轻度认知功能障碍和不同程度Alzheimer病患者认知功能与内颞叶结构体积的关系

目的：研究轻度认知功能障碍（mild cognitive impairment，MCI）和不同程度阿尔茨海默病（Alzheimer disease，AD）患者的认知功能与内颞叶结构体积的相关关系。方法：16例MCI、20例轻度AD和19例中重度AD患者分别接受临床评估、神经心理学检查和头颅核磁共振（MR）扫描，在重建的图像上测量杏仁核、海马、内嗅皮质及颞角的体积并行标准化处理，然后对神经心理学指标与内颞叶结构MR指标进行相关性分析。其中神经心理学检查包括简易精神状态检查量表（mini mental state examination，MMSE）和无意义图形再认、逻辑记忆、数字广度、延迟回忆、画钟测验、词语流畅性测验及日常生活行为量表。结果：三组间各结构MR标化体积除左、右颞角外差异均无统计学意义（P〉0．05）。在MCI组中，注意力计算力、数字广度测验得分与左侧杏仁核体积负相关（r=-0．51～-0．57，P〈0．05），无意义图形再认得分与右侧海马体积正相关（r=0．77，P〈0．001）；在轻度AD组中，MMSE总分、无意义图形再认得分与杏仁核体积正相关（r=0．46～0．55，P〈0．05）；在中重度AD组中，定向力得分与右侧内嗅皮质体积正相关（r=0．47，P=0．041）。结论：无意义图形再认和数字广度测验等与内颞叶结构MR体积之间存在中度相关关系；杏仁核在AD的发展过程中可能起着更萤要的作用。     

阿尔茨海默病患者松果体MRI研究

目的　观察阿尔茨海默病（Alzheimer’s disease,AD)发病进程中松果体的MRI形态学改变。 方法　依据AD发病进程,分别采集NC组24例、MCI组18例、轻度AD组16例、中-重度AD组20例受试者大脑MRI扫描图像,测量松果体矢径、横径、高、体积,并分析组间各测量值变化趋势。 结果　松果体标化高MCI期、轻度AD期较NC组增大（P＜0.05）,中-重度AD期标化高较MCI期、轻度AD缩小（P＜0.05）;松果体标化矢径、标化横径、标化体积MCI期、轻度AD、中-重度AD与NC组比无明显变化（P＞0.05）,但中-重度AD较MCI期组缩小（P＜0.05）。 结论　在AD发病进程中松果体高先增大再萎缩,松果体高对MCI期、轻度AD患者的诊断有较大价值。     

基于结构磁共振成像海马多特征组合的阿尔茨海默病分类新方法

本文提出了一种利用结构磁共振图像多特征组合的阿尔茨海默病(AD)分类新方法。首先,利用FreeSurfer软件进行海马分割及皮层厚度、体积测量。然后,采用直方图、梯度、灰度共生矩阵及游程长度矩阵提取海马三维纹理特征,选取AD、MCI及NC三组间均具有显著差异的参数,与MMSE评分进行相关性研究。最后,利用极限学习机,对AD、MCI及NC进行分类识别。结果显示,无论左侧还是右侧,纹理特征相比于体积特征可以提供更好的分类结果;纹理、体积和皮层厚度互补的特征参量具有更高的分类识别率,且右侧(100%)分类正确率高于左侧(91.667%)。结果表明三维纹理分析可反映AD及MCI患者海马结构的病理变化,并且结合多特征的分析更能反映AD与MCI的认知障碍实质差别,更有利于临床鉴别诊断。     

完全性生长激素缺乏患儿大脑皮质形态变化的3.0 T MRI研究

目的 探讨完全性生长激素缺乏(CGHD)患儿与特发性矮小(ISS)患儿大脑结构的灰质体积、皮层表面积及皮层厚度的差异。方法 回顾性队列研究。纳入2015年1月—2019年1月山东省立医院确诊的12例CGHD患儿(男8例、女4例,年龄5~14岁,生长激素刺激释放试验峰值小于5.0 μg/L)与12例ISS患儿(男9例、女3例,年龄5~14岁,生长激素刺激释放试验峰值大于10.0 μg/L)。在首次就诊时采集患者高分辨率、高信噪比三维T₁WI MRI。利用FreeSurfer软件图像后处理方法获得两组患儿左右大脑半球及全脑灰质体积、皮层表面积与皮层厚度值,统计分析组间的差异情况。将每组患儿的上述形态学参数值分别进行平均以获得该组患儿的均值分布图。将两组患儿的测量均值进行相减,即获得两组患儿该测量均值的差异值分布图。结果 CGHD患儿左、右侧大脑半球的灰质体积分别为(228.50±36.72)cm³、 (229.10±34.95)cm³;皮层表面积分别为(737.02±140.48)cm²、(738.68±135.26)cm²;皮层厚度分别为(2.43±0.09)mm、(2.44±0.09)mm。ISS患儿左、右侧大脑半球的灰质体积分别为(272.36±34.77)cm³、 (272.54±32.76)cm³;皮层表面积分别为(841.88±141.75)cm²、(839.98±135.69)cm²;皮层厚度分别为(2.55±0.18)mm、(2.57±0.17)mm。CGHD患儿与ISS患儿的双侧半球与全脑的灰质体积(F_左=17.884, F_右=20.115, F_全=19.009)、皮层表面积(F_左=11.105, F_右=11.453, F_全=11.337)及皮层厚度(F_左=5.907, F_右=6.109, F_全=6.066)的差异均有统计学意义(P值均<0.05)。测量值的均值分布图与均值的差异值分布图显示两组患儿的灰质体积、皮层表面积与皮层厚度在诸多脑区存在差异。结论 CGHD患儿较ISS患儿的大脑灰质体积、皮层表面积与皮层厚度均较小,这可能与其智力、运动或其它功能发育相对落后相关。     

连线测验(中文修订版)在早期识别阿尔茨海默病中的作用

目的：中文修订版的连线测验（TMT）在识别轻度认知功能障碍（MCI）和轻度阿尔茨海默病（AD）中的作用。方法：对正常老人94名．遗忘型MCI组107例和轻度AD组54例进行MMSE、TMT在内的8种神经心理测验。结果：正常老人与MCI组TMT完成率均高于轻度AD组。年龄与教育程度对TMT—B的影响比TMT—A更大。TMT-A、B与MMSE、CFT模仿、CWCR、CFT回忆、AVLT延迟回忆均有显著相关性。完成TMT—A、B测验．NC组、MCI组与轻度AD组两两比较均有显著差异，TMT可以清楚的区分三组。结论：TMT对MCI病人有一定的辅助识别作用，对轻度AD病人有较强的辅助识别作用．     

阿尔茨海默病患者海马结构的断层影像学研究

目的观察阿尔茨海默病(AD)发病进程中海马结构在断层影像上的形态学改变。方法依据AD发病进程,分别采集正常对照(NC)组、轻度认知损害(MCI)组、AD组各34例共102例受试者脑核磁共振图像,每组男、女各17例。观测海马面积、横径、矢径和颞叶钩回间距、颞角宽度等。分析组间各测量值变化趋势,以及海马面积等相关测量值与各神经评定量表评分的相关性。结果各组海马面积侧别均无统计学差异。各组间测量值比较,AD组海马面积小于NC组及MCI组(P均<0.05);AD组海马横径小于NC组及MCI组,MCI组海马横径小于NC组(P均<0.01);AD组颞叶钩回间距大于NC组及MCI组(P均<0.01),MCI组颞叶钩回间距大于NC组(P<0.05)。海马面积、海马横径与临床痴呆分级量表(CDR)及汉密尔顿抑郁量表(HAMD)评分均呈负相关,与蒙特利尔认知评估量表(MoCA)评分均呈正相关;颞叶钩回间距与神经心理量表评分相关性同海马面积、海马横径相反。结论海马面积与海马横径随AD病情进展逐渐缩小,颞叶钩回间距随AD病情进展逐渐增大;海马结构的改变可损伤其认知功能。     

髋臼骨折不同台阶状移位及程度对髋关节接触特性的影响

目的 模拟累及关节面负重区的髋臼骨折,分别对不同方向旋转所形成的台阶状移位进行生物力学研究,以了解应力分布及接触面积等的改变情况。方法 分别测量10个完整髋臼 (I组)、解剖复位（K组）、不同台阶移位（A组：1mm;B组：2mm;C组:3mm;D组：4mm;a组：-1mm;b组：-2mm;c组:-3mm;d组：-4mm）时髋臼与股骨头之间的接触特性。所获数据经统计学分析软件进行分析比较差异。 结果 完整髋臼负重时接触面积总面积为（7.59±4.42）cm²;K组髋臼以及A组移位髋臼保持了髋臼的解剖形态,未引起髋臼接触面积显著变化。其余类型移位均造成髋臼骨折总接触面积减小(P<0.05)。负重区的接触面积在完整髋臼时为（3.72±0.04）cm²,骨折后也使之减小。解剖复位组负重区接触面积为（3.64±0.87）cm²（与完整髋臼负重区面积相比 P>0.05）,当内旋使台阶移位达到3mm或更大,外旋移位台阶移位到3mm或更大时,负重区接触面积显著减小。 结论 髋臼骨折产生的台阶状移位改变了正常髋关节的生物力学特性,使髋关节的接触面积发生了重新分布。     

超声引导前锯肌平面阻滞联合胸神经Ⅰ型阻滞在机器人辅助冠状动脉旁路移植术围术期镇痛中的应用

目的 探讨超声引导前锯肌平面阻滞（SAPB）联合胸神经（PECS）Ⅰ型阻滞对机器人辅助直视下冠状动脉旁路移植术（RADCAB）患者围术期镇痛的应用效果。方法 前瞻性随机对照研究。纳入2020年2月—2022年4月天津市第一中心医院行择期RADCAB患者60例,按数字表法随机分为对照组（C组）和SAPB联合PECS Ⅰ阻滞组（SP组）,每组30例。2组患者均采用全身麻醉和术后自控静脉镇痛（PCIA）,SP组患者于麻醉诱导前行超声引导下SAPB联合PECS Ⅰ型阻滞。记录2组患者拔除气管插管后2 h（T₁）、4 h（T₂）、12 h（T₃）和24 h（T₄）静息状态及咳嗽时的疼痛视觉模拟评分法（VAS）评分,比较术中及术后24 h内舒芬太尼用量、术后24 h内PCIA有效按压次数、首次补救镇痛时间、补救镇痛率、拔管时间、ICU停留时间和术后并发症发生情况。结果 C组术中转为开胸手术1例剔除观察。2组患者T₄静息状态和咳嗽时疼痛VAS评分的比较,差异均无统计学意义（P值均>0.05）。SP组患者T₁~T₃静息状态疼痛VAS评分[（2.2±0.7）分、（2.7±0.5）分、（3.1±0.5）分]均低于C组[（4.0±0.6）分、（3.7±0.5）分、（3.7±0.5）分],差异均有统计学意义（t=10.80、7.40、4.04,P值均<0.001）;T₁~T₃咳嗽时疼痛VAS评分[（2.9±0.7）分、（3.4±0.6）分、（3.5±0.6）分]均低于C组[（5.1±0.4）分、（4.6±0.6）分、（4.1±0.5）分],差异均有统计学意义（t=15.44、8.33、3.98,P值均<0.05）。SP组患者术中和术后24 h内舒芬太尼用量分别为（109±13）μg和（62±10）μg,均低于C组[（146±21）μg和（72±10）μg],差异均有统计学意义（t=8.01、3.74,P值均<0.001）。SP组患者术后24 h内PCIA有效按压次数为（4. 4±2.1）次,低于C组的（8.4±1.9）次;首次补救镇痛时间为术后（18.2±3.1）h,大于C组的（8.0±1.7）h;补救镇痛率为26.7%（8/30）,低于C组的82.8%（24/29）：差异均有统计学意义（t=7.57、11.90,χ²=18.70,P值均<0.001）。SP组患者拔管时间为术后（4.4±1.3）h,ICU停留时间为（44.7±10.7）h,均低于C组[（5.4±1.5）h和（54.6±9.7）h],差异均有统计学意义（t=2.81、3.71,P值均<0.001）。SP组患者术后24 h内恶心呕吐发生率为13.3%（4/30）,皮肤瘙痒发生率为3.3%（1/30）,肺不张发生率为3.3%（1/30）,均低于C组[41.4%（12/29）、27.6%（8/29）和27.6%（8/29）],差异均有统计学意义（χ²=5.87、4.97、4.97,P值均<0.05）。结论 超声引导SAPB联合PECS Ⅰ型阻滞能够为RADCAB患者提供安全有效的围术期镇痛,降低阿片类药物用量,减少术后并发症发生,加速患者康复。     

成人非创伤性股骨头坏死不同部位骨密度结合骨转换标志物特点研究

目的研究成人非创伤性股骨头坏死(ONFH)不同部位的骨密度以及骨转换标志物特点。 方法收集2017年9月至2019年3月在广州中医药大学第一附属医院三骨科住院诊断为非创伤性ONFH的患者共150例278髋(坏死组),男92例、女58例,平均年龄为(40.9±9.5)岁,其中酒精性ONFH 43例,特发性ONFH 23例,激素性ONFH 84例,国际骨循环研究会(ARCO)分期Ⅱ期84例,Ⅲ期ARCO 66例。收集同期在广州中医药大学第一附属医院行骨密度检查的健康人群共101例(对照组),男61例、女40例,平均年龄为(41.9±10.7)岁。采用双能X线骨密度测量仪测量2组股骨颈、腰椎(L1～L4)、髋关节的骨密度值,抽血检测2组血清Ⅰ型胶原氨基端延长肽(P1NP)、Ⅰ型胶原降解产物(β-CTx)及碱性磷酸酶(ALP)等骨转换标志物的水平。数据比较采用独立样本t检验与单因素方差分析。 结果(1)坏死组的股骨颈骨密度值[(0.97±0.15) g/cm²]高于对照组股骨颈骨密度值[(0.91±0.14) g/cm²],差异有统计学意义(t＝3.148,P＝0.002),坏死组髋关节骨密度值[(0.94±0.12) g/cm²]、腰椎骨密度值[(1.11±0.14) g/cm²]与对照组髋关节骨密度值[(0.96±0.14) g/cm²]、腰椎骨密度值[(1.12±0.15) g/cm²]相比,差异均无统计学意义(t＝－0.548、－1.461,P＝0.584、0.145);坏死组患者血清P1NP[(65.44±28.64) ng/mL]、ALP[(68.89±19.15) U/L]水平均高于对照组血清P1NP[(56.82±23.49) ng/mL]、ALP[(59.64±23.72) U/L],而血清β-CTx[(0.54±0.27) ng/mL]水平低于对照组[(0.62±0.29) ng/mL],差异均有统计学意义(t＝2.608、3.404、－2.095, P＝0.010、0.001、0.037)。(2)坏死组中酒精性ONFH股骨颈骨密度值[(1.02±0.15) g/cm²]高于激素性ONFH[(0.96±0.14) g/cm²]与特发性ONFH[(0.93±0.14) g/cm²],差异有统计学意义(F＝3.954,P＝0.021);3种坏死类型间腰椎与髋关节的骨密度值、血清P1NP 、β-CTx水平比较,差异均无统计学意义(P值均大于0.05),酒精性ONFH血清ALP[(76.09±18.36) U/L]水平高于激素性ONFH[(65.49±18.82) U/L],差异有统计学意义(P<0.05)。(3)坏死组中ARCO Ⅱ期患者股骨颈骨密度[(0.95±0.15 )g/cm²]低于ARCO Ⅲ期[(1.00±0.14) g/cm²],差异有统计学意义(t＝－2.346,P＝0.020),腰椎与髋关节骨密度值差异均无统计学意义(P值均大于0.05);ARCO Ⅱ期患者血清P1NP[(70.24±32.11) ng/mL]、血清β-CTx水平[(0.60±0.27) ng/mL]均高于ARCO Ⅲ期[(59.33±22.26) ng/mL、(0.47±0.25) ng/mL]患者,差异均有统计学意义(t＝2.454、2.985,P＝0.015、0.003),两期患者血清ALP水平比较,差异无统计学意义(P>0.05)。 结论成人非创伤ONFH的坏死周围区域骨密度可能会升高,且随着病情的进展,坏死部位的修复,坏死周围区域的骨密度呈上升趋势。而在不同坏死类型中,酒精性ONFH周围区域骨密度增高最明显。     

改良注射肿胀麻醉结合气动取皮刀在头皮取皮术中的应用

目的观察改良注射肿胀麻醉结合气动取皮刀在头皮取皮术中的临床应用效果。 方法回顾性分析2010年1月至2015年1月扬州大学附属苏北人民医院收治的62例行头部取皮术患者,将予改良注射肿胀麻醉结合气动取皮刀进行头皮取皮患者设为试验组(34例),予传统肿胀麻醉及滚轴式取皮刀进行取皮患者为对照组(28例)。比较2组患者每100 cm²取皮面积出血量、取皮耗时、单次手术取皮面积,供皮区创面愈合时间,皮片成活率,每100 cm²取皮面积注液量及不良反应的发生情况。数据比较采用t检验和χ²检验。 结果出血量试验组为(2.5±0.3) g/100 cm²,对照组为(3.7±0.5) g/100 cm²,差异有统计学意义(t＝－2.401,P<0.05);取皮耗时试验组为(3.3±1.4) min/100 cm²,对照组为(6.2±2.7) min/100 cm²,差异有统计学意义(t＝－6.4943,P<0.05);单次手术取皮面积试验组为(3.8±0.5)%总体表面积,对照组为(3.3±0.6)%,差异有统计学意义(t＝3.5805,P<0.05);供皮区创面愈合时间试验组为(5.9±1.6) d,对照组为(7.3±2.8) d,差异有统计学意义(t＝－2.4695,P<0.05);皮片成活率试验组为97%,对照组96%,差异无统计学意义(χ²＝0.2216,P>0.05);注液量试验组为(125.2± 27.9) mL/100 cm²,对照组为(120.4±24.2) mL/100 cm²,差异无统计学意义(t＝0.1886,P>0.05);2组患者术后头发均生长良好,无一例出现头皮坏死、感染及脱发等不良反应。 结论改良注射肿胀麻醉结合气动取皮刀进行头皮取皮术是一种安全、高效的头皮取皮方法,具有较好的临床应用价值。     

Hippocampus and entorhinal cortex in mild cognitive impairment and early AD

Magnetic resonance imaging (MRI) has been suggested as a useful tool in early diagnosis of Alzheimer's disease (AD). Based on MRI-derived volumes, we studied the hippocampus and entorhinal cortex (ERC) in 59 controls, 65 individuals with mild cognitive impairment (MCI) and 48 patients with AD. The controls and individuals with MCI were derived from population-based cohorts. Volumes of the hippocampus and ERC were significantly reduced in the following order: control > MCI > AD. Stepwise discriminant function analysis showed that the most efficient overall classification between controls and individuals with MCI subjects was achieved with ERC measurements (65.9%). However, the best overall classification between controls and AD patients (90.7%), and between individuals with MCI and AD patients (82.3%) was achieved with hippocampal volumes. Our results suggest that the ERC atrophy precedes hippocampal atrophy in AD. The ERC volume loss is dominant over the hippocampal volume loss in MCI, whereas more pronounced hippocampal volume loss appears in mild AD.     

MRI of hippocampus and entorhinal cortex in mild cognitive impairment: a follow-up study

The concept of mild cognitive impairment (MCI) has been proposed to represent a transitional stage between normal aging and dementia. We studied the predictive value of the MRI-derived volumes of medial temporal lobe (MTL) structures, white matter lesions (WML), neuropsychological tests, and Apolipoprotein E (APOE) genotype on conversion of MCI to dementia and AD. The study included 60 subjects with MCI identified from population cohorts. During the mean follow-up period of 34 months, 13 patients had progressed to dementia (9 to Alzheimer's disease (AD)). In Cox regression analysis the baseline volumes of the right hippocampus, the right entorhinal cortex and CDR sum of boxes predicted the progression of MCI to dementia during the follow-up. In a bivariate analysis, only the baseline volumes of entorhinal cortex predicted conversion of MCI to AD. The Mini-Mental State Examination (MMSE) score at baseline, WML load, or APOE genotype were not significant predictors of progression. The MTL volumetry helps in identifying among the MCI subjects a group, which is at high risk for developing AD.     

MRI-derived entorhinal volume is a good predictor of conversion from MCI to AD

With high-resolution quantitative magnetic resonance imaging (MRI) techniques, it is possible to examine alterations in brain anatomy in vivo and to identify regions affected in the earliest stages of Alzheimer's disease (AD). In the present study, 27 patients diagnosed with mild cognitive impairment (MCI) received a high-resolution MRI scan at baseline and were followed with yearly clinical evaluations. Ten of the 27 patients converted to AD during a 36-month period following the baseline clinical evaluation. Hippocampal and entorhinal cortex volumes derived from the baseline scan were compared to determine which of these two regions, known to be pathologically involved very early in the course of AD, could best differentiate MCI converters from non-converters. Although both entorhinal and hippocampal volumes were found to be independent predictors of the likelihood of conversion to AD, it was the right hemisphere entorhinal volume that best predicted conversion with a concordance rate of 93.5%.     

Rate of entorhinal and hippocampal atrophy in incipient and mild AD: relation to memory function

In the present study, as part of a more extensive longitudinal investigation of the in vivo anatomical markers of early and incipient AD in our laboratory, three groups of elderly participants were followed with yearly clinical evaluations and high resolution MRI scans over a 6-year period (baseline and 5 years of follow-up). At baseline, participants consisted of: (1) 35 old subjects with no cognitive impairment (controls); (2) 33 participants with amnestic mild cognitive impairment (MCI); and (3) 14 patients with very mild AD. 11 participants with amnestic MCI received a diagnosis of AD over the follow-up period and 9 controls declined in cognitive function. T1 weighted MRI scans were acquired using a 3D SPGR pulse sequence. At baseline, both the amnestic MCI and mild AD groups differed from the controls in hippocampal and entorhinal cortex volume, but not from each other. Longitudinal analyses showed that the rate of atrophy of the entorhinal cortex and hippocampus for the stable controls differed significantly from MCI participants who converted to AD and the AD groups. Furthermore, longitudinal decreases in hippocampal and entorhinal volume were related to longitudinal decline in declarative memory performance. These findings suggest that the rate of atrophy of mesial temporal lobe structures can differentiate healthy from pathological aging.     

Hippocampal formation glucose metabolism and volume losses in MCI and AD.

We used MRI volume sampling with coregistered and atrophy corrected FDG-PET scans to test three hypotheses: 1) hippocampal formation measures are superior to temporal neocortical measures in the discrimination of normal (NL) and mild cognitive impairment (MCI); 2) neocortical measures are most useful in the separation of Alzheimer disease (AD) from NL or MCI; 3) measures of PET glucose metabolism (MRglu) have greater diagnostic sensitivity than MRI volume. Three groups of age, education, and gender matched NL, MCI, and AD subjects were studied. The results supported the hypotheses: 1) entorhinal cortex MRglu and hippocampal volume were most accurate in classifying NL and MCI; 2) both imaging modalities identified the temporal neocortex as best separating MCI and AD, whereas widespread changes accurately classified NL and AD; 3) In most between group comparisons regional MRglu measures were diagnostically superior to volume measures. These cross-sectional data show that in MCI hippocampal formation changes exist without significant neocortical changes. Neocortical changes best characterize AD. In both MCI and AD, metabolism reductions exceed volume losses.     

Prediction of Alzheimer's disease in mild cognitive impairment: a prospective study in Taiwan

The relationship between apolipoprotein E (ApoE) and clinical manifestations of mild cognitive impairment (MCI) has not been investigated in non-Caucasian populations. This prospective study was conducted in an ethnic Chinese population to evaluate the correlations of ApoE genotype, cognitive performance, medial temporal structure volumes, and clinical outcome in amnestic MCI. Twenty normal elders, 58 MCI, and 20 mild Alzheimer's disease (AD) patients received neuropsychological, MRI, and ApoE genotype assessments at baseline. Patients with MCI had intermediate cognitive performance and hippocampal volumes between those in normal and AD groups. In each diagnostic group, 4 carriers (E4+) consistently had smaller hippocampal volume than non-carriers (E4−) did. Nineteen MCI subjects (32.7%) converted to AD during the 3-year study period. Compared with MCI non-converters and E4− MCI converters, E4+ MCI converters had the smallest hippocampal volume. However, 4 was not a predictor for AD. Both cognitive performance and hippocampal volume were predictive for progression to AD. However, stepwise Cox regression model integrating both neuropsychological and radiological variables showed that global cognitive performance was the only significant predictor for AD. A poor global cognitive score may be more crucial than a small hippocampal volume in the prediction of AD.     

Posterior cingulate cortex atrophy and regional cingulum disruption in mild cognitive impairment and Alzheimer's disease

This study aimed to investigate the atrophy of the posterior cingulate cortex (PCC) and medical temporal lobe (MTL) structures (i.e., the entorhinal cortex (ERC) and hippocampus) and the regional disruption of the cingulum bundle in mild cognitive impairment (MCI) and Alzheimer's disease (AD) patients. The relationships between atrophy of these structures and regional cingulum disruption were also explored. Three-dimensional MRI and diffusion tensor imaging were applied to 19 MCI, 19 probable AD patients, and 18 normal controls (NC). Fractional anisotropy (FA) values were obtained from three different regions of the cingulum. Both MCI and AD patients showed decreased PCC volumes compared with NC. ERC atrophy was also significant in AD and MCI, while hippocampus atrophy was significant only in AD. MCI patients showed a significant FA decrease in the parahippocampal cingulum (PH-C), whereas AD patients had lower FA values in the posterior cingulate cingulum (PC-C) and PH-C, as compared with NC. However, the middle cingulate cingulum (MC-C) showed no significant FA differences between groups. Moreover, the volumes of MTL structures were significantly correlated with PH-C and PC-C FA values. In terms of PCC functional deficit in MCI or early AD, our results support both the direct effect of PCC atrophy itself and the indirect effect of cingulum fiber degeneration secondary to MTL atrophy.     

Volume reduction of the entorhinal cortex in subjective memory impairment

To examine the biological basis of subjective memory impairment (SMI), defined as the feeling of memory worsening with normal memory performance, we measured the volume of the entorhinal cortex (EC) and the hippocampus in SMI subjects, patients with mild cognitive impairment (MCI), patients with Alzheimer's disease (AD) and healthy controls (CO). Compared with controls, the EC was smaller in the SMI group (left: p = 0.060; right: p = 0.045) and in the other two groups in the following order: CO > SMI > MCI > AD. The same sequence was observed with regard to hippocampal volumes, but the volume reduction of the left hippocampus in the SMI group only reached a trend towards significance (p = 0.072) and the right was not significantly smaller compared with controls (p = 0.37). Compared with controls the average (left/right) volume reduction of the EC was 18% (SMI), 26% (MCI) and 44% (AD). The mean volume reduction of the hippocampus was 6% (SMI), 16% (MCI) and 19% (AD). Our results mirror the temporal sequence of neurodegeneration in AD and support the concept of SMI as the first clinical manifestation of dementia.     

Changes in the levels of plasma soluble fractalkine in patients with mild cognitive impairment and Alzheimer's disease

Soluble fractalkine plays a distinctive role in the inflammatory processes of the nervous system; however, the role of soluble fractalkine in Alzheimer's disease (AD) has not yet been investigated. In the present study, we evaluated the levels of plasma soluble fractalkine in patients with mild cognitive impairment (MCI), patients with AD and healthy controls. We also investigated the changes in the levels of plasma soluble fractalkine in patients with AD. A total of 102 patients with cognitive impairment, including 51 patients with MCI, 51 patients with AD, and 57 healthy control subjects, were enrolled in this study. The Mini-Mental Status Examination (MMSE) was used to evaluate the severity of cognitive impairment in patients with MCI and AD. The levels of plasma soluble fractalkine were measured using a specific enzyme-linked immunosorbent assay. There were significant group differences in the levels of plasma soluble fractalkine between the MCI, AD, and control groups. Post hoc analyses revealed significant differences between the MCI and control groups, the AD and control groups, and the MCI and AD groups. The level of plasma soluble fractalkine was significantly greater in the patients with mild to moderate AD than in the patients with severe AD. In addition, there was a positive correlation between MMSE score and plasma soluble fractalkine level in the patients with AD. This study provides preliminary evidence that soluble fractalkine is involved in the pathogenesis of AD.     

Effects of ApoE4 and maternal history of dementia on hippocampal atrophy

We applied an automated hippocampal segmentation technique based on adaptive boosting (AdaBoost) to the 1.5 T magnetic resonance imaging (MRI) baseline and 1-year follow-up data of 243 subjects with mild cognitive impairment (MCI), 96 with Alzheimer's disease (AD), and 145 normal controls (NC) scanned as part of the Alzheimer's Disease Neuroimaging Initiative (ADNI). MCI subjects with positive maternal history of dementia had smaller hippocampal volumes at baseline and at follow-up, and greater 12-month atrophy rates than subjects with negative maternal history. Three-dimensional maps and volumetric multiple regression analyses demonstrated a significant effect of positive maternal history of dementia on hippocampal atrophy in MCI and AD after controlling for age, ApoE4 genotype, and paternal history of dementia, respectively. ApoE4 showed an independent effect on hippocampal atrophy in MCI and AD and in the pooled sample.