Nonlesional Sources of Contrast Enhancement on Postgadolinium "Black-Blood" 3D T1-SPACE Images in Patients with Multiple Sclerosis

BACKGROUND AND PURPOSE

We hypothesized that 3D T1-TSE "black-blood" images may carry an increased risk of contrast-enhancing lesion misdiagnosis in patients with MS because of the misinterpretation of intraparenchymal vein enhancement. Thus, the occurrence of true-positive and false-positive findings was compared between standard MPRAGE and volumetric interpolated brain examination techniques.

MATERIALS AND METHODS

Sampling perfection with application-optimized contrasts by using different flip-angle evolution (SPACE) images obtained from 232 patients with MS, clinically isolated syndrome, or radiologically isolated syndrome were compared with standard MPRAGE and volumetric interpolated brain examination images. The intraparenchymal vein contrast-to-noise ratio was estimated at the level of the thalami. Contrast-enhancing lesions were blindly detected by 2 expert readers and 1 beginner reader. True- and false-positives were determined by senior readers' consensus. True-positive and false-positive frequency differences and patient-level diagnosis probability were tested with the McNemar test and OR. The contrast-to-noise ratio and morphology were compared using the Mann-Whitney U and χ² tests.

RESULTS

The intraparenchymal vein contrast-to-noise ratio was higher in SPACE than in MPRAGE and volumetric interpolated brain examination images (P < .001, both). There were 66 true-positives and 74 false-positives overall. SPACE detected more true-positive and false-positive results (P range < .001-.07) but did not increase the patient's true-positive likelihood (OR = 1 1.29, P = .478-1). However, the false-positive likelihood was increased (OR = 3.03-3.55, P = .008-.027). Venous-origin false-positives (n = 59) with contrast-to-noise ratio and morphology features similar to small-sized (≤14 mm³ P = .544) true-positives occurred more frequently in SPACE images (P < .001).

CONCLUSIONS

Small intraparenchymal veins may confound the diagnosis of enhancing lesions on postgadolinium black-blood SPACE images.

Migraine in Multiple Sclerosis Patients Affects Functional Connectivity of the Brain Circuitry Involved in Pain Processing

Migraine is particularly common in patients with multiple sclerosis (MS) and has been linked to the dysfunction of the brain circuitry modulating the peripheral nociceptive stimuli. Using MRI, we explored whether changes in the resting state-functional connectivity (RS-FC) may characterize the occurrence of migraine in patients with MS. The RS-FC characteristics in concerned brain regions were explored in 20 MS patients with migraine (MS+M) during the interictal phase, and compared with 19 MS patients without migraine (MS-M), which served as a control group. Functional differences were correlated to the frequency and severity of previous migraine attacks, and with the resulting impact on daily activities. In MS+M, the loss of periaqueductal gray matter (PAG) positive connectivity with the default mode network and the left posterior cranial pons was associated with an increase of migraine attacks frequency. In contrast, the loss of PAG negative connectivity with sensorimotor and visual network was linked to migraine symptom severity and related daily activities impact. Finally, a PAG negative connection was established with the prefrontal executive control network. Migraine in MS+M patients and its impact on daily activities, underlies RS-FC rearrangements between brain regions involved in pain perception and modulation.

Volume of hippocampal subfields and cognitive deficits in neuromyelitis optica spectrum disorders

BACKGROUND

Aquaporin-4 (AQP4) water channel is involved in hippocampal plasticity and is the target of neuromyelitis optica spectrum disorders (NMOSD) autoimmunity. We measured volumes of hippocampal subfields and their association with cognitive performance in AQP4-seropositive NMOSD patients.

METHODS

Global and regional hippocampal volumes were derived from 28 AQP4-seropositive NMOSD patients and 101 healthy controls (HC) from 3D-T1-weighted images. Normalized brain volumes were also calculated. A neuropsychological evaluation, including the Brief Repeatable Battery of Neuropsychological Tests, was performed in patients. Based on HC data, we estimated mean z-scores of volumes in the whole NMOSD group and compared them according to the status of global and domain-selective cognitive impairment.

RESULTS

Global cognitive impairment was detected in 46.4% of NMOSD patients, with attentive (60.7%) and executive (21.4%) domains being the most affected. NMOSD patients had left hippocampal atrophy at global (p = 0.012) and regional level (fimbria, Cornu Ammonis [CA] 3, molecular layer, dentate gyrus [DG], and subicular complex, p values ranging between 0.033 and <0.001). On the right side the fimbria and hippocampal tail were atrophic (p = 0.024 for both). Cognitively impaired patients showed atrophy in the left CA3 and CA4 (p = 0.025-0.028), while patients presenting verbal and visual memory impairment had significant CA3 and DG atrophy. Those patients with attentive or executive impairment had preserved brain and hippocampal volumes.

CONCLUSIONS

NMOSD patients showed hippocampal atrophy associated with verbal and visual memory impairment. Such damage did not explain attention and executive function alterations, which were the most common cognitive deficits in this population.

Resting state network functional connectivity abnormalities in systemic lupus erythematosus: correlations with neuropsychiatric impairment

Neuropsychiatric manifestations are highly prevalent in systemic lupus erythematosus (SLE)-patients. We aimed to unravel the substrates of these manifestations by investigating abnormalities of resting state (RS) functional connectivity (FC) and their correlations with neuropsychiatric variables in SLE-patients. Thirty-two SLE-patients and 32 age- and sex-matched healthy controls (HC) underwent brain 3T RS fMRI. Neuropsychological assessment was performed for all SLE-patients. The main large-scale cognitive and psychiatric functional networks were derived and between-group comparisons and correlations with neuropsychological measures were performed. Compared to HC, SLE-patients exhibited increased RS FC in the right middle cingulate cortex and decreased RS FC in the left precuneus within default-mode network (DMN). They also showed increased RS FC in the left cerebellar crus I and left posterior cingulate cortex, and decreased RS FC in the left angular gyrus within working-memory networks (WMN). Compared to HC, SLE-patients exhibited increased RS FC in the left insular cortex and decreased RS FC in the right anterior cingulate cortex within salience network (SN), as well as decreased RS FC in the right middle frontal gyrus within executive-control network (ECN). Correlation analysis indicated a maladaptive role for left angular gyrus and cerebellar RS FC abnormalities in WMN, affecting memory and executive functions; and for precuneus and insular abnormalities in DMN and SN for psychiatric symptoms. Cingulate cortex modifications within DMN and SN correlated with better memory and global cognitive performance. Significant RS FC alterations in relevant cognitive and psychiatric networks occur in SLE-patients and participate in the pathophysiology of neuropsychiatric symptoms.

Contribution of sleep disturbances to fatigue in multiple sclerosis: a prospective study using clinical and polysomnographic parameters

Background and purpose

Fatigue is amongst the most frequent and disabling symptoms of multiple sclerosis and a close relation between fatigue and sleep quality has been hypothesized. In this study the contribution of sleep disturbances measured by clinical and polysomnographic parameters to fatigue in multiple sclerosis was investigated.

Methods

This was a prospective instrumental study performed at the Neurocenter of Southern Switzerland. Demographic data and clinical characteristics including fatigue (as measured by the modified fatigue impact scale [MFIS]), neurological disability, psychiatric symptoms, medications and sleep‐related variables were collected at baseline visit and by a home full‐night polysomnography. The associations between sleep‐related variables and the MFIS were tested using partial correlations adjusted by demographic and sleep‐unrelated clinical factors.

Results

Seventy‐six patients were included in the study, of whom 53 (69.7%) had an MFIS ≥38 points (median 49.5, interquartile range 31.0–62.0). MFIS scores were positively associated with age, neurological disability, symptoms of depression and anxiety, and use of benzodiazepines and selective serotonin reuptake inhibitors. When adjusting for these variables, the presence of restless legs syndrome (RLS) (r = 0.37, p = 0.005) and periodic leg movements index (r = −0.33, p = 0.014) were associated with MFIS. Excessive daytime sleepiness, total sleep time, sleep efficiency, respiratory disturbances, and percentage of time spent in the different sleep stages (N1, N2, N3 and rapid eye movement) were not associated with fatigue.

Conclusions

Multiple sclerosis patients with a diagnosis of RLS had significantly higher global fatigue scores compared to those without RLS. Future studies should investigate whether medical treatment of RLS can ameliorate fatigue.

Effect of cognitive reserve on structural and functional MRI measures in healthy subjects: a multiparametric assessment

BACKGROUND

Cognitive reserve (CR) contributes to inter-individual variability of cognitive performance and to preserve cognitive functioning facing aging and brain damage. However, brain anatomical and functional substrates of CR still need to be fully explored in young healthy subjects (HS). By evaluating a relatively large cohort of young HS, we investigated the associations between CR and structural and functional magnetic resonance imaging (MRI) measures in early adulthood.

METHODS

A global Cognitive Reserve Index (CRI), combining intelligence quotient, leisure activities and education, was measured from 77 HS and its brain anatomical and functional substrates were evaluated through a multiparametric MRI approach. Substrates of the three subdomains (cognitive/social/physical) of leisure activities were also explored.

RESULTS

Higher global and subdomain CRIs were associated with higher gray matter volume of brain regions involved in motor and cognitive functions, such as the right (R) supplementary motor area, left (L) middle frontal gyrus and L cerebellum. No correlation with measures of white matter (WM) integrity was found. Higher global and subdomains CRIs were associated with lower resting-state functional connectivity (RS FC) of L postcentral gyrus and R insula in sensorimotor network, L postcentral gyrus in salience network and R cerebellum in the executive-control network. Moreover, several CRIs were also associated with higher RS FC of R cuneus in default-mode network.

CONCLUSIONS

CR modulates structure and function of several brain motor and cognitive networks responsible for complex cognitive functioning already in young HS. CR could promote optimization of the recruitment of brain networks.

De-escalating rituximab dose results in stability of clinical, radiological, and serum neurofilament levels in multiple sclerosis

BACKGROUND

Phase II and observational studies support the use of rituximab in multiple sclerosis. Standard protocols are lacking, but studies suggest comparable efficacy between low- and high-dose regimens.

OBJECTIVE

To evaluate effectiveness and safety of de-escalating rituximab dose from 1000 to 500 mg/6 months in multiple sclerosis.

METHODS

Patients were switched from rituximab 1000 to 500 mg/6 months and prospectively followed for 12 months. Relapses, disability, occurrence of brain/spinal magnetic resonance imaging (MRI) lesions, serum neurofilament light chain (NfL), CD19⁺ B cell, and IgG concentrations were analyzed.

RESULTS

Fifty-nine patients were included (37 relapsing-remitting, 22 secondary progressive). No relapses occurred, with no difference in expanded disability status scale (EDSS) between baseline (4 (2.5-4.5) and 12 months (3.5 (2.5-5.5) p = 0.284). Overall, three new T2 lesions appeared during follow-up. NfL concentration was stable between baseline (7.9 (5.9-45.2) pg/mL) and 12 months (9.1 (5.9-21.3) pg/mL, p = 0.120). IgG concentrations decreased with greater rituximab load (coefficient = -0.439, p = 0.041). IgG deficient patients had greater risk of infections (OR = 6.27, 95% CI = 1.71-22.9, p = 0.005).

CONCLUSION

De-escalating rituximab dose from 1000 to 500 mg/6 months is safe, results in clinical and radiological stability, and does not affect serum NfL over 12 months. Rituximab load negatively influences IgG concentrations, and IgG deficient patients are at higher risk of infections.

Effects of Natalizumab and Fingolimod on Clinical, Cognitive, and Magnetic Resonance Imaging Measures in Multiple Sclerosis

Studies comparing the effects of natalizumab and fingolimod in relapsing-remitting multiple sclerosis (RRMS) are limited. We aimed to compare natalizumab and fingolimod effects on clinical, neuropsychological, and MRI measures in RRMS patients after 2 years of treatment. RRMS patients starting natalizumab (n = 30) or fingolimod (n = 25) underwent neurologic, neuropsychological, and brain MRI assessments at baseline, month (M) 6, M12, and M24. Volumes of lesions, brain, gray matter (GM), white matter (WM), and deep GM were measured. Fifteen healthy controls (HC) were also scanned at baseline and M24. Treatment groups were matched for baseline variables. At M24 versus baseline, both drugs reduced the relapse rate (p value < 0.001), stabilized disability, and improved cognitive function (fingolimod: p value = 0.03; natalizumab: p value = 0.01), without between-group differences. The natalizumab group had a higher proportion of freedom from MRI activity (67% vs 36%, p value = 0.02) and no evidence of disease activity-3 (NEDA-3) (57% vs 28%, p value = 0.04). At M24 vs M6, brain (- 0.35%, p value = 0.002 [fingolimod]; - 0.42%, p value < 0.001 [natalizumab]), GM (- 0.62%, p value < 0.001 [fingolimod]; - 0.64%, p value < 0.001 [natalizumab]), and WM (- 0.98%, p value < 0.001 [fingolimod]; - 0.99%, p value < 0.001 [natalizumab]) atrophy progressed at higher rates than in HC, but similarly between treatment groups, whereas only the natalizumab group showed deep GM atrophy (- 0.79%, p value = 0.02) (p value vs fingolimod not significant). In both groups, atrophy progression was correlated with lesion accumulation (r from - 0.49 to - 0.36, p values from 0.013 to 0.05), whereas no correlation was found between clinical and MRI changes. Natalizumab and fingolimod reduce disease activity and improve cognition in RRMS. Natalizumab seems superior to limit lesion accumulation, whereas both drugs similarly modify atrophy progression.

Influence of CNS T2-focal lesions on cervical cord atrophy and disability in multiple sclerosis

Background:

Mechanisms associated with cervical spinal cord (CSC) and upper thoracic spinal cord (TSC) atrophy in multiple sclerosis (MS) are poorly understood.

Objective:

To assess the influence of brain, CSC and TSC T2-hyperintense lesions on cord atrophy and disability in MS.

Methods:

Thirty-four MS patients underwent 3T brain, cervical and thoracic cord magnetic resonance imaging (MRI) and Expanded Disability Status Scale (EDSS) score assessment. CSC/TSC lesion number and volume (LV), whole-brain and cortico-spinal tract (CST) LVs were obtained. Normalized whole CSC and upper TSC cross-sectional areas (CSAn) were also derived. Age- and sex-adjusted regression models assessed associations of brain/cord lesions with CSAn and EDSS and identified variables independently associated with CSAn and EDSS with a stepwise variable selection.

Results:

CSC CSAn (β = −0.36, p = 0.03) and TSC CSAn (β = −0.60, p < 0.001) were associated with CSC T2 LV. EDSS (median = 3.0) was correlated with CSC T2 LV (β = 0.42, p = 0.01), brain (β = 0.34, p = 0.04) and CST LV (β = 0.35, p = 0.03). The multivariate analysis retained CSC LV as significant predictor of CSC CSAn ( R2 = 0.20, p = 0.023) and TSC CSAn ( R2 = 0.51, p < 0.001) and retained CSC and CST LVs as significant predictors of EDSS ( R2 = 0.55, p = 0.001).

Conclusions:

CSC LV is an independent predictor of cord atrophy. When neurological impairment is relatively mild, central nervous system (CNS) lesion burden is a better correlate of disability than atrophy.

Brain Tumor-Enhancement Visualization and Morphometric Assessment: A Comparison of MPRAGE, SPACE, and VIBE MRI Techniques

BACKGROUND AND PURPOSE

Postgadolinium MR imaging is crucial for brain tumor diagnosis and morphometric assessment. We compared brain tumor enhancement visualization and the "target" object morphometry obtained with the most commonly used 3D MR imaging technique, MPRAGE, with 2 other routinely available techniques: sampling perfection with application-optimized contrasts by using different flip angle evolutions (SPACE) and volumetric interpolated brain examination (VIBE).

MATERIALS AND METHODS

Fifty-four contrast-enhancing tumors (38 gliomas and 16 metastases) were assessed using MPRAGE, VIBE, and SPACE techniques randomly acquired after gadolinium-based contrast agent administration on a 3T scanner. Enhancement conspicuity was assessed quantitatively by calculating the contrast rate and contrast-to-noise ratio, and qualitatively, by consensus visual comparative ratings. The total enhancing tumor volume and between-sequence discrepancy in the margin delineation were assessed on the corresponding 3D target objects contoured with a computer-assisted software for neuronavigation. The Wilcoxon signed rank and Pearson χ² nonparametric tests were used to investigate between-sequence discrepancies in the contrast rate, contrast-to-noise ratio, visual conspicuity ratings, tumor volume, and margin delineation estimates. Differences were also tested for 1D (Response Evaluation Criteria in Solid Tumors) and 2D (Response Assessment in Neuro-Oncology) measurements.

RESULTS

Compared with MPRAGE, both SPACE and VIBE obtained higher contrast rate, contrast-to-noise ratio, and visual conspicuity ratings in both gliomas and metastases (P range, <.001-.001). The between-sequence 3D target object margin discrepancy ranged between 3% and 19.9% of lesion tumor volume. Larger tumor volumes, 1D and 2D measurements were obtained with SPACE (P range, <.01-.007).

CONCLUSIONS

Superior conspicuity for brain tumor enhancement can be achieved using SPACE and VIBE techniques, compared with MPRAGE. Discrepancies were also detected when assessing target object size and morphology, with SPACE providing more accurate estimates.

Action observation training modifies brain gray matter structure in healthy adult individuals

Action observation training (AOT) is thought to facilitate motor system function. We applied voxelwise methods to assess the regional modifications of brain gray matter (GM) volumes and white matter (WM) architecture in healthy subjects following AOT and their correlations with improvements at motor and cognitive functional scales. Forty-two righ-handed healthy subjects were randomized into an experimental (AOT-G, n = 20) and a control (C-G, n = 22) group. The training lasted 2 weeks and consisted of 10 sessions of 45 min each during which subjects watched videos of daily-life actions (AOT-G) or landscapes (C-G), alternated by the execution with the right hand of actions presented in the AOT-G videos. At baseline and follow up, motor and cognitive functional measures as well as brain structural MRI scans were obtained. Tensor-based morphometry and tract-based spatial statistics were used to map longitudinal modifications of GM and WM structures and their correlation with functional scales. After training, both groups improved at cognitive tests, whereas the AOT-G also improved hand motor performance. Following training, no modifications of WM diffusion tensor MRI indexes were detected. After training, compared to C-G, AOT-G had increased volume of the left superior frontal gyrus and decreased volume of the right lingual gyrus. Compared to AOT-G, C-G showed increased volume of the right middle frontal gyrus and left inferior temporal gyrus. In AOT-G, GM volume changes correlated with improvements at cognitive tests. Ten-day AOT in healthy individuals modifies GM structure, promoting structural brain plasticity and functional competence.

Hippocampal-related memory network in multiple sclerosis: A structural connectivity analysis

Background:

We used graph theoretical analysis to quantify structural connectivity of the hippocampal-related episodic memory network and its association with memory performance in multiple sclerosis (MS) patients.

Methods:

Brain diffusion and T1-weighted sequences were obtained from 71 MS patients and 50 healthy controls (HCs). A total of 30 gray matter regions (selected a priori) were used as seeds to perform probabilistic tractography and create connectivity matrices. Global, nodal, and edge graph theoretical properties were calculated. In patients, verbal and visuospatial memory was assessed.

Results:

MS patients showed decreased network strength, assortativity, transitivity, global efficiency, and increased average path length. Several nodes had decreased strength and communicability in patients, whereas insula and left temporo-occipital cortex increased communicability. Patients had widespread decreased streamline count (SC) and communicability of edges, although a few ones increased their connectivity. Worse memory performance was associated with reduced network efficiency, decreased right hippocampus strength, and reduced SC and communicability of edges related to medial temporal lobe, thalamus, insula, and occipital cortex.

Conclusion:

Impaired structural connectivity occurs in the hippocampal-related memory network, decreasing the efficiency of information transmission. Network connectivity measures correlate with episodic memory, supporting the relevance of structural integrity in preserving memory processes in MS.

Cognitive reserve, cognition, and regional brain damage in MS: A 2 -year longitudinal study

BACKGROUND

According to the cognitive reserve (CR) theory, enriching experiences protect against cognitive decline.

OBJECTIVES

To investigate the dynamic interaction between CR and global/regional measures of brain white matter (WM) and gray matter (GM) damage and their effect on cognitive performance in multiple sclerosis (MS).

METHODS

Baseline and 2 -year three-dimensional (3D) T1-weighted scans were obtained from 54 MS patients and 20 healthy controls. Patients' cognitive functions were tested and a cognitive reserve index (CRI) was calculated. Baseline regional atrophy and longitudinal volume changes were investigated using voxel-wise methods. Structural damage and CRI effects on cognitive performance were explored with linear models.

RESULTS

At baseline, MS patients showed atrophy of the deep GM nuclei, GM/WM frontal-temporal-parietal-occipital regions, and left cerebellum. Controlling for atrophy, higher CRI explained significant portions of variance in verbal memory and verbal fluency (∆ R² = 0.07-0.16; p < 0.03). The interaction between thalamic volume and CRI was significant (∆ R² = 0.05; p = 0.03). Longitudinal changes in memory and attention performance were associated with local/global variations of GM/WM and T2 lesions. CRI had no effect on longitudinal cognitive changes.

CONCLUSION

In MS, CR may have a protective role in preserving cognitive functions, moderating the effect of structural damage on cognitive performance. This protective role may diminish with disease progression.

Imaging patterns of gray and white matter abnormalities associated with PASAT and SDMT performance in relapsing-remitting multiple sclerosis

Objectives:

To map the regional patterns of white matter (WM) microstructural abnormalities and gray matter (GM) atrophy exclusively associated with reduced performance in the Symbol Digit Modalities Test (SDMT) and Paced Auditory Serial Addition Test (PASAT) in relapsing-remitting (RR) multiple sclerosis (MS) patients.

Methods:

In all, 177 RRMS patients and 80 healthy controls (HC) were studied. WM microstructural abnormalities were investigated on diffusion tensor images using tract-based spatial statistics analysis, and regional GM atrophy was estimated on three-dimensional (3D) T1-weighted images using voxel-based morphometry.

Results:

Compared to HC, RRMS patients showed the expected pattern of cortical–subcortical GM atrophy and WM microstructural abnormalities. In patients, diffusivity abnormalities of supratentorial WM tracts correlated with both SDMT and PASAT scores. Lower SDMT performance was also associated with WM damage in several infratentorial WM tracts. Lower SDMT scores correlated with atrophy of the right anterior cingulate cortex, left postcentral gyrus, and right middle temporal gyrus, whereas lower PASAT scores correlated with atrophy of the deep GM nuclei, bilaterally, and several fronto-temporo-occipital regions.

Conclusion:

In RRMS patients, regional damage of different neural systems helps explaining reduced performance in SDMT and PASAT. WM microstructural damage typified reduced SDMT performance, whereas atrophy of several GM regions distinguished reduced PASAT performance.

Progression of regional atrophy in the left hemisphere contributes to clinical and cognitive deterioration in multiple sclerosis: A 5-year study

In this longitudinal study, we investigated the regional patterns of focal lesions accumulation, and gray (GM) and white matter (WM) atrophy progression over a five-year follow-up (FU) in multiple sclerosis (MS) patients and their association with clinical and cognitive deterioration. Neurological, neuropsychological and brain MRI (dual-echo and 3D T1-weighted sequences) assessments were prospectively performed at baseline (T0) and after a median FU of 4.9 years from 66 MS patients (including relapse-onset and primary progressive MS) and 16 matched controls. Lesion probability maps were obtained. Longitudinal changes of GM and WM volumes and their association with clinical and cognitive deterioration were assessed using tensor-based morphometry and SPM12. At FU, 36/66 (54.5%) MS patients showed a significant disability worsening, 14/66 (21.2%) evolved to a worse clinical phenotype, and 18/63 (28.6%) developed cognitive deterioration. At T0, compared to controls, MS patients showed a widespread pattern of GM atrophy, involving cortex, deep GM and cerebellum, and atrophy of the majority of WM tracts, which further progressed at FU (P < 0.001, uncorrected). Compared to stable patients, those with clinical and cognitive worsening showed a left-lateralized pattern of GM and WM atrophy, involving deep GM, fronto-temporo-parieto-occipital regions, cerebellum, and several WM tracts (P < 0.001, uncorrected).GM and WM atrophy of relevant brain regions occur in MS after 5 years. A different vulnerability of the two brain hemispheres to irreversible structural damage may be among the factors contributing to clinical and cognitive worsening in these patients. Hum Brain Mapp 38:5648-5665, 2017. © 2017 Wiley Periodicals, Inc.

Functional network connectivity abnormalities in multiple sclerosis: Correlations with disability and cognitive impairment

OBJECTIVE

To investigate resting state (RS) functional connectivity (FC) abnormalities within the principal brain networks in a large cohort of multiple sclerosis (MS) patients, to define the trajectory of FC changes over disease stages and their relation with clinical and structural magnetic resonance imaging (MRI) measures.

METHODS

RS functional magnetic resonance imaging (fMRI), clinical, and neuropsychological evaluation were obtained from 215 MS patients and 98 healthy controls. Connectivity abnormalities and correlations with clinical/neuropsychological/imaging measures were evaluated. We analyzed seed-voxel FC with seven major hubs, producing one visual/sensory, one motor, two cognitive, one cerebellar, and two subcortical networks.

RESULTS

MS patients showed reduced network average RS FC versus controls in the default-mode network. At regional level, a complex pattern of decreased and increased RS FC was found. Reduced RS FC mainly involved sensorimotor, cognitive, thalamic, and cerebellar networks, whereas increased RS FC involved visual/sensory and subcortical networks. Reduced RS FC correlated with T2 lesions. Reduced thalamic RS FC correlated with better neuropsychological performance, whereas for all remaining networks reduced FC correlated with more severe clinical/cognitive impairment.

CONCLUSION

Increased and decreased RS FC occurs in MS and contributes to a wide spectrum of clinical manifestations. RS FC reduction is related to T2 lesions. Such a paradigm is inverted for the thalamic network.

Gray matter trophism, cognitive impairment, and depression in patients with multiple sclerosis

BACKGROUND

Cognitive impairment and depression frequently affects patients with multiple sclerosis (MS). However, the relationship between the occurrence of depression and cognitive impairment and the development of cortical atrophy has not been fully elucidated yet.

OBJECTIVES

To investigate the association of cortical and deep gray matter (GM) volume with depression and cognitive impairment in MS.

METHODS

Three-dimensional (3D) T1-weighted scans were obtained from 126 MS patients and 59 matched healthy controls. Cognitive impairment was assessed using the Brief Repeatable Battery of Neuropsychological Tests and depression with the Montgomery-Asberg Depression Rating Scale (MADRS). Using FreeSurfer and FIRST software, we assessed cortical thickness (CTh) and deep GM volumetry. Magnetic resonance imaging (MRI) variables explaining depression and cognitive impairment were investigated using factorial and classification analysis. Multivariate regression models correlated GM abnormalities with symptoms severity.

RESULTS

Compared with controls, MS patients exhibited widespread bilateral cortical thinning involving all brain lobes. Depressed MS showed selective CTh decrease in fronto-temporal regions, whereas cognitive impairment MS exhibited widespread fronto-parietal cortical and subcortical GM atrophy. Frontal cortical thinning was the best predictor of depression ( C-statistic = 0.7), whereas thinning of the right precuneus and high T2 lesion volume best predicted cognitive impairment ( C-statistic = 0.8). MADRS severity correlated with right entorhinal cortex thinning, whereas cognitive impairment severity correlated with left entorhinal and thalamus atrophy.

CONCLUSION

MS-related depression is linked to circumscribed CTh changes in areas deputed to emotional behavior, whereas cognitive impairment is correlated with cortical and subcortical GM atrophy of circuits involved in cognition.

Cerebellar contribution to motor and cognitive performance in multiple sclerosis: An MRI sub-regional volumetric analysis

OBJECTIVE

To investigate the role of cerebellar sub-regions on motor and cognitive performance in multiple sclerosis (MS) patients.

METHODS

Whole and sub-regional cerebellar volumes, brain volumes, T2 hyperintense lesion volumes (LV), and motor performance scores were obtained from 95 relapse-onset MS patients and 32 healthy controls (HC). MS patients also underwent an evaluation of working memory and processing speed functions. Cerebellar anterior and posterior lobes were segmented using the Spatially Unbiased Infratentorial Toolbox (SUIT) from Statistical Parametric Mapping (SPM12). Multivariate linear regression models assessed the relationship between magnetic resonance imaging (MRI) measures and motor/cognitive scores.

RESULTS

Compared to HC, only secondary progressive multiple sclerosis (SPMS) patients had lower cerebellar volumes (total and posterior cerebellum). In MS patients, lower anterior cerebellar volume and brain T2 LV predicted worse motor performance, whereas lower posterior cerebellar volume and brain T2 LV predicted poor cognitive performance. Global measures of brain volume and infratentorial T2 LV were not selected by the final multivariate models.

CONCLUSION

Cerebellar volumetric abnormalities are likely to play an important contribution to explain motor and cognitive performance in MS patients. Consistently with functional mapping studies, cerebellar posterior-inferior volume accounted for variance in cognitive measures, whereas anterior cerebellar volume accounted for variance in motor performance, supporting the assessment of cerebellar damage at sub-regional level.

Structural MRI correlates of cognitive impairment in patients with multiple sclerosis: A Multicenter Study

In a multicenter setting, we applied voxel-based methods to different structural MR imaging modalities to define the relative contributions of focal lesions, normal-appearing white matter (NAWM), and gray matter (GM) damage and their regional distribution to cognitive deficits as well as impairment of specific cognitive domains in multiple sclerosis (MS) patients. Approval of the institutional review boards was obtained, together with written informed consent from all participants. Standardized neuropsychological assessment and conventional, diffusion tensor and volumetric brain MRI sequences were collected from 61 relapsing-remitting MS patients and 61 healthy controls (HC) from seven centers. Patients with ≥2 abnormal tests were considered cognitively impaired (CI). The distribution of focal lesions, GM and WM atrophy, and microstructural WM damage were assessed using voxel-wise approaches. A random forest analysis identified the best imaging predictors of global cognitive impairment and deficits of specific cognitive domains. Twenty-three (38%) MS patients were CI. Compared with cognitively preserved (CP), CI MS patients had GM atrophy of the left thalamus, right hippocampus and parietal regions. They also showed atrophy of several WM tracts, mainly located in posterior brain regions and widespread WM diffusivity abnormalities. WM diffusivity abnormalities in cognitive-relevant WM tracts followed by atrophy of cognitive-relevant GM regions explained global cognitive impairment. Variable patterns of NAWM and GM damage were associated with deficits in selected cognitive domains. Structural, multiparametric, voxel-wise MRI approaches are feasible in a multicenter setting. The combination of different imaging modalities is needed to assess and monitor cognitive impairment in MS.

Abnormal adaptation over time of motor network recruitment in multiple sclerosis patients with fatigue

OBJECTIVES

Using functional magnetic resonance imaging (fMRI) during a motor task, we investigated the functional correlates of central fatigue in multiple sclerosis (MS), and adaptation of motor network recruitment during a prolonged effort.

METHODS

Motor fMRI was obtained from 79 MS patients (50 fatigued (F), 29 non-fatigued (nF)) and 26 matched healthy controls (HC). Cognitive and physical fatigue were rated using the Modified Fatigue Impact Scale (MFIS).

RESULTS

Compared to HC and nF patients, F-MS patients experienced reduced activations of the left middle temporal gyrus, left supplementary motor area (SMA), bilateral superior frontal gyrus, left postcentral gyrus and basal ganglia regions. They also showed increased activation of the right middle frontal gyrus (MFG). Time-modulation analysis showed a reduced activity of the SMA and right precentral gyrus, and increased activity of the basal ganglia in HC. Such a trend was impaired in F-MS patients. In MS patients, increased MFG activity was related to MFIS scores. Physical MFIS score was related to a reduced recruitment of the right thalamus and SMA.

CONCLUSIONS

Abnormalities and impaired timing of activation between different areas of the motor and executive networks occur in F-MS patients. The dysfunction of critical cortical areas contributes to the occurrence of central fatigue.

Relevance of asymptomatic spinal MRI lesions in patients with multiple sclerosis

BACKGROUND

The impact of new asymptomatic spinal cord lesions (a-SL) in multiple sclerosis (MS) course is poorly characterized.

OBJECTIVE

The objective of this research paper is to assess the prognostic value of a-SL in predicting MS course.

METHODS

Relapsing-remitting MS patients who received serial MRI (brain and spinal) at baseline (t1) and within 12 to 36 months (t2) during clinical stability, and had a follow-up (t2-t3) ⩾24 months were included. Relapses and disability progression were evaluated between t2 and t3.

RESULTS

Of 413 consecutive screened MS patients, 103 patients (65 females, median age 43 years) were included. After a median t1-t2 interval of 17 (IQR 13-26) months, 25.2% and 43.7% patients had ⩾1 new a-SL (a-SL+) and asymptomatic brain lesions (a-BL+), respectively. Relapse risk between t2 and t3 (median interval: 42 (IQR 32-57.5) months) was significantly increased in a-SL+ and/or a-BL+ vs a-BL- and a-SL- (HR = 2.31, 95% CI = 1.13-4.72, p = 0.02). No differences in the risk of disability progression were found in a-SL+ and/or a-BL+ vs a-SL- and a-BL-.

CONCLUSION

a-SL occur in one-quarter of clinically stable RRMS, and combined with a-BL contribute significantly in predicting future disease course.

Natalizumab in spinal multiple sclerosis in a daily clinical setting

OBJECTIVE

We aimed to investigate the influence of natalizumab (NTZ) treatment on multiple sclerosis course in patients with and without spinal involvement.

METHODS

Annualized relapse rate (ARR), disability progression and occurrence of new brain and spinal T2 lesions (N2TL) in 68 spinal (S-P) versus 68 non-spinal matched patients (NS-P) were retrospectively collected and compared between before (2 years) and after NTZ treatment using multivariate regression models.

RESULTS

Mean duration of NTZ treatment was 31.3 ± 16.3 months in S-P and 32.1 ± 15.1 months in N-SP (p = 0.56). The mean ARR after NTZ treatment was similarly reduced in both S-P (0.07 ± 0.19) and N-SP (0.07 ± 0.16) (p < 0.001 for both). Disability progression after NTZ start was similarly low in S-P and NS-P. However, when compared to before NTZ start, disability progression was significantly reduced in S-P (p = 0.017), but not in NS-P (p = 0.68). This was largely mediated by a higher disability progression before NTZ start in S-P than N-SP. The risk of developing N2TL during NTZ was not different between S-P and NS-P (p = 0.10).

CONCLUSIONS

NTZ similarly reduced the occurrence of relapses and NT2L in S-P and NS-P, whereas the effect on disability progression was particularly evident in the presence of spinal involvement. NTZ appears to be a treatment of high efficacy in both S-P and NS-P.

Forceps minor damage and co-occurrence of depression and fatigue in multiple sclerosis

OBJECTIVE

Using diffusion tensor magnetic resonance imaging (DT MRI), we analyzed the architectural integrity of the brain white matter (WM) from a large cohort of MS patients to identify the structural substrates of the concomitant presence of depression and fatigue.

METHODS

Brain dual-echo, 3D T1-weighted and DT MRI scans were acquired from 147 MS patients and 90 gender- and age-matched healthy controls (HCs). Patients were stratified by the presence of depression (92 depressed (D), 55 not depressed (nD)) and fatigue (81 fatigued (F), 66 not fatigued (nF)). Sixty-five patients had co-occurrence of depression and fatigue (DF). Whole-brain voxel-wise comparisons of WM DT MRI abnormalities were performed using tract-based-spatial-statistics (TBSS). Tract-specific analyses were run in brain WM tracts using standard-space templates.

RESULTS

Whole-brain voxel-wise analysis yielded no significant differences between patient subgroups. At tract-specific analysis, DF patients had reduced fractional anisotropy (FA) of the forceps minor. Reduced FA of the right anterior thalamic radiation and right uncinate fasciculus was found in F-MS vs not F-MS patients after correcting for depression. No significant differences were found between D vs not D-MS patients, after correcting for fatigue.

CONCLUSIONS

This study provides evidence for partially overlapping damage to frontal and fronto-temporal pathways underlying depression and fatigue in MS.

Treatment satisfaction, adherence and behavioral assessment in patients de-escalating from natalizumab to interferon β

Background

De-escalating natalizumab (NTZ) to interferon beta 1b (IFN B 1B) is a possible treatment option in multiple sclerosis (MS) patients interrupting NTZ because of increased risk of progressive multifocal leukoencephalopathy (PML). The aim of this study was to evaluate satisfaction and adherence to treatment, behavioral and fatigue changes in patients switched to IFN B 1B compared to continued NTZ treatment.

Methods

A 1 year, prospective, randomized, rater-blinded, parallel-group study. Nineteen relapsing remitting (RR) MS patients, randomly assigned to undergo either NTZ (n = 10) or IFN B 1B (n = 9) treatment, who had previously received NTZ for at least 12 months with disease stability and fearing or at risk for PML were included. Patients underwent behavioral and treatment assessments at baseline, after 24-week and 1 year follow-up. Behavioral assessment included measures of cognition, fatigue and quality of life. Treatment assessment included measures of satisfaction, persistence and adherence to treatment. Clinical-radiological disease activity and safety were also assessed.

Results

Baseline characteristics of patients were similar between groups except for Euro Quality Visual Analogue Scale, being higher in the NTZ group (p = 0.04). Within-group comparisons at the three time points, as well as interaction analysis of treatment effect over time did not show any statistically significant differences in behavioral or treatment assessments, but a coherent trend favoring NTZ over IFN B 1B.

Conclusions

De-escalating NTZ to IFN B 1B is feasible and associated with overall good patient related outcome and persistently stable behavioral measures.