Modulation of transcutaneous auricular vagus nerve stimulation on default mode network in patients with primary insomnia / 中国针灸

OBJECTIVE@#To explore the modulation of transcutaneous auricular vagus nerve stimulation (taVNS) on default mode network (DMN) in patients with primary insomnia (PI).@*METHODS@#A total of 22 PI patients (one patient dropped off and two patients were excluded) were included and treated with taVNS. The bilateral auricular points of Xin (CO15) and Shen (CO10) were selected and treated with disperse-dense wave at frequency of 4 Hz/20 Hz, the intensity was based on the patient's tolerance. taVNS was given once in the morning and once in the evening for 30 minutes each time. The treatment lasted for at least 5 days a week for 4 weeks. At the same time, 16 healthy subjects matched with gender and age were recruited. The Pittsburgh sleep quality index (PSQI) score was evaluated before and after treatment in PI patients. The resting-state functional magnetic resonance imaging (rs-fMRI) data of PI patients before and after treatment and healthy subjects at baseline period were collected to observe the effect of taVNS on the functional connection (FC) between posterior cingulate cortex (PCC) and whole brain.@*RESULTS@#After treatment, the total score of PSQI in PI patients was lower than that before treatment (P<0.01). Compared with healthy subjects, the FC of the left PCC was increased either with the left orbital superior frontal gyrus or with left middle frontal gyrus (P<0.001), and the FC between right PCC and left middle frontal gyrus was increased in PI patients before treatment (P<0.001). Compared before treatment, the FC between left PCC and left middle frontal gyrus was decreased (P<0.05), and the FC of the right PCC was decreased either with the right medial prefrontal cortex or with the left middle frontal gyrus in PI patients after treatment (P<0.001, P<0.01).@*CONCLUSION@#taVNS can modulate the FC between anterior and posterior DMN, and between DMN and cognitive control network of PI patients, which may be one of the brain effect mechanisms of taVNS in the treatment of PI patients.

Posterior cingulate gyri metabolic alterations in HIV-positive patients with and without memory deficits / Alterações metabólicas no giro do cíngulo posterior em pacientes HIV-positivos com e sem déficit de memória

Abstract Objective: We aimed to evaluate whether human immunodeficiency virus (HIV)-positive patients with and without clinically significant memory deficits and healthy control participants differ on in vivo hydrogen-1 magnetic resonance spectroscopy (H-MRS) in the posterior cingulate gyri. Materials and Methods: In total, 21 HIV-positive patients with memory deficit (HIV+wMD) were compared with 15 HIV-positive patients without memory deficit (HIV+wOMD) and 22 sex-, age-, and education-matched control participants. Memory impairments were classified based on the participants' performance on the Rey Auditory Verbal Learning Test. Short echo time (30 ms), single-voxel H-MRS was performed using a 1.5-T magnetic resonance scanner. Results: The HIV+wMD and HIV+wOMD groups had higher choline/creatine ratio in the posterior cingulate gyri than the control group. There were no significant metabolite ratio differences between the HIV+wMD and HIV+wOMD groups. Conclusion: HIV-positive patients with and without memory deficits had significantly higher choline/creatine ratios than controls in the posterior cingulate gyri, which may reflect cerebral inflammation, altered cell membrane metabolism, microgliosis, and/or astrocytosis.

Resumo Objetivo: Nós avaliamos se os pacientes HIV-positivos com e sem déficits de memória clinicamente significativos e controles saudáveis diferem na espectroscopia de prótons do giro do cíngulo posterior, por ressonância magnética (RM) cerebral. Materiais e Métodos: Vinte e um pacientes HIV-positivos com déficit de memória foram comparados com 15 pacientes HIV-positivos sem déficit de memória e 22 controles, pareados por sexo, idade e escolaridade. As deficiências de memória foram classificadas por meio do desempenho no Teste de Aprendizagem Auditivo-Verbal de Rey. A espectroscopia de prótons foi realizada com tempo de eco curto (30 ms), por voxel único, no giro do cíngulo posterior, utilizando aparelho de RM de 1,5 T. Resultados: Os pacientes HIV-positivos com e sem déficit de memória apresentaram aumento da relação colina/creatina no giro do cíngulo posterior, comparados aos controles. Não houve diferenças significativas nas relações metabólicas no grupo HIV-positivo com déficit de memória, em relação ao grupo de pacientes HIV-positivo sem déficit. Conclusão: Pacientes HIV-positivos com e sem déficits de memória apresentaram relações colina/creatina significativamente aumentadas em relação aos controles, no giro do cíngulo posterior, o que pode refletir inflamação cerebral, alteração do metabolismo da membrana celular, microgliose e/ou astrocitose.

Distinct Neural Correlates of Executive Function by Amyloid Positivity and Associations with Clinical Progression in Mild Cognitive Impairment

PURPOSE: This study aimed to identify the neural basis of executive function (EF) in amnestic mild cognitive impairment (aMCI) according to beta-amyloid (Aβ) positivity. Furthermore, we explored if the identified brain areas could serve as predictors for clinical progression. MATERIALS AND METHODS: We included individuals with aMCI using data from [¹⁸F]-florbetapir-positron emission tomography (PET), fluorodeoxyglucose-PET, and EF scores, as well as follow-up clinical severity scores at 1 and 5 years from baseline from the Alzheimer's Disease Neuroimaging Initiative database. The correlations between EF score and regional cerebral glucose metabolism (rCMglc) were analyzed separately for aMCI with low Aβ burden (aMCI Aβ−, n=230) and aMCI with high Aβ burden (aMCI Aβ+, n=268). Multiple linear regression analysis was conducted to investigate the associations between rCMglc and clinical progression. RESULTS: Longitudinal courses differed between aMCI Aβ− and aMCI Aβ+ groups. On average, aMCI Aβ− subjects maintained their level of clinical severity, whereas aMCI Aβ+ subjects showed progression. EF impairment in aMCI Aβ− was related to the anterior cingulate cortex (ACC), whereas that in aMCI Aβ+ was related to Alzheimer's Disease-vulnerable brain regions. ACC and the posterior cingulate cortex were associated with clinical progression in aMCI Aβ− and aMCI Aβ+, respectively. CONCLUSION: Our findings suggest that although MCI subjects showed similar behavioral phenotypes at the time of diagnosis, EF and further progression were associated with different brain regions according to Aβ burden. Clarification of the etiologies and nature of EF impairment in aMCI are critical for disease prognosis and management.

Dysfunctional Social Reinforcement Processing in Disruptive Behavior Disorders: An Functional Magnetic Resonance Imaging Study

OBJECTIVE: Prior functional magnetic resonance imaging (fMRI) work has revealed that children/adolescents with disruptive behavior disorders (DBDs) show dysfunctional reward/non-reward processing of non-social reinforcements in the context of instrumental learning tasks. Neural responsiveness to social reinforcements during instrumental learning, despite the importance of this for socialization, has not yet been previously investigated. METHODS: Twenty-nine healthy children/adolescents and 19 children/adolescents with DBDs performed the fMRI social/non-social reinforcement learning task. Participants responded to random fractal image stimuli and received social and non-social rewards/non-rewards according to their accuracy. RESULTS: Children/adolescents with DBDs showed significantly reduced responses within the caudate and posterior cingulate cortex (PCC) to non-social (financial) rewards and social non-rewards (the distress of others). Connectivity analyses revealed that children/adolescents with DBDs have decreased positive functional connectivity between the ventral striatum (VST) and the ventromedial prefrontal cortex (vmPFC) seeds and the lateral frontal cortex in response to reward relative to non-reward, irrespective of its sociality. In addition, they showed decreased positive connectivity between the vmPFC seed and the amygdala in response to non-reward relative to reward. CONCLUSION: These data indicate compromised reinforcement processing of both non-social rewards and social non-rewards in children/adolescents with DBDs within core regions for instrumental learning and reinforcement-based decision-making (caudate and PCC). In addition, children/adolescents with DBDs show dysfunctional interactions between the VST, vmPFC, and lateral frontal cortex in response to rewarded instrumental actions potentially reflecting disruptions in attention to rewarded stimuli.

Abnormal Effective Connectivity of the Anterior Forebrain Regions in Disorders of Consciousness / 神经科学通报·英文版

A number of studies have indicated that disorders of consciousness result from multifocal injuries as well as from the impaired functional and anatomical connectivity between various anterior forebrain regions. However, the specific causal mechanism linking these regions remains unclear. In this study, we used spectral dynamic causal modeling to assess how the effective connections (ECs) between various regions differ between individuals. Next, we used connectome-based predictive modeling to evaluate the performance of the ECs in predicting the clinical scores of DOC patients. We found increased ECs from the striatum to the globus pallidus as well as from the globus pallidus to the posterior cingulate cortex, and decreased ECs from the globus pallidus to the thalamus and from the medial prefrontal cortex to the striatum in DOC patients as compared to healthy controls. Prediction of the patients' outcome was effective using the negative ECs as features. In summary, the present study highlights a key role of the thalamo-basal ganglia-cortical loop in DOCs and supports the anterior forebrain mesocircuit hypothesis. Furthermore, EC could be potentially used to assess the consciousness level.

1H-MRS detection of metabolites in posterior cingulate gyrus of Parkinson disease with cognitive impairment patients / 中国医学影像技术

Objective To investigate the value of 1H-MRS technology combined with linear combination model (LCmodel) software in diagnosis of Parkinson disease (PD) cognitive impairment.Methods Thirty-five PD patients (PD group) and 22 matched healthy subjects (control group) were collected.Patients in PD group were divided into PDN and PDMCI subgroups according to whether having cognitive impairment or not.The concentration of metabolites of posterior cingulate gyrus (PCG)was applied with 1H-MRS technology combined with LCmodel software.The differences of metabolites were compared between the two groups,and the correlations between metabolites level and cognitive status were analyzed.Results The absolute concentrations of metabolites in PDN subgroup were not significantly different from those in control group (all P＞0.05).The absolute concentrations of total creatine (tCr),N-acetyl aspartate (NAA),myo-inositol (mI) and glycerophosphocholine+ phosphocholine (tCho) in PDMCI subgroup were lower than those in control group (all P＜0.05).The absolute concentration of tCr in PDMCI subgroup was lower than that in PDN subgroup (P＜0.05).There was positive correlation among the absolute concentration of tCr (r=0.444,P=0.01),glutathione (GSH;r=0.393,P=0.024) and MMSE scores,as well as among the absolute concentration of tCr (r=0.367,P=0.035),GSH (r=0.376,P=0.031),tCho (r=0.375,P=0.031) and MoCA scores.Conclusion 1 H-MRS technology combined with LCmodel software can quantitatively analyze the changes of metabolites in PCG,therefore being helpful to evaluating PD cognitive impairment.

Magnetic resonance spectroscopy study of the left posterior cingulate cortex in type 2 diabetic encephalopathy patients / 实用放射学杂志

Objective To analyze the changes of metabolites in the left posterior cingulate cortex (PCC)in patients with type 2 diabetes mellitus (T2DM),diabetic encephalopathy(DE)and healthy control(HC),to discuss the pathogenesis and to provide the biological information for the early diagnosis of DE.Methods 46 patients with clinical diagnosis of T2DM and 26 matched HC were received single-voxel MRS on the left PCC using Siemens Verio 3.0T MR scanner.Participants were divided into two groups based on MoCA scoring criteria and diabetic retinopathy,including DM group (n=31)and DE group (n=15).All T2DM patients were received fasting blood glucose,glycated hemoglobin (HbAlc)and other clinical labortory tests before MR scans.SPSS 21.0 software package was used for statistical analysis.Results (1)Ins and Ins/Cr were increased gradually in DE compared with HC and DM groups(P＜0.05).(2) NAA/Ins ratio in DE group was significant lower than that in DM and HC group,but no significant difference was observed between DM and DE groups(P＞0.05).No significant differences exsited in NAA/Cr among these three groups(P＞0.05).Conclusion MRS can be more sensitive to detect DE patients on the left PCC-related metabolic abnormalities and help DE with early screening and preliminary clinical diagnosis.The increase Ins/Cr in the left PCC area is more sensitive to the brain injury of T2DM and can refelect the progress degree.It is necessary to expand the sample size to verify its diagnostic efficacy and early warning of the brain injury.

Primary research of multi-voxel proton-magnetic resonance spectroscopy in Alzheimer's disease / 实用放射学杂志

Objective To explore the spatial distribution of abnormal brain areas and metabolic changes in Alzheimer's disease (AD),and provide a reference for early clinical diagnosis of AD.Methods Sixteen cases of AD patients and 1 6 healthy controls (HC)underwent multi-voxel 1H-MRS examination with semi-LASER sequence.The posterior cingulate gyrus section was localized as the volume of interest(VOI)level.The VOI consisted of bilateral posterior cingulate gyrus,occipital lobe cortex,lateral ventricle paratrigonal white matter and dorsal thalamus.N-acetylaspartate (NAA),creatine (Cr),choline (Cho),myo-inositol (MI)and glutamate-glutamine (Glx)concentration were measured.Differences in metabolite were compared between AD and HC groups.Relationships between metabolite and clinical mini-mental state examination(MMSE)score were analyzed.Results For metabolite index in VOI of right hemisphere:the AD group displayed significantly lower NAA,NAA/Cr,NAA/MI and higher MI,MI/Cr levels in posterior cingulate gyrus,lower NAA,Glx levels in occipital lobe cortex,lower NAA and higher Cho levels in dorsal thalamus.For metabolite index in VOI of left hemisphere:the AD group displayed significantly lower NAA,NAA/Cr,NAA/MI,Glx/Cr and higher MI/Cr levels in posterior cingulate gyrus,lower NAA and higher Cho/Cr levels in occipital lobe cortex,lower NAA and higher cho levels in lateral ventricle paratrigonal white matter,lower Glx and higher Cho levels in dorsal thalamus.NAA/Cr was positively correlated with Glx/Cr in left posterior cingulate gyrus in AD group.Conclusion NAA is decreased while MI is increased in posterior cingulate gyrus in AD patients.Cho is increased in both grey and white matter.Glx is decreased mainly within grey matter,involving both cortex and sub cortex structures.

Comprometimento cognitivo vascular: leucoaraiose, hipocampos e espectroscopia de prótons ? Estudo preliminar / Vascular cognitive impairment: leucoaraiosis, hippocampi, and proton spectroscopy – Preliminary study

Introdução: O continuum do comprometimento cognitivo vascular (CCV) compreende segmento não demência (CCV-ND), segmento demência (CCV-D ou DV), sendo o subtipo mais frequente o CCV subcortical, e inclui, ainda, formas mistas (CCV + DA). Ressonância magnética (RM) do cérebro é o método mais apropriado para avaliação das lesões vasculares, dimensão dos hipocampos e do espectro de prótons (1HMRS). Objetivo: Comparar os valores de metabólitos dos hipocampos (HC) e da região do cíngulo posterior (CP) em grupos de casos de CCV subcortical. Métodos: Casos (n = 55) foram selecionados a partir do banco de dados sobre CCV. Imagens obtidas por equipamento Signa Horizon LX-GE de 1,5T, com protocolo-padrão para aquisição estrutural (incluindo FLAIR, T2 e aquisição para 1H-MRS). Metabólitos estudados (relações) incluíram: Naa/Cr, Co/Cr e mI/Cr. Os casos foram definidos radiologicamente (leucoaraiose grau 3 pela escala de Fazekas modificada) e subdivididos de acordo com a escala de Leon (0-3) em dois em grupos hipocampais (grHC): grHC [0+1] e grHC [2+3]. Análise estatística pelo ANOVA e Tukey. Resultados: A relação Naa/Cr nos HC mostrou diferença significativa entre o grHC [0+1] e o grHC [2+3], o que representa diminuição de integridade (perda) neuronal no segundo, enquanto os CP desses grupos mantiveram os valores estáveis. Houve diferença significativa entre o grHC [2+3] em relação aos CP de ambos os grupos, enquanto o grHC [0+1] ficou compatível com os valores dos CP. Comparação dos valores obtidos em estudos anteriores em CCL e DA mostrou o Naa/Cr com valor intermediário entre os do CCL e da DA nos HC e equivalência de valores nos CP. Conclusão: A 1HMRS possibilita analisar o grau de perda neuronal, além de alterações de membrana e neuroglial dessas regiões. Assim, podem ser obtidas informações para melhor compreender o continuum CCV subcortical (que pode incluir CCV + DA), visando determinar a contribuição dessas duas patologias, caso haja, ao comprometimento cognitivo...

Introduction: Vascular cognitive impairment (VCI) continuum comprisesno-dementia segment (VCI-ND), dementia segment (VCI-D or VaD), with subcortical VCI as the most frequent subtype, and additionally mixed forms (VCI + AD). Magnetic resonance imaging (MRI) of the brain is the most proper method for vascular lesions, hippocampal size, and proton spectrum (1HMRS) assessment. Objective: Comparison of the values of metabolites at the hippocampi (HC) and posterior cingulate (PC) region of groups of cases of subcortical VCI. Methods: Cases (n = 55) were selected from a database on VCI. Images were obtained with Signa Horizon LX-GE de 1.5T equipment and a standard protocol for structural and 1H-MRS acquisitions. Studied metabolites (reasons) were: Naa/Cr, Coh/Cr e mI/Cr. The cases were radiologically defined (grade 3 leucoaraiosis on modified Fazekas scale), and according de Leon?s scale (0-3) subdivided in two hippocampal groups (grHC): grHC[0+1] and grHC[2+3]. Statistical analysis with ANOVA and Tukey. Results: The reason Naa/Cr at the HC showed a significant difference between the grHC[0+1] and grHC[2+3], that represents a reduction of neuronal integrity (loss) in the latter, while at PC these groups maintained stable values. There was a significant difference between grHC [2+3] in relation to PC of both groups, while grHC [0+1] remained compatible with PC values. The comparison of the values obtained from previous studies on MCI and AD showed Naa/Cr with intermediate values between MCI and AD at the HC, and equivalence at the PC. Conclusion: 1HMRS allows for the analysis of the degree of neuronal loss, besides membrane and neuroglial changes of these regions. Thus, information may be obtained for a better understanding of the subcortical VCI continuum (that may include VCI + AD), aiming to determine the contribution of these two pathologies, if present, to the cognitive impairment...

Changes of resting-state default-mode network functional connectivity in patients with treatment-resistant depression / 中国医学影像技术

Objective To explore the difference of resting-state default-mode network functional connectivity in patients with treatment-resistant depression (TRD) and in healthy subjects. Methods Ten patients with TRD and 12 healthy control subjects underwent 440 s fMRI scans while resting quietly. Functional connectivity analysis was used to isolate the default mode network in each subject. Group maps of the default-mode network were generated and compared between the two groups. A within-group analysis was performed in the depressed group to explore effects of depression refractoriness on network functional connectivity. Results Functional connectivity of both side of middle temporal gyrus, rectal gyrus, precuneus gray matter, left orbital gyrus, right inferior parietal lobule, and post cingulate gyrus in TRD group weakened compared with that of the control subjects. Conclusion There are resting default network connection weakening in multiple brain areas in TRD patients, which may lead to self-control and emotional behavior abnormal in patients.