Advanced diffusion magnetic resonance imaging in patients with Alzheimer’s and Parkinson’s diseases

The prevalence of neurodegenerative diseases is increasing as human longevity increases. The objective biomarkers that enable the staging and early diagnosis of neurodegenerative diseases are eagerly anticipated. It has recently become possible to determine pathological changes in the brain without autopsy with the advancement of diffusion magnetic resonance imaging techniques. Diffusion magnetic resonance imaging is a robust tool used to evaluate brain microstructural complexity and integrity, axonal order, density, and myelination via the micron-scale displacement of water molecules diffusing in tissues. Diffusion tensor imaging, a type of diffusion magnetic resonance imaging technique is widely utilized in clinical and research settings;however, it has several limitations. To overcome these limitations, cutting-edge diffusion magnetic resonance imaging techniques, such as diffusional kurtosis imaging, neurite orientation dispersion and density imaging, and free water imaging, have been recently proposed and applied to evaluate the pathology of neurodegenerative diseases. This review focused on the main applications, findings, and future directions of advanced diffusion magnetic resonance imaging techniques in patients with Alzheimer's and Parkinson's diseases, the first and second most common neurodegenerative diseases, respectively.     

采用儿童仿真模体研究胸部DR不同千伏照射下的有效剂量

目的 采用1岁儿童仿真模体计算胸部数字化摄影（DR）不同千伏条件下儿童各组织、器官的吸收剂量，估算并比较不同千伏下有效剂量。方法 塑料管分装的热释光剂量计（TLD）布放入儿童模体预留的插孔，在60、 70、80和90 kV时，自动曝光控制（AEC）模式下各曝光20次，然后回收TLD，回实验室测量。计算出不同千伏下组织、器官的吸收剂量，并分别估算出受照儿童模体全身有效剂量。结果 在60、70、80和90 kV时照射野范围内各组织、器官随千伏的增高吸收剂量逐渐降低。4个实验组中有效剂量分别为0.43、0.34、0.29和0.23 μSv。结论 儿童模体胸部摄影使用较高千伏可减少组织、器官的吸收剂量和全身有效剂量。     

Increased foot strike variability during turning in Parkinson’s disease patients with freezing of gait

BackgroundTurning is a common trigger for freezing episodes in patients with Parkinson’s disease (PD). Freezing during turning can lead to falls and fractures and decreased quality of life.Research questionDoes foot-strike contact variability also increase during turning, as previously reported in straight gait in PD patients with Freezing of Gait (FOG)?MethodsSubjects were instructed to walk on a gait mat, making “normal pivot” (180°) turns at each end. ProtoKinetics Movement Analysis Software (PKMAS) software was used for analysis. Video recordings and foot-pressure-prints were studied to identify and define turn segments. Spatiotemporal gait and turn measures were then determined only for the turn segments. A movement disorders neurologist determined clinical freezes.Results100 subjects (28 controls, 38 noFOG and 34 FOG) were included. Compared to non-freezers (noFOG), FOG subjects had a smaller foot-strike during turning (a measure of completeness of foot contact with the mat) and increased foot-strike variability. FOG subjects also had a shorter stride-length, slower stride-velocity, and greater swing phase time and percentage during turns. After adjusting for turn direction, inner/outer leg dynamics showed heavier inner leg footsteps in FOG subjects. 38% of FOG subjects experienced freezes during turning. 69% of freezes occurred during the middle third of the turn. Turn-freezers had more severe spatiotemporal gait deficits.SignificanceDeveloping targeted therapies to retrain subjects to plant their whole foot on the ground with more consistency could help decrease episodes of freezing of gait.     

某肝病专科医院住院患者肝病疾病谱变化趋势分析

采用SPSS21.0版本统计软件对近10年来收治的所有肝病患者疾病谱特征及比例变化趋势进行分析,结果显示从进展程度来看,肝硬化及肝癌略有上升趋势;肝病的主要病因中,病毒性肝炎比例最高但呈下降趋势,药物性肝损伤及酒精性肝病呈明显上升趋势;病毒性肝炎患者中,乙型肝炎呈下降趋势但仍占大多数,丙型肝炎呈明显上升趋势;非感染性肝病呈现高发态势,应引起关注和重视。     

Characterization of a Parkinson’s disease rat model using an upgraded paraquat exposure paradigm

Animal models of human diseases are crucial experimental tools to investigate the mechanisms involved in disease pathogenesis and to develop new therapies. In spite of the numerous animal models currently available that reproduce several neuropathological features of Parkinson disease (PD), it is challenging to have one that consistently recapitulates human PD conditions in both motor behaviors and biochemical pathological outcomes. Given that, we have implemented a new paradigm to expose rats to a chronic low dose of paraquat (PQ), using osmotic minipumps and characterized the developed pathologic features over time. The PQ exposure paradigm used lead to a rodent model of PD depicting progressive nigrostriatal dopaminergic neurodegeneration, characterized by a 41% significant loss of dopaminergic neuron in the substantia nigra pars compacta (SNpc), a significant decrease of 18% and 40% of dopamine levels in striatum at week 5 and 8, respectively, and a significant 1.5‐fold decrease in motor performance. We observed a significant increase of microglia activation state, sustained levels of α‐synucleinopathy and increased oxidative stress markers in the SNpc. In summary, this is an explorative study that allowed to characterize an improved PQ‐based rat model that recapitulates cardinal features of PD and may represent an attractive tool to investigate several mechanisms underlying the various aspects of PD pathogenesis as well as for the validation of the efficacy of new therapeutic approaches that targets different mechanisms involved in PD neurodegeneration.     

Domain specific cognitive impairment in Parkinson’s patients with mild cognitive impairment

Mild cognitive impairment (MCI) affects nearly 20–50% patients with Parkinson’s disease (PD). It may be the prodromal stage of dementia and impacts quality of life of the patient and caregiver. Characterizing PD cognition at the stage of MCI may help in understanding of cognitive pathophysiology. This study assessed and compared cognition in patients with PD and mild cognitive impairment (PD-MCI, n = 32, age = 61.09 ± 5.97 years), PD patients with normal cognition (PD-NC, n = 32, age = 58.81 ± 6.15 years) and healthy controls (HC, n = 38, age = 57.39 ± 7.14 years). Montreal Cognitive Assessment Test (MoCA) was used for categorization of subjects. Cognitive assessment of five domains: executive function, attention, visuospatial function, memory and language (using two tests in each domain) were performed. The effect of PD clinical scores on cognition and cognitive domain specificity in diagnosing PD-MCI were assessed by correlation and receiver operating curve (ROC) analyses, respectively. All the analyses followed removal of potential confounds (age, education and clinical scores). Attention, memory, executive and visuospatial functions were impaired in PD-MCI on comparison with HC and PD-NC groups. Performance in digit span forward and trail making tests for attention and memory (immediate recall) were comparable in both the PD groups. Both the PD groups revealed impairment in attention, memory and language with respect to HC, suggesting the fronto-striatal and posterior cortical syndrome in PD. Highly significant Visual-N-back correlation with UPDRS-III may implicate the shared motor-visuospatial neural pathways. Visual-N-back/PGI delayed recall domains are promising in characterizing PD-MCI stage.     

COVID-19, SARS and MERS: A neurological perspective

Central to COVID-19 pathophysiology is an acute respiratory infection primarily manifesting as pneumonia. Two months into the COVID-19 outbreak, however, a retrospective study in China involving more than 200 participants revealed a neurological component to COVID-19 in a subset of patients. The observed symptoms, the cause of which remains unclear, included impaired consciousness, skeletal muscle injury and acute cerebrovascular disease, and appeared more frequently in severe disease. Since then, findings from several studies have hinted at various possible neurological outcomes in COVID-19 patients. Here, we review the historical association between neurological complications and highly pathological coronaviruses including SARS-CoV, MERS-CoV and SARS-CoV-2. We draw from evidence derived from past coronavirus outbreaks, noting the similarities and differences between SARS and MERS, and the current COVID-19 pandemic. We end by briefly discussing possible mechanisms by which the coronavirus impacts on the human nervous system, as well as neurology-specific considerations that arise from the repercussions of COVID-19.     

无症状WHOⅡ级脑胶质瘤的疾病特征和术后生存分析

目的分析无症状世界卫生组织(WHO)分级Ⅱ级脑胶质瘤的疾病特征和术后生存情况。方法回顾性分析2011年1月至2016年12月郑州大学第一附属医院神经外科手术治疗的271例WHOⅡ级脑胶质瘤患者的临床资料。将其分为无症状组(34例)和有症状组(237例)。对比分析两组患者疾病特征和预后的差异。多因素Cox回归分析方法分析影响预后的危险因素。结果与有症状组比较,无症状组肿瘤侵犯功能区的比率较低[分别为58.2%(138/237)、38.2%(13/34),P=0.041],年龄、性别、组织学类型、异柠檬酸脱氢酶(IDH)和端粒酶逆转录酶启动子(TERTp)是否突变、1p/19q是否共缺失,两组比较差异均无统计学意义(均P>0.05)。无症状组和有症状组术后肿瘤的全切除率分别为94.1%(32/34)、78.5%(186/237),行放疗的比率分别为97.1%(33/34)、78.5%(186/237),差异均有统计学意义(均P<0.05)。所有患者的随访时间为1.1~86.0个月(中位数为43.0个月),无症状组和有症状组的复发率分别为8.8%(3/34)、27.4%(65/237),中位生存期分别为45.5(28.5~80.0)个月、43.0(1.1~86.0)个月,差异均有统计学意义(均P<0.05)。Kaplan-Meier生存分析显示,随访期无症状组的总体生存率和无进展生存率均高于有症状组,差异均有统计学意义(均P<0.05)。多因素Cox回归分析结果显示,侵犯功能区(HR=2.048,95%CI:1.017~4.125,P=0.045)和复发(HR=0.009,95%CI:0.002~0.038,P<0.001)是患者术后生存的独立危险因素。而有、无症状不是术后生存的独立影响因素(HR=1.570,95%CI:0.200~12.346,P=0.668)。结论无症状与有症状WHOⅡ级脑胶质瘤患者比较,肿瘤位于功能区的比率和术后复发率低,术后患者的生存期更长,病理学特征无明显差异。     

经Ⅰ期造瘘口单部位腹腔镜辅助Martin-Duhamel术在全结肠型巨结肠症治疗中的应用

目的探讨经Ⅰ期造瘘口单部位腹腔镜辅助Martin-Duhamel术在先天性全结肠型巨结肠症患儿治疗中的应用价值,并对患儿术后排便功能进行评价。方法回顾性分析2014年6月至2017年6月间河北医科大学第二医院小儿外科收治的15例先天性全结肠型巨结肠症患儿的诊治及术后随访资料,其中男11例,女4例,月龄(5.11±2.67)个月,所有患儿Ⅰ期行回肠末端造瘘术,Ⅱ期行腹腔镜辅助Martin-Duhamel手术。术后随访2年,采用李正肛门功能临床评分法进行排便功能评分。定期肛管直肠测压,记录和比较患儿排便频率、性状及近远期并发症情况。结果15例均顺利完成手术,无中转开腹和死亡病例。手术时间(184.43±30.46)min,出血量(27.57±10.63)mL,肠功能恢复时间(3.29±0.91)d,术后住院时间(7.86±1.77)d。术后1~3个月排便频率为8~20次/日,术后6~9个月排便频率为4~8次/日,术后1~2年排便频率为2~4次/日(接近正常水平)。术后3个月和术后6个月排便评分无显著性差异(P=0.115),术后6个月和术后1年排便评分有显著性差异(P=0.040),术后1年和术后2年排便评分无显著性差异(P=0.542)。肛管直肠测压从术后6个月开始逐渐恢复至正常范围,与术前比较有显著性差异(肛管反射舒张压P=0.027;肛管静息压P=0.010;直肠静息压P=0.034)。术后6个月内因排便次数多致肛周湿疹、皮肤破溃6例,予以造口粉、氧化锌或芦荟软膏涂抹后恢复;小肠结肠炎1例,经保守治疗后缓解;无便秘等其他并发症发生。结论经Ⅰ期造瘘口单部位腹腔镜辅助Martin-Duhamel术治疗全结肠型巨结肠症患儿安全可行;排便功能可在术后6个月至1年逐渐恢复至接近正常儿童的水平。