أمجاد ابراهيم عبدالرحمن الطخيس

البحوث المنشورة

Iron Rims as an Imaging Biomarker in MS: A Systematic Mapping

Multiple sclerosis (MS) is an autoimmune, inflammatory, demyelinating and degenerative disease of the central nervous system

(CNS). To date, there is no definitive imaging biomarker for diagnosing MS. The current diagnostic criteria are mainly based on

clinical relapses supported by the presence of white matter lesions (WMLs) on MRI. However, misdiagnosis of MS is still a

significant clinical problem. The paramagnetic, iron rims (IRs) around white matter lesions have been proposed to be an imaging

biomarker in MS. This study aimed to carry out a systematic mapping review to explore the detection of iron rim lesions (IRLs),

on clinical MR scans, and describe the characteristics of IRLs presence in MS versus other MS-mimic disorders. Methods:

Publications from 2001 on IRs lesions were reviewed in three databases: PubMed, Web of Science and Embase. From the

initial result set 718 publications, a final total of 38 papers were selected. Results: The study revealed an increasing interest in

iron/paramagnetic rims lesions studies. IRs were more frequently found in perivent

Investigating Brain Microstructural Alterations in Type 1 and Type 2 Diabetes Using Diffusion Tensor Imaging: A Systematic Review

Type 1 and type 2 diabetes mellitus have an impact on the microstructural environment and cognitive functions of the brain due to its microvascular/macrovascular complications. Conventional Magnetic Resonance Imaging (MRI) techniques can allow detection of brain volume reduction in people with diabetes. However, conventional MRI is insufficiently sensitive to quantify microstructural changes. Diffusion Tensor Imaging (DTI) has been used as a sensitive MRI-based technique for quantifying and assessing brain microstructural abnormalities in patients with diabetes. This systematic review aims to summarise the original research literature using DTI to quantify microstructural alterations in diabetes and the relation of such changes to cognitive status and metabolic profile.

A total of thirty-eight published studies that demonstrate the impact of diabetes mellitus on brain microstructure using DTI are 3 included, and these demonstrate that both type 1 diabetes mellitus and type 2 diabetes mellitus may affect cognitive abilities due to the alterations in brain microstructures.

Investigating Microstructural Changes in White Matter in Multiple Sclerosis: A Systematic Review and Meta-Analysis of Neurite Orientation Dispersion and Density Imaging

Multiple sclerosis (MS) is characterised by widespread damage of the central nervous system that includes alterations in normal-appearing white matter (NAWM) and demyelinating white matter (WM) lesions. Neurite orientation dispersion and density imaging (NODDI) has been proposed to provide a precise characterisation of WM microstructures. NODDI maps can be calculated for the Neurite Density Index (NDI) and Orientation Dispersion Index (ODI), which estimate orientation dispersion and neurite density. Although NODDI has not been widely applied in MS, this technique is promising in investigating the complexity of MS pathology, as it is more specific than diffusion tensor imaging (DTI) in capturing microstructural alterations. We conducted a meta-analysis of studies using NODDI metrics to assess brain microstructural changes and neuroaxonal pathology in WM lesions and NAWM in patients with MS. Three reviewers conducted a literature search of four electronic databases. We performed a random-effect meta-analysis and the extent of between-study heterogeneity was assessed with the I2 statistic. Funnel plots and Egger’s tests were used to assess publication bias. We identified seven studies analysing 374 participants (202 MS and 172 controls). The NDI in WM lesions and NAWM were significantly reduced compared to healthy WM and the standardised mean difference of each was –3.08 (95%CI −4.22 to (−1.95), p ≤ 0.00001, I2 = 88%) and –0.70 (95%CI −0.99 to (−0.40), p ≤ 0.00001, I2 = 35%), respectively. There was no statistically significant difference of the ODI in MS WM lesions and NAWM compared to healthy controls. This systematic review and meta-analysis confirmed that the NDI is significantly reduced in MS lesions and NAWM than in WM from healthy participants, corresponding to reduced intracellular signal fraction, which may reflect underlying damage or loss of neurites.

المؤتمرات العلمية

ACTRIMS American committee for treatment in multiple

sclerosis

Background: Multiple sclerosis (MS) is an autoimmune, inflammatory, demyelinating, and degenerative disease of the CNS. To date, there is no definitive imaging biomarker for diagnosing MS. The current diagnostic criteria are mainly based on clinical relapses supported by the presence of white matter lesions (WMLs) on MRI. However, still misdiagnosis of MS is a significant clinical problem. The paramagnetic, iron rims (IRs) around WMLs were proposed to be an imaging biomarker of MS.

Objectives: This study aimed to carry out a systematic mapping review to explore the detection of Iron rim lesions (IRLs), on clinical MR scans, and describe the characteristics of IRLs presence in MS versus other MS-mimics disorders.

Methods: Publications from 2001 on IRs lesions were reviewed in three databases: PubMed, Web of Science and Embase. From the initial result set 718 publications, a final total of 38 papers were selected.

Results: The study revealed an increasing interest in iron/paramagnetic rims lesions studies. IRs were more frequently found in periventricular regions of young males with RRMS. Additionally, IRLs could be linked with a higher disability and appear to be absent in MS-mimicking disorders. Different prevalence was reported of IRLs; the prevalence was calculated from the included studies based on lesions and patients counts. (5-97%, 50-72% respectively). The lesion volume of IRs showed a gradual increase in size and fusion with neighboring IR lesions within 3.5 years. Pathologically, IRLs are a sign of chronic active inflammation and persisting demyelinating activity.

Conclusions: Although IRs were proposed as a diagnostic imaging biomarker and disease progression, there is still much to learn about the aetiology and mechanisms underlying IRLs, especially regarding the link between IRLs and clinical impact and IRLs evolution and prevalence. To answer these questions, more extended observation in larger cohorts is required. Meta-analysis may further be considered.

ECTRIMS European committee for treatment in multiple sclerosis

Introduction: The role of iron rims in white matter (WM) lesions in multiple sclerosis (MS) has generated a lot of interest as it has been suggested that their presence might signify a more severe disease course. Longitudinal MRI studies have reported that iron rims are present in chronic expanding WM lesions reflecting a more destructive process. Only small longitudinal clinical cohorts have been reported so far.

Objective: To assess if the presence and frequency of iron rim lesions (IRL) in MS patients is associated with more severe disability or disease course.