Glatiramer acetate as a clinically and cost-effective treatment of relapsing multiple sclerosis over 10 years of use within the National Health Service: Final results from the UK Risk Sharing Scheme

Background

The UK Risk Sharing Scheme (RSS) provided information on the effect of first-line multiple sclerosis (MS) disease-modifying treatments on long-term disability.

Objective

The aim is to provide results specific to glatiramer acetate (GA; Copaxone®) from the final 10-year analysis of the RSS.

Methods

A Markov model was used to assess clinical effectiveness measured as Expanded Disability Status Scale (EDSS) progression and utility loss. Untreated patients from the British Columbia MS cohort (1980-1995) were used as a 'virtual comparator' group. A separate Markov model assessed cost-effectiveness, based on a 50-year time horizon (with a 50% treatment waning effect imposed at 10 years) and using NHS list price (£513.95 per 28 days). Results were expressed in quality-adjusted life years (QALYs).

Results

In total, 755 patients with relapsing-remitting MS (RRMS) received GA, with a mean follow-up of 7.1 (standard deviation 1.3) years. EDSS progression was reduced by 23% (progression ratio 76.7, 95% confidence interval [CI] 69.0-84.3) and utility loss by 39% (progression ratio 61.0, 95% CI 52.7-69.3) compared with no treatment. There was no persistent waning in GA treatment effect over time (EDSS: p = 0.093; utilities: p = 0.119). The cost per QALY was £17,841.

Conclusion

GA had a beneficial effect on long-term disability and was a cost-effective treatment for RRMS.

Disability in multiple sclerosis is related to normal appearing brain tissue MTR histogram abnormalities

Background: Magnetization transfer ratio (MTR) histogram analysis provides a global measure of disease burden in multiple sclerosis (MS). MTR abnormalities in normal appearing brain tissue (NABT) provide quantitative information on the extent of tissue damage undetected by conventional T2-weighted (T2W) magnetic resonance imaging (MRI). A ims: 1) To compare the MTR histograms from NABT across a broad spectrum of relapse onset MS patients, including relapsing-remitting (RR) MS (including newly diagnosed and benign subgroups) and secondary progressive (SP) MS. 2) To determine the relationship between clinical disability and NA BT MTR histograms. Methods: 2D spin echo magnetization transfer imaging was performed on 70 RRMS and 25 SPMS patients and compared with 63 controls. MTR histograms were acquired for NA BT after extracting lesions and cerebrospinal fluid (C SF). T2W images were used to measure the brain parenchymal fraction (BPF) and T2 lesion load. Results: MS patients had a disease duration ranging from 0.5 to 37 years and an Expanded Disability Status Scale (EDSS) score ranging from 0 to 8.5. There was a significant decrease in NA BT mean MTR (± standard deviation) compared with controls (33.07 pu± 1.06 versus 34.26 pu± 0.47; P < 0.001) with an effect size of 2.56. The reductio n in NA BT mean MTR varied among patient groups from 4.9% for SPMS, 3% for all RRMS, 2.7% for early RRMS and 2.5% for benign MS, compared with controls. NA BT mean MTR correlated significantly with T2 lesion load (r = -0.82) and BPF (r =0.58). EDSS score correlated with NA BT mean MTR (r = -0.43), BPF (r = -0.33) and with T2 lesion load (r =0.59). Multivariate analysis using NA BT MTR peak height, T2 lesion load and BPF combined only accounted for 38% of the variance in the EDSS (r =0.62; P <0.001). Disease duration accounted for an additional 14% of variance in the EDSS (r =0.72; P <0.001). Conclusions: There is evidence of diffuse abnormalities in NA BT in addition to global brain atrophy in relapse onset MS patients, including those with recently diagnosed RRMS and benign MS. The abnormalities are greatest in patients with the more disabling SPMS. A trophy, NA BT and lesion abnormalities are all partly correlated; the processes marked by these MR measures all contribute to disability in MS, providing complementary information relevant to the complex pathological processes that occur in MS.

Protocol for a multicentre randomiSed controlled TRial of IntraVEnous immunoglobulin versus standard therapy for the treatment of transverse myelitis in adults and children (STRIVE)

INTRODUCTION

Transverse myelitis (TM) is an immune-mediated disorder of the spinal cord which causes motor and sensory disturbance and limited recovery in 50% of patients. Standard treatment is steroids, and patients with more severe disease appear to respond to plasma exchange (PLEX). Intravenous immunoglobulin (IVIG) has also been used as an adjunct to steroids, but evidence is lacking. We propose the first randomised control trial in adults and children, to determine the benefit of additional treatment with IVIG.

METHODS AND ANALYSIS

170 adults and children aged over 1 year with acute first episode TM or neuromyelitis optica (with myelitis) will be recruited over a 2.5-year period and followed up for 12 months. Participants randomised to the control arm will receive standard therapy of intravenous methylprednisolone (IVMP). The intervention arm will receive the above standard therapy, plus additional IVIG. Primary outcome will be a 2-point improvement on the American Spinal Injury Association (ASIA) Impairment scale at 6 months postrandomisation by blinded assessors. Additional secondary and tertiary outcome measures will be collected: ASIA motor and sensory scales, Kurtzke expanded disability status scale, International Spinal Cord Injury (SCI) Bladder/Bowel Data Set, Client Services Receipt Index, Pediatric Quality of Life Inventory, EQ-5D, SCI Pain and SCI Quality of Life Data Sets. Biological samples will be biobanked for future studies. After 6-months' follow-up of the first 52 recruited patients futility analysis will be carried out. Health economics analysis will be performed to calculate cost-effectiveness. After 6 months' recruitment futility analysis will be performed.

ETHICS AND DISSEMINATION

Research Ethics Committee Approval was obtained: 14/SC/1329. Current protocol: v3.0 (15/01/2015). Study findings will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBERS

This study is registered with EudraCT (REF: 2014-002335-34), Clinicaltrials.gov (REF: NCT02398994) and ISRCTN (REF: 12127581).

Disability and T2 MRI lesions: a 20-year follow-up of patients with relapse onset of multiple sclerosis

Clinically isolated syndromes (CIS), such as optic neuritis, brainstem or spinal cord syndromes are frequently the first clinical presentations of multiple sclerosis. However, not all CIS patients develop multiple sclerosis and in those who do, disability is highly variable. In previous follow-up studies, brain lesions on T2-weighted MRI are associated with increased risk of multiple sclerosis and to an extent disability. We evaluated the longitudinal relationships between the MRI lesions and clinical course over a period of 20 years. CIS patients were recruited between 1984 and 1987 and previously followed up after 1, 5, 10 and 14 years. Of the 140 subjects who were initially recruited with a CIS for a baseline MRI study, we followed up 107 patients after a mean of 20.2 years (range 18-27.7). Multiple sclerosis was diagnosed as clinically definite on clinical grounds only and disability determined using the Expanded Disability Status Scale (EDSS) and Multiple Sclerosis Functional Composite (MSFC) score. Clinically definite multiple sclerosis developed in 67 out of 107 (63%) overall: 60 out of 73 (82%) with abnormal and 7 out of 34 (21%) with normal baseline MRI. Multiple sclerosis was still relapsing-remitting in 39 (58%)--including 26 (39%) with a 'benign' course (EDSS < or = 3)--whilst 28 (42%) had developed secondary progression. T2 lesion volume at all time-points correlated moderately with 20-year EDSS (r(s) values 0.48 to 0.67; P < 0.001) and MSFC z-score [r(s) values (-0.50) to (-0.61); P < 0.001]. In those developing multiple sclerosis, a concurrent correlation of change in T2 lesion volume with change in EDSS was most evident in years 0-5 (r(s) = 0.69, P < 0.001). The estimated rate of lesion growth over 20 years was 0.80 cm3/year in those who retained a relapsing remitting multiple sclerosis course, and 2.89 cm3/year in those who developed secondary progressive multiple sclerosis, a difference of 2.09 cm3/year (95% CI: 0.77, 2.96; P < 0.001). This study extends previous follow-up of CIS patients and sheds new light on how the lesions evolve according to the natural history. Baseline MRI findings are predictive for development of clinically definite multiple sclerosis. Lesion volume and its change at earlier time points are correlated with disability after 20 years. Lesion volume increases for at least 20 years in relapse-onset multiple sclerosis and the rate of lesion growth is three times higher in those who develop secondary progressive than in those who remain relapsing remitting multiple sclerosis.

The longitudinal relation between brain lesion load and atrophy in multiple sclerosis: a 14 year follow up study

BACKGROUND

Studies have suggested that T2 lesion activity is prominent in early relapsing-remitting multiple sclerosis, whereas brain atrophy, while seen early, appears more evident in later progressive disease. The temporal relation between these processes remains unclear.

OBJECTIVE

To explore the association between changing brain lesion loads and subsequent tissue atrophy in multiple sclerosis.

METHODS

28 subjects with clinically probable or definite multiple sclerosis (mean age 46.0 years; 17 female and 11 male) were followed for 14 years after first onset of symptoms. T2 lesion loads were estimated soon after symptom onset and at around five, 10, and 14 years later. Disease related atrophy was estimated at the 14 year follow up by comparing brain tissue volumes (proportional to total intracranial volumes) determined in the multiple sclerosis group with data from 29 normal control subjects (mean age 36.7 years; 16 female, 13 male) using multiple linear regression analyses to allow for differences in age and sex distributions.

RESULTS

Change in lesion load in the first five years was more closely correlated to disease related brain atrophy at 14 years than later changes in lesion load, although the correlation was only moderate (Spearman correlation = -0.528, p = 0.004).

CONCLUSIONS

From this, it appears that early rather than later focal lesion accumulation relates to subsequent brain atrophy, but factors unconnected directly with lesion formation probably also play a significant role in determining such atrophy.

Spinal cord MRI in clinically isolated optic neuritis

BACKGROUND/METHODS

One hundred and fifteen patients with clinically isolated optic neuritis underwent magnetic resonance imaging (MRI) of the brain and spinal cord within 3 months of the onset of symptoms.

RESULTS

Eighty one (70%) patients had brain lesions and 31 (27%) had cord lesions. Cord lesions were seen in 12% with a normal brain MRI, 21% with between one and eight brain lesions, and 45% with nine or more brain lesions. When the new diagnostic criteria for MS were applied, MRI cord imaging used for evidence of dissemination in time and space allowed a diagnosis of MS in only one additional asymptomatic patient at 1 year, two additional asymptomatic patients at 3 years.

CONCLUSIONS

Using existing criteria, spinal cord imaging rarely contributes to the diagnosis in patients with clinically isolated optic neuritis.

Interferon beta-1a in primary progressive MS: an exploratory, randomized, controlled trial

BACKGROUND

Patients with primary progressive MS have atypical clinical and MRI characteristics and have been excluded from most therapeutic trials. The authors report a randomized, controlled trial restricted to primary progressive MS.

METHODS

Fifty subjects were randomized to weekly IM interferon beta-1a 30 microg, 60 microg, or placebo for 2 years. The primary endpoint was time to sustained progression in disability. Secondary outcomes included the timed 10-meter walk, nine-hole peg test, and on MRI, T2 and T1 brain lesion loads and brain and spinal cord atrophy.

RESULTS

The 30- microg dose of interferon beta-1a was well tolerated, but the 60- microg dose caused severe flulike reactions and raised liver enzymes. No treatment effect was seen on the primary endpoint. Subjects on interferon beta-1a 30 microg had a lower rate of accumulation of T2 lesion load than controls (p = 0.025); subjects on 60 microg had a greater rate of ventricular enlargement than controls (p = 0.025).

CONCLUSIONS

This study has demonstrated that interferon beta-1a 30 microg was well tolerated, identified useful outcome measures, but showed no efficacy on the primary outcome measure or on most of the secondary outcome measures.

Progressive ventricular enlargement in patients with clinically isolated syndromes is associated with the early development of multiple sclerosis

BACKGROUND

In patients with clinically isolated syndromes (CIS) suggestive of multiple sclerosis (MS), the extent of brain magnetic resonance imaging (MRI) lesion load influences the probability and time to development of clinically definite MS. Cerebral atrophy is recognised in established MS, but its time of onset and whether, in early disease, it is related to MRI lesion load or clinical outcome is less certain.

OBJECTIVES

This study investigated ventricular enlargement over one year in CIS patients and explored its relation with lesion load and clinical outcome.

METHODS

A semi-automated thresholding technique for measuring ventricular volume (MIDAS) was applied to MRI scans in a cohort of 55 patients with CIS, recruited consecutively and imaged within three months of the onset of symptoms and again after one year.

RESULTS

Clinical MS had developed after one year in 16 of 40 patients with an abnormal baseline T2 scan and 2 of 15 with a normal scan. Significant ventricular enlargement was seen in 27 of 55 patients who fulfilled the new McDonald MRI criteria for MS using all available MRI at clinical follow up (median increase 0.3 cm(3), p=0.005) Significant increase in ventricular volume was also seen in the 18 of 55 patients who developed clinical MS over the follow up period (median increase 0.5 cm(3), p=0.006). There were significant but modest correlations between baseline lesion measures and subsequent ventricular enlargement.

CONCLUSIONS

(1) Lesions and atrophy are both associated with early relapse leading to a diagnosis of clinical MS; (2) while lesions contribute to the development of atrophy, atrophy may also develop by other mechanisms. This suggests that MR measures have a complementary role in monitoring the course of MS, even from the earliest clinical stage.

Continuing optic nerve atrophy following optic neuritis: a serial MRI study

To investigate optic neuritis as a model for atrophy in multiple sclerosis (MS) lesions we performed serial magnetic resonance imaging (MRI) on 10 patients with a history of optic neuritis using a fat saturated short-echo fast fluid-attenuated inversion recovery (sTE fFLAIR) sequence. The first study was performed a median of 19.5 months after the onset of optic neuritis and the second 1 year later. Using a computer-assisted contouring technique, a blinded observer calculated the mean area of the intro-orbital optic nerves. The mean area of affected optic nerves decreased over 1 year by 0.9 mm2 from 11.1 to 10.2 mm2 (p = 0.01). Poor visual acuity and decreased visual-evoked potential (VEP) amplitude were associated with atrophy. These findings suggest that atrophy is a feature of focal demyelinating lesions, it may evolve over several years, and may have functional significance. Optic neuritis provides a model to study the effect of inflammatory demyelination through the ability to accurately measure visual function and to visualize and measure the optic nerves using magnetic resonance imaging.

Normal-appearing brain tissue MTR histograms in clinically isolated syndromes suggestive of MS

Segmented normal-appearing brain tissue (NABT) was investigated in 40 patients with a recent onset and 13 patients with a remote onset of a clinically isolated syndrome (CIS) using magnetization transfer ratio (MTR) histograms. Abnormalities were present in patients with a high risk for MS (recent onset and T2-weighted lesions present) and in those with a low risk for relapse (recent onset without T2-weighted lesions). Similar mild NABT abnormality was present with CIS and no further disease activity 14 years later. NABT MTR abnormality in CIS may indicate susceptibility to demyelination but not to disease progression.

Quantitative 1H MRS imaging 14 years after presenting with a clinically isolated syndrome suggestive of multiple sclerosis

clinically isolated syndromes (CIS) are events suggestive for emerging multiple sclerosis (MS). A majority of patients develop MS within months or years whilst others remain clinically isolated. The goal of this study was to investigate whether biochemical metabolites detectable by 'H magnetic resonance spectroscopy (MRS) may serve to distinguish between these two groups. We investigated 41 patients 14 years after presentation with a CIS and 21 controls with combined quantitative short echo 'H MRS and magnetic resonance imaging (MRI) and assessed disability according to the Expanded Disability Status Scale (EDSS). At follow-up, 32 had developed MS, and 9 still had CIS. Compared with controls, MS patients demonstrated significantly higher concentrations of myo-inositol (Ins) in normal appearing white matter (NAWM) and lesions. Lesions also demonstrated a reduced N-acetyl-aspartate (NAA) level and an increase in choline-containing compounds (Cho). The NAWM Ins concentration was correlated with EDSS (r = 0.48, p = 0.005). MS normal appearing cortical grey matter (CGM) exhibited a decreased NAA. Patients who remained CIS did not differ significantly from controls in any MRS measure. Metabolite changes in normal appearing white and grey matter in MS indicate diffuse involvement of the entire MS brain, which was not seen in the persisting CIS patients. Elevated Ins in MS NAWM appeared functionally relevant It may indicate glial cell proliferation or gliosis.

The effect of IFNbeta-1b on the evolution of enhancing lesions in secondary progressive MS

BACKGROUND

After the resolution of contrast enhancement, the majority of new MS lesions become isointense with surrounding white matter on T1-weighted MRI. Less commonly, a hypointense T1 lesion develops, representing the development of more severe focal tissue damage. Interferon beta (IFNbeta) reduces both the number of new enhancing lesions and the duration of contrast enhancement.

OBJECTIVE

To determine if IFNbeta affects the degree of tissue damage within new lesions and if its effects are related to lesion size.

METHODS

One hundred twenty-five patients with secondary progressive MS from seven European sites were randomized to receive either IFNbeta-1b or placebo. Monthly, contrast-enhanced T1-weighted MR images were acquired at baseline, at months 1 to 6, and at months 19 to 24. The size of all new enhancing lesions developing between months 1 and 6 was recorded and their appearance at follow-up documented.

RESULTS

In the first 6 months, fewer new enhancing lesions occurred in the IFNbeta-1b arm. This difference was greater for small (70% decrease) than for large (46% decrease) lesions. Hypointense T1 lesions were more likely to form from large (25%) than from small (9%) enhancing lesions in both treatment arms. Patients taking IFNbeta-1b developed fewer hypointense T1 lesions; however, the proportion of enhancing lesions developing into hypointense T1 lesions was similar in both arms.

CONCLUSION

IFNbeta-1b reduced the number of new enhancing lesions, with a greater effect on small lesions. However, when a new enhancing lesion did become established, treatment with IFNbeta-1b did not alter its subsequent course.

Magnetization transfer imaging in patients with clinically isolated syndromes suggestive of multiple sclerosis

BACKGROUND AND PURPOSE

In patients with multiple sclerosis (MS), reduced magnetization transfer ratios (MTRs) have been reported in white matter that appears normal on studies obtained with conventional imaging techniques. The stage in the disease when this first becomes detectable is unclear. The purpose of this study was to measure the MTR of normal-appearing white matter (NAWM) and lesions in patients with clinically isolated syndromes (CIS), many of whom are at the earliest stages of MS, and to determine the prognostic value of any observed changes.

METHODS

Twenty-seven CIS patients and 13 matched control subjects were studied. The mean MTR was measured from 10 regions of NAWM and, when present, from lesions. The patients were followed-up clinically for a median of 12 months.

RESULTS

There was no significant difference in the mean MTR between NAWM in control subjects (38.5% units) and that in CIS patients (38.4% units). After 12 months' follow-up, MS developed in 26% of the patients. The MTR of NAWM in these patients did not differ from that of the other patients or the control subjects.

CONCLUSION

The reduced MTR in NAWM, described in established MS, was not detectable in patients with CIS. MTR did not provide prognostic information for this short period of follow-up.

Measurement of spinal cord area in clinically isolated syndromes suggestive of multiple sclerosis

Atrophy of the spinal cord is known to occur in multiple sclerosis but the cause and the timing of its onset are not clear. Recent evidence suggests that atrophy may start to occur early in the disease. The aim was to determine whether atrophy of the spinal cord could be detected in vivo using MRI techniques, in patients presenting with a clinically isolated syndrome, which in many cases is the earliest clinical stage of multiple sclerosis. The cross sectional area of the spinal cord was measured in 43 patients presenting with a clinically isolated syndrome and 15 matched controls. T2 weighted imaging of the brain was also performed to determine the number and volume of high signal lesions consistent with disseminated demyelination. Both patients and controls were restudied after 1 year. The spinal cord area was significantly smaller in the 74% of patients with an abnormal brain MRI at presentation than in controls (mean areas 73.9 mm(2) and 78.1 mm(2) respectively, p=0.03). No significant difference was found in the spinal cord area between controls and patients with normal baseline brain imaging. The annual rate of change in patients did not differ significantly from controls. In conclusion, the finding of a smaller cord area in the subgroup of patients with clinically isolated syndrome with the highest risk of developing multiple sclerosis-that is, with an abnormal brain MRI, suggests that atrophy has developed in some patients with multiple sclerosis even before their first clinical symptoms. However, the lack of a detectable change in cord area over 1 year of follow up contrasts strikingly with the results of an earlier study of patients with relapsing-remitting multiple sclerosis, suggesting that the rate of atrophy increases as the disease becomes more established.

Assessing the risk of early multiple sclerosis in patients with clinically isolated syndromes: the role of a follow up MRI

OBJECTIVES

With increasing evidence that permanent tissue damage occurs early in the course of multiple sclerosis, it is important that treatment trials include patients in the earliest stages of the disease. For many patients with multiple sclerosis the first presentation is a clinically isolated syndrome. Not all patients with a clinically isolated syndrome develop multiple sclerosis, however, and treatment of all such patients would be unwarranted. A single abnormal brain MRI identifies patients at a higher risk for the early development of multiple sclerosis, but current criteria are limited by either poor specificity (T2 lesions) or sensitivity (contrast enhancing lesions). The aim of the study was to assess the positive predictive value, sensitivity, and specificity of MRI indices for the development of multiple sclerosis after 1 year from two MRI examinations obtained 3 months apart.

METHODS

MRI examinations were performed in 68 patients with a clinically isolated syndrome, with a clinical assessment after 1 year.

RESULTS

Contrast enhancing lesions at both time points were the most predictive indices for developing multiple sclerosis (positive predictive value 70%) but had low sensitivity (39%). The combination of T2 lesions at baseline with new T2 lesions at follow up had the best overall positive predictive value (53%), sensitivity (83%), and specificity (76%). In patients with T2 lesions at baseline, the presence or absence of new T2 lesions at follow up significantly altered the risk of multiple sclerosis within 1 year (55% and 5% respectively, p<0.001). Multiple sclerosis also developed in 10% of patients with a normal baseline MRI.

CONCLUSIONS

Serial imaging in patients with clinically isolated syndromes improved the positive predictive value, sensitivity, and specificity of MRI for the development of early multiple sclerosis and also identified patients at a lower risk of early multiple sclerosis than would have been expected from their abnormal baseline MRI. Selection of patients with clinically isolated syndromes for therapeutic intervention or clinical trials may benefit from serial MRI, to target those at greatest risk of early development of multiple sclerosis.

Detection of optic nerve atrophy following a single episode of unilateral optic neuritis by MRI using a fat-saturated short-echo fast FLAIR sequence

We describe an MRI technique for quantifying optic nerve atrophy resulting from a single episode of unilateral optic neuritis. We imaged 17 patients, with a median time since onset of optic neuritis of 21 months (range 3-81 months), using a coronal-oblique fat-saturated short-echo fast fluid-attenuated inversion-recovery (sTE fFLAIR) sequence. The mean cross-sectional area of the intraorbital portion of the optic nerves was calculated by a blinded observer from five consecutive 3 mm slices from the orbital apex forwards using a semiautomated contouring technique and compared with data from 16 controls. The mean optic nerve area was 11.2 mm2 in the affected eye of the patients, 12.9 mm2 in the contralateral eye (P = 0.006 compared to the affected eye) and 12.8 mm2 in controls (P = 0.03 compared to the affected eyes). There was a significant negative correlation between disease duration and the size of the affected optic nerve (r = -0.59, P = 0.012). The measurement coefficient of variation was 4.8%. The sTE fFLAIR sequence enables measurement of optic nerve area with sufficient reproducibility to show optic nerve atrophy following a single episode of unilateral optic neuritis. The correlation of increasing optic nerve atrophy with disease duration would be consistent with ongoing axonal loss in a persistently demyelinated lesion, or Wallerian degeneration following axonal damage during the acute inflammatory phase.

The precision of T1 hypointense lesion volume quantification in multiple sclerosis treatment trials: a multicenter study

The volume of hypointense lesions on T1 weighted brain MRI represents an increasingly used MR endpoint in phase III MS treatment trials. In this study we evaluated the reproducibility of hypointense T1 lesion volume quantification in a cohort of Multiple Sclerosis (MS) patients. The gadolinium enhanced T1 weighted brain MR images of 33 MS patients from three European centers were used in this study. These images were acquired as part of a phase III trial of interferon beta-1b in secondary progressive MS. The MRI machine manufacturers and imaging parameters varied according to the MRI acquisition center. Three experienced observers used a semi-automated local thresholding technique to quantify the hypointense T1 lesion volume on two occasions, separated by a delay. The intra and inter observer coefficients of variation were 3.7% and 4.9% respectively, with similar values derived for images obtained at all three sites. There was a generally high level of agreement between the lesion volumes obtained by the three raters. However, a modest but significant measurement drift was identified between the first and second sessions for one of the three raters, highlighting the very real possibility of measurement drift even for experienced observers. Our results support the increasing role for T1 hypointense lesion volume as an outcome measure in multicenter phase III MS treatment trials. Multiple Sclerosis (2000) 6 237 - 240

A (1)H magnetic resonance spectroscopy study of aging in parietal white matter: implications for trials in multiple sclerosis

1H magnetic resonance spectroscopy (MRS) provides a unique tool to detect and quantify brain metabolites. In multiple sclerosis it can be used to investigate axonal loss or dysfunction through measurement of N-acetyl aspartate (NAA), a neuronal marker. Previous studies in adults have reported variable effects of aging on metabolite concentrations but have predominantly focused on changes in the elderly. This study has examined a younger adult age group to provide a reference database more applicable to the multiple sclerosis population. Single voxel (1)H MRS was carried out in 44 subjects between 22 and 62 years of age. Sixteen subjects underwent repeat examination after one year. Absolute concentrations of NA (the sum of NAA and N-acetyl aspartate glutamate), NAA, creatine/phosphocreatine (Cr), choline containing compounds (Cho) and myo-inositol (mI) were measured. NA, NAA and mI concentrations did not correlate with age but there were significant correlations between age and Cr (r = 0.43, p = 0.004) and Cho (r = 0.38, p = 0. 011) concentrations. No significant differences in metabolite concentrations were seen over one year. This study provides evidence that age-related changes of metabolite concentrations occur even in a young to middle aged adult population. This emphasizes the need to perform absolute quantification of metabolite concentrations rather than ratios and the importance of age-matching in (1)H MRS studies of multiple sclerosis.

Lesion heterogeneity in multiple sclerosis: a study of the relations between appearances on T1 weighted images, T1 relaxation times, and metabolite concentrations

OBJECTIVES

Multiple sclerosis lesions appear as areas of high signal on T2 weighted MRI. A proportion of these lesions, when viewed on T1 weighted MRI, appear hypointense compared with surrounding white matter. These hypointense T1 lesions are thought to represent areas of greater tissue damage compared with the more non-specific, total T2 lesion load. This study aimed to better characterise the properties of high signal T2 lesions with differing appearances on T1 weighted MRI using quantitative MR techniques.

METHODS

Eleven patients with secondary progressive multiple sclerosis were studied. Two high signal T2 lesions were selected from each patient-one of which appeared hypointense and one isointense on a T1 weighted image. A voxel was positioned around each lesion and for this volume of brain the metabolite concentrations were estimated using proton MR spectroscopy ((1)H-MRS) and the T1 relaxation time within each voxel calculated from a T1 map generated using a multislice technique.

RESULTS

Compared with isointense T1 lesions, hypointense T1 lesions exhibited a significantly lower absolute concentration of N-acetyl derived metabolites (tNAA) and a significantly higher absolute concentration of myo-inositol (Ins). T1 relaxation time correlated significantly with both tNAA (r=-0.8, p < 0.001) and Ins (r=0.5, p=0. 012). There was no correlation between T1 relaxation times and creatine/phosphocreatine or choline containing compounds.

CONCLUSIONS

Prolonged T1 relaxation times seem to reflect the severity of axonal damage or dysfunction (inferred by a low tNAA) and possibly also gliosis (inferred by a high Ins) in chronic multiple sclerosis lesions.

Detection of ventricular enlargement in patients at the earliest clinical stage of MS

The aim of this study was to determine whether atrophy could be detected at the earliest clinical stages of MS. Patients were selected from a 1-year follow-up MRI study of clinically isolated syndromes. Nine patients who developed MS were compared with eight matched patients who had no further symptoms. Significant ventricular enlargement occurred in the group that developed MS but not in the other group. Our findings show that atrophy, albeit mild, can be detected early in the course of MS.

Recovery from optic neuritis is associated with a change in the distribution of cerebral response to visual stimulation: a functional magnetic resonance imaging study

OBJECTIVES

Recovery to normal or near normal visual acuity is usual after acute demyelinating optic neuritis, despite the frequent persistence of conduction abnormalities as evidenced by the visual evoked potential (VEP). This raises the possibility that cortical adaptation to a persistently abnormal input contributes to the recovery process. The objective of this study was to investigate the pattern of cerebral response to a simple visual stimulus in recovered patients in comparison to normal subjects.

METHODS

Functional magnetic resonance imaging (fMRI) was used to study the brain activation pattern induced by a periodic monocular 8Hz photic stimulus in seven patients who had recovered from a single episode of acute unilateral optic neuritis, and in seven normal controls. VEPs and structural optic nerve MRI were performed on patients.

RESULTS

Stimulation of either eye in controls activated only the occipital visual cortex. However, in patients, stimulation of the recovered eye also induced extensive activation in other areas including the insula-claustrum, lateral temporal and posterior parietal cortices, and thalamus; stimulation of the clinically unaffected eye activated visual cortex and right insula-claustrum only. The volume of extraoccipital activation in patients was strongly correlated with VEP latency (r = 0.71, p = 0.005).

CONCLUSIONS

The extraoccipital areas that were activated in patients all have extensive visual connections, and some have been proposed as sites of multimodal sensory integration. The results indicate a functional reorganisation of the cerebral response to simple visual stimuli after optic neuritis that may represent an adaptive response to a persistently abnormal input. Whether this is a necessary part of the recovery process remains to be determined.

Multisequence MRI in clinically isolated syndromes and the early development of MS

OBJECTIVE

To apply multisequence MRI techniques to patients with clinically isolated syndromes, to document the pattern and frequency of abnormalities at baseline and early follow-up, and to determine their predictive values for the early development of clinical MS.

BACKGROUND

Disseminated lesions on T2-weighted brain MRI confer an increased risk of progression to clinically definite MS. Newer MRI techniques increase detection of lesions in both brain and spinal cord, and clarify further their pathology. The predictive value of such techniques for the development of clinical MS needs to be defined.

METHODS

Brain and spinal MRI were performed on 60 patients after their first demyelinating event. A total of 50 patients were followed for 1 year, and 49 underwent repeat brain MRI 3 months after the initial scan.

RESULTS

At baseline, 73% of patients had lesions on T2-weighted fast spin-echo (FSE) brain images and 42% had asymptomatic spinal cord lesions. Fast fluid-attenuated inversion-recovery brain did not improve detection of brain lesions. Repeat brain MRI demonstrated new FSE lesions in 43% of patients. After 1 year, 26% of patients developed MS. The MRI features that provided the best combination of sensitivity and specificity for the development of MS were the presence of new FSE lesions at follow-up and enhancing lesions at baseline. The frequency of developing clinical MS was higher for those with both brain and spinal cord lesions at baseline (48%) than brain lesions alone (18%).

CONCLUSIONS

The combination of baseline MRI abnormalities and new lesions at follow-up, indicating dissemination in space and time, was associated with a high sensitivity and specificity for the early development of clinical MS. These data suggest a potential role for new diagnostic criteria for MS based on early MRI activity. Such criteria may be useful in selecting patients for therapeutic trials at this early clinical stage.

Proton MR spectroscopy in clinically isolated syndromes suggestive of multiple sclerosis

The concentration of the metabolite N-acetyl aspartate (NAA), thought to be a marker of axonal loss or damage, has been shown to be reduced in lesions, as demonstrated by high signal areas on T2-weighted MRI, and in normal-appearing white matter (NAWM) in established multiple sclerosis (MS). The stage of the disease when these changes first appear is not known. To try to determine this we studied 20 patients with clinically isolated syndromes, many of whom will be at the earliest clinical stages of MS, and 20 age- and sex-matched controls with single-voxel proton magnetic spectroscopy (MRS). MRS was performed using a General Electric 1.5T Signa EchoSpeed scanner (TR 3000 ms, TE 30 ms, PRESS). Absolute metabolite concentrations were determined using the LCModel fitting software. No significant reduction of NAA concentration was evident in the NAWM of the patients (patients: median 7.3 mM; controls: median 7.7 mM; P=0.19). There was, however, a significantly lower concentration of NAA in lesions (median 6.6 mM, P=0.015). Absolute values of choline-containing compounds, creatine and myo-inositol were significantly raised in the lesions (P=0.007, P=0.011 and P=0.002 respectively). The low NAA in lesions is consistent with axonal loss, damage or dysfunction occurring focally at the earliest clinical phase of the disease. The lack of any significant reduction in NAA in patient NAWM demonstrates that more widespread axonal changes are not yet detectable at this early clinical stage. A larger cohort and follow-up will be necessary to determine whether or not MRS findings have any prognostic significance for individual patients or sub-groups. This will also enable the clarification of the time course, pathogenesis and pathophysiological significance of the development of the low NAA, which is found in the NAWM of many patients with established MS.