Transcranial Sonography in Neurodegenerative Diseases with Cognitive Decline

Non-Invasive Screening for Early Cognitive Impairment in Elderly Hyperuricaemic Men Using Transcranial Colour-Coded Duplex Sonography

Objectives: Hyperuricaemia has been linked to cognitive decline, yet cerebral structural and haemodynamic changes in this population remain poorly defined. We evaluated transcranial colour-coded duplex (TCCD) sonography as a non-invasive screening tool for early mild cognitive impairment (MCI) in elderly hyperuricaemic men. Methods: In this cross-sectional study, 195 men aged ≥ 60 years with hyperuricaemia were stratified by the Montreal Cognitive Assessment (MoCA) into HUA + MCI (MoCA < 26, n = 46) and HUA (MoCA ≥ 26, n = 149) groups. TCCD measured third-ventricle width (TVW) and peak systolic/end-diastolic velocities to calculate resistive (RI) and pulsatility (PI) indices in the middle (MCA) and posterior (PCA) cerebral arteries. Serum uric acid was recorded. Kernel density plots and receiver operating characteristic (ROC) curves assessed diagnostic performance. Results: The HUA + MCI group exhibited higher serum uric acid (508.5 ± 36.3 vs. 492.9 ± 44.0 µmol/L; p = 0.031), greater TVW (0.55 ± 0.11 vs. 0.51 ± 0.08 cm; p = 0.037), and elevated left PCA RI (0.69 ± 0.07 vs. 0.64 ± 0.06) and PI (1.05 ± 0.17 vs. 0.95 ± 0.12; both p < 0.001). ROC analysis identified left PCA PI as the most specific marker (AUC = 0.701; specificity 90.6%; sensitivity 45.7%). Kernel density plots confirmed distinct distributions of key parameters. Conclusions: TCCD-detected ventricular enlargement and raised PCA pulsatility accurately distinguish MCI among hyperuricaemic men. As a non-invasive, accessible technique with high specificity, TCCD may complement MRI and cognitive testing in early screening of at-risk populations.

A database of magnetic resonance imaging-transcranial ultrasound co-registration

PURPOSE

As a portable and cost-effective imaging modality with better accessibility than Magnetic Resonance Imaging (MRI), transcranial sonography (TCS) has demonstrated its flexibility and potential utility in various clinical diagnostic applications, including Parkinson's disease and cerebrovascular conditions. To better understand the information in TCS for data analysis and acquisition, MRI can provide guidance for efficient imaging with neuronavigation systems and the confirmation of disease-related abnormality. In these cases, MRI-TCS co-registration is crucial, but relevant public databases are scarce to help develop the related algorithms and software systems.

ACQUISITION AND VALIDATION METHODS

This dataset comprises manually registered MRI and transcranial ultrasound volumes from eight healthy subjects. Three raters manually registered each subject's scans, based on visual inspection of image feature correspondence. Average transformation matrices were computed from all raters' alignments for each subject. Inter- and intra-rater variability in the transformations conducted by raters are presented to validate the accuracy and consistency of manual registration. In addition, a population-averaged MRI brain vascular atlas is provided to facilitate the development of computer-assisted TCS acquisition software.

DATA FORMAT AND USAGE NOTES

The dataset is provided in both NIFTI and MINC formats and is publicly available on the OSF data repository: https://osf.io/zdcjb/.

POTENTIAL APPLICATIONS

This dataset provides the first public resource for the development and assessment of MRI-TCS registration with manual ground truths, as well as resources for establishing neuronavigation software in data acquisition and analysis of TCS. These technical advancements could greatly boost TCS as an imaging tool for clinical applications in the diagnosis of neurological conditions such as Parkinson's disease and cerebrovascular disorders.

Simple biomarkers to distinguish Parkinson's disease from its mimics in clinical practice: a comprehensive review and future directions

In the last few years, a plethora of biomarkers have been proposed for the differentiation of Parkinson's disease (PD) from its mimics. Most of them consist of complex measures, often based on expensive technology, not easily employed outside research centers. MRI measures have been widely used to differentiate between PD and other parkinsonism. However, these measurements were often performed manually on small brain areas in small patient cohorts with intra- and inter-rater variability. The aim of the current review is to provide a comprehensive and updated overview of the literature on biomarkers commonly used to differentiate PD from its mimics (including parkinsonism and tremor syndromes), focusing on parameters derived by simple qualitative or quantitative measurements that can be used in routine practice. Several electrophysiological, sonographic and MRI biomarkers have shown promising results, including the blink-reflex recovery cycle, tremor analysis, sonographic or MRI assessment of substantia nigra, and several qualitative MRI signs or simple linear measures to be directly performed on MR images. The most significant issue is that most studies have been conducted on small patient cohorts from a single center, with limited reproducibility of the findings. Future studies should be carried out on larger international cohorts of patients to ensure generalizability. Moreover, research on simple biomarkers should seek measurements to differentiate patients with different diseases but similar clinical phenotypes, distinguish subtypes of the same disease, assess disease progression, and correlate biomarkers with pathological data. An even more important goal would be to predict the disease in the preclinical phase.

Characterising cerebrovascular reactivity and the pupillary light response-a comparative study

Introduction

Smooth muscle is integral to multiple autonomic systems, including cerebrovascular dynamics through vascular smooth muscle cells and in ocular muscle dynamics, by regulating pupil size. In the brain, smooth muscle function plays a role in cerebrovascular reactivity (CVR) that describes changes in blood vessel calibre in response to vasoactive stimuli. Similarly, pupil size regulation can be measured using the pupillary light response (PLR), the pupil's reaction to changes in light levels. The primary aim of this study was to explore the interplay between cerebral blood flow and pupil dynamics, evaluated using CVR and PLR, respectively.

Methods

A total of 20 healthy adults took part in a CVR gas stimulus protocol and a light and dark flash PLR protocol. CVR was calculated as the blood flow velocity change in the middle cerebral artery, measured using transcranial Doppler ultrasound in response to a 5% increase in CO2. Multiple PLR metrics were evaluated with a clinical pupillometer.

Results

CVR and PLR metrics were all within the expected physiological ranges for healthy adults. Nine different PLR metrics, assessed through the light and dark flash protocols, were compared against CVR. A significant negative relationship was observed between the latency of the PLR in the dark flash protocol and CVR. No statistically significant relationships were found between CVR and other PLR metrics.

Conclusion

This is the first study to investigate the relationship between cerebral blood flow and pupil dynamics. A significant relationship between dark flash latency and CVR was observed. Future work includes evaluating these relationships using more robust CVR and PLR measurement techniques in a larger, more diverse cohort. Notably, more research is warranted into the PLR using a dark flash protocol and its connection to cerebrovascular function.

Prospective study on ultrasound-guided stellate ganglion block improves cerebral blood flow in patients with stroke

OBJECTIVES

The effect of routine internal medicine and stroke rehabilitation treatment was not good. To confirm that ultrasound-guided stellate ganglion block (SGB) can improve cerebral blood flow in patients with stroke, Transcranial Doppler (TCD) and carotid ultrasound were used to monitor the cerebral blood flow parameters of ultrasound-guided SGB in patients with stroke.

METHODS

A prospective study of 40 patients with stroke from January 2021 to October 2022 randomly divided into two groups (group SGB: undergoing ultrasound-guided SGB and standard medical procedures, control group: undergoing standard medical procedures) with 20 cases in each was conducted in People's Hospital of Chongqing Liang Jiang New Area. TCD and carotid artery ultrasound were monitored before and after treatment. There were no significant differences in general data on age, gender, disease course, and stroke type between two groups (P>0.05).

RESULTS

After treatment, the bilateral ACA Vm of group SGB was significantly higher, the bilateral internal carotid artery RI and left VA RI were significantly lower than in control group (P<0.05). In group SGB, the Vm of bilateral MCA, bilateral PCA, right ACA, bilateral VA, and BA after treatment were significantly (P<0.05) increased compared to before treatment. PI of bilateral MCA, right ACA, and left VA after treatment were significantly (P<0.05) decreased compared to before treatment. RI of bilateral MCA, bilateral PCA, and bilateral VA after treatment were significantly (P<0.05) decreased compared to before treatment. Right internal carotid artery D after treatment was significantly (P<0.05) higher than before treatment. RI of bilateral internal carotid artery after treatment was significantly (P<0.05) lower than before treatment.

CONCLUSIONS

Ultrasound-guided stellate ganglion block could improve local cerebral blood flow and vascular compliance in patients with stroke, and reduce vascular resistance.

Image-guided/improved diseases management: From immune-strategies and beyond

Timely and accurate assessment and diagnosis are extremely important and beneficial for all diseases, especially for some of the major human disease, such as cancers, cardiovascular diseases, infectious diseases, and neurodegenerative diseases. Limited by the variable disease microenvironment, early imperceptible symptoms, complex immune system interactions, and delayed clinical phenotypes, disease diagnosis and treatment are difficult in most cases. Molecular imaging (MI) techniques can track therapeutic drugs and disease sites in vivo and in vitro in a non-invasive, real-time and visible strategies. Comprehensive visual imaging and quantitative analysis based on different levels can help to clarify the disease process, pathogenesis, drug pharmacokinetics, and further evaluate the therapeutic effects. This review summarizes the application of different MI techniques in the diagnosis and treatment of these major human diseases. It is hoped to shed a light on the development of related technologies and fields.

Transcranial sonography imaging of brainstem raphe, substantia nigra and cerebral ventricles in patients with geriatric depression

OBJECTIVES

Geriatric depression is a special condition associated with a chronic course, treatment resistance and vascular processes. However, its neurobiology has not been fully elucidated. There is no study in geriatric depression evaluating deep brain structures with transcranial sonography (TCS) which is a low-cost, non-invasive and practical tool. The present study aimed to evaluate the changes in the echogenicity of brainstem raphe (BR), substantia nigra (SN) and ventricular diameters by TCS in association with cognitive dysfunctions in patients with geriatric depression.

METHODS

Echogenicity of BR and SN were assessed and transverse diameters of the third ventricle and frontal horns of the lateral ventricles were measured by TCS in 34 patients with DSM-5 major depression and 31 healthy volunteers aged 60 and older. Cognitive functions were evaluated by using Mini Mental State Examination, Montreal Cognitive Assessment Tool, Clock Drawing Test and Subjective Memory Complaints Questionnaire.

RESULTS

Although depressed patients had more subjective memory complaints than controls, they had similar cognitive performances. Reduced echogenicity (interrupted/invisible echogenic line) of BR was found to be significantly higher and the ventricular diameters were larger in the depressed group. There was no difference between the groups in terms of SN echogenicity. There was no correlation between ventricular diameters and depression severity or cognitive functions.

CONCLUSIONS

Results of the present study are important in terms of pointing out neurobiological changes related to geriatric depression which are in parallel with the results of the studies in younger patients with depression. However, long-term follow-up studies are required for accurate differentiation of neurocognitive disorders.

Publication Trends for Alzheimer's Disease Worldwide and in China: A 30-Year Bibliometric Analysis

Background: Alzheimer's disease, the most common form of dementia, has tremendous social and economic impact worldwide. This study aimed to analyze global trends in Alzheimer's disease research and to investigate China's contribution to this research.

Methods: The quantity and influence of publications related to Alzheimer's disease in China and elsewhere were compared. The Web of Science (WOS) and PubMed databases were searched from 1988 to 2017 using the terms “Alzheimer's disease” or “Alzheimers disease.” Global Alzheimer's disease publications were classified and analyzed. Keywords, countries, and institutions publishing articles on Alzheimer's disease were analyzed, and citations of these articles were examined.

Results: A total of 181,116 articles regarding Alzheimer's disease research were identified and analyzed. Neuroscience and neurology were the main research categories both globally and in China. Basic research dominated Alzheimer's publications, accounting for 30.93% of global publications and 95.31% of publications in China. A total of 8,935 journals published articles related to Alzheimer's disease. The journal Neurobiology of Aging published the most Alzheimer's disease-related articles, numbering 5,206 over the time period examined. The National Institutes of Health, the National Institute on Aging, and the Department of Health and Human Services jointly sponsored 11,809 articles, ranking first in the world. The National Natural Science Foundation of China funded the largest number of studies on Alzheimer's disease in China and recognized the importance of traditional Chinese medicine in Alzheimer's disease research.

Conclusions: The present study provides data for global researchers to understand research perspectives and develop future research directions. In recent years, Chinese researchers have contributed significantly to global Alzheimer's research. Still, strengthening international cooperation could improve the quality and number of publications regarding Alzheimer's disease.