Elevated caudate connectivity in cognitively normal Parkinson's disease patients

Resting-state functional MRI study of conventional MRI-negative intractable epilepsy in children

Objective

The study aimed at investigating functional connectivity strength (FCS) changes in children with MRI-negative intractable epilepsy (ITE) and evaluating correlations between aberrant FCS and both disease duration and intelligence quotient (IQ).

Methods

Fifteen children with ITE, 24 children with non-intractable epilepsy (nITE) and 25 matched healthy controls (HCs) were subjected to rs-fMRI. IQ was evaluated by neuropsychological assessment. Voxelwise analysis of covariance was conducted in the whole brain, and then pairwise comparisons were made across three groups using Bonferroni corrections.

Results

FCS was significantly different among three groups. Relative to HCs, ITE patients exhibited decreased FCS in right temporal pole of the superior temporal gyrus, middle temporal gyrus, bilateral precuneus, etc and increased FCS values in left triangular part of the inferior frontal gyrus, parahippocampal gyrus, supplementary motor area, caudate and right calcarine fissure and surrounding cortex and midbrain. The nITE patients presented decreased FCS in right orbital superior frontal gyrus, precuneus etc and increased FCS in bilateral fusiform gyri, parahippocampal gyri, etc. In comparison to nITE patients, the ITE patients presented decreased FCS in right medial superior frontal gyrus and left inferior temporal gyrus and increased FCS in right middle temporal gyrus, inferior temporal gyrus and calcarine fissure and surrounding cortex. Correlation analysis indicated that FCS in left caudate demonstrated correlation with verbal IQ (VIQ) and disease duration.

Conclusion

ITE patients demonstrated changed FCS values in the temporal and prefrontal cortices relative to nITE patients, which may be related to drug resistance in epilepsy. FCS in the left caudate nucleus associated with VIQ, suggesting the caudate may become a key target for improving cognitive impairment and seizures in children with ITE.

Topological alteration of the brain structural network in Parkinson's disease with apathy

BACKGROUND

Apathy is a common neuropsychiatric manifestations in Parkinson's disease (PD), but neural network mechanisms still remain elusive. We aim to investigate the topological alteration of the brain structural network in PD with apathy.

METHOD

In the present study, a total of 47 apathetic PD (aPD) patients, 37 non-apathetic PD (naPD) patients, and 40 healthy controls (HCs) were enrolled. Diffusion tensor imaging (DTI) in conjunction with graph-theoretic approaches were used to explore the alterations of topological properties of the WM structural network arising from apathy in PD. One-way analysis of covariance and post hoc analyses were performed to explore differences among the three groups. Correlations were ascertained to examine relationships between the Starkstein Apathy Scale (AS) scores and significantly different network metrics among the three groups.

RESULTS

Both aPD and naPD patients remained small-world topology. However, compared with the naPD patients, aPD patients showed increased clustering coefficient (Cp) at the global level. At the regional level, aPD exhibited decreased nodal properties, mainly in the right dorsolateral prefrontal cortex (DLPFC), the right caudate nucleus (CAU), the right hippocampus, and the right superior parietal gyrus. Further, AS scores were negatively correlated with degree centrality of the right DLPFC (r = -0.254, p = 0.020) and the right CAU ( r = -0.357, p = 0.001) in the pooled patients with PD.

CONCLUSIONS

The findings suggested that apathy in PD presented relatively optimized global topological properties of the brain structural network and disrupted topological organization of the regional network, particularly involving the fronto-striatal-limbic circuits. The altered topological properties of abnormal brain regions might be used to understand the physiopathologic mechanism of the neural network in aPD patients.

Functional correlates of cognitive abilities vary with age in pediatric multiple sclerosis

BACKGROUND

Pediatric multiple sclerosis (PedMS) can hamper brain maturation. Aim of this study was to assess the neuropsychological profile of PedMS patients and their resting-state functional connectivity (RS FC).

METHODS

We assessed intelligence quotient (IQ), executive speed, and language in 76 PedMS patients. On a 3.0T scanner RS FC of brain networks was estimated with a seed-based analysis (subset of 58 right-handed PedMS patients and 22 matched healthy controls). Comparisons were run between controls and PedMS (whole cohort and by age).

RESULTS

Ninety-five% of patients had normal IQ. The highest rate of failure was observed in executive speed. PedMS showed reduced RS FC in all networks than controls, especially in the basal ganglia. In younger patients (<16-year-old, n = 32) reduced RS FC in the basal ganglia, language, and sensorimotor networks associated with poorer cognitive performance (p < 0.05; r range: 0.39; 0.56). Older patients (≥16-year-old, n = 26) showed increased RS FC in the basal ganglia, default-mode, sensorimotor, executive, and language networks, associated with poorer performance in executive speed and language abilities (p < 0.05; r range: -0.40; -0.59). In both groups, lower RS FC of the caudate nucleus associated with poorer executive speed.

CONCLUSIONS

The effect of PedMS on RS FC is clinically relevant and differs according to patients' age.

Task-Related Reorganization of Cognitive Network in Parkinson's Disease Using Electrophysiology

BACKGROUND

Cognitive deficits in Parkinson's disease (PD) patients are well described, however, their underlying neural mechanisms as assessed by electrophysiology are not clear.

OBJECTIVES

To reveal specific neural network alterations during the performance of cognitive tasks in PD patients using electroencephalography (EEG).

METHODS

Ninety participants, 60 PD patients and 30 controls underwent EEG recording while performing a GO/NOGO task. Source localization of 16 regions of interest known to play a pivotal role in GO/NOGO task was performed to assess power density and connectivity within this cognitive network. The connectivity matrices were evaluated using a graph-theory approach that included measures of cluster-coefficient, degree, and global-efficiency. A mixed-model analysis, corrected for age and levodopa equivalent daily dose was performed to examine neural changes between PD patients and controls.

RESULTS

PD patients performed worse in the GO/NOGO task (P < 0.001). The power density was higher in δ and θ bands, but lower in α and β bands in PD patients compared to controls (interaction group × band: P < 0.001), indicating a general slowness within the network. Patients had more connections within the network (P < 0.034) than controls and these were used for graph-theory analysis. Differences between groups in graph-theory measures were found only in cluster-coefficient, which was higher in PD compared to controls (interaction group × band: P < 0.001).

CONCLUSIONS

Cognitive deficits in PD are underlined by alterations at the brain network level, including higher δ and θ activity, lower α and β activity, increased connectivity, and segregated network organization. These findings may have important implications on future adaptive deep brain stimulation. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Slowing of EEG waves correlates with striatal [18 F]fluorodopa PET/CT uptake and executive dysfunction in Parkinson's disease

Parkinson's disease (PD) research on specific neuroimaging and neurophysiological biomarkers revealing executive dysfunction mechanisms is limited, necessitating validation. Thus, our study aimed to assess associations between electroencephalographic power spectral density (PSD-EEG), striatal [18 F]Fluorodopa uptake and neuropsychological executive function (EF) testing parameters in PD, while also estimating their diagnostic accuracy. We compared resting PSD-EEG, striatal [18 F]Fluorodopa uptake ratios based on positron emission computed tomography ([18 F]FDOPA PET/CT) and neuropsychological EF tests outcomes [Trail Making Test (TMT) and Stroop Test (ST)] between PD patients and healthy controls (HCO) and then calculated correlations among these measures separately for each group. Additionally, we estimated PD diagnostic accuracy of the PSD-EEG and [18 F]FDOPA PET/CT parameters. In PD patients, we observed the following: (i) slower EEG waves, reflected in increased power of the EEG theta and lower-alpha bands in frontal lobe areas; (ii) reduced [18 F]FDOPA PET/CT uptake in the putaminal and caudate nuclei, along with a decreased putamen-to-caudate ratio ([18 F]FDOPA PET/CT PCR); and (iii) longer performance times evident in nearly all EF tests' parameters. Slower EEG waves correlated negatively with [18 F]FDOPA PET/CT PCR and positively with most of the EF test parameters. Furthermore, we found negative correlations between [18 F]FDOPA PET/CT PCR and certain EF measures related to ST. [18 F]FDOPA PET/CT ratios and several PSD-EEG parameters, particularly those from the prefrontal cortex, demonstrated clinically reasonable diagnostic accuracy for PD. In conclusion, EEG waves slowing in the frontal lobe were correlated with striatal dopaminergic deficiency and impaired executive function in mild PD patients and showed promise as a biomarker of PD-related executive dysfunction.

Blood transcriptomic signatures associated with molecular changes in the brain and clinical outcomes in Parkinson's disease

The ability to use blood to predict the outcomes of Parkinson's disease, including disease progression and cognitive and motor complications, would be of significant clinical value. We undertook bulk RNA sequencing from the caudate and putamen of postmortem Parkinson's disease (n = 35) and control (n = 40) striatum, and compared molecular profiles with clinical features and bulk RNA sequencing data obtained from antemortem peripheral blood. Cognitive and motor complications of Parkinson's disease were associated with molecular changes in the caudate (stress response) and putamen (endothelial pathways) respectively. Later and earlier-onset Parkinson's disease were molecularly distinct, and disease duration was associated with changes in caudate (oligodendrocyte development) and putamen (cellular senescence), respectively. Transcriptome patterns in the postmortem Parkinson's disease brain were also evident in antemortem peripheral blood, and correlated with clinical features of the disease. Together, these findings identify molecular signatures in Parkinson's disease patients' brain and blood of potential pathophysiologic and prognostic importance.

Early-Life Critical Windows of Susceptibility to Manganese Exposure and Sex-Specific Changes in Brain Connectivity in Late Adolescence

Background

Early-life environmental exposures during critical windows (CWs) of development can impact life course health. Exposure to neuroactive metals such as manganese (Mn) during prenatal and early postnatal CWs may disrupt typical brain development, leading to persistent behavioral changes. Males and females may be differentially vulnerable to Mn, presenting distinctive CWs to Mn exposure.

Methods

We used magnetic resonance imaging to investigate sex-specific associations between early-life Mn uptake and intrinsic functional connectivity in adolescence. A total of 71 participants (15-23 years old; 53% female) from the Public Health Impact of Manganese Exposure study completed a resting-state functional magnetic resonance imaging scan. We estimated dentine Mn concentrations at prenatal, postnatal, and early childhood periods using laser ablation-inductively coupled plasma-mass spectrometry. We performed seed-based correlation analyses to investigate the moderating effect of sex on the associations between Mn and intrinsic functional connectivity adjusting for age and socioeconomic status.

Results

We identified significant sex-specific associations between dentine Mn at all time points and intrinsic functional connectivity in brain regions involved in cognitive and motor function: 1) prenatal: dorsal striatum, occipital/frontal lobes, and middle frontal gyrus; 2) postnatal: right putamen and cerebellum; and 3) early childhood: putamen and occipital, frontal, and temporal lobes. Network associations differed depending on exposure timing, suggesting that different brain networks may present distinctive CWs to Mn.

Conclusions

These findings suggest that the developing brain is vulnerable to Mn exposure, with effects lasting through late adolescence, and that females and males are not equally vulnerable to these effects. Future studies should investigate cognitive and motor outcomes related to these associations.

Basal Ganglia Compensatory White Matter Changes on DTI in Alzheimer's Disease

The volume reduction of the gray matter structures in patients with Alzheimer's disease is often accompanied by an asymmetric increase in the number of white matter fibers located close to these structures. The present study aims to investigate the white matter structure changes in the motor basal ganglia in Alzheimer's disease patients compared to healthy controls using diffusion tensor imaging. The amounts of tracts, tract length, tract volume, quantitative anisotropy, and general fractional anisotropy were measured in ten patients with Alzheimer's disease and ten healthy controls. A significant decrease in the number of tracts and general fractional anisotropy was found in patients with Alzheimer's disease compared to controls in the right caudate nucleus, while an increase was found in the left and the right putamen. Further, a significant decrease in the structural volume of the left and the right putamen was observed. An increase in the white matter diffusion tensor imaging parameters in patients with Alzheimer's disease was observed only in the putamen bilaterally. The right caudate showed a decrease in both the diffusion tensor imaging parameters and the volume in Alzheimer's disease patients. The right pallidum showed an increase in the diffusion tensor imaging parameters but a decrease in volume in Alzheimer's disease patients.

Longitudinal striatal dopamine transporter binding and cerebrospinal fluid alpha-synuclein, amyloid beta, total tau, and phosphorylated tau in Parkinson's disease

BACKGROUND

Previous studies investigated CSF levels of α-synuclein (α-syn), amyloid-β (Aβ1-42), total tau (t-tau), and phosphorylated tau (p-tau) with clinical progression of Parkinson's disease (PD). However, there is limited data on the association between CSF biomarkers and dopamine uptake status in PD.

AIM

In the current study, we aim to investigate the longitudinal association between striatal dopaminergic neuronal loss assessed by dopamine active transporter single photon emission computerized tomography (DaTSCAN) imaging with CSF α-syn, t-tau, p-tau, and Aβ1-42.

METHODS

A total of 413 early-stage PD patients and 187 healthy controls (HCs) from the PPMI. Striatal binding ratios (SBRs) of DaTSCAN images in caudate and putamen nuclei were calculated. We investigated the cross-sectional and longitudinal association between CSF biomarkers and dopamine uptake using partial correlation models adjusted for the effect of age, sex, and years of education over 24 months of follow-up.

RESULTS

The level of CSF α-syn, Aβ1-42, t-tau, and p-tau was significantly higher in HCs compared to PD groups at any time point. We found that higher CSF α-syn was associated with a higher SBR score in the left caudate at baseline (P = 0.038) and after 12 months (P = 0.012) in PD patients. Moreover, SBR scores in the left caudate and CSF Aβ1-42 were positively correlated at baseline (P = 0.021), 12 months (P = 0.006), and 24 months (P = 0.014) in patients with PD. Our findings demonstrated that change in CSF Aβ1-42 was positively correlated with change in SBR score in the left caudate after 24 months in the PD group (P = 0.043).

CONCLUSION

We found that cross-sectional levels of α-syn and Aβ1-42 could reflect the degree of dopaminergic neuron loss in the left caudate nucleus. Interestingly, longitudinal changes in CSF Aβ1-42 could predict the severity of left caudal dopaminergic neuron loss throughout the disease. This suggested that Aβ pathology might precede dopaminergic loss in striatal nuclei in this case left caudate and subsequently cognitive impairment in PD patients, although future studies are needed to confirm our results and expand the understanding of the pathophysiology of cognitive dysfunction in PD.

Structural connectivity and brain network analyses in Parkinson's disease: A cross-sectional and longitudinal study

Introduction

Parkinson's disease (PD) is an idiopathic disease of the central nervous system characterized by both motor and non-motor symptoms. It is the second most common neurodegenerative disease. Magnetic resonance imaging (MRI) can reveal underlying brain changes associated with PD.

Objective

In this study, structural connectivity and white matter networks were analyzed by diffusion MRI and graph theory in a cohort of patients with PD and a cohort of healthy controls (HC) obtained from the Parkinson's Progression Markers Initiative (PPMI) database in a cross-sectional analysis. Furthermore, we investigated longitudinal changes in the PD cohort over 36 months.

Result

Compared with the control group, participants with PD showed lower structural connectivity in several brain areas, including the corpus callosum, fornix, and uncinate fasciculus, which were also confirmed by a large effect-size. Additionally, altered connectivity between baseline and after 36 months was found in different network paths inside the white matter with a medium effect-size. Network analysis showed trends toward lower network density in PD compared with HC at baseline and after 36 months, though not significant after correction. Significant differences were observed in nodal degree and strength in several nodes.

Conclusion

In conclusion, altered structural and network metrics in several brain regions, such as corpus callosum, fornix, and cingulum were found in PD, compared to HC. We also report altered connectivity in the PD group after 36 months, reflecting the impact of both PD pathology and aging processes. These results indicate that structural and network metrics might yield insight into network reorganization that occurs in PD.

Stereotactic Surgery of Parkinson’s Disease with Magnetic Resonance Imaging under Three-Dimensional Mark Point Positioning Algorithm

This research aimed to study the application of magnetic resonance imaging (MRI) under three-dimensional mark point positioning algorithm in stereotactic surgery for Parkinson's disease (PD) and improve clinical treatment effect. Eighty patients with PD in Tianjin Medical University General Hospital were selected as the research objects and randomly divided into two groups. The three-dimensional mark point positioning algorithm was applied to perform feature positioning on the MRI images of PD patients, and the international unified Parkinson's disease rating scale (UPDRS) was assessed before and after single-target surgery of the two groups. There was a significant difference in the postoperative treatment effect between the two groups compared with the preoperative one (P < 0.05). Among the patients in the observation group, 37 cases were marked as markedly effective, accounting for 92.5% of the total group; 1 case was ineffective and 2 cases were improved, accounting for 2.5% and 5%, respectively. In the control group, 35, 2, and 3 cases were assessed as markedly effective, ineffective, and improved, accounting for 87.5%, 5%, and 7.5%, respectively. The overall curative effect of the observation group was better than that of the control group, and the difference was significant (P < 0.05). The MRI manifestations of PD patients were diversified. MRI under the three-dimensional mark point positioning algorithm had a high value for the stereotactic treatment of PD patients, which was beneficial to the clinical surgery.

Altered Intrinsic Regional Spontaneous Brain Activity in Patients With Severe Obesity and Meibomian Gland Dysfunction: A Resting-State Functional Magnetic Resonance Imaging Study

Purpose

To evaluate potential regional homogeneity (ReHo) cerebrum function lesions in people with severe obesity and meibomian gland dysfunction (SM) and probe the connection between aberrant cerebrum activity and clinical manifestations.

Patients and Methods

An aggregation of 12 patients with SM, and 12 healthy controls (HCs) closely matched in age and gender were enrolled. We applied corneal confocal microscopy and fundus angiography to compare imaging distinctions between the two groups. SMs were required to carefully fill out the Hospital Anxiety Depression Scale (HADS) forms, and a correlation analysis was performed. ReHo was also utilized to appraise partial differences in spontaneous cerebrum function. Receiver operating characteristic (ROC) curves were created to partition ReHo values between patients with SM and the HCs.

Results

ReHo values for the left cerebellum (LC), right fusiform gyrus (RFG), left inferior temporal gyrus (LITG), left rectus gyrus (LRG), right thalamus (RT), right caudate (RC), left insula (LI), and left thalamus (LT) of subjects with SM were notably higher than those of the HCs (P < 0.05). ReHo values of the right middle frontal gyrus (RMFG) in subjects with SM were decreased notably compared to the HCs (P < 0.05). ReHo values for the RMFG showed a negative correlation with the anxiety scores (ASs; r = −0.961, P < 0.001) and ReHo values for the RFG showed a positive correlation with the depression scores (DSs; r = 0.676, P = 0.016). The areas under the ROC curve were 1.000 (P < 0.001) for the RMFG, LC, LITG, LRG, RC, LI, and LT and 0.993 (P < 0.001) for the RFG and RT. The results from the ROC curve analysis indicated that changes in the ReHo values of some brain regions may help diagnose SM.

Conclusion

Our research emphasized that patients with SM had lesions in synchronized neural activity in many encephalic areas. Our discoveries may provide beneficial information for exploring the neuromechanics of SM.

Frontoparietal network resilience is associated with protection against cognitive decline in Parkinson's disease

Though Parkinson's disease is primarily defined as a movement disorder, it is also characterized by a range of non-motor symptoms, including cognitive decline. The onset and progression of cognitive decline in individuals with Parkinson's disease is variable, and the neurobiological mechanisms that contribute to, or protect against, cognitive decline in Parkinson's disease are poorly understood. Using resting-state functional magnetic resonance imaging data collected from individuals with Parkinson's disease with and without cognitive decline, we examined the relationship between topological brain-network resilience and cognition in Parkinson's disease. By leveraging network attack analyses, we demonstrate that relative to individuals with Parkinson's disease experiencing cognitive decline, the frontoparietal network in cognitively stable individuals with Parkinson's disease is significantly more resilient to network perturbation. Our findings suggest that the topological robustness of the frontoparietal network is associated with the absence of cognitive decline in individuals with Parkinson's disease.

Changes in Metabolic Activity and Gait Function by Dual-Task Cognitive Game-Based Treadmill System in Parkinson's Disease: Protocol of a Randomized Controlled Trial

Balance and gait impairments, and consequently, mobility restrictions and falls are common in Parkinson’s disease (PD). Various cognitive deficits are also common in PD and are associated with increased fall risk. These mobility and cognitive deficits are limiting factors in a person’s health, ability to perform activities of daily living, and overall quality of life. Community ambulation involves many dual-task (DT) conditions that require processing of several cognitive tasks while managing or reacting to sudden or unexpected balance challenges. DT training programs that can simultaneously target balance, gait, visuomotor, and cognitive functions are important to consider in rehabilitation and promotion of healthy active lives. In the proposed multi-center, randomized controlled trial (RCT), novel behavioral positron emission tomography (PET) brain imaging methods are used to evaluate the molecular basis and neural underpinnings of: (a) the decline of mobility function in PD, specifically, balance, gait, visuomotor, and cognitive function, and (b) the effects of an engaging, game-based DT treadmill walking program on mobility and cognitive functions. Both the interactive cognitive game tasks and treadmill walking require continuous visual attention, and share spatial processing functions, notably to minimize any balance disturbance or gait deviation/stumble. The ability to “walk and talk” normally includes activation of specific regions of the prefrontal cortex (PFC) and the basal ganglia (site of degeneration in PD). The PET imaging analysis and comparison with healthy age-matched controls will allow us to identify areas of abnormal, reduced activity levels, as well as areas of excessive activity (increased attentional resources) during DT-walking. We will then be able to identify areas of brain plasticity associated with improvements in mobility functions (balance, gait, and cognition) after intervention. We expect the gait-cognitive training effect to involve re-organization of PFC activity among other, yet to be identified brain regions. The DT mobility-training platform and behavioral PET brain imaging methods are directly applicable to other diseases that affect gait and cognition, e.g., cognitive vascular impairment, Alzheimer’s disease, as well as in aging.