Free Water MR Imaging of White Matter Microstructural Changes is a Sensitive Marker of Amyloid Positivity in Alzheimer's Disease.

BACKGROUND: Extracellular free water (FW) resulting from white matter degeneration limits the sensitivity of diffusion tensor imaging (DTI) in predicting Alzheimer's disease (AD). PURPOSE: To evaluate the sensitivity of FW-DTI in detecting white matter microstructural changes in AD. To validate the effectiveness of FW-DTI indices to predict amyloid-beta (Aß) positivity in mild cognitive impairment (MCI) subtypes. STUDY TYPE: Retrospective. POPULATION: Thirty-eight Aß-negative cognitively healthy (CH) controls (68.74 ± 8.28 years old, 55% female), 15 Aß-negative MCI patients (MCI-n) (68.87 ± 8.83 years old, 60% female), 29 Aß-positive MCI patients (MCI-p) (73.03 ± 7.05 years old, 52% female), and 29 Aß-positive AD patients (72.93 ± 9.11 years old, 55% female). FIELD STRENGTH/SEQUENCE: 3.0T; DTI, T1 -weighted, T2 -weighted, T2 star-weighted angiography, and Aß PET (18 F-florbetaben or 11 C-PIB). ASSESSMENT: FW-corrected and standard diffusion indices were analyzed using trace-based spatial statistics. Area under the curve (AUC) in distinguishing MCI subtypes were compared using support vector machine (SVM). STATISTICAL TESTS: Chi-squared test, one-way analysis of covariance, general linear regression analyses, nonparametric permutation tests, partial Pearson's correlation, receiver operating characteristic curve analysis, and linear SVM. A P value <0.05 was considered statistically significant. RESULTS: Compared with CH/MCI-n/MCI-p, AD showed significant change in tissue compartment indices of FW-DTI. No difference was found in the FW index among pair-wise group comparisons (the minimum FWE-corrected P = 0.114). There was a significant association between FW-DTI indices and memory and visuospatial function. The SVM classifier with tissue radial diffusivity as an input feature had the best classification performance of MCI subtypes (AUC = 0.91), and the classifying accuracy of FW-DTI was all over 89.89%. DATA CONCLUSION: FW-DTI indices prove to be potential biomarkers of AD. The classification of MCI subtypes based on SVM and FW-DTI indices has good accuracy and could help early diagnosis. EVIDENCE LEVEL: 4 TECHNICAL EFFICACY: Stage 2.

Early MRI imaging and follow-up study in cerebral amyloid angiopathy.

AIM: To study the imaging features of leukoaraiosis (LA) and hemorrhage in cerebral amyloid angiopathy (CAA) patients. METHODS: The earliest MRI images of probable CAA patients and non-CAA patients were collected. The characteristics of LA in the two groups were analyzed. Cerebral micro bleeding (CMB), superficial siderosis (SS), and intracranial hemorrhage (ICH) were recorded in the follow-up study. The space relationship between CMB or SS and ICH was assessed. RESULTS: We found that 10/21 (47.6%) patients had occipital prominent LA and 14/21 (66.7%) patients had subcortical punctate LA before the ICH, which was higher than that of the ones in the control group (p = 0.015 and 0.038, respectively). The recurrence rate of ICH was 100% (3/3) in patients with diffuse SS and 36.4% (4/11) in patients without. The recurrence rate of ICH was 60% (3/5) in patients with multiple-lobe CMBs and 44.4% (4/9) in those without. The location of the ICH and CMB was inconsistent. ICH occurred in the ipsilateral cerebral hemisphere of SS in three patients with diffuse SS. CONCLUSION: LA, diffuse SS, and multiple-lobe CMBs are important imaging characteristics of CAA, which may help make early diagnosis and predict the recurrence of ICH.

Aberrant voxel-based degree centrality in Parkinson's disease patients with mild cognitive impairment.

The purpose was to explore the intrinsic dysconnectivity pattern of whole-brain functional networks in Parkinson's disease patients with mild cognitive impairment (PD-MCI) using a voxel-wise degree centrality (DC) analysis approach. The resting-state functional magnetic resonance imaging (rs-fMRI) scanning was performed in all subjects including PD-MCI, PD patients with no cognitive impairment (PD-NCI), and healthy controls (HCs). DC mapping was used to identify functional connectivity (FC) alterations among these groups. Correlation between abnormal DC and clinical features was performed. Secondary seed-based FC analyses and voxel-based morphometry (VBM) analyses were also conducted. Compared with HCs, PD-MCI and PD-NCI showed DC abnormalities mainly in the right temporal lobe, thalamus, left cuneus, middle frontal gyrus, and corpus callosum. Compared with PD-NCI, PD-MCI showed abnormal DC in the left fusiform gyrus (FFG) and left cerebellum lobule VI, left cuneus, right hippocampus, and bilateral precuneus. In PD-MCI patients, correlation analyses revealed that DC in the left FFG was positively correlated with the Montreal Cognitive Assessment (MoCA) scores, and DC in the left precuneus was negatively correlated with the MoCA scores. Secondary seed-based FC analysis further revealed FC changes mainly in the default mode network, right middle cingulum, right supramarginal gyrus, and right postcentral/precentral gyrus. However, no significant difference was found in the secondary VBM analysis. The findings suggest that dysfunction in extensive brain areas is involved in PD-MCI. Among these regions, the left precuneus, FFG, and cerebellum VI may be the key hubs in the pathogenesis of PD-MCI.

Structural and Functional Thalamic Changes in Parkinson's Disease With Mild Cognitive Impairment.

BACKGROUND: The thalamus is a key node of deep gray matter and previous studies have demonstrated that it is involved in the modulation of cognition. PURPOSE: To investigate the volume changes of the thalamus and its subregions and altered thalamus functional connectivity patterns in Parkinson's disease (PD) patients with and without mild cognitive impairment (MCI). STUDY TYPE: Prospective. POPULATION: Thirty-three patients with MCI (PD-MCI), 36 PD patients having no cognitive impairment (PD-NCI), 21 healthy controls (HCs). SEQUENCE: 3.0T MRI scanner; 3D T1 -weighted fast spoiled gradient recalled echo (3D T1 -FSPGR); resting-state fMRI ASSESSMENT: Voxel-based morphometry (VBM) was performed to calculate the volume of the thalamus and its subregions. The left and right total thalamus were considered seeds and seed-based functional connectivity (FC) was analyzed. Additionally, correlations between volumes and cognitive performance and between FC values and cognitive performance were examined separately. STATISTICAL TEST: Analysis of covariance (ANCOVA); two-sample t-tests; partial correlation analysis. RESULTS: The volumes of the total thalamus (PD-MCI vs. PD-NCI vs. HCs: 18.39 ± 1.67 vs. 19.63 ± 1.79 vs. 19.47 ± 1.35) and its subregions were significantly reduced in PD-MCI as compared to PD-NCI (total thalamus: P = 0.002) and HCs (total thalamus: P = 0.012). Compared with PD-NCI, PD-MCI showed increased FC between the thalamus and bilateral middle cingulate cortex and left posterior cingulate cortex, and decreased FC between thalamus and the left superior occipital gyrus, left cuneus, left precuneus, and left middle occipital gyrus. Volumes of thalamus and the subregions, as well as the FC of thalamus with the identified regions, were significantly correlated (P < 0.05, FDR-corrected) with neuropsychological scores in PD patients. DATA CONCLUSION: We noted volume loss and altered FC of thalamus in PD-MCI patients, and these changes were correlated with global cognitive performance. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICIENCY: Stage 2 J. Magn. Reson. Imaging 2020;52:1207-1215.

Alterations of regional homogeneity in Parkinson's disease with mild cognitive impairment: a preliminary resting-state fMRI study.

PURPOSE: Mild cognitive impairment (MCI) is commonly observed in Parkinson's disease (PD), even in the early stages. However, the neural substrates of cognitive impairment in PD remain unclear. The aim of the current study was to investigate the change of local brain function in PD patients with MCI. METHODS: Fifty patients with PD, including 25 PD patients with MCI (PD-MCI) and 25 PD patients with normal cognition (PD-NC), and 25 age- and sex-matched healthy controls (HC) were enrolled. Conventional magnetic resonance imaging (MRI), 3D structural images, and resting state-functional MRI (rs-fMRI) were performed in all subjects. Regional homogeneity (ReHo) was measured based on the rs-fMRI images to investigate the altered local brain functions. RESULTS: Brain regions with decreased ReHo were located in the left posterior cerebellar lobe in PD sub-groups compared to the HC group, and the brain regions with increased ReHo were located in the limbic lobe (right precuneus/bilateral middle cingulate cortex) in PD-MCI compared with HC group. PD-MCI presented with increased ReHo in the bilateral precuneus/left superior parietal lobe and decreased ReHo in the left insula compared to PD-NC. ReHo values for the left precuneus were negatively related to neuropsychological scores, and ReHo values for the left insula were positively related to neuropsychological scores in PD subjects. CONCLUSION: The present study demonstrated abnormal spontaneous synchrony in the left insula and left precuneus in patients with PD-MCI compared to PD-NC, which might provide a novel insight into the diagnosis and clinical treatment of cognitive impairment in PD.

Altered functional connectivity of the marginal division in Parkinson's disease with mild cognitive impairment: A pilot resting-state fMRI study.

BACKGROUND: The marginal division (MrD) is an important subcortical center involved in learning and memory. Mild cognitive impairment (MCI) is commonly seen in patients with Parkinson's disease (PD), but the neurobiological basis is yet to be elucidated. PURPOSE: To use resting-state functional magnetic resonance imaging (rs-fMRI) to explore the altered functional connectivity (FC) of the MrD in patients with PD-MCI. STUDY TYPE: Prospective pilot study. POPULATION: Twenty-five patients with PD-MCI; 25 PD patients and no cognitive impairment (PD-NCI); and 25 healthy control (HC) participants. SEQUENCE: 3.0 T GE Healthcare MRI scanner; three-dimensional T1 -weighted fast spoiled gradient recalled echo (3D T1 -FSPGR); rs-fMRI. ASSESSMENT: The MrD was defined using manual delineation, which was the seed point to compute the FC to examine correlations between low-frequency fMRI signal fluctuations in MrD and the whole brain. STATISTICAL TESTS: Between-group comparisons of the rs-fMRI data were computed using two-sample t-tests in a voxelwise manner after controlling for age and sex, to determine the brain regions that showed significant differences in FC with the bilateral MrDs. Correlation analyses were performed for FC values and cognitive abilities in patients with PD. RESULTS: In the PD-MCI group, compared with the PD-NCI group, we observed lesser FC between the MrD bilaterally and right putamen, left insula, left cerebellum, and left thalamus; greater FC between the MrD bilaterally and left middle cingulate cortex, left middle frontal gyrus, left superior frontal gyrus, left supplementary motor area, and left middle/inferior occipital gyrus. Moreover, the strength of FC between the MrD and regions that showed differences between the PD-MCI and PD-NCI groups was significantly correlated with neuropsychological scores in patients with PD. DATA CONCLUSION: The current study suggests that MrD dysfunction may contribute to MCI in PD. However, the mechanisms underlying this process require further investigation. Level of Evidence 1. Technical Efficacy Stage 2. J. Magn. Reson. Imaging 2019;50:183-192.

Multi-modality molecular imaging characteristics of dementia with Lewy bodies.

Objective Dementia with Lewy bodies (DLB) is a common type of neurodegenerative dementia. Molecular neuroimaging using dopamine transporter (DaT), Pittsburgh compound B (PIB), and fluorodeoxyglucose (FDG) positron emission tomography (PET) has advantages in detecting dopaminergic neuron loss, abnormal amyloid ß-protein deposition, and glucose metabolism changes in patients with neurodegenerative disorders. However, the multi-modality molecular imaging features of patients with DLB have rarely been reported. Methods Five patients with a probable diagnosis of DLB were enrolled. PET/magnetic resonance imaging was performed with three tracers: 11C-ß-CFT, 11C-PIB, and 18F-FDG. Clinical and imaging characteristics were analyzed. Results All patients with DLB showed reduced uptake in the bilateral putamen on DaT PET, increased uptake throughout the cerebral cortex on PIB PET, and intact metabolism of the posterior cingulate gyrus on FDG PET. Conclusion Multimodal molecular imaging is helpful for early diagnosis of DLB. Studies with larger sample sizes are needed to confirm the molecular imaging differences between DLB and Alzheimer's disease and Parkinson's disease dementia.

C-reactive Protein -717A>G and -286C>T>A Gene Polymorphism and Ischemic Stroke.

BACKGROUND: Inflammation plays a pivotal role in the formation and progression of ischemic stroke. Recently, more and more epidemiological studies have focused on the association between C-reactive protein (CRP) -717A > G and -286C > T > A genetic polymorphisms and ischemic stroke. However, the findings of these researches are not conclusive. METHODS: We performed a meta-analysis to determine whether these two polymorphisms are associated with the risk of ischemic stroke. Eligible studies were identified from the database of PubMed, Medline, Embase, Web of Science, CNKI, Weipu, and Wanfang. We calculated odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association. RESULTS: Four articles were included in our study, including 1926 cases and 2678 controls for -717A > G polymorphism, 652 cases and 1103 controls for -286C > T > A polymorphism. The results of meta-analysis showed that single nucleotide polymorphism (SNP) -717A > G was not significantly associated with the risk of ischemic stroke (GG vs. AA, OR = 1.12, 95% CI = 0.83-1.50, P = 0.207; GG + GA vs. AA, OR = 1.04, 95% CI = 0.93-1.17, P = 0.533; GG vs. GA + AA, OR = 1.10, 95% CI = 0.82-1.47, P = 0.220). Meta-analysis of SNP - 286C > T > A also demonstrated no statistical evidence of a significant association with the risk of ischemic stroke (AA vs. CC, OR = 0.86, 95% CI = 0.59-1.25, P = 0.348; AA vs. CC, OR = 0.92, 95% CI = 0.80-1.06, P = 0.609; AA vs. CC, OR = 0.89, 95% CI = 0.62-1.30, P = 0.374). CONCLUSIONS: This meta-analysis demonstrated little evidence to support a role of CRP gene -717A > G, -286C > T > A polymorphisms in ischemic stroke predisposition. However, to draw comprehensive and more reliable conclusions, further larger studies are needed to validate the association between CRP gene polymorphisms and ischemic stroke in various ethnic groups.

Typical or atypical progressive supranuclear palsy: a comparative clinicopathologic study of three Chinese cases.

Progressive supranuclear palsy (PSP) is an atypical parkinsonism, which is the third most common geriatric neurodegenerative disease. We reported three pathology-confirmed Chinese PSP cases with special focus on the pathological accumulations of tau, a-synuclein and A-beta in the three PSP brains. Cases 1 and 2 initiated with extrapyramidal signs and gait disorders, while case 3 suffered behavioral abnormalities with cognitive decline at the beginning. In neuropathology, PSP-changes such as tau-positive tufed astrocytes, oligdendrocytes with the tau-positive coiled-body and threads and globose NFTs were widely seen in the basal ganglia, isocortex and allocortex, as well as in brainstem, cerebellum and spinal cord. In addition, numerous AGs were found in the hippocampus of cases 1 & 2, while Aß amyloid depositions were found in hippocampus and leptomeningeal vessels of case 1 and in neocortex, entorhinal cortex, hippocampus, cingulate gyrus and amygdale of case 3. Vessel infarcts were observed in cases 1. Cortical laminar III necrosis in case 1 suggested the ischemic damage. Cervical spinal cords in cases 2 & 3 were obtained with tau-positive globose NFTs, tufted astrocytes and neuropil threads were respectively found in the neurons of anterior horn and surrounding white matters. In summary, pathological examination is crucial for the ambiguous cases to exclude other neurodegenerative diseases. Furthermore, cervical spinal cord should be routinely examined in the PSP autopsy.

[Efficacy and safety of ropinirole in the treatment of Parkinson's disease: a multi-center, randomized, double-blind and bromocriptine-controlled trial].

OBJECTIVE: To explore the efficacy and safety of ropinirole in the treatment of Parkinson's disease. METHODS: From November 2005 to April 2007, a total of 221 subjects from 7 hospitals of Beijing, Lanzhou and Wuhan participated in a 12-week multi-center, randomized, bromocriptine-controlled, double-blind, double-dummy and parallel-group trial. The efficacy of ropinirole was assessed with the unified Parkinson's disease rating scale (UPDRS) score, "off" time according to the patient's diary and the overall evolution of clinical efficacy. The safety was assessed on the basis of adverse events, blood pressure, pulse, laboratory measurement and electrocardiographic recordings. And the statistical analyses were performed with t, paired t, χ(2) and covariance tests. RESULTS: In the intent-to-treat population, the average UPDRSIII score decreased to (11 ± 9) in ropinirole group and (11 ± 10) in bromocriptine group while the UPDRSIIscore decreased to (4 ± 4) and (3 ± 5) respectively at Week 12 versus baseline. It showed that ropinirole was non-inferior to bromocriptine. The "off" time at Week 12 [(3.0 ± 1.2)h, (3.8 ± 1.6)h] versus baseline [(4.2 ± 2.0)h, (4.4 ± 1.7)h] decreased (t = 10.772, t = 5.746, P = 0.000) in ropinirole and bromocriptine groups. Ropinirole offered a better overall improvement rate (q = 7.241, P = 0.007). The adverse events occurring at a ratio of over 5% caused by ropinirole included orthostatic hypotension, nausea, dizziness, upper abdominal discomfort, insomnia and palpitation. No significant difference existed in the frequency of adverse events between two groups. CONCLUSIONS: Ropinirole is both effective and safe in the treatment of Chinese patients with Parkinson's disease.

[Effects of Enshi green tea tea polysaccharide on serum glucose in experimental diabetic rats].

OBJECTIVE: To study the effects of Enshi green tea tea polysaccharide on serum glucose in experimental diabetic rats. METHODS: Diabetic rats model were established by alloxan, Enshi green tea tea polysaccharide was poured into rats' stomach for four weeks, then the changes of the level about fasting blood glucose (FBG), glucokinase (GK), insulin (INS), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), spleen index and thymus index were observed. RESULTS: Enshi green tea tea polysaccharide could reduce the level of FBG in diabetic rats, and increase the activity of KG, SOD and GSH-Px, moreover, it could reduce the level of MDA and increase the spleen index and thymus index. CONCLUSION: Enshi green tea tea polysaccharide has remarkable effect on playing down the blood sugar, and can increase the antioxygenic activity and immunity.

[The protective effects of Shenfu injection on the global cerebral ischemia/reperfusion injury of rats].

OBJECTIVE: To study the the protective effects and mechanism of Shenfu injection on the global cerebral ischemia/reperfusion (I/R) injury of rats. METHODS: Divided 40 SD male rats into 4 groups randomly (n = 10): sham operation group, model control group, nimodipine group( 30 mg/kg) and Shenfu injection group (10 mg/kg). Made global cerebral ischemia/reperfusion injury model (CI/R) by adopting Pulsinelli's Four Arterial Acclusion method,and then practised administration three times, respectively one day before the surgery, one hour before the surgery and 30 minutes before reperfusion. Finally, measured the contents of brain tissue glutamate (Glu), aspartic acid (Asp) and Glycine (Gly) by means of High Performance Liquid Chromatography, the content of Ca2+ by means of Atomic absorption spectrophotometry, the brain water content by means of wet and dry weight, the activity of brain tissue superoxide dismutase (SOD) and content of malondialdehyde (MDA) by means of chemical colorimetry. RESULTS: Compared with the sham operation group, the contents of Glu, Ca2+, MDA and water in the brains of CI/R model group rats increased remarkably (P < 0.05 or P < 0.01), while the activity of SOD decreased apparently (P < 0.05); Shenfu injection could significantly decrease the contents of Glu, Ca2+ and water (P < 0.05, P < 0.01) in brain tissue and remarkably increased the activity if SOD and the ration of SOD/MDA (P < 0.05). CONCLUSION: The mechanism of Shenfu injection preventing cerebral ischemia/reperfusion injury is relevant to excitatory amino acid toxicity reduction, Ca2+ overload blockage and antioxidant capacity improvement.

[Neuropsychological features of elderly patients with mild cognitive impairment susceptible to Alzheimer's disease].

OBJECTIVE: To explore the neuropsychological features of elderly patients with mild cognitive impairment (MCI) susceptible to Alzheimer's disease (AD). METHODS: A total of 47 patients with MCI diagnosed from June to October 2008 and 21 controls with normal cognition at the same convalescent camp were selected and followed up for two years. Montreal cognitive assessment (MoCA), mini mental state examination (MMSE) and clock drawing test (CDT) were performed for all subjects at the onset of study and repeated annually. RESULTS: At Month 12, the visuospatial skill scores of MCI patients decreased significantly versus those of the control (0.6 ± 0.7 vs 0.1 ± 0.6, P = 0.008). No one progressed to AD in neither groups. And at Month 24, both visuospatial skill scores (0.9 ± 0.9 vs 0.4 ± 0.9) and attention scores (1.0 ± 1.0 vs 0.2 ± 0.8) of MCI patients declined significantly versus the control (P = 0.021, 0.001). Among 47 MCI patients, 7 progressed to AD. No obvious difference existed in the score of all items between the AD converters and non-converters at baseline. However, the scores of MMSE (27.6 ± 0.8 vs 28.9 ± 1.0), MoCA (24.3 ± 3.1 vs 27.9 ± 1.6) and such MoCA subitems as visuospatial skill (3.9 ± 0.7 vs 4.5 ± 0.6), language (1.86 ± 0.38 vs 2.65 ± 0.53) and delayed recall (2.1 ± 1.5 vs 3.9 ± 1.0) of the converters were obviously lower than those of the non-converters at Month 12 (P < 0.05). Furthermore, all other scores of the AD converters, except for designation and abstract, were significantly lower than those of the non-converters at Month 24 (P < 0.05). CONCLUSION: The visuospatial skill, executive function, delayed recall and language function of MCI patients progressing to AD tend to have early impairment and significant changes. It may be useful to predict AD among the MCI patients.