Thalamic asymmetry in Multiple Sclerosis.

BACKGROUND: Multiple Sclerosis (MS) is a chronic neuroinflammatory disease that affects the central nervous system. Asymmetry is one of the finding in brain MRI of these patients, which is related to the debilitating symptoms of the disease. This study aimed to investigate and compare the thalamic asymmetry in MS patients and its relationship with other MRI and clinical findings of these patients. METHODS: This cross-sectional study conducted on 83 patients with relapse-remitting MS (RRMS), 43 patients with secondary progressive MS (SPMS), and 89 healthy controls. The volumes of total intracranial, total gray matter, total white matter, lesions, thalamus, and also the thalamic asymmetry indices were calculated. The 9-hole peg test (9-HPT) and Expanded Disability Status Scale (EDSS) were assessed as clinical findings. RESULTS: We showed that the normalized whole thalamic volume in healthy subjects was higher than MS patients (both RRMS and SPMS). Thalamic asymmetry index (TAI) was significantly different between RRMS patients and SPMS patients (p = 0.011). The absolute value of TAI was significantly lower in healthy subjects than in RRMS (p < 0.001) and SPMS patients (p < 0.001), and SPMS patients had a higher absolute TAI compared to RRMS patients (p = 0.037). CONCLUSIONS: In this cross-sectional study we showed a relationship between normalized whole thalamic volume and MS subtype. Also, we showed that the asymmetric indices of the thalamus can be related to the progression of the disease. Eventually, we showed that thalamic asymmetry can be related to the disease progression and subtype changes in MS.

Abnormal thalamic functional connectivity correlates with cardiorespiratory fitness and physical activity in progressive multiple sclerosis.

BACKGROUND: Altered thalamic volumes and resting state (RS) functional connectivity (FC) might be associated with physical activity (PA) and cardiorespiratory fitness (CRF) in people with progressive multiple sclerosis (PMS). OBJECTIVES: To assess thalamic structural and functional alterations and investigate their correlations with PA/CRF levels in people with PMS. METHODS: Seven-day accelerometry and cardiopulmonary exercise testing were used to assess PA/CRF levels in 91 persons with PMS. They underwent 3.0 T structural and RS fMRI acquisition with 37 age/sex-matched healthy controls (HC). Between-group comparisons of MRI measures and their correlations with PA/CRF variables were assessed. RESULTS: PMS people had lower volumes compared to HC (all p < 0.001). At corrected threshold, PMS showed decreased intra- and inter-thalamic RS FC, and increased RS FC between the thalamus and the hippocampus, bilaterally. At uncorrected threshold, decreased thalamic RS FC with caudate nucleus, cerebellum and anterior cingulate cortex (ACC), as well as increased thalamic RS FC with occipital regions, were also detected. Lower CRF, measured as peak oxygen consumption (VO2peak), correlated with lower white matter volume (r = 0.31, p = 0.03). Moreover, lower levels of light PA correlated with increased thalamic RS FC with the right hippocampus (r = - 0.3, p = 0.05). DISCUSSION: People with PMS showed widespread brain atrophy, as well as pronounced intra-thalamic and thalamo-hippocampal RS FC abnormalities. White matter atrophy correlated with CRF, while increased thalamo-hippocampal RS FC was associated to worse PA levels. Thalamic RS FC might be used to monitor physical impairment and efficacy of rehabilitative and disease-modifying treatments in future studies.

N-Acetyl Cysteine as a Neuroprotective Agent in Progressive Multiple Sclerosis (NACPMS) trial: Study protocol for a randomized, double-blind, placebo-controlled add-on phase 2 trial.

INTRODUCTION: Patients with progressive multiple sclerosis (PMS) experience relentless disability worsening. Current approved therapies have very modest effects on disability progression and purely focus on immunomodulation. While some inflammatory processes exist in non-active PMS, other biological processes such as neuronal injury from oxidative stress are likely more critical. N-acetyl cysteine (NAC) directly scavenges free radicals and restores neuronal glutathione, a major endogenous antioxidant. Our group has recently evaluated the safety of high dose NAC in a pilot trial in PMS with no tolerability concerns. We aim now to assess the safety, tolerability, and effect of NAC on progression of several MRI, clinical and biological markers in PMS patients. METHODS: The NACPMS trial is a multi-site, randomized, double-blind, parallel-group, placebo-controlled add-on phase 2 trial. Ninety-eight PMS patients with EDSS 3.0-7.0 and aged 40-70 years will be randomized to NAC 1200 mg TID or matching placebo (1:1) as an add-on to the standard of care stratified by site and disease type during a 15-month intervention period. It is hypothesized that a reduction in oxidative stress injury will lessen brain atrophy estimated by MRI. The primary outcome analysis will compare the percent change over 12 months (Month 15 vs Month 3) between treatment and control arms using multivariable linear regression adjusted by age, sex, and disease duration. ETHICS: This study was approved by the Institutional Review Board at the University of California, San Francisco (IRB21-34143), and an Investigational New Drug approval was obtained from the FDA (IND127184). TRIAL REGISTRATION: NCT05122559.

Gray Matter Atrophy in the Cortico-Striatal-Thalamic Network and Sensorimotor Network in Relapsing-Remitting and Primary Progressive Multiple Sclerosis.

Gray matter atrophy in multiple sclerosis (MS) is thought to be associated with disability and cognitive impairment, but previous studies have sometimes had discordant results, and the atrophy patterns of relapsing-remitting multiple sclerosis (RRMS) and primary progressive multiple sclerosis (PPMS) remain to be clarified. We conducted a meta-analysis using anisotropic effect-size-based algorithms (AES-SDM) to identify consistent findings from whole-brain voxel-based morphometry (VBM) studies of gray matter volume (GMV) in 924 RRMS patients and 204 PPMS patients. This study is registered with PROSPERO (number CRD42019121319). Compared with healthy controls, RRMS and PPMS patients showed gray matter atrophy in the cortico-striatal-thalamic network, sensorimotor network, and bilateral insula. RRMS patients had a larger GMV in the left insula, cerebellum, right precentral gyrus, and bilateral putamen as well as a smaller GMV in the bilateral cingulate, caudate nucleus, right thalamus, superior temporal gyrus and left postcentral gyrus than PPMS patients. The disease duration, Expanded Disability Status Scale score, Paced Auditory Serial Addition Test z-score, and T2-weighted lesion load were associated with specific gray matter regions in RRMS or PPMS. Alterations in the cortico-striatal-thalamic networks, sensorimotor network, and insula may be involved in the common pathogenesis of RRMS and PPMS. The deficits in the cingulate gyrus and caudate nucleus are more apparent in RRMS than in PPMS. The more severe cerebellum atrophy in PPMS may be a brain feature associated with its neurological manifestations. These imaging biomarkers provide morphological evidence for the pathophysiology of MS and should be verified in future research.

High-dose biotin in progressive multiple sclerosis: A prospective study of 178 patients in routine clinical practice.

BACKGROUND: A recent controlled trial suggested that high-dose biotin supplementation reverses disability progression in patients with progressive multiple sclerosis. OBJECTIVE: To analyze the impact of high-dose biotin in routine clinical practice on disability progression at 12 months. METHODS: Progressive multiple sclerosis patients who started high-dose biotin at Nantes or Rennes Hospital between 3 June 2015 and 15 September 2017 were included in this prospective study. Disability outcome measures, patient-reported outcome measures, relapses, magnetic resonance imaging (MRI) data, and adverse events were collected at baseline, 6, and 12 months. RESULTS: A total of 178 patients were included. At baseline, patients were 52.0 ± 9.4 years old, mean Expanded Disability Status Scale (EDSS) score was 6.1 ± 1.3, mean disease duration was 16.9 ± 9.5 years. At 12 months, 3.8% of the patients had an improved EDSS score. Regarding the other disability scales, scores either remained stable or increased significantly. In total, 47.4% of the patients described stability, 27.6% felt an improvement, and 25% described a worsening. Four patients (2.2%) had a relapse. Of the 74 patients (41.6%) who underwent an MRI, 20 (27.0%) had new T2 lesions, 8 (10.8%) had gadolinium-enhancing lesions. Twenty-five (14%) reported adverse event. CONCLUSION: In this study, high-dose biotin did not seem to be associated with a clear improvement in disability.

Looking into cognitive impairment in primary-progressive multiple sclerosis.

BACKGROUND AND PURPOSE: Cognitive impairment in primary-progressive multiple sclerosis (PP-MS) is correlated with global brain atrophy. Unfortunately, brain volume computation requires processing resources that are not widely available in clinical practice. Therefore, we decided to test the predictive role of retinal atrophy metrics on cognitive decline, applying them as a proxy of gray matter atrophy in PP-MS. METHODS: Twenty-five patients with PP-MS completed the Brief International Cognitive Assessment for Multiple Sclerosis and underwent spectral-domain optical coherence tomography (OCT) and 3.0-T magnetic resonance imaging. We tested, through a stepwise logistic regression, whether OCT metrics [retinal nerve fiber layer, ganglion cell + inner plexiform layer (GCIPL) and total macular volume] predicted cognitive impairment and explored the role of gray matter atrophy in mediating these correlations. RESULTS: Among OCT metrics, only GCIPL was associated with cognitive impairment (rp = 0.448, P = 0.036) and predictive of objective cognitive impairment (Wald [1] = 4.40, P = 0.036). Controlling for demographics, normalized brain volume and thalamic volume were correlated with GCIPL (rp = 0.427, P = 0.047 and rp = 0.674, P = 0.001, respectively) and cognitive scores (rp = 0.593, P = 0.004 and rp = 0.501, P = 0.017, respectively), with thalamic volume nearly mediating the association between GCIPL and cognition (Sobel z = 1.86, P = 0.063). CONCLUSIONS: The GCIPL thickness is a suitable measure of neurodegeneration. In comparison with brain atrophy, GCIPL offers higher histopathological specificity, being a pure correlate of neuronal loss, and may be a non-invasive, easy-to-perform way to quantitatively evaluate and monitor neuronal loss related to cognitive impairment in PP-MS.

Mapping of thalamic magnetic susceptibility in multiple sclerosis indicates decreasing iron with disease duration: A proposed mechanistic relationship between inflammation and oligodendrocyte vitality.

Recent advances in susceptibility MRI have dramatically improved the visualization of deep gray matter brain regions and the quantification of their magnetic properties in vivo, providing a novel tool to study the poorly understood iron homeostasis in the human brain. In this study, we used an advanced combination of the recent quantitative susceptibility mapping technique with dedicated analysis methods to study intra-thalamic tissue alterations in patients with clinically isolated syndrome (CIS) and multiple sclerosis (MS). Thalamic pathology is one of the earliest hallmarks of MS and has been shown to correlate with cognitive dysfunction and fatigue, but the mechanisms underlying the thalamic pathology are poorly understood. We enrolled a total of 120 patients, 40 with CIS, 40 with Relapsing Remitting MS (RRMS), and 40 with Secondary Progressive MS (SPMS). For each of the three patient groups, we recruited 40 controls, group matched for age- and sex (120 total). We acquired quantitative susceptibility maps using a single-echo gradient echo MRI pulse sequence at 3 T. Group differences were studied by voxel-based analysis as well as with a custom thalamus atlas. We used threshold-free cluster enhancement (TFCE) and multiple regression analyses, respectively. We found significantly reduced magnetic susceptibility compared to controls in focal thalamic subregions of patients with RRMS (whole thalamus excluding the pulvinar nucleus) and SPMS (primarily pulvinar nucleus), but not in patients with CIS. Susceptibility reduction was significantly associated with disease duration in the pulvinar, the left lateral nuclear region, and the global thalamus. Susceptibility reduction indicates a decrease in tissue iron concentration suggesting an involvement of chronic microglia activation in the depletion of iron from oligodendrocytes in this central and integrative brain region. Not necessarily specific to MS, inflammation-mediated iron release may lead to a vicious circle that reduces the protection of axons and neuronal repair.

High dose biotin as treatment for progressive multiple sclerosis.

BACKGROUND: Published data suggested high dose biotin improved patients with progressive MS. We wished to determine benefits and side effects of administering daily high dose biotin to patients with progressive multiple sclerosis in a large MS specialty clinic. METHODS: Forty-three patients with progressive multiple scleroses were prescribed pharmaceutical grade biotin as a single daily dose of 300mg/day. Brain MRIs were performed at baseline and after one year on biotin. Quantitative neurologic exams (EDSS) and blood work monitoring for biotin toxicity were performed at baseline and every three months thereafter. RESULTS: High dose biotin was safe, and well tolerated, with no evidence of toxicity on blood work and no new lesions on brain MRIs. None of the patients' EDSS scores improved. One-third of patients (38-43%) worsened, most often with increased lower extremity weakness, worsened balance, and more falling, with two patients worsening sufficiently to increase their EDSS scores by 0.5. Several worsened patients improved after stopping biotin. CONCLUSION: High dose biotin was safe and well tolerated, but of no demonstrable long-term benefit. More than one-third of patients worsened while on biotin, most likely due to their disease, but in some patients also possibly due to the inability of their injured central nervous systems to respond to the increased metabolic demands induced by biotin.

Thalamic Iron Differentiates Primary-Progressive and Relapsing-Remitting Multiple Sclerosis.

BACKGROUND AND PURPOSE: Potential differences between primary progressive and relapsing remitting multiple sclerosis are the subject of ongoing controversial discussions. The aim of this work was to determine whether and how primary-progressive and relapsing-remitting multiple sclerosis subtypes differ regarding conventional MR imaging parameters, cerebral iron deposits, and their association with clinical status. MATERIALS AND METHODS: We analyzed 24 patients with primary-progressive MS, 80 with relapsing-remitting MS, and 20 healthy controls with 1.5T MR imaging for assessment of the conventional quantitative parameters: T2 lesion load, T1 lesion load, brain parenchymal fraction, and corpus callosum volume. Quantitative susceptibility mapping was performed to estimate iron concentration in the deep gray matter. RESULTS: Decreased susceptibility within the thalamus in relapsing-remitting MS compared with primary-progressive MS was the only significant MR imaging difference between these MS subtypes. In the relapsing-remitting MS subgroup, the Expanded Disability Status Scale score was positively associated with conventional parameters reflecting white matter lesions and brain atrophy and with iron in the putamen and caudate nucleus. A positive association with putaminal iron and the Expanded Disability Status Scale score was found in primary-progressive MS. CONCLUSIONS: Susceptibility in the thalamus might provide additional support for the differentiation between primary-progressive and relapsing-remitting MS. That the Expanded Disability Status Scale score was associated with conventional MR imaging parameters and iron concentrations in several deep gray matter regions in relapsing-remitting MS, while only a weak association with putaminal iron was observed in primary-progressive MS suggests different driving forces of disability in these MS subtypes.

Hypothalamic damage in multiple sclerosis correlates with disease activity, disability, depression, and fatigue.

OBJECTIVES: Disturbances in the hypothalamo-pituitary axis are supposed to modulate activity of multiple sclerosis (MS). We hypothesised that the extent of HYP damage may determine severity of MS and may be associated with the disease evolution. We suggested fatigue and depression may depend on the degree of damage of the area. METHOD: 33 MS patients with relapsing-remitting and secondary progressive disease, and 24 age and sex-related healthy individuals (CON) underwent 1H-MR spectroscopy (1H-MRS) of the hypothalamus. Concentrations of glutamate + glutamin (Glx), cholin (Cho), myoinositol (mIns), N-acetyl aspartate (NAA) expressed as ratio with creatine (Cr) and NAA were correlated with markers of disease activity (RIO score), Multiple Sclerosis Severity Scale (MSSS), Depressive-Severity Status Scale and Simple Numerical Fatigue Scale. RESULTS: Cho/Cr and NAA/Cr ratios were decreased and Glx/NAA ratio increased in MS patients vs CON. Glx/NAA, Glx/Cr, and mIns/NAA were significantly higher in active (RIO 1-2) vs non-active MS patients (RIO 0). Glx/NAA and Glx/Cr correlated with MSSS and fatigue score, and Glx/Cr with depressive score of MS patients. In CON, relationships between Glx/Cr and age, and Glx/NAA and fatigue score were inverse. CONCLUSION: Our study provides the first evidence about significant hypothalamic alterations correlating with clinical outcomes of MS, using 1H-MRS. The combination of increased Glu or mIns with reduced NAA in HYP reflects whole-brain activity of MS. In addition, excess of Glu is linked to severe disease course, depressive mood and fatigue in MS patients, suggesting superiority of Glu over other metabolites in determining MS burden.

Cognitive impairment and magnetic resonance imaging correlates in primary progressive multiple sclerosis.

OBJECTIVES: To characterize cognitive impairment in primary progressive multiple sclerosis (PPMS) and to correlate the pattern of cognitive deficits with brain magnetic resonance imaging (MRI) volumetric data. MATERIALS AND METHODS: In a multicenter cross-sectional study, we recruited consecutive patients with PPMS as well as age, sex, and education level-matched healthy controls (HC). All participants underwent neuropsychological (NP) assessment, and brain MRI was performed in patients with PPMS for analysis of lesion load, subcortical GM volumes, and regional cortical volumes. RESULTS: We recruited 55 patients with PPMS and 36 HC. Thirty-six patients were included in the MRI analysis. Patients with PPMS performed significantly worse than HC in all NP tests. Subcortical GM volume was significantly correlated with all NP tests, except for Stroop Test, with the largest effect for the thalamus (r=-.516 [BVMT-R DR, P=.016 FDR-corrected] to r=.664 [SDMT, P<.001 FDR-corrected]). In the stepwise linear regression model, thalamic volume was the only predictor of performance in all NP tests. CONCLUSION: Cognitive impairment is common in PPMS and affects all evaluated cognitive domains. Subcortical GM volume, particularly of the thalamus, is a strong predictor of cognitive performance, suggesting it has a central role in the pathophysiology of PPMS-related cognitive dysfunction.

Localized atrophy of the thalamus and slowed cognitive processing speed in MS patients.

BACKGROUND: Deep gray matter (DGM) atrophy is common in multiple sclerosis (MS), but no studies have investigated surface-based structure changes over time with respect to healthy controls (HCs). Moreover, the relationship between cognition and the spatio-temporal evolution of DGM atrophy is poorly understood. OBJECTIVES: To explore DGM structural differences between MS and HCs over time in relation to neuropsychological (NP) outcomes. METHODS: The participants were 44 relapsing-remitting and 20 secondary progressive MS patients and 22 HCs. All were scanned using 3T magnetic resonance imaging (MRI) at baseline and 3-year follow-up. NP examination emphasized consensus standard tests of processing speed and memory. We performed both volumetric and shape analysis of DGM structures and assessed their relationships with cognition. RESULTS: Compared to HCs, MS patients presented with significantly smaller DGM volumes. For the thalamus and caudate, differences in shape were mostly localized along the lateral ventricles. NP outcomes were related to both volume and shape of the DGM structures. Over 3 years, decreased cognitive processing speed was related to localized atrophy on the anterior and superior surface of the left thalamus. CONCLUSIONS: These findings highlight the role of atrophy in the anterior nucleus of the thalamus and its relation to cognitive decline in MS.

Transcranial brain sonography findings predict disease progression in multiple sclerosis.

OBJECTIVE: In multiple sclerosis (MS), an early neurodegenerative affection of subcortical gray matter has been suggested. Transcranial sonography (TCS) shows hyperechogenic lesions of substantia nigra (SN) and basal ganglia, thought to reflect iron accumulation, in a number of primary neurodegenerative diseases. The present study deals with the question of whether TCS can also display deep gray matter lesions in patients with MS and whether sonographic findings relate to severity and progression of MS. METHODS: We prospectively studied 75 patients with different courses of MS and 55 age-matched healthy subjects clinically and with TCS. Twenty-three patients additionally had 1.5-T MRI at the time of TCS. Disease progression was assessed clinically 2 years after TCS. RESULTS: Abnormal hyperechogenicity of SN, lenticular nucleus (LN), caudate nucleus, and thalamus was found in 41%, 54%, 40%, and 8% of the patients with MS, with similar frequency in patients with relapsing-remitting and primary or secondary progressive MS if corrected for disease duration, but only in 13%, 13%, 5% (each, p < 0.001), and none (p = 0.028) of the control subjects. Hyperechogenicity of SN and LN correlated with more pronounced MRI T2 hypointensity, thought to reflect iron deposition. Larger bilateral SN echogenic area was related to higher rate of disease progression, whereas small SN echogenic area (SN hypoechogenicity) predicted a disease course without further progression within 2 years. CONCLUSIONS: Neurodegenerative disease-like deep gray matter lesions can be frequently detected by transcranial sonography (TCS) in patients with multiple sclerosis (MS). Findings suggest that TCS shows changes of brain iron metabolism which correlate with future progress of MS.

Axonal injury and overall tissue loss are not related in primary progressive multiple sclerosis.

BACKGROUND: There is an increasing body of evidence that magnetic resonance imaging-occult tissue damage is an important component of primary progressive multiple sclerosis (PPMS) pathology. Proton magnetic resonance spectroscopy (1H-MRS) can be used to measure in vivo whole-brain N-acetylaspartate (WBNAA) concentrations, the decrease of whose levels is considered a marker of neuronal-axonal injury. OBJECTIVES: To study WBNAA 1H-MRS as a tool to provide information about irreversible brain damage in PPMS and to investigate the relationship between WBNAA and other magnetic resonance imaging measures of MS disease burden, including brain atrophy. METHODS: The following magnetic resonance pulse sequences of the brain were obtained from 32 patients with PPMS and 16 age-matched healthy subjects: (1) dual-echo turbo spin-echo; (2) T1-weighted spin-echo; and (3) 1H-MRS to measure WBNAA concentration. Brain total lesion volumes were measured. Normalized brain volumes were calculated using a fully automated technique. Absolute WBNAA amounts were calculated using a phantom replacement method and were then corrected for individual subjects' brain size. RESULTS: Levels of WBNAA concentrations and normalized brain volumes were significantly lower in patients with PPMS (mean values, 10.2 mm and 1500.0 mL, respectively) than in healthy controls (mean values, 12.9 mm and 1585.2 mL). Both WBNAA concentrations and normalized brain volumes were included as independent factors in the final model of a multivariable analysis predicting the subjects' condition. No significant correlations were found between WBNAA values and normalized brain volumes, WBNAA and T2-weighted or T1-weighted lesion volumes. CONCLUSIONS: Axonal-neuronal damage in the brain of patients with PPMS seems to occur, at least partially, independently of the burden of magnetic resonance imaging-visible lesions. Whole-brain N-acetylaspartate values and normalized brain volumes were unrelated in this cohort, thereby suggesting that 1H-MRS and atrophy assessment may provide in vivo complementary information about the actual extent of brain damage in PPMS.