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Biomedical subjects

M Rovaris

Publications and source records attributed to M Rovaris.

At least 19 recordsLinked to original sources
PubMed2006

Grey matter damage predicts the evolution of primary progressive multiple sclerosis at 5 years.

Reliable prognostic markers of primary progressive (PP) multiple sclerosis evolution are still needed. Diffusion tensor (DT) MRI can quantify normal-appearing white matter (NAWM) and grey matter (GM) damage in multiple sclerosis patients. We investigated whether conventional and DT-MRI-derived measures can predict the long-term clinical evolution of PP multiple sclerosis. In 54 PP multiple sclerosis patients, conventional and DT-MRI scans of the brain and T1-weighted scans of the cervical cord were acquired at baseline and after a median follow-up of 15 months. Another clinical evaluation was performed, 56 months after baseline, in 52 patients. Measures of lesion load, brain and cord atrophy were obtained. Histograms of the mean diffusivity (MD) and fractional anisotropy (FA) values from the NAWM and GM were analysed. At follow-up, 35 patients (65%) experienced a confirmed disability progression. Baseline expanded disability status scale score and average GM MD were independent predictors of subsequent clinical deterioration in a multivariable model (Nagelkerke R2: 0.44; discriminating ability: 81%). A lower level of disability and a more severe GM damage identify PP multiple sclerosis patients with an increased risk of disease progression over the subsequent 5 years. These data may be relevant to select patients for future exploratory phase II trials.

Adult↗
PubMed2006

Multimodal evoked potentials to assess the evolution of multiple sclerosis: a longitudinal study.

BACKGROUND: Evoked potentials are used in the functional assessment of sensory and motor pathways. Their usefulness in monitoring the evolution of multiple sclerosis has not been fully clarified. OBJECTIVE: The aim of this longitudinal study was to examine the usefulness of multimodal evoked potential in predicting paraclinical outcomes of disease severity and as a prognostic marker in multiple sclerosis. METHODS: Eighty four patients with clinically definite multiple sclerosis underwent Expanded Disability Status Scale (EDSS) and functional system scoring at study entry and after a mean (standard deviation) follow-up of 30.5 (11.7) months. Sensory and motor evoked potentials were obtained in all patients at study entry and at follow-up in 64 of them, and quantified according to a conventional score. RESULTS: Cross-sectionally, the severity of each evoked potential score significantly correlated with the corresponding functional system (0.32 < R < 0.60, p < 0.01, for all but follow-up visual evoked potential) and with EDSS (0.34 < R < 0.61; p < 0.001 for all but brain stem evoked potential). EDSS significantly correlated with global evoked potential score severity (baseline R = 0.60, follow-up R = 0.46, p < 0.001). Using longitudinal analysis, only changes in somatosensory evoked potential scores were significantly correlated with changes of sensory functional system (R = 0.34, p = 0.006). However, patients with multiple sclerosis with disability progression at follow-up had more severe baseline evoked potential scores than patients who remained stable. Patients with severe baseline global evoked potential score (higher than the median value) had a risk of 72.5% to progress on disability at follow-up, whereas patients with multiple sclerosis with lower scores had a risk of only 36.3%. CONCLUSIONS: These results suggest that evoked potential is a good marker of the severity of nervous damage in multiple sclerosis and may have a predictive value regarding the evolution of disability.

Adult↗
PubMed2006

Influence of aging on brain gray and white matter changes assessed by conventional, MT, and DT MRI.

BACKGROUND: Conventional MRI can reveal decreases in brain volumes with aging but fails to provide information about the underlying microstructural modifications. Magnetization transfer (MT) and diffusion tensor (DT) MRI can in part overcome these limitations. OBJECTIVE: To investigate the influence of aging on conventional and MT and DT MRI-derived measurements in brain white (WM) and gray (GM) matter. METHODS: Dual-echo, T1-weighted, MT and DT MR images of the brain were obtained in 89 healthy subjects (age range 11 to 76 years). Normalized GM and WM volumes were measured and MT ratio (MTR) and mean diffusivity (MD) histograms produced for both tissue compartments. RESULTS: Normalized brain (r = -0.78), GM (r = -0.75), and WM (r = -0.34) volumes and the number of brain T2 hyperintensities (r = 0.49) were correlated with age. Additionally, all GM MT- and DT-derived parameters also correlated with age (r values ranging from 0.28 to 0.64), whereas only the peak height (ph) of the normal-appearing (NA) WM MD histogram did so (r = -0.34). After correcting for the number of T2 hyperintensities, gender, and the corresponding normalized tissue volumes, only the correlations between age and GM average MD (r = 0.24), GM-MD-ph (r = -0.37), and NAWM-MD-ph (r = -0.29) remained significant. A multivariate regression analysis including both brain tissues variables retained the GM volume (beta = -0.18, SE = 0.02, p < 0.001) and the GM average MD (beta = 45, SE = 19, p = 0.02) as independent predictors of subject's age. CONCLUSIONS: Brain white matter and gray matter have different vulnerabilities to aging. Microstructural imaging is important to achieve a complete picture of the complex changes occurring in the aging brain.

Adolescent↗
PubMed2005

Diffusion MRI in multiple sclerosis.

Diffusion imaging is a quantitative, MR-based technique potentially useful for the study of multiple sclerosis (MS), due to its increased pathologic specificity over conventional MRI and its ability to assess in vivo the presence of tissue damage occurring outside T2-visible lesions, i.e., in the so-called normal-appearing white and gray matter. The present review aims at critically summarizing the state-of-the-art and providing a background for the planning of future diffusion studies of MS. Several pieces of evidence suggest that diffusion-weighted and diffusion tensor MRI are sensitive to MS damage and able to detect its evolution over relatively short periods of time. Although a significant relationship between diffusion-weighted MRI findings and MS clinical disability was not found in the earliest studies, with improved diffusion imaging technology correlations between diffusion abnormalities and MS clinical aspects are now emerging. However, the best acquisition and postprocessing strategies for MS studies remain a matter of debate and the contribution of newer and more sophisticated techniques to diffusion tensor MRI investigations in MS needs to be further evaluated. Although changes in diffusion MRI indices reflect a net loss of structural organization, at present we can only speculate on their possible pathologic substrates in the MS brain. Postmortem studies correlating diffusion findings with histopathology of patients with MS are, therefore, also warranted.

Autopsy↗
PubMed2005

Axonal injury in early multiple sclerosis is irreversible and independent of the short-term disease evolution.

OBJECTIVE: To define the nature and the temporal evolution of neuronal/axonal injury in patients at the earliest clinical stage of multiple sclerosis (MS), using whole brain N-acetylaspartate (WBNAA) proton MR spectroscopy (1H-MRS). METHODS: Thirty-five patients at presentation with clinically isolated syndromes (CIS) and MRI evidence of disease dissemination in space were studied. The following scans of the brain were acquired within 3 months from the onset of the disease and after 12 months: 1) dual-echo; 2) WBNAA 1H-MRS; 3) pre- and postcontrast T1-weighted. The same scans were obtained in 12 age-matched healthy subjects, without contrast administration. In patients, conventional MRI scans were also repeated 3 months after the first scanning session, to assess the presence of early disease dissemination in time (DIT). RESULTS: Over the study period, 24 patients showed MRI evidence of disease DIT, thus fulfilling the criteria for a diagnosis of MS. The average WBNAA amount was lower in CIS patients than in controls both at baseline (13.7 vs 16.9 mM, p < 0.001) and at 1-year follow-up (12.6 vs 16.2 mM, p < 0.001), but the average yearly percentage change of WBNAA did not differ between the two groups. No MRI or 1H-MRS quantities were significantly associated with the disease DIT over the study period. CONCLUSION: Irreversible brain damage associated with axonal dysfunction occurs at a very early stage in patients with clinically isolated syndromes, but it does not seem to be related with the disease evolution in the subsequent short-term period.

Adult↗
PubMed2005

Mitoxantrone for multiple sclerosis.

BACKGROUND: Mitoxantrone (MX) has been shown to be moderately effective in reducing the clinical outcome measures of disease activity in multiple sclerosis (MS) patients. OBJECTIVES: The objective was to assess the efficacy and safety of MX in relapsing-remitting MS (RRMS), progressive relapsing MS (PRMS) and secondary progressive MS (SPMS). SEARCH STRATEGY: We searched the Cochrane MS Group Trials Register (searched April 2005), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 4, 2004), MEDLINE (Pub Med) (January 1966 to April 2005), EMBASE (January 1974 to April 2005), and reference lists of articles. We also undertook hand searching and contacting trialists and pharmaceutical companies. SELECTION CRITERIA: The trials were selected if double-blinded, placebo-controlled, randomised, irrespective of eventual additive therapy (such as steroids). DATA COLLECTION AND ANALYSIS: Three reviewers independently selected articles for inclusion, assessed trials' quality and extracted data. MAIN RESULTS: Four trials involving 270 participants were included. MX was found to reduce the progression of disability at 2 years follow-up (proportion of participants with 6-months confirmed progression of disability: Odds Ratios (OR) 0.3, p = 0.05). Similar figures were found regarding the reduction in annualised relapse rate and the proportion of patients free from relapses at 1 and 2 years, as well as the number of patients with active MRI lesions at 6 months/ 1 year only. Side effects reported in the trials were more frequent in treated patients than in controls. Caution must be exercised in drawing conclusions from such data because of the heterogeneous quality and characteristics of the included trials, which are different in terms of treatment schedule and type of enrolled patients. More than half of the included patients came from a single study. Moreover, from the included trials, it was not possible to estimate the long-term efficacy and safety of MX, which may raise concerns about the risk of cardiotoxicity and therapy-related leukemias, which is increasingly reported in the literature. AUTHORS' CONCLUSIONS: MX is moderately effective in reducing the disease progression and the frequency of relapses in patients affected by RR, PR and SP MS in the short-term follow-up (2 years), even if the results are based on trials heterogeneous in terms of drug dosage and inclusion criteria. No major neoplastic or symptomatic cardiotoxicity related to MX have been reported from the trials. However, longer follow-up studies are highly warranted to better explore the efficacy and safety of the drug, mainly as regards the long-term risk of therapy-related leukemias and cardiotoxicity. As a conclusion, MX has a partial efficacy, but, due to its unclear long-term safety profile, it should be used to treat patients with worsening RR and SP MS with evidence of worsening disability.

Humans↗
PubMed2005

Evidence for progressive gray matter loss in patients with relapsing-remitting MS.

Little is known about the temporal evolution of gray matter damage occurring early in the course of multiple sclerosis (MS). The authors investigated the evolution of gray matter volume loss in 117 patients with relapsing-remitting MS, scanned monthly for a 9-month period. Time-trend analysis revealed a decrease of gray matter volumes over the study period (p < 0.001). This study shows that gray matter damage in relapsing-remitting MS evolves markedly over a short period of observation.

Adult↗
PubMed2005

Long-term clinical outcome of primary progressive MS: predictive value of clinical and MRI data.

The authors sought to identify clinical and MRI predictors of outcome in primary progressive multiple sclerosis (PPMS). Clinical and MRI assessments were performed at baseline and 2 and 5 years (clinical only). At baseline, disease duration, expanded disability status scale (EDSS) and brain volume predicted outcome. Adding short-term change variables, baseline EDSS, changes in T2* lesion load and cord area, and number of new lesions were predictive. Clinical and MRI variables predict long-term outcome in PPMS.

Atrophy↗
PubMed2005

Movement preparation is affected by tissue damage in multiple sclerosis: evidence from EEG event-related desynchronization.

OBJECTIVE: To investigate the impact of brain tissue damage in Multiple Sclerosis (MS) on the efficiency of programming of voluntary movement, assessed using event-related desynchronization of the EEG. METHODS: The onset latency of mu ERD (percent desyncronization of the mu rhythm preceding movement onset) to hand movement was studied in 34 MS patients. ERD onset was compared with normative data and correlated with T1 and T2 total lesion volume (TLV) at magnetic resonance imaging (MRI). RESULTS: ERD onset latency was significantly correlated with T1-TLV (r = 0.53, P = 0.001) and T2 lesion load (r = 0.5, P = 0.003), even after correcting for disability. Patients with higher T1-TLV had significantly delayed ERD onset compared with normal subjects and with patients with lower T1-TLV; patients with higher T2-TLV had significantly delayed ERD compared with normal subjects only. ERD onset latency was not correlated to clinical disability. CONCLUSIONS: Our finding of delayed ERD onset in patients with more severe measures of brain damage, independently from clinical disability, suggests that functional cortico-cortical and cortico-subcortical connections underlying the expression of ERD during programming of voluntary movement are disrupted by the MS related pathological process. Further, studies are needed to evaluate the role of specific anatomical cortico-subcortical circuits in determining this abnormality. SIGNIFICANCE: The extent of brain lesion load in multiple sclerosis affects cortical changes related to motor preparation, detected by analysis of onset latency of event-related desynchronization (ERD) of the mu rhythm to self-paced movement.

Adult↗
PubMed2005

Quantification of cervical cord pathology in primary progressive MS using diffusion tensor MRI.

OBJECTIVE: To investigate the extent and severity of cervical cord damage using diffusion tensor MRI (DT-MRI) and histogram analysis in patients with primary progressive MS (PPMS). METHODS: Diffusion-weighted sensitivity-encoded (SENSE) echoplanar images of the cervical cord and brain dual-echo and diffusion-weighted scans were acquired from 24 patients with PPMS and 13 healthy controls. Cord and brain mean diffusivity and fractional anisotropy histograms were produced. An analysis of variance model, adjusting for cord volume, was used to compare cord DT-MRI parameters from controls and patients. RESULTS: Compared to healthy controls, PPMS patients had reduced cervical cord cross-sectional area and average cord fractional anisotropy (p = 0.007), and increased cord mean diffusivity (p = 0.024). No correlations were found between DT-MRI metrics of the cord and quantities obtained from conventional and DT-MRI of the brain. CONCLUSIONS: DT-MRI of the cervical cord can quantify the extent of diffuse cord pathology in patients with PPMS. Such cord diffusivity changes in patients with PPMS are likely to reflect irreversible axonal injury and reactive gliosis and seem to be independent of brain damage.

Adult↗
PubMed2005

Defining the response to multiple sclerosis treatment: the role of conventional magnetic resonance imaging.

During the last two decades, conventional MRI (cMRI) has been extensively used in the diagnostic workup of multiple sclerosis (MS) patients, to monitor the natural history of the disease and to evaluate the efficacy of experimental treatments in randomised, controlled clinical trials. In the latter context, a major issue is represented by the high intra- and inter-individual heterogeneity of the MS patterns of disease activity and evolution. Such heterogeneity might explain, at least partially, the weak correlations found between clinical and cMRI aspects in patients with established MS, which is particularly evident when individual patients are considered. As a consequence, the definition of response to MS treatment, when based upon cMRI aspects, is still a challenging task. Although the use of cMRI-derived quantities as a standalone approach to define treatment options and strategies at an individual patient level should be discouraged, an evidence-based integration of clinical and cMRI data might be helpful in selected cases for an optimal work-up of patients undergoing immunomodulating or immunosuppressive treatments.

Evidence-Based Medicine↗
PubMed2004

An MT MRI study of the cervical cord in clinically isolated syndromes suggestive of MS.

Cervical cord magnetization transfer ratio (MTR) histograms were obtained from 45 patients at presentation with clinically isolated syndromes (CIS) suggestive of multiple sclerosis (MS). The mean values of MTR histogram-derived metrics were not different between CIS patients and healthy control subjects or between patients with and without evidence of disease dissemination in time. Only three patients showed significantly lower cord MTR values than control subjects. These findings suggest the absence of intrinsic structural damage of the cervical cord soon after the onset of CIS suggestive of MS, even in those patients with an early evolution to MS.

Adolescent↗
PubMed2004

Measurement error of two different techniques for brain atrophy assessment in multiple sclerosis.

The measurement errors associated with two techniques for brain atrophy assessment in multiple sclerosis (MS) were estimated. The measurement error of a semiautomated, nonnormalized technique with partial brain coverage was about twofold higher than that of a fully automated, normalized technique with full brain coverage (Structural Image Evaluation of Normalized Atrophy software [SIENA]). As shown by the analysis of data from a clinical trial of glatiramer acetate, the use of SIENA increases the study power to detect a treatment effect on brain volume changes in MS patients.

Atrophy↗
PubMed2003

Whole-brain atrophy in multiple sclerosis measured by two segmentation processes from various MRI sequences.

Recent MRI and pathologic studies have drawn attention to the destructive nature of the multiple sclerosis (MS) disease process, including the early occurrence of axonal and neuronal loss, leading to macroscopic brain and spinal cord atrophy. Measurement of brain atrophy from MRI has emerged as a potential outcome measure and marker of disease severity in MS and neurodegenerative diseases such as Alzheimer's. However, the optimal method for quantifying atrophy has not been established, including the choice of pulse sequence and segmentation algorithm employed. Using two different MRI scanners to ensure generalizability of results, we compared the reproducibility of four pulse sequences and two analysis methods (fully automated [FA] and semi-automated [SA]) when obtaining brain parenchymal fraction (BPF), a normalized measure of whole-brain atrophy, in patients with MS (n=13) and normal controls (n=2). In order to ensure the validity of our fully automated analysis technique, we also used it to evaluate the atrophy rate over nine months in 57 MS patients from the placebo arm of a clinical trial. All pulse sequences were capable of yielding reproducibility of around 1% coefficient of variation (CoV) or better. The best reproducibility was obtained using 2D multi-slice sequences (conventional spin echo [SE] and fluid-attenuated inversion recovery [FLAIR]), with fully automated analysis. Fully automated analysis of the longitudinal data (conventional spin echo) showed an atrophy rate of -0.5% change in BPF per year, in line with previous findings from a similar cohort of patients. In conclusion, BPF measurement is affected by both pulse sequence and segmentation method. Automated measurement has high reproducibility especially when 2D sequences are used. Semi-automated measurement may have increased accuracy, but with a decreased efficiency and reliability.

Adult↗
PubMed2003

The effect of interferon beta-1b on quantities derived from MT MRI in secondary progressive MS.

BACKGROUND: Magnetization transfer (MT) MRI can provide in vivo markers reflecting the severity of irreversible, MS-related brain damage occurring within and outside T2-visible lesions. OBJECTIVE: To assess the effect of interferon (IFN) beta-1b treatment on the accumulation of brain damage in patients with secondary progressive (SP) MS, measured using MT MRI. METHODS: Eighty-two patients with SPMS from five centers participating in a European, multicenter, double-blind, placebo-controlled trial of IFNbeta-1b in SPMS underwent brain T2-weighted and MT MRI at baseline. Evaluable follow-up data were available for 75 patients at 12 months, 54 at 24 months, and 47 at 36 months. MT MRI scans were postprocessed and analyzed to obtain histograms of MT ratio (MTR) values from the whole brain. A region of interest-based analysis of MTR values from the normal-appearing white matter (NAWM) was also performed. RESULTS: In both the treatment arms, there was a decrease of average brain MTR values from baseline to month 24 (mean change -4.9%) and month 36 (mean change -4.3%). These changes were significant for the placebo group at both timepoints and for the IFNbeta-1b group at month 24 only, with no significant treatment effect. A decrease of NAWM MTR was also observed, with no significant difference between the two treatment arms. CONCLUSION: In this cohort of patients with secondary progressive MS, interferon beta-1b did not show an overall effect on the worsening of magnetization transfer MRI measures, when compared with placebo. The data show that change in magnetization transfer ratio is a promising tool for monitoring disease evolution in secondary progressive MS and that the information obtained from magnetization transfer MRI complements that obtained from MRI measures of lesion load and inflammation.

Adult↗
PubMed2003

Evidence for widespread axonal damage at the earliest clinical stage of multiple sclerosis.

Although axonal pathology is recognized as one of the major pathological features of multiple sclerosis, it is less clear how early in its course it occurs and how it correlates with MRI-visible lesion loads. To assess this early axonal pathology, we quantified the concentration of whole-brain N-acetylaspartate (WBNAA) in a group of patients at the earliest clinical stage of the disease and compared the results with those from healthy controls. Conventional brain MRI and WBNAA using unlocalized proton magnetic resonance spectroscopy were obtained from 31 patients at presentation with clinically isolated syndromes suggestive of multiple sclerosis and paraclinical evidence of dissemination in space, and from 16 matched controls. An additional conventional MRI scan was obtained in all patients 4-6 months later to detect dissemination of lesions in time. The mean WBNAA concentration was significantly lower in patients compared with the controls (P < 0.0001). It was not significantly different between patients with and without enhancing lesions at the baseline MRI or between patients with and without lesion dissemination in time. No correlation was found between WBNAA concentrations and lesion volumes. Widespread axonal pathology, largely independent of MRI-visible inflammation and too extensive to be completely reversible, occurs in patients even at the earliest clinical stage of multiple sclerosis. This finding lessens the validity of the current concept that the axonal pathology of multiple sclerosis is the end-stage result of repeated inflammatory events, and argues strongly in favour of early neuroprotective intervention.

Adult↗
PubMed2003

Beta endorphin concentrations in PBMC of patients with different clinical phenotypes of multiple sclerosis.

The possible link between the opioid peptide beta endorphin and the heterogeneity of the clinical course of multiple sclerosis (MS) was investigated. Peripheral blood mononuclear cells (PBMC) concentrations of beta endorphin were measured in 50 patients in different phases of MS. Thirty nine patients also underwent post-contrast magnetic resonance imaging of the brain. Among MS forms, the highest beta endorphin concentrations were found in PBMC from patients with relapsing remitting MS and the lowest in patients with the progressive forms. Average beta endorphin concentrations were lower, although not significantly, in patients with than in those without magnetic resonance imaging enhanced lesions. These data suggest that beta endorphin may have a role in the downregulation of the inflammatory process.

Adult↗