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Background: The central autonomic network (CAN) plays a critical role in the body's sympathetic and parasympathetic control. However, functional connectivity (FC) changes of the CAN in patients with multiple system atrophy (MSA) remain unknown. Purpose: To investigate FC alterations of CAN in MSA patients. Study Type: Prospective. Population: Eighty‐two subjects (47 patients with MSA [44.7% female, 60.5 ± 6.9 years], 35 age‐ and sex‐matched healthy controls [HC] [57.1% female, 62.5 ± 6.6 years]). Field Strength/Sequence: 3‐T, resting‐state functional magnetic resonance imaging (rs‐fMRI) using gradient echo‐planar imaging (EPI), T1‐weighted three‐dimensional magnetization‐prepared rapid gradient echo (3D MPRAGE) structural MRI. Assessment: FC alterations were explored by using core modulatory regions of CAN as seeds, including midcingulate cortex, insula, amygdala, and ventromedial prefrontal cortex. Bartlett factor score (BFS) derived from a factor analysis of clinical assessments on disease severity was used as a grouping factor for moderate MSA (mMSA: BFS < 0) and severe MSA (sMSA: BFS > 0). Statistical Tests: For FC analysis, the one‐way ANCOVA with cluster‐level family‐wise error correction (statistical significance level of P < 0.025), and post hoc t‐testing with Bonferroni correction or Tamhane's T2 correction (statistical significance level of adjusted‐P < 0.05) were adopted. Correlation was assessed using Pearson correlation or Spearman correlation (statistical significance level of P < 0.05). Results: Compared with HC, patients with MSA exhibited significant FC aberrances between the CAN and brain areas of sensorimotor control, limbic network, putamen, and cerebellum. For MSA patients, most FC alterations of CAN, especially concerning FC between the right anterior insula and right primary sensorimotor cortices, were found to be significantly correlated with disease severity. FC changes were found to be more significant in sMSA group than in mMSA group when compared with HCs. Data Conclusion: MSA shows widespread FC changes of CAN, suggesting that abnormal functional integration of CAN may be involved in disease pathogenesis of MSA. Level of Evidence: 2 Technical Efficacy: Stage 3 [ABSTRACT FROM AUTHOR]

The visualization and identification of the deep cerebellar nuclei (DCN) (dentate [DN], interposed [IN] and fastigial nuclei [FN]) are particularly challenging. We aimed to visualize the DCN using quantitative susceptibility mapping (QSM), predict the contrast differences between QSM and T2* weighted imaging, and compare the DCN volume and susceptibility in movement disorder populations and healthy controls (HCs). Seventy‐one Parkinson's disease (PD) patients, 39 essential tremor patients, and 80 HCs were enrolled. The PD patients were subdivided into tremor dominant (TD) and postural instability/gait difficulty (PIGD) groups. A 3D strategically acquired gradient echo MR imaging protocol was used for each subject to obtain the QSM data. Regions of interest were drawn manually on the QSM data to calculate the volume and susceptibility. Correlation analysis between the susceptibility and either age or volume was performed and the intergroup differences of the volume and magnetic susceptibility in all the DCN structures were evaluated. For the most part, all the DCN structures were clearly visualized on the QSM data. The susceptibility increased as a function of volume for both the HC group and disease groups in the DN and IN (p <.001) but not the FN (p =.74). Only the volume of the FN in the TD‐PD group was higher than that in the HCs (p =.012), otherwise, the volume and susceptibility among these four groups did not differ significantly. In conclusion, QSM provides clear visualization of the DCN structures. The results for the volume and susceptibility of the DCN can be used as baseline references in future studies of movement disorders. [ABSTRACT FROM AUTHOR]

MRI has been used to develop biomarkers for movement disorders such as Parkinson disease (PD) and other neurodegenerative disorders with parkinsonism such as progressive supranuclear palsy and multiple system atrophy. One of these imaging biomarkers is neuromelanin (NM), whose integrity can be assessed from its contrast and volume. NM is found mainly in certain brain stem structures, namely, the substantia nigra pars compacta (SNpc), the ventral tegmental area, and the locus coeruleus. Another major biomarker is brain iron, which often increases in concert with NM degeneration. These biomarkers have the potential to improve diagnostic certainty in differentiating between PD and other neurodegenerative disorders similar to PD, as well as provide a better understanding of pathophysiology. Mapping NM in vivo has clinical importance for gauging the premotor phase of PD when there is a greater than 50% loss of dopaminergic SNpc melanized neurons. As a metal ion chelator, NM can absorb iron. When NM is released from neurons, it deposits iron into the intracellular tissues of the SNpc; the result is iron that can be imaged and measured using quantitative susceptibility mapping. An increase of iron also leads to the disappearance of the nigrosome‐1 sign, another neuroimage biomarker for PD. Therefore, mapping NM and iron changes in the SNpc are a practical means for improving early diagnosis of PD and in monitoring disease progression. In this review, we discuss the functions and location of NM, how NM‐MRI is performed, the automatic mapping of NM and iron content, how NM‐related imaging biomarkers can be used to enhance PD diagnosis and differentiate it from other neurodegenerative disorders, and potential advances in NM imaging methods. With major advances currently evolving for rapid imaging and artificial intelligence, NM‐related biomarkers are likely to have increasingly important roles for enhancing diagnostic capabilities in PD. Evidence Level: 1 Technical Efficacy: Stage 2 [ABSTRACT FROM AUTHOR]

Introduction: Cognitive training and physical exercise have shown positive effects on delaying progression of mild cognitive impairment (MCI) to dementia. Methods: We explored the enhancing effect from Tai Chi when it was provided with cognitive training for MCI. In the first 12 months, the cognitive training group (CT) had cognitive training, and the mixed group (MixT) had additional Tai Chi training. In the second 12 months, training was only provided for a subgroup of MixT. Results: In the first 12 months, MixT and CT groups were benefited from training. Compared to the CT group, MixT had additional positive effects with reference to baseline. In addition, Compared to short‐time training, prolonged mixed training further delayed decline in global cognition and memory. Functional magnetic resonance imaging showed more increased regional activity in both CT and MixT. Discussion: Tai Chi enhanced cognitive training effects in MCI. Moreover, Tai Chi and cognitive mixed training showed effects on delaying cognitive decline. [ABSTRACT FROM AUTHOR]

Objective: The subthalamic nucleus (STN) and internal globus pallidus (GPi) are the most effective targets in deep brain stimulation (DBS) for Parkinson's disease (PD). However, the common and specific effects on brain connectivity of stimulating the 2 nuclei remain unclear. Methods: Patients with PD receiving STN‐DBS (n = 27, 6 women, mean age 64.8 years) or GPi‐DBS (n = 28, 13 women, mean age 64.6 years) were recruited for resting‐state functional magnetic resonance imaging to assess the effects of STN‐DBS and GPi‐DBS on brain functional dynamics. Results: The functional connectivity both between the somatosensory‐motor cortices and thalamus, and between the somatosensory‐motor cortices and cerebellum decreased in the DBS‐on state compared with the off state (p < 0.05). The changes in thalamocortical connectivity correlated with DBS‐induced motor improvement (p < 0.05) and were negatively correlated with the normalized intersection volume of tissues activated at both DBS targets (p < 0.05). STN‐DBS modulated functional connectivity among a wider range of brain areas than GPi‐DBS (p = 0.009). Notably, only STN‐DBS affected connectivity between the postcentral gyrus and cerebellar vermis (p < 0.001) and between the somatomotor and visual networks (p < 0.001). Interpretation: Our findings highlight common alterations in the motor pathway and its relationship with the motor improvement induced by both STN‐ and GPi‐DBS. The effects on cortico‐cerebellar and somatomotor‐visual functional connectivity differed between groups, suggesting differentiated neural modulation of the 2 target sites. Our results provide mechanistic insight and yield the potential to refine target selection strategies for focal brain stimulation in PD. ANN NEUROL 2021;90:670–682 [ABSTRACT FROM AUTHOR]

In Keren's figure 5, they show a clear correlation between the density of staining of the tyrosine hydroxylase and LC neurons with the MR enhancement seen in the LC. Their excellent paper shows a colocation of NM cells in the LC that corresponds to norepinephrine neurons with the MTC NM-MRI data. Thus, LC/SN signal intensity is, although not attributable to NM, likely to correlate with NM (as well as with intracellular water) because NM as an effective metal chelator provides neuronal protection and decreases with NA/DA neuron loss.". [Extracted from the article]

Introduction: Cognitive training and physical exercise have shown positive effects on delaying progression of mild cognitive impairment (MCI) to dementia., Methods: We explored the enhancing effect from Tai Chi when it was provided with cognitive training for MCI. In the first 12 months, the cognitive training group (CT) had cognitive training, and the mixed group (MixT) had additional Tai Chi training. In the second 12 months, training was only provided for a subgroup of MixT., Results: In the first 12 months, MixT and CT groups were benefited from training. Compared to the CT group, MixT had additional positive effects with reference to baseline. In addition, Compared to short-time training, prolonged mixed training further delayed decline in global cognition and memory. Functional magnetic resonance imaging showed more increased regional activity in both CT and MixT., Discussion: Tai Chi enhanced cognitive training effects in MCI. Moreover, Tai Chi and cognitive mixed training showed effects on delaying cognitive decline., (© 2022 the Alzheimer's Association.)

Background: Previous studies have revealed abnormality of iron deposition in the brain of patients with depression. The progression of iron deposition associated with depression remains to be elucidated., Methods: This is a longitudinal study. We explored brain iron deposition with disease progression in 20 patients older than 55 years with depression and on antidepressants, using magnetic resonance imaging (MRI)-based quantitative susceptibility mapping (QSM). Magnetic susceptibility values of the whole brain were compared between baseline and approximately one-year follow-up scans using permutation testing. Furthermore, we examined the relationship of changes between the susceptibility values and disease improvement using Spearman's partial correlation analysis, controlling for age, gender, and the visit interval., Results: Compared to the initial scan, increased magnetic susceptibility values were found in the medial prefrontal cortex (mPFC), dorsal anterior cingulate cortex (dACC), occipital areas, habenula, brainstem, and cerebellum (P<0.05, corrected). The susceptibility values decreased in the dorsal part of the mPFC, middle and posterior cingulate cortex (MCC and PCC), right postcentral gyrus, right inferior parietal lobule, right precuneus, right supramarginal gyrus, left lingual gyrus, left dorsal striatum, and right thalamus (P<0.05, corrected). Notably, the increase in susceptibility values at the mPFC and dACC negatively correlated with the changes in depression scores, as calculated using the Hamilton Depression Scale (HAMD) (r=-0.613, P=0.009), and the increase in susceptibility values at the cerebellum and habenula negatively correlated with the changes in cognitive scores, which were calculated using the Mini-Mental State Examination (MMSE) (cerebellum: r=-0.500, P=0.041; habenula: r=-0.588, P=0.013). Additionally, the decreased susceptibility values at the white matter near the mPFC (anterior corona radiata) also correlated with the changes in depression scores (r=-0.541, P=0.025), and the decreased susceptibility values at the left lingual gyrus correlated with the changes in cognitive scores (r=-0.613, P=0.009)., Conclusions: Our study identified brain areas where iron deposition changed with the progression of depression while on antidepressants. The linear relationship of changes in the magnetic susceptibility values in the mPFC, dACC, and some subcortical areas with changes in depression symptoms and cognitive functions of patients is highlighted. Our results strengthen the understanding of the alterations of brain iron levels associated with disease progression in patients with late-life depression., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-21-1137/coif). HW reports support from the National Natural Science Foundation of China (Nos. 61901256 and 91949120), Science and Technology Commission of Shanghai Municipality (No. 20DZ2220400), and SJTU (Shanghai Jiao Tong University) Trans-med Awards Research (No. WF540162605/001). NH reports support from the Innovative Research Team of High-level Local Universities in Shanghai. BS reports support from SJTU (Shanghai Jiao Tong University) Trans-med Awards Research (No. WF540162605). CZ reports support from the National Natural Science Foundation of China (No. 82101547) and the Shanghai Sailing Program (No. 20YF1426500). The other authors have no conflicts of interest to declare., (2022 Quantitative Imaging in Medicine and Surgery. All rights reserved.)

Objective: Functional connectivity shows the ability to predict the outcome of subthalamic nucleus deep brain stimulation (DBS) in Parkinson disease (PD). However, evidence supporting its value in predicting the outcome of globus pallidus internus (GPi) DBS remains scarce. In this study the authors investigated patient-specific functional connectivity related to GPi DBS outcome in PD and established connectivity models for outcome prediction., Methods: The authors reviewed the outcomes of 21 patients with PD who received bilateral GPi DBS and presurgical functional MRI at the Ruijin Hospital. The connectivity profiles within cortical areas identified as relevant to DBS outcome in the literature were calculated using the intersection of the volume of tissue activated (VTA) and the local structures as the seeds. Combined with the leave-one-out cross-validation strategy, models of the optimal connectivity profile were constructed to predict outcome., Results: Connectivity between the pallidal areas and primary motor area, supplementary motor area (SMA), and premotor cortex was identified through the literature as related to GPi DBS outcome. The similarity between the connectivity profile within the primary motor area, SMA, pre-SMA, and premotor cortex seeding from the VTA-GPi intersection from an out-of-sample patient and the constructed in-sample optimal connectivity profile predicts GPi DBS outcome (R = 0.58, p = 0.006). The predictions on average deviated by 13.1% ± 11.3% from actual improvements. On the contrary, connectivity profiles seeding from the GPi (R = -0.12, p = 0.603), the VTA (R = 0.23, p = 0.308), the VTA outside the GPi (R = 0.12, p = 0.617), or other local structures were found not to be predictive., Conclusions: The results showed that patient-specific functional connectivity seeding from the VTA-GPi intersection could help in GPi DBS outcome prediction. Reproducibility remains to be determined across centers in larger cohorts stratified by PD motor subtype.