Brain, Vol. 124, No. 9, 1803-1812,
September 2001
© 2001 Oxford University Press
Short-term brain volume change in relapsingremitting multiple sclerosis
Effect of glatiramer acetate and implications
.
1 Neuroimaging Research Unit and 2 Clinical Trials Unit, Department of Neuroscience, Scientific Institute and University Ospedale San Raffaele, Milan, Italy, 3 The University of TexasHouston, Health Science Center, Houston, Texas
Correspondence to:
Massimo Filippi, Department of Neuroscience, Scientific Institute Ospedale San Raffaele, via Olgettina 60, 20132 Milan, Italy E-mail: filippi.massimo{at}hsr.it
| Abstract |
|---|
|
|
|---|
The assessment of brain volume change with serial MRI provides an objective measure of an important component of the pathology of multiple sclerosis. Glatiramer acetate (GA) has a beneficial effect on clinical and MRI measures of disease activity and burden in patients with relapsingremitting (RR) multiple sclerosis. This study investigated the impact of GA treatment on the development of brain atrophy in RR multiple sclerosis patients. The study consisted of a 9-month, double-blind, placebo-controlled phase followed by a 9-month open-label phase. Patients were randomized to receive either 20 mg GA or placebo by daily subcutaneous injections and underwent brain MRI scans every month during the first phase, and every 3 months during the second phase of the study. Using a semi-automated segmentation technique based on local thresholding, brain volume was measured from seven contiguous periventricular slices from the scans obtained at baseline, the end of the double-blind phase and the end of the study. From the original trial cohort, image sets from 113 out of 119 patients randomized to GA, and 114 out of 120 randomized to placebo treatment were evaluated. Brain volume was significantly correlated with patients' disability at each time-point. No significant differences between placebo- and GA-treated patients were found for baseline brain volume and rate of brain volume change over the study, even though a possible late trend for treatment with GA to retard the loss of brain volume was observed. There was a significant, but modest, correlation between MRI activity during the double-blind phase, and brain volume change over the entire study among patients originally treated with placebo. The modest correlation between enhancement frequency and brain atrophy loss indicates that the suppression of inflammatory activity in RR multiple sclerosis patients is not fully and rapidly associated with a similar effect on the global neurodegenerative processes. This study also suggests that any effect of GA in preventing brain volume decrease is not evident early following institution of treatment.
multiple sclerosis; brain volume; MRI; glatiramer acetate; clinical trial
ANCOVA = analysis of covariance; EDSS = Expanded Disability Status Scale; GA = glatiramer acetate; Gd = gadolinium; RR = relapsingremitting
| Introduction |
|---|
|
|
|---|
A decrease of parenchymal volume leading to global brain atrophy is frequent in patients with multiple sclerosis (Jagust and Noseworthy, 2000
Cross-sectional and longitudinal studies with MRI (Losseff et al., 1996
; Dastidar et al., 1999
; Edwards et al., 1999
; Liu et al., 1999
; Rudick et al., 1999
; Simon et al., 1999
; Stevenson et al., 1999
; Fox et al., 2000
; Ge et al., 2000b
; Paolillo et al., 2000
; Wolinsky et al., 2000
) have investigated the magnitude of the correlation between brain volume and multiple sclerosis clinical findings. These studies showed that brain atrophy can develop in the early, relapsingremitting (RR) phases of the disease (Rudick et al., 1999
; Simon et al., 1999
; Ge et al., 2000b
; Paolillo et al., 2000
). The amount of tissue loss is, however, more pronounced in patients with more disabling, chronic progressive disease courses (Losseff et al., 1996
; Dastidar et al., 1999
; Stevenson et al., 1999
; Ge et al., 2000b
; Wolinsky et al., 2000
). Since conventional MRI measures lack pathological specificity and are only modestly correlated with disability (Rovaris and Filippi, 1999
), the measurement of brain volume has been claimed as an objective marker of multiple sclerosis severity with the potential to accurately monitor disease evolution (Jagust and Noseworthy, 2000
). For these reasons, recent clinical trials (Paolillo et al., 1999
; Rudick et al., 1999
; Filippi et al., 2000
; Molyneux et al., 2000
) included brain volume measurements as an additional exploratory measure of outcome.
Glatiramer acetate (GA; Copaxone®; TEVA Pharmaceutical Industries Ltd, Petah Tiqua, Israel) is an immunomodulating drug currently approved in several countries for the treatment of RR multiple sclerosis (Johnson et al., 1995
, 1998
). GA is the acetate salt of a mixture of synthetic polypeptides and it appears to act against multiple sclerosis via production of specific T-suppressor cells that cross react with myelin basic protein in the central nervous system (Aharoni et al., 1999
, 2000
). On stimulation, these cells secrete regulatory cytokines of the type that characterize Th2 or regulatory T cells (Duda et al., 2000
; Neuhaus et al., 2000
). Clinically, GA significantly reduces the frequency of relapses in RR multiple sclerosis (Johnson et al., 1995
, 1998
). In addition, a recent multicentre, placebo-controlled study (Comi et al., 2001
) has demonstrated that GA is also effective in reducing multiple sclerosis activity and accumulated burden of disease as measured by serial MRI scans of the brain.
Only a pilot study of a small subcohort of patients participating in the pivotal US trial (Ge et al., 2000a
) addressed the issue of the effect of GA treatment on MRI-measured brain volume change. The study showed that the rate of brain volume decrease was significantly higher in placebo than in treated patients over a 2-year follow-up. In addition, a cross-sectional analysis of data from the extended, open-label follow-up of the same trial (Wolinsky et al., 2001
) seems to indicate that long-term treatment with GA might prevent the loss of brain parenchyma in RR multiple sclerosis patients.
The present study probed: (i) the extent, if any, of the effect of GA treatment on brain atrophy in RR multiple sclerosis; (ii) the correlations between the effects of GA on different MRI markers reflecting several pathological aspects of multiple sclerosis; and (iii) the relationship of brain atrophy with previous and concomitant inflammatory activity. Data from the European/Canadian multiple sclerosis/MRI Copaxone Trial (Comi et al., 2001
) were analysed for these purposes.
| Material and methods |
|---|
|
|
|---|
Patients
All patients had to have an age of 1850 years inclusive, a diagnosis of clinically definite multiple sclerosis (Poser et al., 1983
Study design
The study consisted of a 1-month screening phase, followed by two treatment phases, each lasting 9 months. For trial purposes, a month was defined as of 4-week duration (28 ± 7 days). The first treatment phase was randomized, double-blind and placebo-controlled. The second was an open-label phase, during which all patients received active treatment. Treatment consisted of daily administration of 20 mg GA or placebo by subcutaneous injection. All patients underwent physical and neurological examination, including EDSS rating, laboratory studies and brain MRI at screening, baseline, every month during the double-blind phase and every 3 months during the open-label phase (Comi et al., 2001
).
MRI acquisition
The imaging protocol consisted of dual echo, pre- and post-contrast (0.1 mmol/kg Gd) T1-weighted SE (spin echo) images of the brain (Comi et al., 2001
). For brain volume measurements, unenhanced T1-weighted images obtained at baseline (i.e. when patients were randomized), the end of double-blind phase (i.e. month 9) and the end of open-label phase (i.e. month 18) were analysed. Acquisition parameters for these images were: TR (repetition time) = 450650 ms; TE (echo time) = 1020 ms; slices = 44, contiguous, 3 mm thick; in-plane resolution = ~1 x 1 mm; signal averages = 2. MRI parameters and scanner were always the same for any given patient for the whole study duration.
MRI analysis
The identification of hyperintense T2 lesions on the dual echo images, and of Gd-enhancing and hypointense lesions on the post-contrast T1-weighted images, was done by consensus of two experienced observers. On the follow-up scans, new Gd-enhancing and new hyperintense T2 lesions were also counted. Total T2 hyperintense, T1 Gd-enhancing and T1 hypointense lesion volumes were then calculated using a semi-automated local thresholding technique for lesion segmentation and marked hardcopies as a reference as previously detailed (Comi et al., 2001
).
Measurements of brain volumes were done using a seed-growing technique for brain parenchyma segmentation from T1-weighted images, which is fully described elsewhere (Rovaris et al., 2000
). The volume was calculated for a slab of brain tissue including the seven contiguous slices rostral to the velum interpositum. A single observer chose the slices to be included in the measurements on the basis of standard neuroanatomical landmarks. Comparison with subsequent scans from each individual patient allowed consistent slice choice and minimized the effects of volume variation due to patient positioning on serial scans. All volume measurements were then done by another observer, who was unaware of the acquisition order of the scans and to whom the scans belonged. Such an approach, which includes the regions where multiple sclerosis pathology is more frequent, has proved to be as sensitive to multiple sclerosis-related changes as measures of the whole of the brain tissue volume (Rovaris et al., 2000
). This approach is also highly reproducible, with a mean intra-observer coefficient of variation for repeated measurements of 1.5% (Rovaris et al., 2000
).
Statistical analysis
Demographic, clinical and MRI characteristics of subjects in the two study arms were compared using the two-sample t-test for the continuous variables and the chi-square test or the Fisher's exact test for the categorical variables. The effect of treatment on brain volume indices was assessed using the analysis of covariance (ANCOVA). This analysis accounted for centre variability and included age, gender, disease duration, brain volume and number of Gd-enhancing lesions at baseline as covariates. ANCOVA was repeated after stratifying patients into those with and without one or more Gd-enhancing lesions on their baseline scans. The significance of the within-group changes during the study periods was analysed using the t-test for paired samples. The correlations between brain volume indices and clinical or MRI-derived variables were assessed using the Spearman rank correlation coefficient.
| Results |
|---|
|
|
|---|
The original trial randomized 119 patients to GA and 120 patients to placebo treatment (Comi et al., 2001
|
|
Brain volume changes
The absolute values of brain volume and their changes during the study for all the patients are reported in Table 3
|
|
Covariate analysis was performed that included age, gender, centre, disease duration and brain volume at baseline. No significant effect of treatment was found on the absolute or percentage change of brain volume during the double-blind phase of the study (ANCOVA; P = 0.92 and 0.88, respectively). No significant treatment effect on the absolute and percentage change of brain volume was found (P = 0.92 and 0.87, respectively) when ANCOVA was repeated after adding the number of Gd-enhancing lesions at baseline to the covariates.
Correlations between brain volume and other MRI-derived measures
The correlations between MRI measures of disease activity or burden at baseline and brain volume change during the study periods are summarized in Table 4
. The number of Gd-enhancing lesions on baseline scans was moderately, but significantly, correlated with the absolute brain volume changes during the double-blind phase of the study in the whole patient cohort and in placebo-treated patients. This correlation was not significant in the GA-treated patients, nor was there any significant correlation between enhancing lesion burden at baseline and brain volume changes during the open-label phase of the study. The total volumes of hyperintense T2 and hypointense T1 lesions on baseline scans were significantly correlated with baseline brain volumes. In placebo-treated patients, baseline lesion volumes were also significantly correlated with the absolute brain volume change during the double-blind phase of the study. The magnitude of these correlations was similar when percentage instead of absolute change of brain volume was considered (data not shown).
|
Table 5
|
Correlations between brain volume and clinical variables
In the entire cohort, brain volume was modestly, but significantly correlated with EDSS score at baseline (r = 0.22, P = 0.0012), month 9 (r = 0.26, P = 0.0003) and month 18 (r = 0.19, P = 0.0065). At baseline, this correlation was stronger in patients randomized to GA treatment (r = 0.30, P = 0.0013) than in those randomized to placebo treatment (r = 0.13, P = 0.16). However, its magnitude did not differ between the two arms at month 9 (r = 0.26). At month 18, the correlation between brain volume and EDSS score was stronger in patients originally randomized to placebo (r = 0.25, P = 0.01) than in those originally randomized to GA treatment (r = 0.13, P = 0.20). No significant correlations were found between brain volume at baseline and frequency of relapses in the two years prior to study entry.
During the double-blind phase of the study, patients treated with GA or placebo had a mean EDSS change of 0.04 and +0.01, and the mean frequency of clinical relapses in the two arms was 0.54 and 0.72, respectively. No significant correlations were found between brain volume at baseline or month 9 and EDSS change or frequency of clinical relapse either in GA or in placebo-treated patients. The frequency of clinical relapses during the first 9 months was not significantly correlated with the decrease of brain volume during the subsequent phase of the study. Brain volume changes and EDSS changes were not significantly correlated during either of the study phases.
All the group and correlation analyses were repeated after excluding patients who underwent month 9 and/or month 18 scans while on steroid treatment (nine and six patients, respectively). None of the results changed significantly (data not shown).
| Discussion |
|---|
|
|
|---|
Several recent placebo-controlled trials (Paolillo et al., 1999
All multiple sclerosis patients participating in the present study had to have MRI evidence of ongoing inflammation at study entry (Comi et al., 2001
). Therefore, the average extent of MRI-monitored multiple sclerosis activity during the first 9 months was high and enabled us to investigate the correlations between brain volume change and other MRI markers of multiple sclerosis activity and burden. T2 lesion load is an overall measure of accumulated disease burden that includes all of the heterogeneous substrates of multiple sclerosis lesions. T1 hypointense lesion load has a higher pathological specificity, reflecting areas of severe tissue disruption and axonal damage (van Walderveen et al., 1998
). We found that both T2 and T1 lesion volumes at baseline were modestly correlated with brain volume at baseline in both treatment groups. In addition, during the first 9 months the rate of brain volume loss in placebo-treated patients modestly correlated with the number of Gd-enhancing lesions and the volumes of Gd-enhancing, T2-hyperintense and T1-hypointense lesions on their baseline scans. The number of active lesions on monthly scans during the double-blind phase was significantly correlated with the rate of brain volume loss during the same period for the whole patient cohort and the placebo group, but not for the treated group. This correlation was still significant when brain volume changes over 18 months were considered. Only for patients treated with GA was the increase of T2 lesion volume during the double-blind phase of the study significantly correlated with baseline brain volume. Hypointense T1 lesion volume change during the first 9 months had a significant, but modest correlation with baseline brain volumes, but not with the rate of brain volume loss during either study phase.
The results of this study indicate that the rate of brain volume loss in RR multiple sclerosis patients over 18 months is weakly, but significantly, influenced by previous and ongoing disease activity. While, in GA-treated patients, the lack of a correlation between changes of brain volume and other MRI measures can be due to the effect of treatment in reducing both lesion activity and accumulation (Mancardi et al., 1998
; Comi et al., 2001
), data from patients treated with placebo during the double-blind phase suggest that mechanisms other than inflammation, including failure of remyelination, loss of trophic factors (Kaplan et al., 1997
), disturbances of electrical conduction (Pfrieger and Barres, 1997
) or long-term sublethal axonal injury in persistently demyelinated fibres might account for the progressive axonal loss observed in multiple sclerosis (Trapp et al., 1999
). Some reparative mechanisms following multiple sclerosis injury, such as remyelination and axonal sprouting, can occur over relatively long periods. Therefore, in patients with early and active RR multiple sclerosis, the effects of these reparative processes in preventing cerebral atrophy might only be apparent late, after a prolonged reduction in the inflammatory activity is well established. Two other factors might, however, contribute to the lack of correlation between baseline MRI-measured multiple sclerosis burden of disease and subsequent brain atrophy development in GA-treated patients. On the one hand, the reduction of inflammatory activity may lead to an apparent decrease of cerebral volume. On the other, a real increase of brain atrophy might occur as a consequence of a diminution of the beneficial effect of inflammation on tissue repair. It is also quite conceivable that the rate of brain volume loss from a given time point on may depend upon the amount of prior inflammatory activity. This is supported by data from a crossover design trial of Campath 1H in secondary progressive multiple sclerosis patients (Coles et al., 1999
; Paolillo et al., 1999
). Despite almost complete suppression of Gd-enhancement, brain atrophy progressed in patients experiencing clinical deterioration at a rate that was highly correlated (r = 0.77) with the frequency of Gd-enhancing lesions during the pre-Campath 1H treatment period.
During the double-blind phase of the study, GA treatment did not have any measurable impact on the decrease of brain volume, which was of similar magnitude in both study arms. The subsequent open-label phase of the study did not show any significant change in the rate of brain volume loss. Over 18 months, the average annual decrease in brain volume was ~1% in the entire trial population, confirming that progressive brain volume loss occurs in RR multiple sclerosis patients over relatively short intervals. This finding is consistent with previous studies (Rudick et al., 1999
; Ge et al., 2000a
, b
), where whole brain volume decreased by 0.51.8% yearly in untreated RR multiple sclerosis patients.
Several factors might explain why, in this study, the effect of GA in reducing clinical and MRI-measured multiple sclerosis activity (Comi et al., 2001
) was not paralleled by an effect against the observed decrease of patients' brain volume. These include: (i) the short duration of the follow-up; (ii) the mechanisms of action of GA; and (iii) the persistence of low-grade inflammation undetected by conventional MRI techniques that could cause progressive tissue loss.
Undoubtedly the short duration of the placebo-controlled phase limited our ability to detect any effect of GA treatment on brain volume change. In this patient group some effect of GA on the MRI measures was discernible 2 months after initiating treatment and the magnitude of the effect of active treatment increased over time. However, the effects of GA on relapses and on other MRI measures of multiple sclerosis activity became significant only after 6 months of treatment (Comi et al., 2001
). These findings fit well with the timing of drug action in the modulation of T-cell immune responses (Neuhaus et al., 2000
). Thus, if the effect of GA treatment in slowing the loss of brain volume in multiple sclerosis is similarly delayed, it may not be surprising that no effect was evident over the 9-month placebo-controlled comparison. The small differences observed between the groups during the second 9 months of observation in the rates of brain volume loss, while not significant, could be predictive of treatment effects on longer follow-up. Similarly, Rudick and colleagues were only able to detect a significant slowing of brain volume loss in RR multiple sclerosis patients treated with interferon beta-1a during the second year of treatment, despite the rapid suppression of MRI inflammatory activity that can be achieved using this drug (Rudick et al., 1999
; Waubant et al., 1999
). Interestingly, we also found that the average rate of brain volume decrease was 50% lower during the second than during the first 9 months of the study (0.4% versus 0.8%, respectively) for patients originally treated with GA, whilst it was similar during the two study phases for patients originally treated with the placebo.
A second explanation for our findings might be the limited ability of GA to modify the pathological mechanisms leading to global tissue loss in multiple sclerosis. A similar apparent divergence between the anti-inflammatory effects and the prevention of brain volume reduction over time was reported for interferon beta-1b (Molyneux et al., 2000
), cladribine (Filippi et al., 2000
) and Campath 1H (Coles et al., 1999
; Paolillo et al., 1999
). The modest magnitude of the correlation between Gd-enhancement and brain tissue loss also supports the hypothesis that the impact of treatment on MRI measures closely related to inflammatory activity may not necessarily be rapidly or fully translated into a beneficial effect on other MRI measures which reflect tissue loss. On the other hand, pathological studies (Trapp et al., 1998
) have shown that axonal damage occurs in inflammatory multiple sclerosis lesions, thus suggesting that preventing brain inflammation should have at least a partial effect on the progressive loss of tissue seen in multiple sclerosis patients. The magnitude of this effect might, however, be too small to be detected by measurements of brain tissue volume over relatively short intervals.
The inability of GA to prevent short-term brain tissue loss in RR multiple sclerosis might also be due to the persistence of low-grade inflammatory activity that could go undetected with standard MRI. That some degree of inflammatory activity could still occur in GA-treated patients is also suggested by the observation that the relapse rate is only partially reduced (Comi et al., 2001
). Whether biologically important inflammatory activity persists in the brains of patients undergoing immunomodulatory treatments that can only be detected with increased sensitivity Gd-enhanced MRI methods (Silver et al., 1997
; Filippi et al., 1998a
, b
) is an unresolved issue. Preliminary data, however, suggest that this is not the case for patients treated with low doses of interferon beta-1a (Rovaris et al., 1999
), since the amount of activity detected by triple dose Gd-enhanced MRI was found to be lower under treatment than during a pre-treatment screening phase. It is also uncertain whether, and to what extent, mild degrees of brain inflammation might contribute to the development of brain atrophy.
In conclusion, we were unable to find a significant effect of GA on reducing the brain tissue loss that occurs in RR multiple sclerosis over 9 months. However, the results of this study have several important implications. First, they confirm that assessment of brain volume on serial MRI provides a reliable measure of brain atrophy, an important component of the pathology of multiple sclerosis. Among RR multiple sclerosis patients selected for high clinical and MRI disease activity, the loss of cerebral volume can be significant even over relatively short intervals, indicating that tissue loss including the loss of myelin and axons occurs even during the earliest, non-disabling phases of multiple sclerosis. Secondly, they indicate that multiple sclerosis inflammatory activity is only in part responsible for the development of brain atrophy. Thirdly, these results strengthen recent evidence that immunomodulating and immunosuppressive treatments that reduce multiple sclerosis inflammatory activity and lesion accumulation may not be translated into a similar effect on progressive tissue loss, either in RR or progressive multiple sclerosis patients. Fourthly, they indicate that brain volume measures might be used to test the efficacy of experimental multiple sclerosis treatments targeted to non-inflammatory components of the disease process. However, such studies must be of considerable duration to assess adequately the efficacy of any treatment on multiple sclerosis-related global cerebral tissue loss.
| Appendix I |
|---|
|
|
|---|
Members of the European/Canadian Glatiramer Acetate Study Group
Principal Investigators
Benelux: D. Guillaume, J. B. D'Harcour, C. J. M. Sindic, T. P. J. Duprez, L. Truyen, G. Nagels, P. M. Parizel, E. A. C. M. Sanders, R. J. Versteylen. Canada: G. Rice, K. Kennedy, L. Metz, D. Patry, M. Yeung, A. Davis, S. Curtis, G. Francis, D. L. Arnold, G. Leroux. France: O. Lyon-Caen, A. Tourbah, M. Bataillard, I. R. Kraehenbuhl, E. A. Cabanis, S. Bracard, M. Debouverie, R. Anxionnat. Germany: B. Storch-Hagenlocher, K. Sartor, W. Gehlen, A. Schmidt, C. Weiller, W. Behrendt. Italy: G. Comi, M. Filippi, M. Rovaris, M. Zaffaroni, C. Fieschi, S. Bastianello, R. Capra, R. Gasparotti, G. L. Mancardi, M. Inglese, F. Sardanelli, V. Cosi, C. Uggetti, F. Zappoli. United Kingdom: C. P. Hawkins, N. Haq, D. Barnes, A. Clifton, D. Bates, A. Coulthard, G. Perkin, I. Colquhoun, C. A. Young, T. Nixon, D. Francis, D. Yates, D. Neary, A. Jackson, L. D. Blumhardt, T. Jaspan, R. Brenner, A. Valentine, I. Pye, G. Cherryman
MRI Steering Committee
M. Filippi (Chair), F. Barkhof, D. L. Arnold, M. A. Horsfield, J. S. Wolinsky
Advisory Committee
K. P. Johnson (Chair), O. Hommes, P. Feigin
Clinical Steering Committee
G. Comi (Chair), D. Bates, M. Filippi, O. Lyon-Caen, G. Rice, J. S. Wolinsky
Organizing Committee
G. Comi, M. Filippi, J. S. Wolinsky, Y. Stark, M. Gurevich, S. Kadosh, B. Zak, I. Pinchassi, D. Ladkani
| Notes |
|---|
* All the contributors are listed in Appendix I
| Acknowledgements |
|---|
|
|
|---|
We wish to thank Drs F. Barkhof and R. A. van Schijndel (University Hospital Vrije Universiteit, Amsterdam, The Netherlands) for kindly providing us with the brain segmentation program we used in this study. This study was supported by TEVA Pharmaceutical Ltd.
| References |
|---|
|
|
|---|
Aharoni R, Teitelbaum D, Arnon R, Sela M. Copolymer 1 acts against the immunodominant epitope 82100 of myelin basic protein by T cell receptor antagonism in addition to major histocompatibility complex blocking. Proc Natl Acad Sci USA 1999; 96: 6349.
Aharoni R, Teitelbaum D, Leitner O, Meshorer A, Sela M, Arnon R. Specific Th2 cells accumulate in the central nervous system of mice protected against experimental autoimmune encephalomyelitis by copolymer 1. Proc Natl Acad Sci USA 2000; 97: 114727.
Allen IV, McKeown SR. A histological, histochemical and biochemical study of the macroscopically normal white matter in multiple sclerosis. J Neurol Sci 1979; 41: 8191.[Web of Science][Medline]
Coles AJ, Wing MG, Molyneux P, Paolillo A, Davie CM, Hale G, et al. Monoclonal antibody treatment exposes three mechanisms underlying the clinical course of multiple sclerosis. Ann Neurol 1999; 46: 296304.[Web of Science][Medline]
Comi G, Filippi M, Wolinsky JS and the European/Canadian Glatiramer Acetate Study Group. European/Canadian multicenter, double-blind, randomized, placebo-controlled study of the effects of glatiramer acetate on magnetic resonance imaging-measured disease activity and burden in patients with relapsing multiple sclerosis. Ann Neurol 2001; 49: 2907.[Web of Science][Medline]
Dastidar P, Heinonen T, Lehtimaki T, Ukkonen M, Peltola J, Erila T, et al. Volumes of brain atrophy and plaques correlated with neurological disability in secondary progressive multiple sclerosis. J Neurol Sci 1999; 165: 3642.[Web of Science][Medline]
Duda PW, Schmied MC, Cook SL, Krieger JI, Hafler DA. Glatiramer acetate (Copaxone) induces degenerate, Th2-polarized immune responses in patients with multiple sclerosis. J Clin Invest 2000; 105: 96776.[Web of Science][Medline]
Edwards SG, Gong QY, Liu C, Zvartau ME, Jaspan T, Roberts N, et al. Infratentorial atrophy on magnetic resonance imaging and disability in multiple sclerosis. Brain 1999; 122: 291301.
Filippi M, Rocca MA, Rizzo G, Horsfield MA, Rovaris M, Minicucci L, et al. Magnetization transfer ratios in multiple sclerosis lesions enhancing after different dose of gadolinium. Neurology 1998a; 50: 128993.
Filippi M, Rovaris M, Capra R, Gasperini C, Yousry TA, Sormani MP, et al. A multi-centre longitudinal study comparing the sensitivity of monthly MRI after standard and triple dose gadolinium-DTPA for monitoring disease activity in multiple sclerosis. Implications for phase II clinical trials. Brain 1998b; 121: 201120.
Filippi M, Rovaris M, Iannucci G, Mennea S, Sormani MP, Comi G. Whole brain volume changes in patients with progressive MS treated with cladribine. Neurology 2000; 55: 171418.
Fox NC, Jenkins R, Leary SM, Stevenson VL, Losseff NA, Crum WR, et al. Progressive cerebral atrophy in MS. A serial study using registered, volumetric MRI. Neurology 2000; 54: 80712.
Ge Y, Grossman RI, Udupa JK, Fulton J, Constantinescu CS, Gonzales-Scarano F, et al. Glatiramer acetate (Copaxone) treatment in relapsing-remitting MS. Quantitative MR assessment. Neurology 2000a; 54: 81317.
Ge Y, Grossman RI, Udupa JK, Wei L, Mannon LJ, Polansky M, Kolson DL. Brain atrophy in relapsing-remitting multiple sclerosis and secondary progressive multiple sclerosis: longitudinal quantitative analysis. Radiology 2000b; 214: 66570.
Jagust WJ, Noseworthy JH. Brain atrophy as a surrogate marker in MS. Faster, simpler, better? [editorial]. Neurology 2000; 54: 7823.
Johnson KP, Brooks BR, Cohen JA, Ford CC, Goldstein J, Lisak RP, et al. Copolymer 1 reduces relapse rate and improves disability in relapsing- remitting multiple sclerosis: results of a phase III multicenter, double-blind placebo-controlled trial. The Copolymer 1 Multiple Sclerosis Study Group. Neurology 1995; 45: 126876.
Johnson KP, Brooks BR, Cohen JA, Ford CC, Goldstein J, Lisak RP, et al. Extended use of glatiramer acetate (Copaxone) is well tolerated and maintains its clinical effect on multiple sclerosis relapse rate and degree of disability. Copolymer 1 Multiple Sclerosis Study Group. Neurology 1998; 50: 7018.
Kaplan MR, Meyer-Franke A, Lambert S, Bennett V, Duncan ID, Levinson SR, et al. Induction of sodium channel clustering by oligodendrocytes. Nature 1997; 386: 7248.[Medline]
Kurtzke JF. Rating neurologic impairment in multiple sclerosis: an expanded disability status scale (EDSS). Neurology 1983; 33: 144452.
Liu C, Edwards S, Gong Q, Roberts L, Blumhardt LD. Three dimensional MRI estimates of brain and spinal cord atrophy in multiple sclerosis. J Neurol Neurosurg Psychiatry 1999; 66: 32330.
Losseff NA, Wang L, Lai HM, Yoo DS, Gawne-Cain ML, McDonald WI, et al. Progressive cerebral atrophy in multiple sclerosis: a serial MRI study. Brain 1996; 119: 200919.
Lublin FD, Reingold SC, National Multiple Sclerosis Society (USA) Advisory Committee on Clinical Trials of New Agents in Multiple Sclerosis. Defining the clinical course of multiple sclerosis: results of an international survey. Neurology 1996; 46: 90711.
Mancardi GL, Sardanelli F, Parodi RC, Melani E, Capello E, Inglese M, et al. Effect of copolymer-1 on serial gadolinium-enhanced MRI in relapsing remitting multiple sclerosis. Neurology 1998; 50: 112733.
Molyneux PD, Kappos L, Polman C, Pozzilli C, Barkhof F, Filippi M, et al. The effect of interferon beta-1b treatment on MRI measures of cerebral atrophy in secondary progressive multiple sclerosis. Brain 2000; 123: 225663.
Neuhaus O, Farina C, Yassouridis A, Wiendl H, Then Bergh F, Dose T, et al. Multiple sclerosis: comparison of copolymer-1-reactive T cell lines from treated and untreated subjects reveals cytokine shift from T helper 1 to T helper 2 cells. Proc Natl Acad Sci USA 2000; 97: 74527.
Paolillo A, Coles AJ, Molyneux PD, Gawne-Cain M, MacManus D, Barker GJ, et al. Quantitative MRI in patients with secondary progressive MS treated with monoclonal antibody Campath 1H. Neurology 1999; 53: 7517.
Paolillo A, Pozzilli C, Gasperini C, Giugni E, Mainero C, Giuliani S, et al. Brain atrophy in relapsing-remitting multiple sclerosis: relationship with `black holes', disease duration and clinical disability. J Neurol Sci 2000; 174: 8591.[Web of Science][Medline]
Pfrieger FW, Barres BA. Synaptic efficacy enhanced by glial cells in vitro. Science 1997; 277: 16847.
Poser CM, Paty DW, Scheinberg L, McDonald WI, Davis FA, Ebers GC, et al. New diagnostic criteria for multiple sclerosis: guidelines for research protocols. Ann Neurol 1983; 13: 22731.[Web of Science][Medline]
Raine CS. The neuropathology of multiple sclerosis. In: Raine CS, McFarland HF, Tourtellotte WW, editors. Multiple sclerosis: clinical and pathogenetic basis. London: Chapman and Hall; 1997. p. 15171.
Rovaris M, Filippi M. Magnetic resonance techniques to monitor disease evolution and treatment trial outcomes in multiple sclerosis. [Review]. Curr Opin Neurol 1999; 12: 33744.[Web of Science][Medline]
Rovaris M, Capra R, Martinelli V, Gasperini C, Prandini F, Pozzilli C, et al. Cumulative effect of a weekly low dose of interferon beta 1a on standard and triple dose contrast-enhanced MRI from multiple sclerosis patients. J Neurol Sci 1999; 171: 1304.[Web of Science][Medline]
Rovaris M, Inglese M, van Schijndel RA, Sormani MP, Rodegher M, Comi G, et al. Sensitivity and reproducibility of volume change measurements of different brain portions on magnetic resonance imaging in patients with multiple sclerosis. J Neurol 2000; 247: 9605.[Web of Science][Medline]
Rudick RA, Fisher E, Lee JC, Simon J, Jacobs L and the Multiple Sclerosis Collaborative Research Group. Use of the brain parenchymal fraction to measure whole brain atrophy in relapsing-remitting MS. Neurology 1999; 53: 1698704.
Silver NC, Good CD, Barker GJ, MacManus DG, Thompson AJ, Moseley IF, et al. Sensitivity of contrast enhanced MRI in multiple sclerosis: effects of gadolinium dose, magnetization transfer contrast and delayed imaging. Brain 1997; 120: 114961.
Simon HJ, Jacobs LD, Campion MK, Rudick RA, Cookfair DL, Herndon RM, et al. A longitudinal study of brain atrophy in relapsing multiple sclerosis. Neurology 1999; 53: 13948.
Stevenson VL, Miller DH, Rovaris M, Barkhof F, Brochet B, Dousset V, et al. Primary and transitional progressive MS. A clinical and MRI cross-sectional study. Neurology 1999; 52: 83945.
Trapp BD, Peterson J, Ransohoff RM, Rudick R, Mork S, Bo L. Axonal transection in the lesions of multiple sclerosis. N Engl J Med 1998; 338: 27885.
Trapp BD, Ransohoff RM, Fisher E, Rudick RA. Neurodegeneration in multiple sclerosis: relationship to neurological disability. Neuroscientist 1999; 5: 4857.
van Walderveen MA, Kamphorst W, Scheltens P, van Waesberghe JH, Ravid R, Valk J, et al. Histopathologic correlate of hypointense lesions on T1-weighted spin-echo MRI in multiple sclerosis. Neurology 1998; 50: 12828.
Waubant E, Goodkin DE, Sloan R, Andersson PB. A pilot study of MRI activity before and during interferon beta-1a therapy. Neurology 1999; 53: 8746.
Wolinsky JS, Narayana PA, Noseworthy JH, Lublin FD, Whitaker JN, Linde A, et al. Linomide in relapsing and secondary progressive MS: part II: MRI results. Neurology 2000; 54: 173441.
Wolinsky JS, Narayana PA, Johnson KP and the Copolymer 1 Multiple Sclerosis Study Group and the MRI Analysis Center. United States open-label glatiramer acetate extension trial for relapsing multiple sclerosis: MRI and clinical correlates. Mult Scler 2001; 7: 3341.
Received January 22, 2001. Revised April 3, 2001. Accepted May 21, 2001.
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
R. Zivadinov, A. T. Reder, M. Filippi, A. Minagar, O. Stuve, H. Lassmann, M. K. Racke, M. G. Dwyer, E. M. Frohman, and O. Khan Mechanisms of action of disease-modifying agents and brain volume changes in multiple sclerosis Neurology, July 8, 2008; 71(2): 136 - 144. [Abstract] [Full Text] [PDF] |
||||
![]() |
D Horakova, J L Cox, E Havrdova, S Hussein, O Dolezal, D Cookfair, M G Dwyer, Z Seidl, N Bergsland, M Vaneckova, et al. Evolution of different MRI measures in patients with active relapsing-remitting multiple sclerosis over 2 and 5 years: a case-control study J. Neurol. Neurosurg. Psychiatry, April 1, 2008; 79(4): 407 - 414. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Duan, P.G. Hildenbrand, M.P. Sampat, D.F. Tate, I. Csapo, B. Moraal, R. Bakshi, F. Barkhof, D.S. Meier, and C.R.G. Guttmann Segmentation of Subtraction Images for the Measurement of Lesion Change in Multiple Sclerosis AJNR Am. J. Neuroradiol., February 1, 2008; 29(2): 340 - 346. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Rovaris, G. Comi, M. Rocca, P. Valsasina, D. Ladkani, E. Pieri, S. Weiss, G. Shifroni, J. Wolinsky, M. Filippi, et al. Long-term follow-up of patients treated with glatiramer acetate: a multicentre, multinational extension of the European/Canadian double-blind, placebo-controlled, MRI-monitored trial Multiple Sclerosis, May 1, 2007; 13(4): 502 - 508. [Abstract] [PDF] |
||||
![]() |
M. Juha, S. Leszek, F. Sten, H. Jan, B. Jakob, F. Olof, and K. W. Maria Progression of non-age-related callosal brain atrophy in multiple sclerosis: a 9-year longitudinal MRI study representing four decades of disease development J. Neurol. Neurosurg. Psychiatry, April 1, 2007; 78(4): 375 - 380. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Sarchielli, M. Zaffaroni, A. Floridi, L. Greco, A. Candeliere, A. Mattioni, S. Tenaglia, M. Di Filippo, and P. Calabresi Production of brain-derived neurotrophic factor by mononuclear cells of patients with multiple sclerosis treated with glatiramer acetate, interferon-{beta} 1a, and high doses of immunoglobulins Multiple Sclerosis, April 1, 2007; 13(3): 313 - 331. [Abstract] [PDF] |
||||
![]() |
J H Simon Brain atrophy in multiple sclerosis: what we know and would like to know Multiple Sclerosis, November 1, 2006; 12(6): 679 - 687. [Abstract] [PDF] |
||||
![]() |
C. M. Dalton, K. A. Miszkiel, P. W. O'Connor, G. T. Plant, G.P.A. Rice, and D. H. Miller Ventricular enlargement in MS: One-year change at various stages of disease Neurology, March 14, 2006; 66(5): 693 - 698. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. D. Richert, T. Howard, J. A. Frank, R. Stone, J. Ostuni, J. Ohayon, C. Bash, and H. F. McFarland Relationship between inflammatory lesions and cerebral atrophy in multiple sclerosis Neurology, February 28, 2006; 66(4): 551 - 556. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Krapf, S. P. Morrissey, O. Zenker, T. Zwingers, R. Gonsette, H. -P. Hartung, and the MIMS Study Group Effect of mitoxantrone on MRI in progressive MS: Results of the MIMS trial Neurology, September 13, 2005; 65(5): 690 - 695. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Sastre-Garriga, G. T. Ingle, D. T. Chard, M. Cercignani, L. Ramio-Torrenta, D. H. Miller, and A. J. Thompson Grey and white matter volume changes in early primary progressive multiple sclerosis: a longitudinal study Brain, June 1, 2005; 128(6): 1454 - 1460. [Abstract] [Full Text] [PDF] |
||||
![]() |
J Versijpt, J C Debruyne, K J Van Laere, F De Vos, J Keppens, K Strijckmans, E Achten, G Slegers, R A Dierckx, J Korf, et al. Microglial imaging with positron emission tomography and atrophy measurements with magnetic resonance imaging in multiple sclerosis: a correlative study Multiple Sclerosis, April 1, 2005; 11(2): 127 - 134. [Abstract] [PDF] |
||||
![]() |
M. Hardmeier, S. Wagenpfeil, P. Freitag, E. Fisher, R. A. Rudick, M. Kooijmans, M. Clanet, E. W. Radue, L. Kappos, and for the European IFNss-1a in Relapsing MS Dose Com Rate of brain atrophy in relapsing MS decreases during treatment with IFN{beta}-1a Neurology, January 25, 2005; 64(2): 236 - 240. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. A. Rizvi and M. A. Agius Current approved options for treating patients with multiple sclerosis Neurology, December 28, 2004; 63(12_suppl_6): S8 - S14. [Abstract] [Full Text] |
||||
![]() |
R. Bakshi, G. J. Hutton, J. R. Miller, and E.-W. Radue The use of magnetic resonance imaging in the diagnosis and long-term management of multiple sclerosis Neurology, December 14, 2004; 63(11_suppl_5): S3 - S11. [Abstract] [Full Text] |
||||
![]() |
L. Locatelli, R. Zivadinov, A. Grop, and M. Zorzon Frontal parenchymal atrophy measures in multiple sclerosis Multiple Sclerosis, October 1, 2004; 10(5): 562 - 568. [Abstract] [PDF] |
||||
![]() |
M. P. Amato, M. L. Bartolozzi, V. Zipoli, E. Portaccio, M. Mortilla, L. Guidi, G. Siracusa, S. Sorbi, A. Federico, and N. De Stefano Neocortical volume decrease in relapsing-remitting MS patients with mild cognitive impairment Neurology, July 13, 2004; 63(1): 89 - 93. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Sharma, M. P. Sanfilipo, R. H. B. Benedict, B. Weinstock-Guttman, F. E. Munschauer III, and R. Bakshi Whole-Brain Atrophy in Multiple Sclerosis Measured by Automated versus Semiautomated MR Imaging Segmentation AJNR Am. J. Neuroradiol., June 1, 2004; 25(6): 985 - 996. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. R. Kreitman and F. Blanchette On the horizon: possible neuroprotective role for glatiramer acetate Multiple Sclerosis, June 1, 2004; 10(1_suppl): S81 - S89. [Abstract] [PDF] |
||||
![]() |
R. R. Kreitman and F. Blanchette On the horizon: possible neuroprotective role for glatiramer acetate Multiple Sclerosis, May 1, 2004; 10(3_suppl): S81 - S89. [Abstract] [PDF] |
||||
![]() |
M. P. Sormani, M. Rovaris, P. Valsasina, J. S. Wolinsky, G. Comi, and M. Filippi Measurement error of two different techniques for brain atrophy assessment in multiple sclerosis Neurology, April 27, 2004; 62(8): 1432 - 1434. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. A. Frank, N. Richert, C. Bash, L. Stone, P. A. Calabresi, B. Lewis, R. Stone, T. Howard, and H. F. McFarland Interferon-{beta}-1b slows progression of atrophy in RRMS: Three-year follow-up in NAb- and NAb+ patients Neurology, March 9, 2004; 62(5): 719 - 725. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Hardmeier, S. Wagenpfeil, P. Freitag, E. Fisher, R. A. Rudick, M. Kooijmans-Coutinho, M. Clanet, E. W. Radue, and L. Kappos Atrophy Is Detectable Within a 3-Month Period in Untreated Patients With Active Relapsing Remitting Multiple Sclerosis Arch Neurol, December 1, 2003; 60(12): 1736 - 1739. [Abstract] [Full Text] [PDF] |
||||
![]() |
X Lin, C R Tench, B Turner, L D Blumhardt, and C S Constantinescu Spinal cord atrophy and disability in multiple sclerosis over four years: application of a reproducible automated technique in monitoring disease progression in a cohort of the interferon {beta}-1a (Rebif) treatment trial J. Neurol. Neurosurg. Psychiatry, August 1, 2003; 74(8): 1090 - 1094. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. De Stefano, P. M. Matthews, M. Filippi, F. Agosta, M. De Luca, M. L. Bartolozzi, L. Guidi, A. Ghezzi, E. Montanari, A. Cifelli, et al. Evidence of early cortical atrophy in MS: Relevance to white matter changes and disability Neurology, April 8, 2003; 60(7): 1157 - 1162. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. L. Galetta, C. Markowitz, and A. G. Lee Immunomodulatory Agents for the Treatment of Relapsing Multiple Sclerosis: A Systematic Review Arch Intern Med, October 28, 2002; 162(19): 2161 - 2169. [Abstract] [Full Text] [PDF] |
||||
![]() |
R Leigh, J Ostuni, D Pham, A Goldszal, B K Lewis, T Howard, N Richert, H McFarland, and J A Frank Estimating cerebral atrophy in multiple sclerosis patients from various MR pulse sequences Multiple Sclerosis, October 1, 2002; 8(5): 420 - 429. [Abstract] [PDF] |
||||
![]() |
R. J. Fox, E. Fisher, R. Rudick, B.O. Khatri, M.P. McQuillen, and D. S. Goodin Disease modifying therapies in multiple sclerosis Neurology, August 13, 2002; 59(3): 471 - 473. [Full Text] [PDF] |
||||
![]() |
D. H. Miller, F. Barkhof, J. A. Frank, G. J. M. Parker, and A. J. Thompson Measurement of atrophy in multiple sclerosis: pathological basis, methodological aspects and clinical relevance Brain, August 1, 2002; 125(8): 1676 - 1695. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Filippi and R. I. Grossman MRI techniques to monitor MS evolution: The present and the future Neurology, April 23, 2002; 58(8): 1147 - 1153. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. A. Calabresi Considerations in the treatment of relapsing-remitting multiple sclerosis Neurology, April 23, 2002; 58(90084): S10 - 22. [Abstract] [Full Text] |
||||
![]() |
D. L. Arnold and P.M. Matthews MRI in the diagnosis and management of multiple sclerosis Neurology, April 23, 2002; 58(90084): S23 - 31. [Abstract] [Full Text] |
||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||







