Imaging resting state brain function in multiple sclerosis

Abstract

In multiple sclerosis (MS), physical and cognitive deficits not only reflect structural damage, but also functional imbalance in and between brain networks. Resting-state functional magnetic resonance imaging (fMRI) allows one to investigate intrinsic, synchronized brain activity across the whole brain, and to measure the degree of functional correlation between different cortical regions. This review describes the major findings obtained in MS patients at different clinical stages using resting state fMRI, and discusses how the use of fMRI techniques may improve our ability to identify novel biomarkers useful in the context of the diagnostic work-up, establishing prognosis and monitoring treatment.

Immune-Inflammatory and Oxidative and Nitrosative Stress Biomarkers of Depression Symptoms in Subjects with Multiple Sclerosis: Increased Peripheral Inflammation but Less Acute Neuroinflammation

“…Indeed, contrast enhancement on gadolinium MRI scan is associated with increased BBB permeability and acute perivascular inflammation [53]. The gadolinium MRI scan enhancing active lesions differentiates between active versus chronic lesions [54,55]. Thus, our results may indicate that the acute injury of BBB disruption and thus acute inflammation is associated with attenuated depressive symptoms.…”

“…Although this progressive state is generally not accompanied by gadolinium enhancement, inflammation and tissue injury may occur even in the absence of BBB breakdown [55]. Pathological studies show that in the chronic active or smoldering state, macrophages are present at the plaque edges [55]. Moreover, the BBB dysfunction hypothesis considers that oxidative stress and neuroinflammation when co-occurring with neurovascular dysfunction may cause subtle increases in BBB permeability which are associated with depression [58].…”

“…The acute inflammatory state is followed by a subacute and a late phase characterized by resorption of inflammatory edema, degeneration, and repair including remyelination [55][56][57]. Although this progressive state is generally not accompanied by gadolinium enhancement, inflammation and tissue injury may occur even in the absence of BBB breakdown [55]. Pathological studies show that in the chronic active or smoldering state, macrophages are present at the plaque edges [55].…”

“…Thus, our results may indicate that the acute injury of BBB disruption and thus acute inflammation is associated with attenuated depressive symptoms. The acute inflammatory state is followed by a subacute and a late phase characterized by resorption of inflammatory edema, degeneration, and repair including remyelination [55][56][57]. Although this progressive state is generally not accompanied by gadolinium enhancement, inflammation and tissue injury may occur even in the absence of BBB breakdown [55].…”

Brain functional plasticity at rest and during action in multiple sclerosis patients

“…With the recent optimization of post-processing methods such as independent component analysis (ICA), it is now possible to extract basal brain activity within the major neuronal networks from low frequency BOLD signal fluctuations [7]. Several studies performed in MS patients at all stages of the disease [8][9][10][11][12][13][14][15] have shown consistent changes in the level of functional connectivity in various resting state networks (RSN), suggesting that this technique is sensitive to brain functional reorganization [16].…”