Lower cognitive control network connectivity in stroke participants with depressive features

Effect of nonpharmacological interventions on poststroke depression: a network meta-analysis

Purpose

To investigate the effects of nonpharmacological interventions (NPIs) on poststroke depression (PSD) in stroke patients.

Methods

Computer searches were conducted on the PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database (VIP), and Wanfang databases from their establishment to December 2023. The selection was made using the inclusion and exclusion criteria, and 40 articles were included to compare the effects of the 17 NPIs on patients with PSD.

Results

Forty studies involving seventeen interventions were included. The network findings indicated that compared with conventional therapy (COT), superior PSD improvement was observed for cognitive behavioral therapy (CBT) + acupoint acupuncture (CBTA) (mean difference [MD], -4.25; 95% CI, -5.85 to -2.65), team positive psychotherapy (MD, -4.05; 95% CI, -5.53 to -2.58), music therapy (MT) + positive psychological intervention (MD, -2.25; 95% CI, -3.65 to -0.85), CBT (MD, -1.52; 95% CI, -2.05 to -0.99), mindfulness-based stress reduction (MD, -1.14; 95% CI, -2.14 to -0.14), MT (MD, -0.95; 95% CI, -1.39 to -0.52), acupoint acupuncture + MT (AAMT) (MD, -0.69; 95% CI, -1.25 to -0.14). Furthermore, CBT (MD, -3.87; 95% CI, -4.57 to -3.17), AAMT (MD, -1.02; 95% CI, -1.41 to -0.62), acupressure + MT (MD, -0.91; 95% CI, -1.27 to -0.54), and narrative care + acupressure (MD, -0.74; 95% CI, -1.19 to -0.29) demonstrated superior Pittsburgh Sleep Quality Index (PSQI) improvement compared with COT.

Conclusion

Evidence from systematic reviews and meta-analyses suggests that CBTA improves depression in patients with PSD. Moreover, CBT improves sleep in these patients. Additional randomized controlled trials are required to further investigate the efficacy and mechanisms of these interventions.

Post-Stroke Depression in Older Adults: An Overview

Detailed data on post-stroke depression (PSD) in older adults are limited in spite of the high vulnerability of this population to stroke. In fact, PSD prevalence in older adults ranges from 16.0 to 43.9%; however, timing and instruments of evaluation often differ significantly across all available studies. The etiology, genetic and inflammatory factors, as well as structural brain alterations, are claimed as part of a multifaceted mechanism of action in PSD onset. Thus, the aim of this narrative review was to further elaborate on the prevalence, etiology, diagnosis, consequences and treatment of PSD in older adults. The consequences of PSD in older adults may be devastating, including a poor functional outcome after rehabilitation and lower medication adherence. In addition, lower quality of life and reduced social participation, higher risk of new stroke, rehospitalization, and mortality have been reported. In this scenario, treating PSD represents a crucial step to prevent these complications. Both pharmacological and non-pharmacological therapies are currently available. The pharmacological treatment utilizes antidepressant drugs, such as selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), monoamine oxidase inhibitors (MAOIs), tricyclic antidepressants (TAs) and new multimodal antidepressants (NMAs). Non-pharmacological therapies include psychological interventions and non-invasive brain stimulation techniques, while excluding drug administration. In the general population experiencing PSD, SSRIs (sertraline in particular) are the most prescribed, whereas the combination of antidepressants and psychotherapy is underused. Furthermore, about one-third of patients do not receive treatment for PSD. In regard to older adults with PSD, the possibility of more adverse effects or contraindications to antidepressant prescription due to comorbidities may limit the therapeutic window. Although drugs such as citalopram, escitalopram, sertraline, venlafaxine, and vortioxetine are usually well tolerated by older patients with PSD, the few randomized controlled trials (RCTs) specifically considering older adults with PSD have been conducted with fluoxetine, fluvoxamine, reboxetine, citalopram and nortriptyline, often with very small patient samples. Furthermore, data regarding the results of non-pharmacological therapies are scarce. High-quality RCTs recruiting large samples of older adults are needed in order to better manage PSD in this population. In addition, adequate screening and diagnosis instruments, with reliable timing of evaluation, should be applied.

Abnormally decreased functional connectivity of the right nucleus basalis of Meynert in Alzheimer's disease patients with depression symptoms

Dysfunction of the basal forebrain is the main pathological feature in patients with Alzheimer's disease (AD). The aim of this study was to explore whether depressive symptoms cause changes in the functional network of the basal forebrain in AD patients. We collected MRI data from depressed AD patients (n = 24), nondepressed AD patients (n = 14) and healthy controls (n = 20). Resting-state functional magnetic resonance imaging data and functional connectivity analysis were used to study the characteristics of the basal forebrain functional network of the three groups of participants. The functional connectivity differences among the three groups were compared using ANCOVA and post hoc analyses. Compared to healthy controls, depressed AD patients showed reduced functional connectivity between the right nucleus basalis of Meynert and the left supramarginal gyrus and the supplementary motor area. These results increase our understanding of the neural mechanism of depressive symptoms in AD patients.

The characteristics of brain network in patient with post-stroke depression under cognitive task condition

Objectives

Post-stroke depression (PSD) may be associated with the altered brain network property. This study aimed at exploring the brain network characteristics of PSD under the classic cognitive task, i.e., the oddball task, in order to promote our understanding of the pathogenesis and the diagnosis of PSD.

Methods

Nineteen stroke survivors with PSD and 18 stroke survivors with no PSD (non-PSD) were recruited. The functional near-infrared spectroscopy (fNIRS) covering the dorsolateral prefrontal cortex was recorded during the oddball task state and the resting state. The brain network characteristics were extracted using the graph theory and compared between the PSD and the non-PSD subjects. In addition, the classification performance between the PSD and non-PSD subjects was evaluated using features in the resting and the task state, respectively.

Results

Compared with the resting state, more brain network characteristics in the task state showed significant differences between the PSD and non-PSD groups, resulting in better classification performance. In the task state, the assortativity, clustering coefficient, characteristic path length, and local efficiency of the PSD subjects was larger compared with the non-PSD subjects while the global efficiency of the PSD subjects was smaller than that of the non-PSD subjects.

Conclusion

The altered brain network properties associated with PSD in the cognitive task state were more distinct compared with the resting state, and the ability of the brain network to resist attack and transmit information was reduced in PSD patients in the task state.

Significance

This study demonstrated the feasibility and superiority of investigating brain network properties in the task state for the exploration of the pathogenesis and new diagnosis methods for PSD.

The Impact of Post-Stroke Depressive Symptoms on Cognitive Performance in Women and in Men: A 4 Month Prospective Study

Background: Depressive symptoms have been associated with cognitive impairment after stroke, and women may be specifically affected. Objective: The aim of this study was to investigate gender-specific characteristics in the relationship between changes in depression severity and changes in cognitive performance after stroke. Methods: We prospectively evaluated 73 patients without a previous history of depression in the first and fourth months after a first ischemic stroke. The severity of depressive symptoms was assessed using the 31-item version of the Hamilton Rating Scale for Depression, and executive function, attention, working memory, and verbal fluency were assessed using a neuropsychological battery. Results: We included 46 (63.0%) men and 27 (36.9%) women, with mean ages of 55.2 (SD ± 15.1) and 46.8 (SD ± 14.7) years, respectively. We found significant improvement in the digit span forward and Stroop dots from month 1 to month 4 post stroke for both men and women. Women, but not men, presented a correlation between changes in phonemic verbal fluency and changes in the 31-item version of the Hamilton Rating Scale for Depression scores. Improvement in depression was correlated with improvement in verbal fluency, and worsening in depression was correlated with worsening in verbal fluency. Conclusions: Our results suggest that women might be more vulnerable to the relationship between depressive symptoms and cognitive performance, and improvement of depression may be necessary for women's improvement in phonemic verbal fluency from the first to the fourth month after a stroke. We did not adjust the results for multiple comparisons. Thus, our findings might be considered preliminary, and confirmatory studies, also focusing on specific characteristics of women that could explain these differences, are warranted.

Reward network dysfunction is associated with cognitive impairment after stroke

Stroke survivors not only suffer from severe motor, speech and neurocognitive deficits, but in many cases also from a "lack of pleasure" and a reduced motivational level. Especially apathy and anhedonic symptoms can be linked to a dysfunction of the reward system. Rewards are considered as important co-factor for learning, so the question arises as to why and how this affects the rehabilitation of stroke patients. We investigated reward behaviour, learning ability and brain network connectivity in acute (3-7d) mild to moderate stroke patients (n = 28) and age-matched healthy controls (n = 26). Reward system activity was assessed using the Monetary Incentive Delay task (MID) during magnetoencephalography (MEG). Coherence analyses were used to demonstrate reward effects on brain functional network connectivity. The MID-task showed that stroke survivors had lower reward sensitivity and required greater monetary incentives to improve performance and showed deficits in learning improvement. MEG-analyses showed a reduced network connectivity in frontal and temporoparietal regions. All three effects (reduced reward sensitivity, reduced learning ability and altered cerebral connectivity) were found to be closely related and differed strongly from the healthy group. Our results reinforce the notion that acute stroke induces reward network dysfunction, leading to functional impairment of behavioural systems. These findings are representative of a general pattern in mild strokes and are independent of the specific lesion localisation. For stroke rehabilitation, these results represent an important point to identify the reduced learning capacity after stroke and to implement individualised recovery exercises accordingly.

Frequency-dependent and time-variant alterations of neural activity in post-stroke depression: A resting-state fMRI study

BACKGROUND

Post-stroke depression (PSD) is one of the most frequent psychiatric disorders after stroke. However, the underlying brain mechanism of PSD remains unclarified. Using the amplitude of low-frequency fluctuation (ALFF) approach, we aimed to investigate the abnormalities of neural activity in PSD patients, and further explored the frequency and time properties of ALFF changes in PSD.

METHODS

Resting-state fMRI data and clinical data were collected from 39 PSD patients (PSD), 82 S patients without depression (Stroke), and 74 age- and sex-matched healthy controls (HC). ALFF across three frequency bands (ALFF-Classic: 0.01-0.08 Hz; ALFF-Slow4: 0.027-0.073 Hz; ALFF-Slow5: 0.01-0.027 Hz) and dynamic ALFF (dALFF) were computed and compared among three groups. Ridge regression analyses and spearman's correlation analyses were further applied to explore the relationship between PSD-specific alterations and depression severity in PSD.

RESULTS

We found that PSD-specific alterations of ALFF were frequency-dependent and time-variant. Specially, compared to both Stroke and HC groups, PSD exhibited increased ALFF in the contralesional dorsolateral prefrontal cortex (DLPFC) and insula in all three frequency bands. Increased ALFF in ipsilesional DLPFC were observed in both slow-4 and classic frequency bands which were positively correlated with depression scales in PSD, while increased ALFF in the bilateral hippocampus and contralesional rolandic operculum were only found in slow-5 frequency band. These PSD-specific alterations in different frequency bands could predict depression severity. Moreover, decreased dALFF in contralesional superior temporal gyrus were observed in PSD group.

LIMITATIONS

Longitudinal studies are required to explore the alterations of ALFF in PSD as the disease progress.

CONCLUSIONS

The frequency-dependent and time-variant properties of ALFF could reflect the PSD-specific alterations in complementary ways, which may assist to elucidate underlying neural mechanisms and be helpful for early diagnosis and interventions for the disease.

Immediate modulatory effects of transcutaneous auricular vagus nerve stimulation on the resting state of major depressive disorder

BACKGROUND

Previous studies have found that transcutaneous auricular vagus nerve stimulation (taVNS) is clinically effective in the treatment of major depressive disorder (MDD), and its efficacy mechanism is related to modulation of the default mode network (DMN) and cognitive control network (CCN). However, the mechanism of the immediate effect of taVNS for MDD remains to be elucidated.

METHODS

A total of 58 patients with MDD and 54 healthy controls(HCs) were included in this study. The MDD group was treated with taVNS for 30 min (20 Hz, 4-6 mA) immediately, and we observed amplitude of low-frequency fluctuations (ALFF) abnormalities in the MDD group and changes in ALFF and functional connectivity (FC) before and after immediate treatment. The ALFF brain regions altered by taVNS induction were used as regions of interest to analyze whole-brain FC changes in the MDD group.

RESULTS

After taVNS treatment, ALFF in the right precuneus was decreased in the MDD group. The FC of the right precuneus with the left middle frontal gyrus, the left posterior cingulate gyrus and the left angular gyrus were decreased in the MDD group. Correlation analysis showed that the FC values between the right precuneus and the left posterior cingulate gyrus in the pre-treatment MDD group was negatively correlated with the 17-item Hamilton depression rating scale scores.

CONCLUSION

TaVNS has an immediate modulatory effect on DMN and CCN. It would be proposed that these functional networks may be effective targets for the long-term treatment of MDD patients with taVNS.

Emotional and qualitative outcomes among patients with left and right hemisphere stroke

The differences in mental health outcomes of right and left hemisphere strokes are well studied; however, there is a long-standing controversy surrounding whether depression is associated with lateralization of stroke or not. In this investigation, we examined the effect of lesion location on post-stroke depression controlling for lesion size and hemiparesis in a longitudinal sample assessed at acute, subacute, and chronic timepoints. As a secondary aim, we further examined the effect of lesion location on self-reported difficulties across a wide array of domains. A series of 134 patients with left hemisphere strokes and 79 with right hemisphere strokes completed the Patient Health Questionnaire-9 and an inventory of post-stroke abilities at within acute, subacute, and chronic windows following stroke. When controlling for hemiparesis and overall lesion volume, we found no difference in depression between groups at any timepoint. Additional exploratory analyses provided a further look at differing challenges associated with depression in each group.

Hyperconnectivity and altered interactions of a nucleus accumbens network in post-stroke depression

Post-stroke depression is a common complication of stroke. To date, no consistent locus of injury is associated with this complication. Here, we probed network dynamics and structural alterations in post-stroke depression in four functional circuits linked to major depressive disorder and a visual network, which served as a control network. Forty-four participants with recent stroke (mean age = 69.03, standard deviation age = 8.59, age range = 51–86 and gender: female = 10) and 16 healthy volunteers (mean age = 71.53, standard deviation age = 10.62, age range = 51–84 and gender: female = 11) were imaged with 3-Tesla structural, diffusion and resting-state functional MRI. The Geriatric Depression Scale was administered to measure depression severity. Associations between depression severity and functional connectivity were investigated within networks seeded from nucleus accumbens, amygdala, dorsolateral prefrontal cortex and primary visual cortex. In addition, the default mode network was identified by connectivity with medial prefrontal cortex and posterior cingulate cortex. Circuits that exhibited altered activity associated with depression severity were further investigated by extracting within-network volumetric and microstructural measures from structural images. In the stroke group, functional connectivity within the nucleus accumbens-seeded network (left hemisphere: P = 0.001; and right hemisphere: P = 0.004) and default mode network (cluster one: P < 0.001; and cluster two: P < 0.001) correlated positively with depressive symptoms. Normal anticorrelations between these two networks were absent in patients with post-stroke depression. Grey matter volume of the right posterior cingulate cortex (Pearson correlation coefficient = −0.286, P = 0.03), as well as microstructural measures in the posterior cingulate cortex (right: Pearson correlation coefficient = 0.4, P = 0.024; and left: Pearson correlation coefficient = 0.3, P = 0.048), right medial prefrontal cortex (Pearson correlation coefficient = 0.312, P = 0.039) and the medial forebrain bundle (Pearson correlation coefficient = 0.450, P = 0.003), a major projection pathway interconnecting the nucleus accumbens-seeded network and linking to medial prefrontal cortex, were associated with depression severity. Depression after stroke is marked by reduced mutual inhibition between functional circuits involving nucleus accumbens and default mode network as well as volumetric and microstructural changes within these networks. Aberrant network dynamics present in patients with post-stroke depression are therefore likely to be influenced by secondary, pervasive alterations in grey and white matter, remote from the site of injury.

Altered functional connectivity in first-episode and recurrent depression: A resting-state functional magnetic resonance imaging study

Background

Functional magnetic resonance imaging (fMRI) studies examining differences in the activity of brain networks between the first depressive episode (FDE) and recurrent depressive episode (RDE) are limited. The current study observed and compared the altered functional connectivity (FC) characteristics in the default mode network (DMN), cognitive control network (CCN), and affective network (AN) between the RDE and FDE. In addition, we further investigated the correlation between abnormal FC and clinical symptoms.

Methods

We recruited 32 patients with the RDE, 31 patients with the FDE, and 30 healthy controls (HCs). All subjects underwent resting-state fMRI. The seed-based FC method was used to analyze the abnormal brain networks in the DMN, CCN, and AN among the three groups and further explore the correlation between abnormal FC and clinical symptoms.

Results

One-way analysis of variance showed significant differences the FC in the DMN, CCN, and AN among the three groups in the frontal, parietal, temporal, and precuneus lobes and cerebellum. Compared with the RDE group, the FDE group generally showed reduced FC in the DMN, CCN, and AN. Compared with the HC group, the FDE group showed reduced FC in the DMN, CCN, and AN, while the RDE group showed reduced FC only in the DMN and AN. Moreover, the FC in the left posterior cingulate cortices and the right inferior temporal gyrus in the RDE group were positively correlated with the 17-item Hamilton Rating Scale for Depression (HAMD-17), and the FC in the left dorsolateral prefrontal cortices and the right precuneus in the FDE group were negatively correlated with the HAMD-17.

Conclusions

The RDE and FDE groups showed multiple abnormal brain networks. However, the alterations of abnormal FC were more extensive and intensive in the FDE group.

A comparative study of amplitude of low-frequence fluctuation of resting-state fMRI between the younger and older treatment-resistant depression in adults

Background

Treatment-resistant depression (TRD) may have different physiopathological neuromechanism in different age groups. This study used the amplitude of low frequency fluctuations (ALFF) to initially compare abnormalities in local functional brain activity in younger and older patients with TRD.

Materials and methods

A total of 21 older TRD patients, 19 younger TRD, 19 older healthy controls (HCs), and 19 younger HCs underwent resting-state functional MRI scans, and the images were analyzed using the ALFF and further analyzed for correlation between abnormal brain regions and clinical symptoms in TRD patients of different age groups.

Results

Compared with the older TRD, the younger TRD group had increased ALFF in the left middle frontal gyrus and decreased ALFF in the left caudate nucleus. Compared with the matched HC group, ALFF was increased in the right middle temporal gyrus and left pallidum in the older TRD group, whereas no significant differences were found in the younger TRD group. In addition, ALFF values in the left middle frontal gyrus in the younger TRD group and in the right middle temporal gyrus in the older TRD were both positively correlated with the 17-item Hamilton Rating Scale for Depression score.

Conclusion

Different neuropathological mechanisms may exist in TRD patients of different ages, especially in the left middle frontal gyrus and left caudate nucleus. This study is beneficial in providing potential key targets for the clinical management of TRD patients of different ages.

Altered functional connectivity within default mode network after rupture of anterior communicating artery aneurysm

Background

Rupture of anterior communicating artery (ACoA) aneurysm often leads to cognitive impairment, especially memory complaints. The medial superior frontal gyrus (SFGmed), a node of the default mode network (DMN), has been extensively revealed to participate in various cognitive processes. However, the functional connectivity (FC) characteristics of SFGmed and its relationship with cognitive performance remain unknown after the rupture of the ACoA aneurysm.

Methods

Resting-state functional MRI (fMRI) and cognitive assessment were acquired in 27 eligible patients and 20 controls. Seed-based FC between unilateral SFGmed and the rest of the brain was calculated separately, and then compared their intensity differences between the two groups. Furthermore, we analyzed the correlation between abnormal FC and cognitive function in patients with ruptured ACoA aneurysm.

Results

Cognitive impairment was confirmed in 51.9% of the patients. Compared with the controls, patients suffering from ruptured ACoA aneurysm exhibited a similar FC decline between each side of SFGmed and predominant nodes within DMN, including the precuneus, angular gyrus, cingulate cortex, left hippocampus, left amygdala, left temporal pole (TPO), and left medial orbitofrontal cortex (mOFC). Besides, significantly decreased FC of left SFGmed and left insula, right middle temporal gyrus (MTG), as well as right mOFC, were also found. In addition, only enhanced insular connectivity with right SFGmed was determined, whereas increased FC of the left SFGmed was not observed. Correlation analyses showed that lower total cognitive performance or stronger subjective memory complaints were related to reduced connectivity in the SFGmed and several cortical regions such as the angular gyrus and middle cingulate cortex (MCC).

Conclusion

Our results suggest that patients with ruptured ACoA aneurysm exist long-term cognitive impairment and intrinsic hypoconnectivity of cognition-related brain regions within DMN. Deactivation of DMN may be a potential neural mechanism leading to cognitive deficits in these patients.

No add-on effect of tDCS on fatigue and depression in chronic stroke patients: A randomized sham-controlled trial combining tDCS with computerized cognitive training

BACKGROUND

Fatigue and emotional distress rank high among self-reported unmet needs in life after stroke. Transcranial direct current stimulation (tDCS) may have the potential to alleviate these symptoms for some patients, but the acceptability and effects for chronic stroke survivors need to be explored in randomized controlled trials.

METHODS

Using a randomized sham-controlled parallel design, we evaluated whether six sessions of 1 mA tDCS (anodal over F3, cathodal over O2) combined with computerized cognitive training reduced self-reported symptoms of fatigue and depression. Among the 74 chronic stroke patients enrolled at baseline, 54 patients completed the intervention. Measures of fatigue and depression were collected at five time points spanning a 2 months period.

RESULTS

While symptoms of fatigue and depression were reduced during the course of the intervention, Bayesian analyses provided evidence for no added beneficial effect of tDCS. Less severe baseline symptoms were associated with higher performance improvement in select cognitive tasks, and study withdrawal was higher in patients with more fatigue and younger age. Time-resolved symptom analyses by a network approach suggested higher centrality of fatigue items (except item 1 and 2) than depression items.

CONCLUSION

The results reveal no add-on effect of tDCS on fatigue or depression but support the notion of fatigue as a relevant clinical symptom with possible implications for treatment adherence and response.

Artificially-reconstructed brain images with stroke lesions from non-imaging data: modeling in categorized patients based on lesion occurrence and sparsity

Brain imaging is necessary for understanding disease symptoms, including stroke. However, frequent imaging procedures encounter practical limitations. Estimating the brain information (e.g., lesions) without imaging sessions is beneficial for this scenario. Prospective estimating variables are non-imaging data collected from standard tests. Therefore, the current study aims to examine the variable feasibility for modelling lesion locations. Heterogeneous variables were employed in the multivariate logistic regression. Furthermore, patients were categorized (i.e., unsupervised clustering through k-means method) by the charasteristics of lesion occurrence (i.e., ratio between the lesioned and total regions) and sparsity (i.e., density measure of lesion occurrences across regions). Considering those charasteristics in models improved estimation performances. Lesions (116 regions in Automated Anatomical Labeling) were adequately predicted (sensitivity: 80.0-87.5% in median). We confirmed that the usability of models was extendable to different resolution levels in the brain region of interest (e.g., lobes, hemispheres). Patients' charateristics (i.e., occurrence and sparsity) might also be explained by the non-imaging data as well. Advantages of the current approach can be experienced by any patients (i.e., with or without imaging sessions) in any clinical facilities (i.e., with or without imaging instrumentation).

Improving Depressive Symptoms of Post-stroke Depression Using the Shugan Jieyu Capsule: A Resting-State Functional Magnetic Resonance Imaging Study

Regional homogeneity (ReHo) and fractional amplitude of low-frequency fluctuation (fALFF) were used to detect the neuroimaging mechanism of Shugan Jieyu Capsule (SG) in ameliorating depression of post-stroke depression (PSD) patients. Fifteen PSD patients took SG for 8 weeks, completed the 24-item Hamilton Depression Scale (HAMD) assessment at the baseline and 8 weeks later, and underwent functional magnetic resonance imaging (fMRI) scanning. Twenty-one healthy controls (HCs) underwent these assessments at the baseline. We found that SG improved depression of PSD patients, in which ReHo values decreased in the left calcarine sulcus (CAL.L) and increased in the left superior frontal gyrus (SFG.L) of PSD patients at the baseline. The fALFF values of the left inferior parietal cortex (IPL.L) decreased in PSD patients at the baseline. Abnormal functional activities in the brain regions were reversed to normal levels after the administration of SG for 8 weeks. Receiver operating characteristic (ROC) analysis found that the changes in three altered brain regions could be used to differentiate PSD patients at the baseline and HCs. Average signal values of altered regions were related to depression in all subjects at the baseline. Our results suggest that SG may ameliorate depression of PSD patients by affecting brain region activity and local synchronization.

Neural Substrates of Poststroke Depression: Current Opinions and Methodology Trends

Poststroke depression (PSD), affecting about one-third of stroke survivors, exerts significant impact on patients’ functional outcome and mortality. Great efforts have been made since the 1970s to unravel the neuroanatomical substrate and the brain-behavior mechanism of PSD. Thanks to advances in neuroimaging and computational neuroscience in the past two decades, new techniques for uncovering the neural basis of symptoms or behavioral deficits caused by focal brain damage have been emerging. From the time of lesion analysis to the era of brain networks, our knowledge and understanding of the neural substrates for PSD are increasing. Pooled evidence from traditional lesion analysis, univariate or multivariate lesion-symptom mapping, regional structural and functional analyses, direct or indirect connectome analysis, and neuromodulation clinical trials for PSD, to some extent, echoes the frontal-limbic theory of depression. The neural substrates of PSD may be used for risk stratification and personalized therapeutic target identification in the future. In this review, we provide an update on the recent advances about the neural basis of PSD with the clinical implications and trends of methodology as the main features of interest.

Effects of Optimized Acupuncture and Moxibustion Treatment on Depressive Symptoms and Executive Functions in Patients With Post-Stroke Depression: Study Protocol for a Randomized Controlled Trial

Background

Post-stroke depression (PSD), a common neuropsychiatric comorbidity after stroke, has a negative impact on the functional recovery and quality of life of survivors. It lacks effective therapeutic drugs with good curative effects and few adverse reactions. Preliminary experiments have shown that the optimized acupuncture and moxibustion treatment (OAMT), including acupuncture, moxibustion, and auricular intradermal acupuncture, improved depressive symptoms and neurological deficits in patients with PSD. However, the evidence for its effectiveness is still insufficient. Hence, we designed this study to evaluate the efficacy and safety of the OAMT in the treatment of PSD and to explore its possible mechanism from the perspective of executive functions.

Methods/Design

This is a randomized controlled trial, which comprises a total of 134 patients with PSD. Participants are randomized into intervention group and control group at a 1:1 ratio. All treatments are given five times per week for 4 weeks. The primary outcome is the severity of depression, which is evaluated by the Hamilton Depression Scale-17 (HAMD-17) and the Beck Depression Rating Scale (BDI). Secondary outcomes are executive abilities, which are measured by several neuropsychological tests, including the Stroop Color and Word Test (SCWT), the Trial Making Test (TMT), the Digit Symbol Substitution Test (DSST), and the Matrix Reasoning Test (MRT). All outcomes have been evaluated at baseline and weeks 4, 8, 12, and 20. At the same time, functional MRI (fMRI) is used to measure the functional connectivity in the cognitive control network (CCN) at baseline and 4 weeks after intervention.

Discussion

This study aims to provide high-quality evidence for the efficacy and safety of the OAMT for treating PSD. In addition, this trial is the first trial to explore if the improvement condition of depression in the OAMT group is related to the improvement of executive functions and the favorable changes in the structure.

Clinical Trial Registration

Chinese Clinical Trial Registry, identifier: ChiCTR2100048431.

Electroacupuncture Ameliorates Depressive-Like Behaviors in Poststroke Rats via Activating the tPA/BDNF/TrkB Pathway

BACKGROUND

Electroacupuncture (EA) is a form of physical therapy that has been widely used in clinical practice in China. Post-stroke depression (PSD) is the most common neuropsychiatric complication after stroke. EA has been shown to have beneficial effects on PSD patients. However, the potential mechanism underlying the protective effects of EA on PSD remains unclear. Here, we investigated whether tissue plasminogen activator (tPA)/brain-derived neurotrophic factor (BDNF)/tyrosine kinase receptor B (TrkB) signaling pathway participates in the therapeutic effects of EA in a rat PSD model.

METHODS

Experimental PSD was induced by combining middle cerebral artery occlusion (MCAO) with chronic unpredictable mild stimulation (CUMS) in adult male rats. Bodyweight gain, neurological score, sucrose preference, and open field test were determined at 0, 7, 14, and 35 days after completing MCAO. The protein expressions of tPA, precursor BDNF (proBDNF), mature BDNF (mBDNF), and TrkB were measured by immunofluorescence and Western blot analysis. The tPA inhibitor plasminogen inhibitor-1 (PAI-1) was used to explore whether tPA plays a crucial role in the protective effects of EA on PSD.

RESULTS

Compared with the sham rats, the PSD rats showed decreased bodyweight, deteriorated neurological score, and significant depressive-like behaviors. EA remarkably reversed bodyweight loss, neurological deficit, and depressive-like behaviors in PSD rats. Immunofluorescence staining and Western blot analysis showed that PSD-induced decreased expression of tPA, mBDNF, and TrkB were prevented by EA. Furthermore, we found that the effects of EA against PSD-induced depressive-like behaviors were abolished by PAI-1, the specific inhibitor of tPA.

CONCLUSION

Our results suggest that the improvement in depressive-like behaviors induced by EA is likely achieved via activation of the tPA/BDNF/TrkB pathway.

Lesions in the right Rolandic operculum are associated with self-rating affective and apathetic depressive symptoms for post-stroke patients

Stroke survivors majorly suffered from post-stroke depression (PSD). The PSD diagnosis is commonly performed based on the clinical cut-off for psychometric inventories. However, we hypothesized that PSD involves spectrum symptoms (e.g., apathy, depression, anxiety, and stress domains) and severity levels. Therefore, instead of using the clinical cut-off, we suggested a data-driven analysis to interpret patient spectrum conditions. The patients’ psychological conditions were categorized in an unsupervised manner using the k-means clustering method, and the relationships between psychological conditions and quantitative lesion degrees were evaluated. This study involved one hundred sixty-five patient data; all patients were able to understand and perform self-rating psychological conditions (i.e., no aphasia). Four severity levels—low, low-to-moderate, moderate-to-high, and high—were observed for each combination of two psychological domains. Patients with worse conditions showed the significantly greater lesion degree at the right Rolandic operculum (part of Brodmann area 43). The dissimilarities between stress and other domains were also suggested. Patients with high stress were specifically associated with lesions in the left thalamus. Impaired emotion processing and stress-affected functions have been frequently related to those lesion regions. Those lesions were also robust and localized, suggesting the possibility of an objective for predicting psychological conditions from brain lesions.

Effect of Tai Chi on post-stroke non-motor disorders: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

To evaluate the state of evidence for the beneficial and harmful effects of Tai Chi on non-motor disorders in post-stroke patients.

DESIGN

Systematic review and meta-analysis of published studies.

SUBJECTS

Stroke survivors who received conventional rehabilitation therapy or Tai Chi training.

DATA SOURCES

We searched seven electronic literature databases and one clinical registry platform to collect data from randomized controlled trials published up to July 26, 2020.

RESULTS

A total of 11 randomized controlled trials with 723 stroke survivors met the inclusion criteria, of which six were included in the meta-analysis. Among the 11 studies, one was assessed as "low", eight were assessed as "moderate", and only two were assessed as "high" for the assessment of methodologic quality. Compared to patients who received conventional rehabilitation therapy, those who received Tai Chi training showed greater improvement in scores of depression (standardized mean difference (SMD) [95% confidence interval (CI)] = 0.36 [0.10, 0.61], Grading of Recommendations Assessment, Development, and Evaluation [GRADE]: very low). There were no differences in the improvements in post-stroke global mental disorders (mean difference (MD [95% CI] = 6.15 [-3.05, 15.36], GRADE: moderate) or sleep disorders (MD [95% CI] = 0.33 [-1.51, 1.81], GRADE: low) between Tai Chi and control groups.

CONCLUSION

Tai Chi may alleviate post-stroke depression in stroke survivors but has no clear effects on post-stroke cognitive and sleep disorders.

Left Prefrontal Connectivity Links Subthalamic Stimulation with Depressive Symptoms

OBJECTIVE

Subthalamic nucleus deep brain stimulation (STN-DBS) in Parkinson's disease (PD) not only stimulates focal target structures but also affects distributed brain networks. The impact this network modulation has on non-motor DBS effects is not well-characterized. By focusing on the affective domain, we systematically investigate the impact of electrode placement and associated structural connectivity on changes in depressive symptoms following STN-DBS, which have been reported to improve, worsen, or remain unchanged.

METHODS

Depressive symptoms before and after STN-DBS surgery were documented in 116 patients with PD from 3 DBS centers (Berlin, Queensland, and Cologne). Based on individual electrode reconstructions, the volumes of tissue activated (VTAs) were estimated and combined with normative connectome data to identify structural connections passing through VTAs. Berlin and Queensland cohorts formed a training and cross-validation dataset used to identify structural connectivity explaining change in depressive symptoms. The Cologne data served as the test-set for which depressive symptom change was predicted.

RESULTS

Structural connectivity was linked to depressive symptom change under STN-DBS. An optimal connectivity map trained on the Berlin cohort could predict changes in depressive symptoms in Queensland patients and vice versa. Furthermore, the joint training-set map predicted changes in depressive symptoms in the independent test-set. Worsening of depressive symptoms was associated with left prefrontal connectivity.

INTERPRETATION

Fibers connecting the electrode with left prefrontal areas were associated with worsening of depressive symptoms. Our results suggest that for the left STN-DBS lead, placement impacting fibers to left prefrontal areas should be avoided to maximize improvement of depressive symptoms. ANN NEUROL 2020;87:962-975.

Comparative efficacy of nine antidepressants in treating Chinese patients with post-stroke depression: A network meta-analysis

BACKGROUND

The efficacy ranking of antidepressants for post-stroke depression (PSD) has not been assessed thoroughly yet due to the lack of network meta-analyses with sufficiently large sample size.

METHODS

Seven databases including PubMed, Embase, CENTRAL, CBM, CNKI, WanFang and VIP were systematically searched for eligible randomized controlled trials (RCTs) regarding nine antidepressants (citalopram, escitalopram, venlafaxine, paroxetine, duloxetine, amitriptyline, doxepin, sertraline and mirtazapine) treating PSD patients. Stata 15 software and R software were utilized for statistical analyses.

RESULTS

51 RCTs were included in this NMA. For the key efficacy outcomes, escitalopram, mirtazapine, sertraline, citalopram, venlafaxine and paroxetine were associated with larger reduction of the Hamilton Depression Scale (HAMD) total score compared with placebo at 2 weeks. Among the nine antidepressants, escitalopram ranked the best while amitriptyline was the least helpful. At 4 weeks, citalopram ranked higher than placebo and the other eight antidepressants. In contrast, amitriptyline and doxepin were associated with minimal reduction of HAMD score. At 8 weeks, changes in HAMD score were significantly greater in nine antidepressants groups compared to placebo group. Besides, mirtazapine ranked higher than citalopram and escitalopram. At endpoint, mirtazapine was related to the highest response rate, followed by venlafaxine and escitalopram, respectively.

LIMITATIONS

No restriction was imposed on doses of every antidepressant.

CONCLUSIONS

Escitalopram was associated with a quicker relief of depression, but mirtazapine was probably the best option when it comes to the efficacy of 8-week treatment duration. Amitriptyline and doxepin were nearly the worst choice regardless of the duration (2, 4 or 8 weeks).

Neuropsychological Deficits Chronically Developed after Focal Ischemic Stroke and Beneficial Effects of Pharmacological Hypothermia in the Mouse

Stroke is a leading cause of human death and disability, with around 30% of stroke patients develop neuropsychological/neuropsychiatric symptoms, such as post-stroke depression (PSD). Basic and translational research on post-stroke psychological disorders is limited. In a focal ischemic stroke mouse model with selective damage to the sensorimotor cortex, sensorimotor deficits develop soon after stroke and spontaneous recovery is observed in 2-4 weeks. We identified that mice subjected to a focal ischemic insult gradually developed depression/anxiety like behaviors 4 to 8 weeks after stroke. Psychological/psychiatric disorders were revealed in multiple behavioral examinations, including the forced swim, tail suspension, sucrose preference, and open field tests. Altered neuronal plasticity such as suppressed long-term potentiation (LTP), reduced BDNF and oxytocin signaling, and disturbed dopamine synthesis/uptake were detected in the prefrontal cortex (PFC) during the chronic phase after stroke. Pharmacological hypothermia induced by the neurotensin receptor 1 (NTR1) agonist HPI-363 was applied as an acute treatment after stroke. A six-hr hypothermia treatment applied 45 min after stroke prevented depression and anxiety like behaviors examined at 6 weeks after stroke, as well as restored BDNF expression and oxytocin signaling. Additionally, hypothermia induced by physical cooling also showed an anti-depression and anti-anxiety effect. The data suggested a delayed beneficial effect of acute hypothermia treatment on chronically developed post-stroke neuropsychological disorders, associated with regulation of synaptic plasticity, neurotrophic factors, dopaminergic activity, and oxytocin signaling in the PFC.

Identification of Potential Metabolite Markers for Middle-Aged Patients with Post-Stroke Depression Using Urine Metabolomics

BACKGROUND

Post-stroke depression (PSD) is one of the most common complications in stroke survivors. But, there are still no objective methods to diagnose PSD. This study aims to identify potential biomarkers for diagnosing PSD in middle-aged stroke survivors.

METHODS

Middle-aged subjects aged 30 to 59 years (92 PSD patients and 89 stroke survivors without depression) were included in this study. Urinary metabolites were detected by gas chromatography-mass spectrometry (GC-MS). Differential urinary metabolites and potential biomarkers were screened by applying statistical analysis.

RESULTS

The different urinary metabolic phenotypes between PSD patients and stroke survivors without depression were identified. A total of 12 differential urinary metabolites were accurately identified by using orthogonal partial least-squares-discriminant analysis. After analyzing those 12 differential urinary metabolites by step-wise logistic regression analysis, only seven metabolites (palmitic acid, hydroxylamine, myristic acid, glyceric acid, lactic acid, tyrosine and azelaic acid) were finally selected as potential biomarkers for diagnosing PSD in middle-aged stroke survivors. A panel consisting of these potential biomarkers could effectively diagnose middle-aged PSD patients.

CONCLUSION

Urinary metabolic profiles were different between middle-aged PSD patients and stroke survivors without depression. Our results would be helpful in future for developing an objective method to diagnose PSD in middle-aged stroke survivors.

Predicted Brain Age After Stroke

Aging is a known non-modifiable risk factor for stroke. Usually, this refers to chronological rather than biological age. Biological brain age can be estimated based on cortical and subcortical brain measures. For stroke patients, it could serve as a more sensitive marker of brain health than chronological age. In this study, we investigated whether there is a difference in brain age between stroke survivors and control participants matched on chronological age. We estimated brain age at 3 months after stroke, and then followed the longitudinal trajectory over three time-points: within 6 weeks (baseline), at 3 and at 12 months following their clinical event. We found that brain age in stroke participants was higher compared to controls, with the mean difference between the groups varying between 3.9 and 8.7 years depending on the brain measure used for prediction. This difference in brain age was observed at 6 weeks after stroke and maintained at 3 and 12 months after stroke. The presence of group differences already at baseline suggests that stroke might be an ultimate manifestation of gradual cerebrovascular burden accumulation and brain degeneration. Brain age prediction, therefore, has the potential to be a useful biomarker for quantifying stroke risk.

A Human Depression Circuit Derived From Focal Brain Lesions

BACKGROUND

Focal brain lesions can lend insight into the causal neuroanatomical substrate of depression in the human brain. However, studies of lesion location have led to inconsistent results.

METHODS

Five independent datasets with different lesion etiologies and measures of postlesion depression were collated (N = 461). Each 3-dimensional lesion location was mapped to a common brain atlas. We used voxel lesion symptom mapping to test for associations between depression and lesion locations. Next, we computed the network of regions functionally connected to each lesion location using a large normative connectome dataset (N = 1000). We used these lesion network maps to test for associations between depression and connected brain circuits. Reproducibility was assessed using a rigorous leave-one-dataset-out validation. Finally, we tested whether lesion locations associated with depression fell within the same circuit as brain stimulation sites that were effective for improving poststroke depression.

RESULTS

Lesion locations associated with depression were highly heterogeneous, and no single brain region was consistently implicated. However, these same lesion locations mapped to a connected brain circuit, centered on the left dorsolateral prefrontal cortex. Results were robust to leave-one-dataset-out cross-validation. Finally, our depression circuit derived from brain lesions aligned with brain stimulation sites that were effective for improving poststroke depression.

CONCLUSIONS

Lesion locations associated with depression fail to map to a specific brain region but do map to a specific brain circuit. This circuit may have prognostic utility in identifying patients at risk for poststroke depression and therapeutic utility in refining brain stimulation targets.

Post-stroke neuronal circuits and mental illnesses

Stroke is one of the leading causes of death in the United States. It is also associated with severe mental illnesses, such as depression and anxiety, that hinder the rehabilitation of surviving patients. Thus, a better understanding of how stroke causes mental illnesses is crucial, but little is known about the neurological mechanisms involved. In this review, we summarized the most common mental illnesses developed after stroke, as well as the underlying mechanisms at the neuronal circuit level.