Neurodegenerative Diseases最新文献

Introduction: Radiomics features, a technique based on quantitative image analysis, can be used to capture tissue and lesion characteristics, such as heterogeneity and shape. Using functional dopaminergic scintigraphy, we aimed to study the value of radiomics features in predicting the diagnosis of dementia with Lewy bodies (DLB).

Materials and methods: We retrospectively analyzed 74 patients (29 F and 45 M, mean age 71.6 ± 9.2) investigated in the Leenaards Memory Center (Lausanne University Hospital) for DLB who underwent quantitative I-123-ioflupane single positron emission computed tomography (SPECT)/CT (DaTscan). All scanned examinations had xSPECT reconstruction, allowing standard uptake value (SUV) quantification. We segmented the right and left striatum using a 3D Slicer and performed radiomics feature extraction and analysis using the QuantImage v2 platform. The dataset was divided into training (80%) and test (20%) sets, and various classification algorithms were used to predict the definitive clinical diagnosis of DLB using xSPECT and/or clinical features. Receiver operating characteristic (ROC) curve analysis was performed to characterize the performance of the obtained models.

Results: Thirty-three of 74 patients (45%) were diagnosed with DLB. The xSPECT radiomics models showing the highest diagnostic performance were developed based on nine non-correlated features from both striatal regions and a support vector classifier (SVC) algorithm. The xSPECT radiomics models demonstrated superior performance compared to models based on SUV intensity features alone (p = 0.001) or clinical features alone (p = 0.001), with area under the ROC curve (AUC) values of 0.932 (0.920-0.944), 0.856 (0.840-0.875), and 0.793 (0.770-0.815), respectively. The combined model, incorporating both clinical and xSPECT features, achieved the highest overall performance with a sensitivity of 100% (95% confidence interval: 100-100), specificity of 89.7% (87.6-91.4), and an AUC of 0.956 (0.945-0.964).

Conclusion: The radiomics model based on quantitative I-123-ioflupane xSPECT/CT showed high diagnostic accuracy in predicting the diagnosis of DLB using diverse features derived from striatal analysis. This tool may improve the diagnostic accuracy of I-123-ioflupane, which is of major importance for DLB diagnosis.

Introduction: Demyelinating neuropathies, such as chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and Charcot-Marie-Tooth type 1A (CMT1A), significantly impair postural control. While both conditions affect sensory integration, differences in compensatory mechanisms remain poorly understood. This study aimed to explore how visual, proprioceptive, and cognitive perturbations influence postural stability in CIDP and CMT1A patients.

Methods: A single-center, prospective study was conducted with 25 CIDP and 24 CMT1A patients. Posturographic recordings were used to assess postural stability under standard conditions and during visual tracking, proprioceptive perturbation (Achilles tendon vibration), and cognitive dual-tasking (DT) (backward counting). Center of pressure parameters, including area, velocity, and body sway, were analyzed to evaluate postural control.

Results: CMT1A patients demonstrated improved postural stability during visual tracking tasks, suggesting better visual integration and long-term compensatory adaptations. In contrast, CIDP patients showed greater postural instability and reliance on static visual cues. Both groups experienced increased postural sway during proprioceptive and cognitive perturbations, with no significant differences between them in DT performance.

Conclusion: The study highlights distinct postural control mechanisms in CIDP and CMT1A patients. CMT1A patients exhibit better adaptation to visual disturbances, while CIDP patients struggle with visual integration and rely more on static visual cues. This difference reflects the progressive nature of CMT1A, which may facilitate better development of compensatory strategies over time. These findings underscore the need for personalized rehabilitation approaches, focusing on visual integration for CIDP patients and reinforcing compensatory mechanisms in CMT1A patients to enhance balance and reduce fall risk.

Introduction: This study assesses the influence of normative gender effects on cognitive outcomes of cognitively unimpaired older adults. The results help to understand how sex/gender identity operates as a structural determinant of AD outcomes and informs future research that is more inclusive of gender-diverse identities.

Methods: We analyze data from 216 adults aged 65 and older who completed survey questions from the Aging Gender Index (AGI), which pertain to often gendered experiences of American men and women, which relate to education, employment experiences, and relationship characteristics. The participants also completed cognitive testing. We conducted bivariate and multivariable analyses, which statistically adjusted for age, education, and race.

Results: In multivariable analyses, being full time employed or partially retired rather than full time retired or part time employed is associated with lower memory and learning scores (β = -0.29 95% CI: -0.56 to -0.01). Fewer years out of the workforce to raise children was associated with higher language scores (β = 0.14, 95% CI: 0.03 to 0.25). While not being a veteran versus being a veteran was associated with lower language scores (β = -0.27, 95% CI: -0.51 to -0.02).

Conclusions: The results of this study show how workforce and other economic experiences, which tend to vary by gender, may associate with some cognitive outcomes. Research is warranted to replicate the findings and build upon this method of inquiry.

Introduction: This study examined how many steps are required to reach a steady state of postural stability, progression velocity, and step length during gait initiation in healthy young adults, healthy elderly adults, and patients with Parkinson's disease (PD).

Methods: Healthy young adults (n = 10), healthy elderly adults (n = 11), and PD patients (n = 12) had to initiate gait and walk straight at spontaneous and maximal velocity to the end of an 11-m long room. Mean values and variability of biomechanical indicators of postural stability ("margin of stability" [MoS], "braking index" [BI]), progression velocity (peak anteroposterior centre-of-mass velocity), and step length were computed along five successive steps using a markerless motion capture system.

Results: The results showed that the number of steps required to reach steady state walking depended on the experimental variable. For the progression velocity, the step length and the BI, two steps were required. For the MoS, one step was required. PD patients and healthy participants used different strategies to reach steady state of BI, which may expose the former to a high risk of instability in the first step. Interestingly, mean BI and variability of PD patients returned to normal following this first step.

Conclusion: These findings suggest that rehabilitation programs aiming to improve walking in PD patients at an early stage of the disease (stage 2 on the Hoen and Year scale) may specifically target the first step.

Introduction: Multiple studies report sex and gender differences in Lewy body dementia (LBD); however, there is a paucity of research investigating social determinants associated with LBD.

Methods: Participants with LBD (51 females, 79 males) and controls with similar age (64 females, 60 males) completed remote surveys assessing various social and demographic variables, and age at LBD onset for LBD group. Sex-stratified comparisons for LBD and control groups, and comparisons of females and males with LBD were done for social determinants. Sex differences for onset age were further analyzed with linear models adjusting for significantly differing social variables between the sexes.

Results: LBD group had lower years of education, income, subjective social status than controls, with larger differences for males than females (p < 0.05 for all). Higher percentage of females with LBD was living alone (p = 0.016) and not married/partnered (p = 0.002) compared to males with LBD. Adjusting for social variables that differed between the sexes, females were younger at cognitive impairment onset (p = 0.037) and diagnosis (p = 0.032). For the overall cohort, being ethnoracial minoritized, sexual and gender minoritized, and having lower education quality were associated with younger age at symptom onset (p < 0.049 for all). For females, lower childhood subjective social status (p = 0.037), and for males, being ethnoracial minoritized (p < 0.001) and lower years of education (p = 0.031) were associated with younger age at diagnosis.

Conclusion: Social determinants, even during childhood, can impact the LBD onset differently for females and males. Interactions between biological and social factors need to be investigated further with inclusive and diverse cohorts in LBD.

Introduction: Experimental data suggest sexual dimorphism in the Locus Coeruleus (LC), with females exhibiting higher neuronal count and noradrenergic activity. In Alzheimer's disease (AD), progressive LC dysfunction may contribute early to pathogenesis, and female sex is a key risk factor for AD. This study aimed to investigate if such sex differences exist in humans and whether they influence the relationship between LC degeneration and AD features, such as cortical atrophy and cognitive decline.

Methods: Fifty-three healthy controls (HCs), 70 mild cognitive impaired (MCI) participants, and 29 Alzheimer's disease demented (ADD) patients underwent high-field brain MRI with LC-sensitive sequences following detailed neuropsychological and neurological assessments. LC integrity was measured using the LC contrast ratio (LCCR) parameter based on a previously published template approach.

Results: Within the HC and MCI groups, females showed higher LCCR values than males. A significant sex effect was observed in the relationship between LC integrity and cortical volume in the frontotemporal cortices, with males showing a stronger association.

Conclusion: LC structure and function may differ between sexes, influencing AD pathophysiology through distinct mechanisms. While this sexual dimorphism may have a minor role, it should be considered in clinical investigations and drug development research.

The association of Swiss Memory Clinics (SMC) provides intersocietal recommendations for the use of anti-amyloid monoclonal antibodies (mAbs) in Switzerland. The recommendations are the result of extensive interdisciplinary discussions in a group of Swiss dementia experts from August 2023 until December 2024. They reflect the opinion of all societies involved in the diagnosis and treatment of dementia patients in Switzerland. Special emphasis is given to aspects that are specific to the Swiss landscape, including recommendations for infrastructural and personnel standards for institutions aiming to administer anti-amyloid mAbs in Switzerland.