Rosaria Sacco

Distributed changes in default-mode resting-state connectivity in multiple sclerosis.

Background: The default-mode network (DMN) has been increasingly recognized as relevant to cognitive status. Objectives: To explore DMN changes in patients with relapsing–remitting (RR) multiple sclerosis (MS) and to relate these to the cognitive status. Methods: Eighteen cognitively impaired (CI) and eighteen cognitively preserved (CP) RRMS patients and eighteen healthy controls (HCs), matched for age, sex and education, underwent neuropsychological evaluation and anatomical and resting-state functional MRI (rs-fMRI). DMN functional connectivity was evaluated from rs-fMRI data via independent component analysis. T2 lesion load (LL) was computed by a semi-automatic method and global and local atrophy was estimated by SIENAX and SPM8 voxel-based morphometry analyses from 3D-T1 images. Results: When the whole group of RRMS patients was compared with HCs, DMN connectivity was significantly weaker in the anterior cingulate cortex, whereas it was significantly weaker in the core but stronger at the periphery of the posterior cingulate cortex. These findings were more evident in CP than CI patients. Observed DMN changes did not correlate with global atrophy or T2-LL, but were locally associated with regional grey matter loss. Conclusion: Relapsing–remitting multiple sclerosis patients show a consistent dysfunction of DMN at the level of the anterior node. DMN distribution changes in the posterior node may reflect a possible compensatory effect on cognitive performance.

Visual resting-state network in relapsing-remitting MS with and without previous optic neuritis

Objective: To investigate functional connectivity of the visual resting-state network (V-RSN) in normal-sighted relapsing-remitting multiple sclerosis (RRMS) patients with and without previous optic neuritis (ON). Methods: Thirty normal-sighted RRMS patients, 16 without (nON-MS) and 14 with (ON-MS) previous ON, and 15 age- and sex-matched healthy controls (HCs) underwent a neuro-ophthalmologic evaluation, including automated perimetry and retinal nerve fiber layer (RNFL) measurement, as well as an MRI protocol, including structural and resting-state fMRI (RS-fMRI) sequences. Functional connectivity of the V-RSN was evaluated by independent component analysis (ICA). Regional gray matter atrophy was assessed by voxel-based morphometry (VBM). A correlation analysis was performed between RS-fMRI results and clinical, neuro-ophthalmologic, and structural MRI variables. Results: Compared to HCs, patients with RRMS showed a reduced functional connectivity in the peristriate visual cortex, bilaterally. Compared to nON-MS, ON-MS patients revealed a region of stronger functional connectivity in the extrastriate cortex, at the level of right lateral middle occipital gyrus, as well as a region of reduced functional connectivity at the level of right inferior peristriate cortex. These latter changes correlated with the number of previous ON. All detected V-RSN changes did not colocalize with regional gray matter atrophy. Conclusions: Normal-sighted RRMS patients show a significant functional disconnection in the V-RSN. RRMS patients recovered from a previous ON show a complex reorganization of the V-RSN, including an increased functional connectivity at the level of extrastriate visual areas.

Psychometric properties and validity of Beck Depression Inventory II in multiple sclerosis

Depression is the most common psychiatric disorder in multiple sclerosis (MS). Self‐report depression scales are frequently used as screening, diagnostic and grading instruments. This study investigated the psychometric properties of the Beck Depression Inventory second edition (BDI‐II) for assessing depressive disorders in a sample of Italian MS patients.

Fatigue in multiple sclerosis: The contribution of occult white matter damage

Background: A functional cortico-subcortical disconnection has been recognized in fatigued multiple sclerosis (MS) patients. Normal appearing white matter (NAWM) damage might contribute to the abovementioned disconnectivity. Objectives: To assess the relationship between fatigue and microstructural NAWM damage in relapsing-remitting (RR) MS. Methods: Sixty RRMS patients and 29 healthy controls (HC) underwent a magnetic resonance imaging (MRI) protocol including diffusion tensor imaging (DTI). Patients with a mean Fatigue Severity Scale (FSS) score ⩾ 4 were considered fatigued (fatigued MS (F-MS)). Tract-based spatial statistics were applied for voxel-wise analysis of DTI indices. A correlation analysis was performed between FSS score and DTI indices in the entire MS group. Results: Thirty MS patients were F-MS. Compared to HC, F-MS patients showed a more extensive NAWM damage than not fatigued MS (NF-MS) patients, with additional damage in the following tracts: frontal and occipital juxtacortical fibers, external capsule, uncinate fasciculus, forceps minor, superior longitudinal fasciculus, cingulum, and pons. No differences were found between F-MS and NF-MS patients. Fatigue severity correlated to DTI abnormalities of corona radiata, cingulum, corpus callosum, forceps minor, superior longitudinal fasciculus, inferior fronto-occipital fasciculus, thalamus and anterior thalamic radiation, cerebral peduncle, and midbrain. Conclusions: Fatigue is associated to a widespread microstructural NAWM damage, particularly in associative tracts connected to frontal lobes.

BDNF Val66Met polymorphism and brain volumes in multiple sclerosis

Brain derived neurotrophic factor (BDNF) regulates several CNS physiological and pathological processes. To investigate in multiple sclerosis (MS) patients, the relationship between the Val66Met polymorphism of BDNF and clinical markers of disease activity and MRI markers of focal and diffuse brain pathologies. 45 MS patients and 34 healthy controls (HCs) were genotyped and subjected to clinical-MRI examination. Global white matter fraction (gWM-f), gray matter-f (GM-f), cerebrospinal fluid-f (CSF-f), and abnormal WM-f were measured. We studied 26 Val/Val and 19 Val/Met patients and 23 Val/Val and 11 Val/Met HCs. We found that Val/Val patients had lower GM-f and higher CSF-f than Val/Val HCs; such differences were not statistically significant comparing Val/Met patients to HCs. The regression analysis showed that both Val/Met genotype and relapse number were associated with lower CSF-f. Our data suggest that Met allele might be a protective factor against MS as it is associated to a lower brain atrophy.

The Contribution of Resting State Networks to the Study of Cortical Reorganization in MS

Resting State fMRI (RS-fMRI) represents an emerging and powerful tool to explore brain functional connectivity (FC) changes associated with neurologic disorders. Compared to activation/task-related fMRI, RS-fMRI has the advantages that (i) BOLD fMRI signals are self-generated and independent of subjects performance during the task and (ii) a single dataset is sufficient to extract a set of RS networks (RSNs) that allows to explore whole brain FC. According to these features RS-fMRI appears particularly suitable for the study of FC changes related to multiple sclerosis (MS). In the present review we will first give a brief description of RS-fMRI methodology and then an overview of most relevant studies conducted so far in MS by using this approach. The most interesting results, in particular, regard the default-mode network (DMN), whose FC changes have been correlated with cognitive status of MS patients, and the visual RSN (V-RSN) whose FC changes have been correlated with visual recovery after optic neuritis. The executive control network (ECN), the lateralized frontoparietal network (FPN), and the sensory motor network (SMN) have also been investigated in MS, showing significant FC rearrangements. All together, RS-fMRI studies conducted so far in MS suggest that prominent RS-FC changes can be detected in many RSNs and correlate with clinical and/or structural MRI measures. Future RS-fMRI studies will further clarify the dynamics and clinical impact of RSNs changes in MS.

Default mode network changes in multiple sclerosis: a link between depression and cognitive impairment?

In multiple sclerosis (MS), depression is a common disorder whose pathophysiology is still debated. To gain insights into the pathophysiology of depression in MS, resting‐state (RS) functional connectivity (FC) changes of the default mode network (DMN), salience network (SN) and executive control network (ECN) were assessed in a group of depressed MS (D‐MS) patients and in appropriately matched control groups.

Anxiety in Multiple Sclerosis: Psychometric properties of the State-Trait Anxiety Inventory

The aims of the present study were to examine psychometric properties of the Spielberger State‐Trait Anxiety Inventory (STAI‐Y‐1 and STAI‐Y‐2, respectively) in a Multiple Sclerosis (MS) population and to identify a cut‐off score to detect those MS patients with high level of state and/or trait anxiety who could be more vulnerable to development of depression and/or cognitive defects.

Dilated perivascular spaces and fatigue: is there a link? Magnetic resonance retrospective 3Tesla study.

IntroductionFatigue (F) is a common, inexplicable, and disabling symptom in multiple sclerosis (MS) patients. The purpose of this study was to evaluate a possible correlation between fatigue and morpho-volumetric features and site of dilated perivascular spaces (dPS), visible on 3T magnetic resonance (MR) in fatigued multiple sclerosis patients (FMS).MethodsWe studied 82 relapsing remitting (RR) FMS patients and 43 HC, matched for age, sex, and education. F was assessed by the Fatigue Severity Scale (FSS). To evaluate a possible correlation between degree of F and characteristics of dPS, patients were divided in two groups: more (mFMS) (FSS ≥ 5; n = 30) and less fatigued (lFMS) (FSS ≥ 4; n = 52), compared to a matched healthy control (HC) subject group. The MR study was performed with 3T scanner by SpinEcho T1, Fast-SpinEcho DP-T2, FLAIR, and 3D FSPGR T1 sequences. dPS volumes were measured with Medical Image Processing Analysis and Visualization (MIPAV); Global Cerebral Atrophy (GCA), expressed as Brain Parenchymal Fraction (BPF), was assessed by FSL SIENAX.ResultsThe t test showed significantly increased dPS number (p = 0.021) in FMS patients (mFMS p = 0.0024 and lFMS p = 0.033) compared to HC. Pearson correlation revealed a significant correlation between dPS number and FSS (r = 0.208 p = 0.051). Furthermore, the chi-squared test confirms the intragroup (HC, mFMS, lFMS) differences about dPS location (p = 0.01) and size (p = 0.0001).ConclusionOur study confirms that PS in MS patients presents with different volumetric and site characteristics as compared to HC; moreover, F severity significantly correlates with dPS number, site, and size.

Mood Dysfunctions in MS and Neuroimaging

Mood dysfunctions (MD) in Multiple Sclerosis (MS) patients have long been considered as reactive disorders. Neuroimaging studies have however suggested a neurobiological basis for MD, showing significant correlations between brain structural damage, as measured by conventional and non-conventional MRI techniques, and MD. More recent functional MRI (fMRI) data have also displayed adaptive cortical changes as well as abnormal functional integration between key emotional regions in MS patients.