially activated the left and right precuneus, the left inferior parietal lobe, the left and right superior parietal lobe, the middle frontal gyri bilaterally and the left precentral gyrus. MT (vs HT) differentially activated the left and right calcarine cortex, the fusiform gyrus bilaterally, the left inferior temporal gyrus, the left and right hippocampus and parahippocampal gyri, and the temporal pole bilaterally. Processing the actor's moving hand modulates the dorsal action observation network (while processing gesture meaning modulates the ventral object recognition stream). The present results suggest instruction-induced modulation on the visual stream during gesture observation.

Altered gray matter structural covariance networks in young adults with obesity.

Overwhelming evidence showed that obesity was associated with abnormal brain functional networks. However, the changes of structural covariance networks (SCNs) based on cortical thickness (CT) and cortical surface area (CSA) in obesity is still unclear. In this study, 243 young adults with obesity and matched 243 lean individuals were enrolled from the Human Connectome Project Release S1200 dataset. All participants underwent magnetic resonance imaging scans following clinical and neuropsychological assessments. SCNs matrices were constructed by Brain Connectivity Toolbox based on both CT and CSA. Nonparametric permutation tests were adopted to examine group differences of these matrices. Young adults with obesity exhibited lower CSA of left entorhinal cortex, but higher CT of both left rostral anterior cingulate cortex and right superior parietal lobule, as well as lower CT of left temporal pole. While in terms of global network measures, there were no significant group differences; in terms of nodal network measures, young adults with obesity exhibited alterations in widespread brain regions including left posterior cingulate cortex, bilateral superior frontal gyrus, left entorhinal cortex and right insula. Young adults with obesity exhibited abnormal nodal network measures in widespread brain regions involved in default mode network, central executive network and salience network. These findings indicate the adverse effects of obesity on young adults might be associated with the altered triple network.

Neural Modulation Alteration to Positive and Negative Emotions in Depressed Patients: Insights from fMRI Using Positive/Negative Emotion Atlas.

Although it has been noticed that depressed patients show differences in processing emotions, the precise neural modulation mechanisms of positive and negative emotions remain elusive. FMRI is a cutting-edge medical imaging technology renowned for its high spatial resolution and dynamic temporal information, making it particularly suitable for the neural dynamics of depression research. To address this gap, our study firstly leveraged fMRI to delineate activated regions associated with positive and negative emotions in healthy individuals, resulting in the creation of the positive emotion atlas (PEA) and the negative emotion atlas (NEA). Subsequently, we examined neuroimaging changes in depression patients using these atlases and evaluated their diagnostic performance based on machine learning. Our findings demonstrate that the classification accuracy of depressed patients based on PEA and NEA exceeded 0.70, a notable improvement compared to the whole-brain atlases. Furthermore, ALFF analysis unveiled significant differences between depressed patients and healthy controls in eight functional clusters during the NEA, focusing on the left cuneus, cingulate gyrus, and superior parietal lobule. In contrast, the PEA revealed more pronounced differences across fifteen clusters, involving the right fusiform gyrus, parahippocampal gyrus, and inferior parietal lobule. These findings emphasize the complex interplay between emotion modulation and depression, showcasing significant alterations in both PEA and NEA among depression patients. This research enhances our understanding of emotion modulation in depression, with implications for diagnosis and treatment evaluation.

Neurobiological response to trauma-related and general negative words in men firefighters with post-traumatic stress disorder, compared to trauma-exposed and trauma non-exposed controls: A pilot study.

Although firefighters frequently encounter various traumatic incidents, few develop posttraumatic stress disorder (PTSD). In this pilot study, we aimed to examine trauma-specific neurobiological alterations in firefighters with PTSD, distinguishing these characteristics from those of trauma-exposed controls. Twenty-two firefighters (11 firefighters with PTSD and 11 trauma-exposed controls) and 25 trauma non-exposed controls completed psychiatric questionnaires and functional magnetic resonance imaging while engaging in a trauma-specific emotional counting Stroop task for firefighters. In response to general negative words, the firefighter group exhibited increased brain activity in the left and right superior parietal lobes, left cingulate gyrus, and right medial frontal gyrus compared to the trauma non-exposed control group. In response to trauma-related words, the firefighter group displayed increased brain activity in the left and right superior parietal lobes, left and right middle temporal gyri, and precuneus compared to the trauma non-exposed control group. In response to general negative words, firefighters with PTSD exhibited increased brain activity in the right and left middle temporal gyri compared to trauma-exposed controls. In response to trauma-related words, firefighters with PTSD displayed decreased brain activity in the right and left middle frontal gyri compared to trauma-exposed controls. Among firefighters with PTSD, brain activity in the left middle frontal gyrus in response to trauma-related words negatively correlated with the Clinician-Administered PTSD Scale total score. Collectively, firefighters with PTSD demonstrate reduced brain activation within the middle frontal gyrus in response to trauma-related words, indicating a compromised top-down control mechanism.

Assessment of cerebral perfusion alterations in dementia with Lewy bodies and Alzheimer's disease.

Dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) are common forms of dementia, characterized by overlapping clinical symptoms. Functional neuroimaging can provide valuable information for precise diagnosis. Our objective was to explore cerebral perfusion alterations in DLB and AD, and to determine which perfusion parameters are helpful in distinguishing DLB and AD. A total of 25 DLB patients, 34 AD patients, and 40 normal controls (NC) underwent neuropsychological testing and pseudo-continuous arterial spin labeling (pcASL) for assessing cerebral perfusion [mean cerebral flow (mCBF); arterial transit time (ATT)] indexes. Differences in perfusion indexes among the three groups were analyzed and the family-wise error (FWE) was used for multiple comparisons. Spearman analysis assessed the relationships between the mCBF and neuropsychological scores [mini-mental state examination (MMSE); Montreal Cognitive Assessment (MoCA)]. A receiver operating characteristic (ROC) analysis was conducted to evaluate the performance and discriminant value of different perfusion indices in distinguishing between the two diseases. Compared with NC, the mCBF of patients with DLB was reduced mainly in the bilateral frontal lobe, bilateral parietal lobes, bilateral temporal lobes, and the right occipital lobe. AD patients showed lower mCBF mainly in the bilateral frontal lobes, the right temporal lobe, and the left parietal lobe. Compared with AD, DLB patients showed decreased mCBF in the bilateral frontal and parietal lobes. ATT in almost all major arterial regions was prolonged in DLB and AD when compared to NC. Compared with AD, ATT was significantly prolonged in DLB (P<0.05). Furthermore, the DLB demonstrated a significant positive correlation between mCBF and MMSE scores, particularly in regions such as the left superior parietal lobule (r=0.596, P=0.002) and the right precuneus (r=0.498, P=0.01). Similarly, AD exhibits a positive correlation between mCBF and MMSE scores within regions, such as the right middle temporal gyrus (r=0.550, P=0.001) and the left inferior parietal lobule (r=0.571, P<0.001). The perfusion indexes could help distinguish DLB from AD. DLB demonstrates a different pattern of regional blood flow reduction and prolonged ATT, which is different from that in AD. ASL-derived parameters provide critical discriminative information for differentiating DLB and AD.

Link Prediction of Cortical Atrophy in Alzheimer’s Disease using Morphometric Correlation Networks

AbstractBackgroundPredictive biomarkers characterizing disease progression are called for in the context of emerging treatments for Alzheimer’s disease. We implemented a link prediction model on morphometric correlation networks(MCN) generated from structural MRI.MethodHigh‐resolution T1MPRAGE images were retrospectively collected at two timepoints (interval 2.6 ± 1.2 years) for each of the 32 AD patients (AD)(mean age 74.6 ± 6.8, 14F/18M) and age‐matched cognitively normal controls (CN)(n = 32, mean age 75.0 ± 6.3, 16F/16M) from Alzheimer’s Disease Neuroimaging Initiative database. Images were processed using Freesurfer(version7.2) cortical reconstruction pipeline followed by cortical volume quantification. Whole‐brain surface‐based analyses (set at p &lt; 0.05 and FDR &lt; 0.05) were performed to identify regions showing significant differences between CN and AD, and significant atrophy between two timepoints across AD followed by computation of interregional correlations of cortical volume changes. Topological robustness of the MCNs for both timepoints were quantified to assess the network robustness of AD in response to the removal of predominant nodes. The MCN was used to build a link prediction model. Graph embedding was implemented to learn and extract features of each node in the MCN, and the light gradient boosting machine algorithm was applied to classify the cortical changes as atrophy. The AUC(area under the receiver operating characteristic curve) was used to evaluate the model’s performance.ResultAD showed widespread cortical volume reduction. When examining the longitudinal cortical atrophy, the left superior temporal gyrus (STGl,p = 0.0108), precuneus (p = 0.0262), inferior(IPLl, p = 0.0019) and superior parietal lobule (SPLl,p = 0.0007), lingual gyrus(LGl,p = 0.0004); the right lateral occipital cortex (LOCr,p = 0.0168) and hippocampus(HCP r,p&lt;0.0001); and bilateral supramarginal gyri(SMGl,p = 0.0227; r,p = 0.0181) showed significant volume loss (Fig. 1) and were identified as predominant nodes in the MCN that led the co‐atrophy as AD progressed (Fig. 2). With AD progression, robustness was weaker and removal of predominant nodes significantly reduced network resilience. The link prediction model predicted the cortical atrophy pattern in AD with AUC of 0.97 (Fig. 3).ConclusionWe successfully implemented a model to predict progression of cortical atrophy and identified atrophy‐leading brain regions in AD. Future clinical translation of our approach can serve as an imaging biomarker.

Connectivity in the Dorsal Visual Stream Is Enhanced in Action Video Game Players.

Action video games foster competitive environments that demand rapid spatial navigation and decision-making. Action video gamers often exhibit faster response times and slightly improved accuracy in vision-based sensorimotor tasks. Background/Objectives: However, the underlying functional and structural changes in the two visual streams of the brain that may be contributing to these cognitive improvements have been unclear. Methods: Using functional and diffusion MRI data, this study investigated the differences in connectivity between gamers who play action video games and nongamers in the dorsal and ventral visual streams. Results: We found that action video gamers have enhanced functional and structural connectivity, especially in the dorsal visual stream. Specifically, there is heightened functional connectivity-both undirected and directed-between the left superior occipital gyrus and the left superior parietal lobule during a moving-dot discrimination decision-making task. This increased connectivity correlates with response time in gamers. The structural connectivity in the dorsal stream, as quantified by diffusion fractional anisotropy and quantitative anisotropy measures of the axonal fiber pathways, was also enhanced for gamers compared to nongamers. Conclusions: These findings provide valuable insights into how action video gaming can induce targeted improvements in structural and functional connectivity between specific brain regions in the visual processing pathways. These connectivity changes in the dorsal visual stream underpin the superior performance of action video gamers compared to nongamers in tasks requiring rapid and accurate vision-based decision-making.

Retinal Damage and Visual Network Reconfiguration Defines Visual Function Recovery in Optic Neuritis.

Recovery of vision after acute optic neuritis (AON) is critical to improving the quality of life of people with demyelinating diseases. The objective of the study was to prospectively assess the changes in visual acuity, retinal layer thickness, and cortical visual network in patients with AON to identify the predictors of permanent visual disability. We studied a prospective cohort of 88 consecutive patients with AON with 6-month follow-up using high and low-contrast (2.5%) visual acuity, color vision, retinal thickness from optical coherence tomography, latencies and amplitudes of multifocal visual evoked potentials, mean deviation of visual fields, and diffusion-based structural (n = 53) and functional (n = 19) brain MRI to analyze the cortical visual network. The primary outcome was 2.5% low-contrast vision, and data were analyzed with mixed-effects and multivariate regression models. We found that after 6 months, low-contrast vision and quality of vision remained moderately impaired. The thickness of the ganglion cell layer at baseline was a predictor of low-contrast vision 6 months later (ß = 0.49 [CI 0.11-0.88], p = 0.012). The structural cortical visual network at baseline predicted low-contrast vision, the best predictors being the betweenness of the right parahippocampal cortex (ß = -036 [CI -0.66 to 0.06], p = 0.021), the node strength of the right V3 (ß = 1.72 [CI 0.29-3.15], p = 0.02), and the clustering coefficient of the left intraparietal sulcus (ß = 57.8 [CI 12.3-103.4], p = 0.015). The functional cortical visual network at baseline also predicted low-contrast vision, the best predictors being the betweenness of the left ventral occipital cortex (ß = 8.6 [CI: 4.03-13.3], p = 0.009), the node strength of the right intraparietal sulcus (ß = -2.79 [CI: -5.1-0.4], p = 0.03), and the clustering coefficient of the left superior parietal lobule (ß = 501.5 [CI 50.8-952.2], p = 0.03). The assessment of the visual pathway at baseline predicts permanent vision disability after AON, indicating that damage is produced early after disease onset and that it can be used for defining vision impairment and guiding therapy.

Diagnostic Challenges in Identifying Atrial Myxoma as a Cause of Transient Ischemic Attacks: A Case Report

Abstract Background A 67-year-old woman presented to hospital on multiple occasions with transient neurological symptoms over a period of 20 months. Initial diagnostics, including computed tomography (CT), carotid Dopplers, and electrocardiogram, were unremarkable. Magnetic resonance imaging (MRI) was arranged following the third neurological event which revealed multi-territory acute ischemic events, suggestive of a cardioembolic source. Transoesophageal echocardiography identified a large mobile atrial myxoma, histologically confirmed. Atrial myxoma, though rare, is an important cause of thromboembolic stroke, underscoring the need for comprehensive cardiac evaluation in cerebrovascular incidents. Methods The patient's case was reviewed, focusing on initial presentations, diagnostic workup, and subsequent management. Initial presentations included transient visual disturbances and transient leg weakness. Routine tests were conducted, including CT brain, carotid Dopplers, and blood tests. MRI and transoesophageal echocardiography were performed which ultimately identified the underlying cause of the patient’s neurological events. Results Initial evaluations (CT, carotid Dopplers) were normal. An MRI performed 20 months after her initial presentation revealed small acute infarcts in the right cerebellar hemisphere and left superior parietal lobe. Transoesophageal echocardiography subsequently detected a large atrial myxoma. The patient's transient symptoms and negative initial workup delayed the diagnosis, highlighting the necessity of including cardiac imaging early in the stroke workup, especially in cases of suspected cardioembolic events. Conclusion This case illustrates the critical role of thorough cardiac evaluation, including echocardiography, in diagnosing the cause of transient ischemic attacks (TIA) and strokes. The patient’s initial negative findings delayed the identification of a cardioembolic source, emphasizing the importance of comprehensive diagnostic protocols for suspected cerebrovascular events. Urgent surgical resection is essential for atrial myxoma to prevent recurrent embolic events. This report highlights the diagnostic and management challenges of cardiac myxomas, advocating for a more rigorous approach to stroke evaluation and timely intervention.

Action expectancy modulates activity in the mirror neuron system and mentalizing system

Action understanding involves two distinct processing levels that engage separate neural mechanisms: perception of concrete kinematic information and recognition of abstract action intentions. The mirror neuron system and the mentalizing system have both been linked to concrete action and abstract information processing, but their specific roles remain debatable. Here, we conducted a functional magnetic resonance imaging study with 26 participants who passively observed expected and unexpected actions. We performed whole-brain activation, region of interest, and effective connectivity analyses to investigate the neural correlates of these actions. Whole-brain activation analyses revealed that expected actions were associated with increased activation in the left medial superior frontal gyrus, while unexpected actions were linked to heightened activity in the left supramarginal gyrus, left superior parietal lobule, right inferior temporal gyrus, and left middle frontal gyrus. Region of interest analyses demonstrated that the left ventral premotor cortex exhibited greater activation during the observation of expected actions compared to unexpected actions, while the left inferior frontal gyrus, left superior parietal lobule, and left precuneus showed stronger activation during the observation of unexpected actions. Effective connectivity was observed between the left ventral premotor cortex and the left angular gyrus, left intraparietal sulcus, left dorsal premotor cortex, and left ventromedial prefrontal cortex with the middle frontal gyrus when observing unexpected, but not expected, actions. These findings suggest that expected actions are primarily processed by the mirror neuron system, whereas unexpected actions engage both the mirror neuron system and the mentalizing system, with these systems playing complementary roles in the understanding of unexpected actions.

Altered Neuronal Activity Patterns of the Prefrontal Cortex in Alzheimer's Disease After Transcranial Alternating Current Stimulation: A Resting-State fMRI Study.

Transcranial alternating current stimulation (tACS) could improve cognition in patients with Alzheimer's disease (AD). However, the effects of tACS on brain activity remain unclear. The purpose is to investigate the change in regional neuronal activity after tACS in AD patients employing resting-state functional magnetic resonance imaging (rs-fMRI). A total of 46 patients with mild AD were enrolled. Each patient received 30 one-hour sessions of real or sham tACS for three weeks (clinical trial: NCT03920826). The fractional amplitude of low-frequency fluctuations (fALFF) and the regional homogeneity (ReHo) measured by rs-fMRI were calculated to evaluate the regional brain activity. Compared to baseline, AD patients in the real group exhibited increased fALFF in the left middle frontal gyrus-orbital part and right inferior frontal gyrus-orbital part, as well as increased ReHo in the left precentral gyrus and right middle frontal gyrus at the end of intervention. At the 3-month follow-up, fALFF increased in the left superior parietal lobule and right inferior temporal gyrus, as well as ReHo, in the left middle frontal gyrus and right superior medial frontal gyrus. A higher fALFF in the right lingual gyrus and ReHo in the right parahippocampal gyrus were observed in the response group than in the nonresponse group. The findings demonstrated the beneficial effects of tACS on the neuronal activity of the prefrontal cortex and even more extensive regions and provided a neuroimaging biomarker of treatment response in AD patients.

Monoaminergic network abnormalities are associated with fatigue in pediatric multiple sclerosis.

Fatigue is commonly observed in pediatric multiple sclerosis (pedMS) patients, but its underlying mechanisms remain largely unexplored. We evaluated whether resting-state (RS) functional connectivity (FC) abnormalities in monoaminergic networks contributed to explain fatigue in pedMS. Fifty-five pedMS and twenty-three matched healthy controls (HC) underwent clinical and RS functional MRI assessment. Patients with Fatigue Severity Scale (FSS) score ≥ 4 were classified as fatigued (F). Patterns of dopamine-, noradrenaline- and serotonin-related RS FC were derived by constrained independent component analysis, using PET atlases for dopamine, noradrenaline, and serotonin transporters obtained in HCs' brain. Compared to non-fatigued (NF)-pedMS patients and HC, F-pedMS patients (15/55, 27.3%) showed decreased dopamine-related RS FC in the right postcentral gyrus. They also showed decreased dopamine-related RS FC in the left insula vs. HC and increased dopamine-related RS FC in the left middle temporal gyrus and cerebellum (lobule VI) vs. NF patients. In the noradrenaline-related network, F-pedMS patients showed decreased RS FC in the left superior parietal lobule and increased RS FC in the right thalamus vs. HC and NF-pedMS. Compared to HC, F-pedMS patients also showed decreased RS FC in the right calcarine cortex and increased RS FC in the right middle frontal gyrus. In the serotonin-related network, F-pedMS patients showed decreased RS FC in the right angular gyrus and increased RS FC in the right postcentral gyrus vs. NF-pedMS patients. In pedMS, fatigue is associated with specific monoaminergic network abnormalities, providing pathological markers for this bothersome symptom and putative targets for its treatment.

Altered spontaneous brain activity patterns in hypertensive retinopathy using fractional amplitude of low-frequency fluctuations: a functional magnetic resonance imaging study.

To study functional brain abnormalities in patients with hypertensive retinopathy (HR) and to discuss the pathophysiological mechanisms of HR by fractional amplitude of low-frequency fluctuations (fALFFs) method. Twenty HR patients and 20 healthy controls (HCs) were respectively recruited. The age, gender, and educational background characteristics of the two groups were similar. After functional magnetic resonance imaging (fMRI) scanning, the subjects' spontaneous brain activity was evaluated with the fALFF method. Receiver operating characteristic (ROC) curve analysis was used to classify the data. Further, we used Pearson's correlation analysis to explore the relationship between fALFF values in specific brain regions and clinical behaviors in patients with HR. The brain areas of the HR group with lower fALFF values than HCs were the right orbital part of the middle frontal gyrus (RO-MFG) and right lingual gyrus. In contrast, the values of fALFFs in the left middle temporal gyrus (MTG), left superior temporal pole (STP), left middle frontal gyrus (MFG), left superior marginal gyrus (SMG), left superior parietal lobule (SPL), and right supplementary motor area (SMA) were higher in the HR group. The results of a t-test showed that the average values of fALFFs were statistically significantly different in the HR group and HC group (P<0.001). The fALFF values of the left middle frontal gyrus in HR patients were positively correlated with anxiety scores (r=0.9232; P<0.0001) and depression scores (r=0.9682; P<0.0001). fALFF values in multiple brain regions of HR patients are abnormal, suggesting that these brain regions in HR patients may be dysfunctional, which may help to reveal the pathophysiological mechanisms of HR.

Obsessive-Compulsive Disorder Comorbid With or Without Obsessive-Compulsive Personality Disorder: Conceptual Implications, Clinical Correlates, and Brain Morphometries

BackgroundObsessive-compulsive disorder (OCD) is often comorbid with obsessive-compulsive personality disorder (OCPD). The relationship between OCD and OCPD is complex, and the impact of comorbid OCPD on OCD remains underexplored, necessitating further research. In this study, we aimed to investigate the clinical correlates and brain morphometries associated with comorbid OCPD in a large sample of unmedicated patients with OCD. MethodsA total of 248 unmedicated patients diagnosed with OCD (45 comorbid with OCPD) were included in this study. All participants were assessed for OCD symptoms, OCPD traits, obsessive beliefs, depression, and anxiety. Among them, 145 patients (23 comorbid with OCPD) volunteered to receive magnetic resonance imaging brain scans. ResultsApproximately 18% (45/248) of patients with OCD were comorbid for OCPD. OCD comorbid with OCPD (OCD+OCPD) exhibited more severe OCD symptoms, obsessive beliefs, depression, and anxiety than OCD comorbid without OCPD. Additionally, the severity of OCPD was positively correlated with OCD symptoms and obsessive beliefs. Furthermore, patients with OCD+OCPD exhibited increased cortical complexity in the left superior parietal lobule and left precuneus, which mediated the relationship between OCPD and OCD symptoms only in OCD patients comorbid without OCPD. ConclusionsThe co-occurrence of OCPD may contribute to the heightened severity of psychopathological symptoms and associated brain morphological alterations in patients with OCD, indicating distinct but interrelated constructs between these 2 disorders.

Altered structural node of default mode network mediated general cognitive ability in young adults with obesity

BackgroundObesity, characterized by excessive adiposity, is associated with brain structural abnormalities. Nevertheless, the relationships between altered structural nodes of default mode network (DMN), body mass index (BMI), general cognitive ability remained unclear in young adults. MethodsIn this study, we divided a large sample of young adults into three BMI-based groups. We then conducted one-way analyses of variance and post-hoc tests with Bonferroni corrections to investigate abnormal structural brain regions associated with obesity. Furthermore, mediation effects models were built to explore whether the structural alterations influenced the relationship between BMI and general cognitive ability. ResultsCompared to their lean and overweight counterparts, young adults with obesity exhibited significantly lower general cognitive ability, higher impulsivity traits, and worse sleep quality. Furthermore, compared with lean group, young adults with obesity exhibited altered cortical thickness of both the left temporal pole and right superior parietal lobule, and abnormal cortical surface area (CSA) of the left entorhinal cortex (EC), a hub within DMN. Moreover, CSA of the left EC mediated the relationship between BMI and general cognitive ability. ConclusionObesity was linked to altered structural node of DMN, which mediated general cognitive ability in young adults. These findings indicated the negative effect of obesity on DMN and general cognitive ability in young adults.

High-Frequency rTMS Broadly Ameliorates Working Memory and Cognitive Symptoms in Stroke Patients: A Randomized Controlled Trial

Objective To explore the efficacy and tolerability of high-frequency repetitive transcranial magnetic stimulation (rTMS) in the treatment of post-stroke working memory (WM) impairment and its changes in brain function. Methods In the present randomized, double-blinded, sham-controlled design, 10 Hz rTMS was administered to the left dorsolateral prefrontal cortex (DLPFC) of patients with post-stroke WM impairment for 14 days. Measures included WM (primary outcome), comprehensive neuropsychological tests, and the functional near-infrared spectroscopy test. Patients were assessed at baseline, after the intervention (week 2), and 4 weeks after treatment cessation (week 6). Results Of 123 stroke patients, 82 finished the trial. The rTMS group showed more WM improvement at week 2 (t = 5.55, P < .001) and week 6 (t = 2.11, P = .045) than the sham group. Most of the neuropsychological test scores were markedly improved in the rTMS group. In particular, the rTMS group exhibited significantly higher oxygenated hemoglobin content and significantly stronger functional connectivity in the left DLPFC, right pre-motor cortex (PMC), and right superior parietal lobule (SPL) at weeks 2 and 6. Dropout rates were equal (18% [9/50 cases] in each group), and headaches were the most common side effect (rTMS: 36% [18/50 cases]; sham: 30% [15/50 cases]). Conclusions High-frequency rTMS was effective in improving post-stroke WM impairment, with good tolerability, and the efficacy lasted up to 4 weeks, which may be due to the activation of the left DLPFC, right PMC, and right SPL brain regions and their synergistic enhancement of neural remodeling.

Brain imaging of a gamified cognitive flexibility task in young and older adults.

The study aimed to develop and validate a gamified cognitive flexibility task through brain imaging, and to investigate behavioral and brain activation differences between young and older adults during task performance. Thirty-one young adults (aged 18-35) and 31 older adults (aged 60-80) were included in the present study. All participants underwent fMRI scans while completing the gamified cognitive flexibility task. Results showed that young adults outperformed older adults on the task. The left inferior frontal junction (IFJ), a key region of cognitive flexibility, was significantly activated during the task in both older and young adults. Comparatively, the percent signal change in the left IFJ was stronger in older adults than in young adults. Moreover, older adults demonstrated more precise representations during the task in the left IFJ. Additionally, the left inferior parietal lobule (IPL) and superior parietal lobule in older adults and the left middle frontal gyrus (MFG) and inferior frontal gyrus in young adults were also activated during the task. Psychophysiological interaction analyses showed significant functional connectivity between the left IFJ and the left IPL, as well as the right precuneus in older adults. In young adults, significant functional connectivity was found between the left IFJ and the left MFG, as well as the right angular. The current study provides preliminary evidence for the validity of the gamified cognitive flexibility task through brain imaging. The findings suggest that this task could serve as a reliable tool for assessing cognitive flexibility and for exploring age-related differences of cognitive flexibility in both brain and behavior.