Assessment of gray matter heterotopia by magnetic resonance imaging

AIM:To evaluate magnetic resonance imaging(MRI) features of different types of gray matter heterotopia.METHODS:Between June 2005 and December 2009,the medical records and MRI studies of patients with gray matter heterotopia were reviewed.The MRI morphologic findings of heterotopia were recorded along with the presence and type of associated cranial malformations.Available clinical and electrophysiological data were also recorded.RESULTS:20 patients were included in the study.Their ages ranged from 9 mo to 39 years with a mean age of 15 years.All patients suffered from epileptic seizures.According to the location of heterotopia,patients were classified into three groups:subependymal(12),subcortical(5) and band(3) heterotopia.CONCLUSION:MRI was useful in diagnosing and differentiating between various types of gray matter heterotopia.The severity of clinical manifestations of heterotopia was related to the location and pattern of heterotopia.Determination of heterotopia type and its extent is useful for management planning and predicting prognosis.

Persistent alterations in gray matter in COVID-19 patients experiencing sleep disturbances:a 3-month longitudinal study

Sleep disturbances are among the most prevalent neuropsychiatric symptoms in individuals who have recovered from severe acute respiratory syndrome coronavirus 2 infections.Previous studies have demonstrated abnormal brain structures in patients with sleep disturbances who have recovered from coronavirus disease 2019(COVID-19).However,neuroimaging studies on sleep disturbances caused by COVID-19 are scarce,and existing studies have primarily focused on the long-term effects of the virus,with minimal acute phase data.As a result,little is known about the pathophysiology of sleep disturbances in the acute phase of COVID-19.To address this issue,we designed a longitudinal study to investigate whether alterations in brain structure occur during the acute phase of infection,and verified the results using 3-month follow-up data.A total of 26 COVID-19 patients with sleep disturbances(aged 51.5±13.57 years,8 women and 18 men),27 COVID-19 patients without sleep disturbances(aged 47.33±15.98 years,9 women and 18 men),and 31 age-and gender-matched healthy controls(aged 49.19±17.51 years,9 women and 22 men)were included in this study.Eleven COVID-19 patients with sleep disturbances were included in a longitudinal analysis.We found that COVID-19 patients with sleep disturbances exhibited brain structural changes in almost all brain lobes.The cortical thicknesses of the left pars opercularis and left precuneus were significantly negatively correlated with Pittsburgh Sleep Quality Index scores.Additionally,we observed changes in the volume of the hippocampus and its subfield regions in COVID-19 patients compared with the healthy controls.The 3-month follow-up data revealed indices of altered cerebral structure(cortical thickness,cortical grey matter volume,and cortical surface area)in the frontal-parietal cortex compared with the baseline in COVID-19 patients with sleep disturbances.Our findings indicate that the sleep disturbances patients had altered morphology in the cortical and hippocampal structures during the acute phase of infection and persistent changes in cortical regions at 3 months post-infection.These data improve our understanding of the pathophysiology of sleep disturbances caused by COVID-19.

Differences in brain structure in patients with distinct sites of chronic pain:A voxel-based morphometric analysis

A reduction in gray matter volume is common in patients with chronic back pain, and different types of pain are associated with gray matter abnormalities in distinct brain regions. To examine differ- ences in brain morphology in patients with low back pain or neck and upper back pain, we investi- gated changes in gray matter volume in chronic back pain patients having different sites of pain using voxel-based morphometry. A reduction in cortical gray matter volume was found primarily in the left postcentral gyrus and in the left precuneus and bilateral cuneal cortex of patients with low back pain. In these patients, there was an increase in subcortical gray matter volume in the bilateral putamen and accumbens, right pallidum, right caudate nucleus, and left amygdala. In upper back pain patients, reduced cortical gray matter volume was found in the left precentral and left postcen- tral cortices. Our findings suggest that regional gray matter volume abnormalities in low back pain patients are more extensive than in upper back pain patients. Subcortical gray matter volume in- creases are found only in patients with low back pain.

Assessment of structural brain changes in patients with type 2 diabetes mellitus using the MRI-based brain atrophy and lesion index

Patients with type 2 diabetes mellitus(T2 DM) often have cognitive impairment and structural brain abnormalities.The magnetic resonance imaging(MRI)-based brain atrophy and lesion index can be used to evaluate common brain changes and their correlation with cognitive function,and can therefore also be used to reflect whole-brain structural changes related to T2 DM.A total of 136 participants(64 men and 72 women,aged 55–86 years) were recruited for our study between January 2014 and December 2016.All participants underwent MRI and Mini-Mental State Examination assessment(including 42 healthy control,38 T2 DM without cognitive impairment,26 with cognitive impairment but without T2 DM,and 30 T2 DM with cognitive impairment participants).The total and sub-category brain atrophy and lesion index scores in patients with T2 DM with cognitive impairment were higher than those in healthy controls.Differences in the brain atrophy and lesion index of gray matter lesions and subcortical dilated perivascular spaces were found between non-T2 DM patients with cognitive impairment and patients with T2 DM and cognitive impairment.After adjusting for age,the brain atrophy and lesion index retained its capacity to identify patients with T2 DM with cognitive impairment.These findings suggest that the brain atrophy and lesion index,based on T1-weighted and T2-weighted imaging,is of clinical value for identifying patients with T2 DM and cognitive impairment.Gray matter lesions and subcortical dilated perivascular spaces may be potential diagnostic markers of T2 DM that is complicated by cognitive impairment.This study was approved by the Medical Ethics Committee of University of South China(approval No.USC20131109003) on November 9,2013,and was retrospectively registered with the Chinese Clinical Trial Registry(registration No.Chi CTR1900024150) on June 27,2019.

Regional brain structural abnormality in ischemic stroke patients:a voxel-based morphometry study

Our previous study used regional homogeneity analysis and found that activity in some brain areas of patients with ischemic stroke changed significantly. In the current study, we examined structural changes in these brain regions by taking structural magnetic resonance imaging scans of 11 ischemic stroke patients and 15 healthy participants, and analyzing the data using voxel-based morphometry. Compared with healthy participants, patients exhibited higher gray matter density in the left inferior occipital gyrus and right anterior white matter tract. In contrast, gray matter density in the right cerebellum, left precentral gyrus, right middle frontal gyrus, and left middle temporal gyrus was less in ischemic stroke patients. The changes of gray matter density in the middle frontal gyrus were negatively associated with the clin- ical rating scales of the Fugl-Meyer Motor Assessment （r = -0.609, P = 0.047） and the left middle temporal gyrus was negatively correlated with the clinical rating scales of the nervous functional deficiency scale （r = -0.737, P = 0.010）. Our findings call objectively identify the functional abnormality in some brain regions of ischemic stroke patients.

脑灰质异位症的临床及MRI诊断

目的探讨脑灰质异位症的临床表现及MRI特点。资料与方法回顾性分析38例经临床及MRI检查确诊的脑灰质异位症,其中男27例,女11例,平均年龄16.8岁。临床表现为频繁癫痫大发作31例,癫痫小发作7例,全部病例均经MRI检查确诊。结果38例MRI检查共发现47个脑灰质异位灶,全部位于幕上大脑半球,其中顶叶19个,颞叶12个,额叶3个,侧脑室周围13个。47个灰质异位灶大小不等,形态各异,但其MRI信号强度与正常脑灰质相同。结论脑灰质异位症具有特征性临床及MRI表现,MRI是其首选的确诊手段。

磁共振弥散白质定量分析在观察脑低级别胶质瘤相关性癫痫白质变化中的应用

目的 采用磁共振弥散白质定量技术观察低级别脑胶质瘤瘤体和瘤周白质变化在胶质瘤相关癫痫(glioma-associated epilepsy, GAE)发生中的影响。材料与方法 回顾性分析了2018年12月至2020年12月在郑州大学第一附属医院磁共振科进行弥散频谱成像(diffusion spectrum imaging, DSI)扫描且经病理证实为低级别胶质瘤患者的临床和影像学信息,共纳入102例WHOⅡ级低级别胶质瘤,其中术前GAE患者37名,术前无GAE患者65名。计算弥散张量成像(diffusion-tensor imaging, DTI)、轴突定向弥散和密度成像(neurite orientation dispersion and density imaging, NODDI)及平均表观传播子(mean apparent propagator, MAP)等弥散模型的定量参数。应用ITK-SNAP软件在b=0的弥散图像上进行肿瘤及瘤周区的感兴趣区(region of interest, ROI)勾画。应用FAE软件进行直方图特征提取、ROI体积计算和形态学特征提取。经单参数分析及共线分析后基于各弥散模型及ROI构建逻辑回归模型,并应用DeLong检验进行模型效能的比较。结果 GAE组间年龄差异有统计学意义(P=0.004);肿瘤位于右侧半球且跨半球生长者GAE的发病率低于位于左侧半球者,差异有统计学意义(P=0.002);年龄和肿瘤所在半球位置所构建GAE预测临床影像学模型AUC=0.779。GAE组肿瘤和瘤周的体积小于无GAE组(P<0.05);肿瘤区诸形态学特征差异无统计学意义;瘤周区长径、短径越小越倾向于GAE发生,同时表面积越小、越倾向于球形者倾向于GAE发生,差异有统计学意义(P<0.05);应用瘤周区形态学特征构建GAE logistic回归模型的AUC=0.730。存在GAE组间差异(P<0.05)的肿瘤区和瘤周区弥散模型定量参数直方图特征包括DTI_FA_Maximum、 NODDI_ODI_90 Percentile、MAP_NG_10 Percentile,其中瘤周区NODDI_ODI_90Percentile值GAE组高于无GAE组,余瘤周区同肿瘤区特征GAE组均低于无GAE组。肿瘤区模型效能略高于瘤周区模型,差异无统计学意义;肿瘤区和瘤周区特征共同构建融合模型的效能最高,较瘤周区差异有统计学意义(P=0.02)。融合模型中,肿瘤特征占绝大部分,OR值最高者为肿瘤DTI_MD_10Percentile,与GAE发生呈正相关。所有基于弥散参数的模型中OR值最高者为瘤周特征NODDI_ODI_Mean,与GAE发生呈正相关。基于肿瘤区、瘤周区的单个弥散模型间预测效能,MAP模型的效能略高于DTI和NODDI模型。临床影像学模型、瘤周形态学模型及基于弥散参数的融合模型的GAE预测效能比较差异无统计学意义。结论 磁共振白质定量分析为早期预测GAE的发生及分析GAE的发生机制提供了条件;肿瘤区白质的损伤同时伴有瘤周区白质分散度增加或相对完整增加了GAE的发生风险。