Advances in monitoring and treatment of multiple sclerosis

Improving structural brain images acquired with the 3D FLASH sequence

The three-dimension Fast Low Angle SHot Magnetic Resonance Imaging (3D FLASH) sequence has been widely adopted in medical diagnostic imaging because of its availability, simplicity, and high spatial resolution. To improve the quality of structural brain images acquired with the 3D FLASH sequence, we developed a parameter optimization scheme and image inhomogeneity correction methods. The optimal imaging parameters were determined by maximizing gray-matter and white-matter CNR efficiency. Compared to protocols based on published parameters, applying the proposed optimal imaging parameters increased CNR efficiency by >10%. Image inhomogeneity, including signal and CNR inhomogeneity, was corrected by the choice of an optimal flip angle, estimated transmit function, and estimated receive sensitivity. As a result, our optimization and image inhomogeneity correction greatly improved the quality of images acquired with the 3D FLASH sequence.

Delayed P100-Like Latencies in Multiple Sclerosis: A Preliminary Investigation Using Visual Evoked Spread Spectrum Analysis

Conduction along the optic nerve is often slowed in multiple sclerosis (MS). This is typically assessed by measuring the latency of the P100 component of the Visual Evoked Potential (VEP) using electroencephalography. The Visual Evoked Spread Spectrum Analysis (VESPA) method, which involves modulating the contrast of a continuous visual stimulus over time, can produce a visually evoked response analogous to the P100 but with a higher signal-to-noise ratio and potentially higher sensitivity to individual differences in comparison to the VEP. The main objective of the study was to conduct a preliminary investigation into the utility of the VESPA method for probing and monitoring visual dysfunction in multiple sclerosis. The latencies and amplitudes of the P100-like VESPA component were compared between healthy controls and multiple sclerosis patients, and multiple sclerosis subgroups. The P100-like VESPA component activations were examined at baseline and over a 3-year period. The study included 43 multiple sclerosis patients (23 relapsing-remitting MS, 20 secondary-progressive MS) and 42 healthy controls who completed the VESPA at baseline. The follow-up sessions were conducted 12 months after baseline with 24 MS patients (15 relapsing-remitting MS, 9 secondary-progressive MS) and 23 controls, and again at 24 months post-baseline with 19 MS patients (13 relapsing-remitting MS, 6 secondary-progressive MS) and 14 controls. The results showed P100-like VESPA latencies to be delayed in multiple sclerosis compared to healthy controls over the 24-month period. Secondary-progressive MS patients had most pronounced delay in P100-like VESPA latency relative to relapsing-remitting MS and controls. There were no longitudinal P100-like VESPA response differences. These findings suggest that the VESPA method is a reproducible electrophysiological method that may have potential utility in the assessment of visual dysfunction in multiple sclerosis.

MicroRNA expression aberration in Chinese patients with relapsing remitting multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease that is caused by an abnormal immune system that attacks the central nervous system. MicroRNAs (miRNAs) are known to play essential roles in the immune system. Most of the previous studies about miRNA dysregulation in MS have focused on European populations. In the present study, the miRNA expression profiles associated with Chinese MS patients are investigated. Here, human miRNA expression profiling experiments were performed on the peripheral blood mononuclear leukocytes from ten MS patients and ten healthy controls. Nine overexpressed and six underexpressed miRNAs were found. The 15 miRNAs were validated independently in a second cohort of 40 MS patients and 40 controls by real-time PCR; six miRNAs were significantly abnormally expressed, and principal component analysis of six miRNAs indicated that the MS patients could be clearly differentiated from the healthy controls based on the miRNA expression patterns. This study provided the indications of abnormal miRNA expression patterns in the peripheral blood mononuclear leukocytes of Chinese MS patients. The potential roles of these differentially expressed miRNAs as MS biomarker and in pathogenesis need to be investigated in future studies.

From bench to MS bedside: challenges translating biomarker discovery to clinical practice

A substantial need exists for developing and validating a range of biomarkers that would address a number of important unmet clinical needs in the MS field. In spite of considerable efforts over last years, very few putative biomarkers have been fully validated or successfully integrated into routine clinical practice. Here, we consider some of the main challenges that have limited such effective translation from biomarker discovery to the bedside in the context of MS, the prototypic chronic human CNS inflammatory illness. We will define the types of biomarkers that would be relevant for MS, identify their ideal attributes, and then discuss individual challenges and strategies to overcome them.