基于磁共振技术的功能性胃肠病中枢病理变化研究现状＊

目的 通过对基于磁共振技术的功能性胃肠病（Functional Gastrointestinal Disorders，FGIDs）中枢病理变化相关文献进行回顾，分析该领域研究现状，以期为今后研究提供参考与借鉴。方法 以Web of Science收录1993年-2019年相关文献为对象，应用CiteSpace软件对文献的基本情况、研究的病种及重点脑区等进行共现分析，并绘制相关可视化图谱。结果 ①共获得文献151篇，发文量总体呈上升趋势，2017年文献发表数达到最高；②发表论文数量排名前3的国家分别是美国、中国、德国；③发文频次位于前3位的作者分别是Emeran A Mayer、K Tillisch、Fang Zeng；④主要是胃肠疾病类与影像学类相关杂志发文，核心期刊为Gastroenterology，Gut，Neurogastroenty and Molity；⑤对关键词进行聚类分析后，形成10个聚类群，分别为functional dyspepsia、brain response、endoanal ultrasound、prefrontal cortex、image cytometry、colonic function、functional constipation、acupuncture、resting-state、diffusion tensor imaging、default mode network。结论 ①基于神经影像技术，对FGIDs相关中枢机制的研究日益受到关注；②研究的主要病种是肠易激综合征、功能性消化不良和功能性便秘；③大脑前额叶皮质，前扣带回皮质，默认网络是FGIDs神经影像领域中备受关注的区域；④针灸是基于磁共振技术的FGIDs中枢机制研究中最常见的干预治疗方式。     

A comparison of neural responses to appetitive and aversive stimuli in humans and other mammals

Distinguishing potentially harmful or beneficial stimuli is necessary for the self-preservation and well-being of all organisms. This assessment requires the ongoing valuation of environmental stimuli. Despite much work on the processing of aversive- and appetitive-related brain signals, it is not clear to what degree these two processes interact across the brain. To help clarify this issue, this report used a cross-species comparative approach in humans (i.e. meta-analysis of imaging data) and other mammals (i.e. targeted review of functional neuroanatomy in rodents and non-human primates). Human meta-analysis results suggest network components that appear selective for appetitive (e.g. ventromedial prefrontal cortex, ventral tegmental area) or aversive (e.g. cingulate/supplementary motor cortex, periaqueductal grey) processing, or that reflect overlapping (e.g. anterior insula, amygdala) or asymmetrical, i.e. apparently lateralized, activity (e.g. orbitofrontal cortex, ventral striatum). However, a closer look at the known value-related mechanisms from the animal literature suggests that all of these macroanatomical regions are involved in the processing of both appetitive and aversive stimuli. Differential spatiotemporal network dynamics may help explain similarities and differences in appetitive- and aversion-related activity.     

Future perspectives on neural mechanisms underlying rhythm and music based neurorehabilitation in Parkinson’s disease

Parkinson’s disease (PD) is characterized primarily by a dysfunctional basal ganglia (BG) system, producing motor and non-motor symptoms. A significant number of studies have demonstrated that rhythmic auditory stimulation can improve gait and other motor behaviors in PD that are not well managed by the conventional therapy. As music, being highly complex stimulus, can modulate brain activity/function in distributed areas of brain, the therapeutic properties of music potentially extend to alleviate non-motor symptoms of PD. Despite the clinical, behavioral evidence and promises of rhythm and music based interventions, the neural substrates underlying the effectiveness are poorly understood. The goal of this review is to appraise the current state of knowledge in order to direct further neuroimaging studies that help to determine the therapeutic effects of rhythm and music based interventions for motor and non-motor symptoms of PD.     

Pre-surgical cortical activation to food pictures is associated with weight loss following bariatric surgery

BackgroundRecent research suggests that preintervention functional magnetic resonance imaging (fMRI) data may predict weight loss outcomes among patients who participate in a behavioral weight loss plan. No study has examined whether presurgical brain activation can predict outcomes following bariatric surgery.MethodThe aim of the present study was to determine if brain activations during a presurgical fMRI food-motivation paradigm are associated with weight loss 3 and 6 months following laparoscopic adjustable gastric banding (LAGB). Nineteen participants viewed food and nonfood pictures from a well-established food motivation paradigm during an fMRI scanning session before LAGB surgery. Weight was assessed presurgery and 3 and 6 months postsurgery; data for all participants was available at each time point. fMRI data were analyzed using the BrainVoyager QX statistical package. Whole brain voxelwise correlations of presurgery (food–nonfood) brain activation and weight, corrected for multiple comparisons, were performed to analyze the relationship between presurgical brain activation and subsequent weight loss. The settings were a medical university brain imaging center and 2 surgical weight loss centers in a major metropolitan area.ResultsIncreased activity in frontal regions associated with cognitive control (medial, middle, superior frontal gyrus) and posterior cingulate cortex was associated with weight loss following LAGB.ConclusionWe found that neural activity in previously established regions associated with cognitive and behavioral self-regulation predicts weight loss following bariatric surgery. These preliminary findings highlight the role of neural circuitry in the success and maintenance of weight loss and suggest a possible future use of fMRI in screening LAGB surgery candidates.     

Introduction and overview of the special issue “Brain imaging and aging”: The new era of neuroimaging in aging research

It is well known that the brain is one of the organs particularly affected by aging in terms of function, relative to the gastrointestinal tract and liver, which exhibit less functional decline. There is also a wide range of age-related neurological disorders such as stroke, Alzheimer’s disease, and Parkinson’s disease. Therefore, it is very important to understand the relationship between functional age-related change and neurological dysfunction. Neuroimaging techniques including magnetic resonance imaging and positron emission tomography have been significantly improved over recent years. Many physicians and researchers have investigated various mechanisms of age-related cerebral change and associated neurological disorders using neuroimaging techniques. In this special issue of Ageing Research Reviews, we focus on cerebral- and neuro-imaging, which are a range of tools used to visualize structure, functions, and pathogenic molecules in the nervous system. In addition, we summarize several review articles about the history, present values, and future perspectives of neuroimaging modalities.     

Neuroimaging and Cognitive Evidence for Combined HIV-Alcohol Effects on the Central Nervous System: A Review

Alcohol use disorder (AUD) among people living with HIV (PLWH) is a significant public health concern. Despite the advent of effective antiretroviral therapy, up to 50% of PLWH still experience worsened neurocognition, which comorbid AUD exacerbates. We report converging lines of neuroimaging and neuropsychological evidence linking comorbid HIV/AUD to dysfunction in brain regions linked to executive function, learning and memory, processing speed, and motor control, and consequently to impairment in daily life. The brain shrinkage, functional network alterations, and brain metabolite disruption seen in individuals with HIV/AUD have been attributed to several interacting pathways: viral proteins and EtOH are directly neurotoxic and exacerbate each other’s neurotoxic effects; EtOH reduces antiretroviral adherence and increases viral replication; AUD and HIV both increase gut microbial translocation, promoting systemic inflammation and HIV transport into the brain by immune cells; and HIV may compound alcohol’s damaging effects on the liver, further increasing inflammation. We additionally review the neurocognitive effects of aging, Hepatitis C coinfection, obesity, and cardiovascular disease, tobacco use, and nutritional deficiencies, all of which have been shown to compound cognitive changes in HIV, AUD, and in their comorbidity. Finally, we examine emerging questions in HIV/AUD research, including genetic and cognitive protective factors, the role of binge drinking in HIV/AUD-linked cognitive decline, and whether neurocognitive and brain functions normalize after drinking cessation.     

Cognitive Dysfunction in Chronic Hepatitis C: A Review

The hepatitis C virus (HCV) is a common blood-borne illness that affects up to 2% of the world’s population and almost 4 million Americans. Cognitive impairment, or difficulty with thinking, has become a well-established symptom in persons with end stage liver disease. It was previously assumed that cognitive impairment was a consequence of cirrhosis-associated hepatic encephalopathy. Recent evidence, however, suggests that approximately one-third of people with chronic HCV experience cognitive impairment even in the absence of cirrhosis and that its occurrence is unrelated to other indices of liver function, such as laboratory values, viral load, and genotype. In the present review, evidence outlining the presence of cognitive deficits associated with HCV, possible etiological factors, effects of antiviral therapy, and co-infection with human immunodeficiency virus (HIV) is presented. Implications of these findings and directions for future work are discussed.     

Verbal episodic memory deficits in remitted bipolar patients: A combined behavioural and fMRI study

Background

Episodic memory deficits affect the majority of patients with bipolar disorder (BD).

Aims

The study investigates episodic memory performance through different approaches, including behavioural measures, physiological parameters, and the underlying functional activation patterns with functional neuroimaging (fMRI).

Methods

26 Remitted BD patients and a matched group of healthy controls underwent a verbal episodic memory test together with monitored autonomic response, psychopathological ratings and functional magnetic resonance imaging (fMRI) during the verbal episodic memory test.

Results

Compared to healthy controls, BD patients performed significantly worse during the episodic memory task. The results further indicate that verbal episodic memory deficits in BD are associated with abnormal functional activity patterns in frontal, occipital and limbic regions, and an increase in stress parameters.

Limitations

We aimed to minimise sample heterogeneity by setting clear criteria for remission, based on the scores of a depression (BDI II) and mania scale (BRMAS) and on the DSM IV criteria. However, our patients were not symptom-free and scored higher on BDI II scores than the control group.

Conclusions

The results are of interest for the treatment of cognitive symptoms in BD patients, as persistent cognitive impairment may hamper full rehabilitation.