Multiple sclerosis disease activity correlates with gadolinium-enhanced magnetic resonance imaging

Metabolic Insights into Iron Deposition in Relapsing-Remitting Multiple Sclerosis via 7 T Magnetic Resonance Spectroscopic Imaging

OBJECTIVE

To investigate the metabolic pattern of different types of iron accumulation in multiple sclerosis (MS) lesions, and compare metabolic alterations within and at the periphery of lesions and newly emerging lesions in vivo according to iron deposition.

METHODS

7 T MR spectroscopic imaging and susceptibility-weighted imaging was performed in 31 patients with relapsing-remitting MS (16 female/15 male; mean age, 36.9 ± 10.3 years). Mean metabolic ratios of four neuro-metabolites were calculated for regions of interest (ROI) of normal appearing white matter (NAWM), "non-iron" (lesion without iron accumulation on SWI), and three distinct types of iron-laden lesions ("rim": distinct rim-shaped iron accumulation; "area": iron deposition across the entire lesions; "transition": transition between "area" and "rim" accumulation shape), and for lesion layers of "non-iron" and "rim" lesions. Furthermore, newly emerging "non-iron" and "iron" lesions were compared longitudinally, as measured before their appearance and one year later.

RESULTS

Thirty-nine of 75 iron-containing lesions showed no distinct paramagnetic rim. Of these, "area" lesions exhibited a 65% higher mIns/tNAA (p = 0.035) than "rim" lesions. Comparing lesion layers of both "non-iron" and "rim" lesions, a steeper metabolic gradient of mIns/tNAA ("non-iron" +15%, "rim" +40%) and tNAA/tCr ("non-iron" -15%, "rim" -35%) was found in "iron" lesions, with the lesion core showing +22% higher mIns/tNAA (p = 0.005) and -23% lower tNAA/tCr (p = 0.048) in "iron" compared to "non-iron" lesions. In newly emerging lesions, 18 of 39 showed iron accumulation, with the drop in tNAA/tCr after lesion formation remaining significantly lower compared to pre-lesional tissue over time in "iron" lesions (year 0: p = 0.013, year 1: p = 0.041) as opposed to "non-iron" lesions (year 0: p = 0.022, year 1: p = 0.231).

CONCLUSION

7 T MRSI allows in vivo characterization of different iron accumulation types each presenting with a distinct metabolic profile. Furthermore, the larger extent of neuronal damage in lesions with a distinct iron rim was reconfirmed via reduced tNAA/tCr concentrations, but with metabolic differences in lesion development between (non)-iron-containing lesions. This highlights the ability of MRSI to further investigate different types of iron accumulation and suggests possible implications for disease monitoring.

C-Reactive Protein Levels and Gadolinium-Enhancing Lesions Are Associated With the Degree of Depressive Symptoms in Newly Diagnosed Multiple Sclerosis

Background: Inflammation is essential for the pathogenesis of multiple sclerosis (MS). While the immune system contribution to the development of neurological symptoms has been intensively studied, inflammatory biomarkers for mental symptoms such as depression are poorly understood in the context of MS. Here, we test if depression correlates with peripheral and central inflammation markers in MS patients as soon as the diagnosis is established. Methods: Forty-four patients were newly diagnosed with relapsing-remitting MS, primary progressive MS or clinically isolated syndrome. Age, gender, EDSS, C-reactive protein (CRP), albumin, white blood cells count in cerebrospinal fluid (CSF WBC), presence of gadolinium enhanced lesions (GE) on T1-weighted images and total number of typical MS lesion locations were included in linear regression models to predict Beck Depression Inventory (BDI) score and the depression dimension of the Symptoms Checklist 90-Revised (SCL90RD). Results: CRP elevation and GE predicted significantly BDI (CRP: p = 0.007; GE: p = 0.019) and SCL90RD (CRP: p = 0.004; GE: p = 0.049). The combination of both factors resulted in more pronounced depressive symptoms (p = 0.04). CSF WBC and EDSS as well as the other variables were not correlated with depressive symptoms. Conclusions: CRP elevation and GE are associated with depressive symptoms in newly diagnosed MS patients. These markers can be used to identify MS patients exhibiting a high risk for the development of depressive symptoms in early phases of the disease.

Sleep disorders as a possible predisposing attack factor in neuromyelitis optica spectrum disorder (NMOSD): A case-control study

BACKGROUND

Sleep disturbances are common in neuromyelitis optica spectrum disorder (NMOSD) and have a great impact on patients' quality of life. According to a report, there is a 64% prevalence of poor sleep quality in NMOSD patients. Therefore, this study was done to evaluate the effect of sleep disturbances on NMOSD acute exacerbations.

MATERIALS AND METHODS

This case-control study was conducted at Sina Hospital in 2019. A total of 60 patients with NMOSD diagnosis were enrolled in the study (30 patients were in the remission phase while 30 patients were hospitalized due to acute attacks). Sleep disorders were evaluated in both groups. Sleep quality was assessed during the last month using the Pittsburgh Sleep Quality Index (PSQI) questionnaire. Data were analyzed by SPSS software version 21.

RESULTS

Among 60 patients who were evaluated in both the control and attack groups, 86.7% were female. The duration of the disease was 68.23 ± 42.89 months in the control group and 69.83 ± 6.90 in the attack group. The mean age of patients was 34.15 years old. Sleep quality was unfavorable in 30% and 56% of patients in control and attack groups, respectively. There were significant differences between the two groups in sleep latency, habitual sleep efficiency, sleep duration, and sleep disturbance.

CONCLUSION

The present study revealed that there was a significant difference in sleep quality between controls and attack patients and could show a direct relationship between sleep disorders and NMOSD attacks.

Aging and efficacy of disease-modifying therapies in multiple sclerosis: a meta-analysis of clinical trials

Background

Disease-modifying therapies (DMTs) for multiple sclerosis (MS) are approved for the treatment of disease activity and are effective in reducing relapses and new magnetic resonance imaging (MRI) lesions. However, disease activity generally subsides with time, and age-dependent changes in DMT efficacy are not well-established. We aimed to investigate whether age impacts the efficacy of DMTs in treating disease activity in patients with relapsing-remitting MS (RRMS).

Methods

DMT efficacy related to age was assessed through a meta-analysis of clinical trials that evaluated the efficacy of DMTs in RRMS patients as measured by reductions in the annualized relapse rate (ARR), new T2 lesions, and gadolinium-enhanced lesions on MRI. Using the mean baseline patient age from each trial, a weighted linear regression was fitted to determine whether age was associated with treatment efficacy on a group level.

Results

Group-level data from a total of 28,082 patients from 26 trials of 14 different DMTs were included in the meta-analysis. There were no statistically significant associations between age and reductions in ARR, new T2 lesions, and gadolinium-enhanced lesions of the treatment group compared with placebo.

Conclusion

DMTs for RRMS show efficacy in treating disease activity independent of age as demonstrated by group-level data from DMT clinical trials. Nevertheless, clinical trials select for patients with baseline disease activity regardless of age, thereby not representing real-world patients with RRMS, where disease activity declines with age.

Concussion in adolescence and the risk of multiple sclerosis: A retrospective cohort study

BACKGROUND

Physical trauma, specifically concussions sustained during adolescence, has been hypothesized to be a risk factor for multiple sclerosis (MS).

OBJECTIVE

To examine the association between adolescent concussions and future MS diagnosis.

METHODS

This retrospective study using linked administrative databases from Ontario, Canada, identified 97,965 adolescents (age 11-18 years) who sustained ⩾1 concussion and presented to an emergency department between 1992 and 2011. Cases were matched 1:3 with individuals who had not sustained a concussion based on age, sex, address, and index date. The primary outcome was MS diagnosis, using a validated MS diagnosis definition: ⩾1 hospitalization or ⩾5 physician billings within 2 years.

RESULTS

A concussion during adolescence was associated with a significantly increased risk of MS (hazard ratio (HR) = 1.29, p = 0.03). Sex-specific analysis revealed that only males who sustained a concussion in adolescence had a raised risk of MS (HR = 1.41, p = 0.04).

CONCLUSION

This study supports an association between concussions in adolescence and future MS diagnoses, highlighting the potentially serious long-term effects of concussions.

Sleep Disorder as a Triggering Factor for Relapse in Multiple Sclerosis

BACKGROUND/AIMS

To determine the effect of sleep disturbances on predisposing multiple sclerosis (MS) patients for acute relapse.

METHODS

This case-control study was conducted on 80 MS patients including 40 patients in the remission phase and 40 in the relapse phase. Patients were asked to fill in the Pittsburgh Sleep Quality Index to determine their sleep quality during the previous month. Individuals with scores of 5 or less were considered having normal sleep quality.

RESULTS

Mean ± SD ages were 32.5 ± 7.7 and 30.2 ± 7.2 years among patients with and without acute relapses, respectively (p > 0.05). The mean disease duration and disease severity (according to Expanded Disability Status Scale [EDSS]) were comparable across the groups (p > 0.05). Among those with and without acute exacerbations, 87.5 and 50% had poor sleep quality, respectively (p = 0.0001), with OR of 1.75 (95% CI 1.25-2.43). The age, gender, EDSS, and disease duration did not associate with sleep quality in either groups (p > 0.05).

CONCLUSIONS

This study showed that sleep disturbance might be a trigger for an acute MS exacerbation. Increasing the awareness of specialists and routine screening of sleep disorders in MS patients are warranted, as treatment of these disorders might decrease the likelihood of acute relapses.

Anterograde-propagation of axonal degeneration in the visual system of wlds mice characterized by diffusion tensor imaging

PURPOSE

To evaluate the feasibility of using diffusion tensor imaging (DTI) to characterize the temporospatial profile of axonal degeneration and its relation to blood-brain barrier (BBB) permeability.

MATERIALS AND METHODS

Longitudinal DTI was performed in Wallerian degeneration slow (WldS) mice following retinal ischemia. In parallel, gadolinium (Gd)-enhanced T₁ -weighted imaging (Gd-T₁ WI) was performed to evaluate BBB permeability in white matter during axonal degeneration. To confirm the in vivo findings, immunohistochemistry using SMI-31 and myelin basic protein (MBP) was performed to examine the axons and myelin, respectively, and Evans blue was used to evaluate the permeability of the BBB.

RESULTS

Reduced axial diffusivity was found in the optic nerve (ON, -15%, P = 0.0063) 1 week and optic tact (OT, -18%, P = 0.0077) 2 weeks after retinal ischemia, which were respectively associated with an 11% (P = 0.0116) and 25% (P = 0.0001) axonal loss. Increased radial diffusivity was found 1-2 weeks after the colocated decrease of axial diffusivity (35% increase, P = 0.0388 in the ON at week 2 and an 80% increase, P = 0.0015 in the OT at week 4). No significant changes were observed using Gd-T₁ WI (P = 0.13-0.75), although an approximately 1-fold increase in Evans blue staining intensity was found in the injured ON and OT starting 1 week after retinal ischemia.

CONCLUSION

We demonstrated the utility of DTI to characterize anterograde-propagating axonal degeneration through the ON and OT following retinal damage. Evans blue staining revealed serum albumin accumulation at injured sites, although there was no BBB leakage detectable using Gd-T₁ WI.

LEVEL OF EVIDENCE

2 J. Magn. Reson. Imaging 2017;45:482-491.

In vivo imaging of neuroinflammation in schizophrenia

In recent years evidence has accumulated to suggest that neuroinflammation might be an early pathology of schizophrenia that later leads to neurodegeneration, yet the exact role in the etiology, as well as the source of neuroinflammation, are still not known. The hypothesis of neuroinflammation involvement in schizophrenia is quickly gaining popularity, and thus it is imperative that we have reliable and reproducible tools and measures that are both sensitive, and, most importantly, specific to neuroinflammation. The development and use of appropriate human in vivo imaging methods can help in our understanding of the location and extent of neuroinflammation in different stages of the disorder, its natural time-course, and its relation to neurodegeneration. Thus far, there is little in vivo evidence derived from neuroimaging methods. This is likely the case because the methods that are specific and sensitive to neuroinflammation are relatively new or only just being developed. This paper provides a methodological review of both existing and emerging positron emission tomography and magnetic resonance imaging techniques that identify and characterize neuroinflammation. We describe \how these methods have been used in schizophrenia research. We also outline the shortcomings of existing methods, and we highlight promising future techniques that will likely improve state-of-the-art neuroimaging as a more refined approach for investigating neuroinflammation in schizophrenia.

Magnetic resonance imaging findings in acute canine distemper virus infection

Demyelination is the prominent histopathological hallmark in the acute stage of canine distemper virus infection. Magnetic resonance imaging is an important diagnostic tool in human beings to determine demyelination in the brain, for example in multiple sclerosis. Five young dogs with clinically suspected canine distemper virus infection were subjected to magnetic resonance imaging of the brain and histopathological and immunohistochemical examinations. Hyperintense lesions and loss of contrast between grey and white matter were detected in T2-weighted images in the cerebellum and/or in the brainstem of three dogs, which correlated with demyelination demonstrated in histopathological examination. Furthermore, increased signal intensities in T2-weighted images were seen in the temporal lobe of four dogs with no evidence of demyelination. Magnetic resonance imaging seems to be a sensitive tool for the visualisation of in vivo myelination defects in dogs with acute canine distemper virus infection. Postictal oedema and accumulation of antigen positive cells have to be considered an important differential diagnosis.

Magnetic resonance imaging of blood–spinal cord barrier disruption in mice with experimental autoimmune encephalomyelitis

Inflammation, demyelination, and blood-spinal cord barrier (BSB) breakdown occur in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. The purpose of this study was to evaluate the utility of MRI for detecting lesions and BSB disruption in vivo during EAE in the mouse lumbar spinal cord, to determine how MR features of BSB disruption change during the course of disease, and to relate such changes to clinical signs and histological features of disease. Following induction of EAE in C57BL/6 mice, contrast-enhanced (CE) T(1)-weighted MR images were acquired to detect BSB disruption in the lumbar spinal cord at the early stage of disease, at peak disease, and at remission, and T(2)-weighted images were obtained to monitor spinal cord morphology. Following imaging the spinal cords were assessed in situ for general features of inflammation, BSB leakage, activated macrophages/microglia, and demyelination. No focal lesions were evident on T(2)-weighted MR images. BSB disruption was greatest at the onset of signs of disease, and decreased progressively thereafter. Inflammation and demyelination were pronounced at the initial stage of disease and at peak disease, and were decreased at remission. Nonuniform contrast enhancement indicated that breakdown of the BSB occurred predominantly within the white matter (WM) of the spinal cord.

Pure albumin is a potent trigger of calcium signalling and proliferation in microglia but not macrophages or astrocytes

Microglial activation is implicated in the neurotoxicity of neurodegenerative diseases. Raised intracerebral levels of albumin are associated with the pathology of Alzheimer's disease, multiple sclerosis, and stroke where blood-brain barrier damage is evident. We report here that treatment of primary cultured microglia and the N9 microglial cell line with pure albumin, or albumin in which fatty acids and immunoglobulins remain attached (fraction V), induced a rise in intracellular calcium. This rise in intracellular calcium was mediated via Src tyrosine kinase and phospholipase C. The albumin-induced calcium response was coupled to microglial proliferation, which was prevented by BAPTA, U73122 or PP2 but not mimicked by thapsigargin. In contrast, peritoneal macrophages were resistant to albumin- or fraction V-induced calcium responses and proliferation, whilst primary cultured astrocytes or the TSA-3 astrocyte cell line were responsive to fraction V albumin but not pure albumin. Furthermore, cerebellar granule neurones did not respond to albumin. These data suggest that albumin may play a role in microglial activation in pathological situations involving blood-brain barrier impairment, and that the specific responses of microglia to albumin allow a distinction to be made between the signalling responses of microglia, blood-borne macrophages, astrocytes and neurones.

Quantitative contrast-enhanced magnetic resonance imaging to evaluate blood-brain barrier integrity in multiple sclerosis: a preliminary study

Gadolinium enhanced magnetic resonance imaging detects focal blood-brain barrier breakdown in new inflammatory multiple sclerosis lesions, but such lesions do not correlate with disease progression. To explore whether the latter might relate to subtle but widespread blood-brain barrier (BBB) breakdown with low grade inflammation mediating tissue damage, quantitative techniques were used to detect subtle gadolinium enhancement within otherwise normal-appearing white matter and within lesions not showing visible enhancement. T1-weighted imaging was performed prior to and at 5, 20 and 40 min following injection of 0.3 mmol/kg gadopentate dimeglumine in 33 patients with multiple sclerosis and five healthy control subjects. In healthy controls, a significant increase in white matter signal 5 min following contrast injection was observed (1.8%, P < 0.0005); the signal returned to baseline values by 20 min. In multiple sclerosis patients, a non-significant trend was noted for signal to remain elevated in normal-appearing white matter at the 20 and 40 min post-contrast time points; this was most apparent in primary progressive multiple sclerosis. Significant increases in signal intensity were noted at all time points post contrast in apparent non-enhancing lesions. The transient post contrast signal increase in controls is likely due to intravascular gadopentate dimeglumine. The persistent increases in signal intensity in non-enhancing lesions suggest more widespread abnormalities in BBB than is visually apparent, but substantiation of BBB leakage in normal appearing white matter will require further study using more sensitive methods.

Acute disseminated encephalomyelitis and multiple sclerosis: magnetic resonance imaging differentiation

The study was undertaken to compare the MR imaging features of acute disseminated encephalomyelitis (ADEM) and multiple sclerosis (MS) in a country with a high prevalence of ADEM. Magnetic resonance scans from 33 patients diagnosed clinically with MS (14 patients) or ADEM (19 patients) were reviewed concurrently by two radiologists blinded to the clinical diagnosis. The size, site, morphology and pattern of brain and spinal cord involvement were recorded and the MR imaging diagnosis was compared with the clinical diagnosis. The MR imaging findings matched with the clinical diagnosis in 11 of 14 patients with MS (sensitivity = 78.6%), and with the clinical diagnosis in 15 of 18 patients with ADEM (sensitivity = 78.9%). Three patients had non-specific findings and in a further three patients discordant imaging features were present. One patient with imaging features typical of Balo's concentric sclerosis was diagnosed clinically as suffering from ADEM. In a country with a high prevalence of ADEM, the majority of patients with ADEM and MS can be differentiated on MR imaging.

MTR and T1 provide complementary information in MS NAWM, but not in lesions

MTR and T1 relaxation times are abnormal in MS lesions and NAWM, and may reflect tissue damage such as demyelination and axonal loss. Their relationship and potential to provide complementary information in tissue characterisation is explored. The aim of this study was to document the relationship between magnetisation transfer ratio (MTR) and T1 relaxation time in Multiple Sclerosis (MS) lesions and normal appearing white matter (NAWM) in order to determine whether the combination provides a more comprehensive tissue characterisation than either parameter in isolation. Ten patients with relapsing remitting MS and 10 age matched healthy controls underwent imaging using a protocol which included the measurement of both MTR and T1 relaxation times. The MTR and T1 values were compared statistically using a commonly adopted correlation approach and a mixed-model regression approach. There was a strong correlation between MTR and T1 in MS lesions (r=0.74). The correlation was seen equally in T1 hypointense and isointense lesions. The relationship was much weaker in MS NAWM (r=0.24) and no correlation was found in control white matter (r=0.06). Mixed-model regression analysis confirmed that the relationship between T1 and MTR is strongly dependent upon tissue type (MS lesion, MS NAWM, or control white matter). The relationship between MTR and T1 relaxation time measurements varies markedly between pathological and normal tissue types. In MS, the complementary information obtained from MTR and T1 is most apparent in NAWM. The results emphasise the potential for combinations of MR parameters to improve tissue characterisation, which in turn should improve understanding of disease pathology and treatment monitoring. Multiple Sclerosis (2000) 6 327 - 331

Serial magnetic resonance imaging in multiple sclerosis: correlation with attacks, disability, and disease stage

Serial MRI and clinical testing was performed on 45 well-defined untreated multiple sclerosis patients in different categories of disease (relapsing-remitting, progressive, stable). Up to 24 MRIs were scheduled over a 1-year period for each patient. Clinical evaluation was performed monthly and at times of attacks using the Expanded Disability Status Scale (EDSS) and the Ambulation Index (AI). MRI scans were performed both with and without gadolinium enhancement. MRI lesion volume was determined by computerized analysis and gadolinium-enhancing lesions were counted by radiologists. We observed an increase in lesion volume over 1 year in all patient groups except those classified clinically as stable. In relapsing-remitting patients there were correlations between increases in the number of gadolinium enhancing lesions and increases in EDSS and the occurrence of attacks. In chronic progressive patients, increases in lesion volume were correlated with both increases in EDSS and AI. These results demonstrate a linkage between MRI and clinical disease that depends both on the stage of MS and the MRI measures used and support the use of MRI as a surrogate marker of clinical disability in the study of multiple sclerosis.

Serial Gadolinium-enhanced MRI in untreated patients with acute optic neuritis: implications for natural history

INTRODUCTION

Serial brain MRIs with and without Gadolinium (Gd)-DTPA were performed in acute optic neuritis (ON).

MATERIAL AND METHODS

Fifty-nine untreated patients (44 female) aged 20-57 years with ON underwent MRI median 16 d from onset of symptoms of ON and at 1 and 12 months follow-up.

RESULTS

At onset of monosymptomatic ON (AMON), 13 of 40 (33%) patients had lesions on MRI without Gd-DTPA compared with 15 of 19 (79%) patients with ON as part of clinically definite multiple sclerosis (CDMS). An initially abnormal MRI never normalized, whereas 3 patients with AMON with initially normal MRI had lesions at follow-up. In AMON enhancing lesions were seen in 5% of patients at onset, in 12% after 1 month, and in 11% after 12 months. The corresponding figures in CDMS were 21%, 38%, and 33%. All enhancing lesions were also seen on MRI without Gd-DTPA. The number of lesions on MRI without Gd-DTPA increased significantly with time in the 8 patients with AMON with enhancing lesions at one or more MRIs. New enhancing lesions appeared in 11 patients (6 AMON), of whom 3 (2 AMON) had an exacerbation. In contrast, 12 (5 AMON) patients had an exacerbation, being accompanied by new enhancing lesions in only 3 (2 AMON) patients.

CONCLUSION

Gd-DTPA did not increase the sensitivity of MRI, which was significantly higher in CDMS than in AMON, but improved the understanding of the natural history of AMON and CDMS. The dynamics of enhancing lesions did not correlate well with exacerbations. Serial MRI and clinical assessment are supplementary in monitoring disease activity.

The controversy surrounding the pathogenesis of the multiple sclerosis lesion

The main issues in multiple sclerosis research revolve around four fundamental questions. (1) What initiates the disease-that is, autoimmune T cells, a virus, or a toxin? (2) Is the inflammatory response primary to the development of demyelination, or is it a secondary response to injury? (3) Is the oligodendrocyte, the myelin-producing cell, the primary target? (4) How can myelin repair be promoted? This review focuses on the controversies revolving around these important questions. Although many investigators believe that T-cell receptors on CD4+ cells interact with myelin antigens to initiate an inflammatory cascade that leads to myelin destruction, others maintain that a viral agent may have a direct or indirect role in the pathogenesis of multiple sclerosis. The concept that the immune system contributes to the tissue destruction in multiple sclerosis is generally accepted; however, the debate about cause versus consequence of the pathologic process remains unresolved, as does the identification of the initial event or focus of the damage. Electron microscopic studies have disclosed evidence of remyelination (albeit often incomplete) in lesions of multiple sclerosis. Enhanced understanding of the factors limiting remyelination could help formulate strategies to promote repair. By innovative experimental design and application of available molecular techniques, the answers to these questions may provide insights on how to prevent or treat multiple sclerosis.

The influence of clinical relapses and steroid therapy on the development of Gd-enhancing lesions: a longitudinal MRI study in relapsing-remitting multiple sclerosis patients

Fifty-three patients with relapsing-remitting multiple sclerosis who had monthly Gd (gadolinium) enhanced MRI (Magnetic Resonance Imaging) and clinical evaluation, were divided into two subgroups: 1) patients with a clinical relapse, treated with IVMP (intravenous methylprednisolone) and at least one enhancing lesion on MRI. 2) patients who did not have a clinical relapse but with at least one enhancing lesion on MRI. In group 1, we evaluated the number and volume of enhancing lesions on the scan before and three scans after IVMP therapy; in group 2, we considered the first scan with enhancing lesions and the subsequent three scans. The mean number and volume of enhancing lesions on the first scan was significantly higher in patients with clinical relapse compared to patients without clinical relapse. In group 1, we found a consistent reduction in the first scan following steroid treatment which returned to initial levels at the following scan. Both volumetric and numerical evaluation are appropriate MRI outcome measures in monitoring therapeutic trials.

Magnetic resonance imaging changes with recombinant human interferon-beta-1a: a short term study in relapsing-remitting multiple sclerosis

OBJECTIVE

To evaluate whether recombinant human interferon-beta-1a significantly affects disease activity as measured by a reduction in the number and volume of Gd enhancing lesions on monthly MRI. The study also evaluated the effect on six-monthly T2 weighted abnormality and relapse frequency.

METHODS

After a baseline scan and a six month pretreatment period, 68 patients were randomly assigned to receive either 3 MIU or 9 MIU of interferon-beta-1a by subcutaneous injection three times a week for six months. All patients were examined by Gd enhanced MRI every month in both pretreatment and treatment periods. The evaluation of Gd enhancing lesions was performed blind at the end of the study.

RESULTS

The mean number of Gd enhancing lesions was higher during the pretreatment period than during treatment. This difference was statistically significant for the two different dose subgroups (3.5 v 1.8, P < 0.001 for the 3 MIU group and 2.4 v 0.9, P < 0.001 for the 9 MIU group, corresponding to a reduction of 49% and 64% respectively). The mean volume of Gd enhancing lesions also significantly decreased by 61% (3 MIU group) and 73% (9 MIU group). These reductions were evident only after the first month of treatment. The six-monthly rate of new lesions as seen in T2 weighted images showed a similar trend of reduction with treatment (65% and 70% respectively). Lesion volume on T2 scans significantly increased during the pretreatment period whereas it remained almost stable during the treatment period in both groups. Clinical relapse rate was significantly reduced by treatment (53% for the 3 MIU group, P < 0.001; 69% for the 9 MIU group, P < 0.001).

CONCLUSION

Interferon-beta-1a seemed effective in reducing disease activity in relapsing-remitting multiple sclerosis at both the doses used.

Partial inhibition of AT-EAE by an antibody to ICAM-1: clinico-histological and MRI studies

The role of quantitative proton magnetic resonance imaging (MRI) for the evaluation of immunopathological lesions in the CNS was studied in adoptively transferred experimental allergic encephalomyelitis (AT-EAE). We utilized a recently established treatment model, inhibition of the cell adhesion molecule ICAM-1 by the monoclonal antibody 1A-29. The animals were scanned on days 3, 5 and 7 after injection of encephalitogenic T-cells, before and after bolus injection of Gd-DTPA by performing T1-measurements to assess the integrity of the blood-brain barrier (BBB). On day 7, immunohistochemistry was performed looking for T-cells, activated macrophages, and albumin staining. There was clinical evidence of partial inhibition of AT-EAE in rats treated with antibodies against ICAM-1. This finding was in line with a significantly reduced number of T-cells in the medulla. However, the number of activated macrophages and the distribution of albumin did not differ from untreated AT-EAE animals. The histological findings are in agreement with the MRI data before and after Gd-DTPA injection which were similar in treated and untreated AT-EAE rats on day 3 and 5. On day 7 after Gd-DTPA injection there was evidence of a delayed breakdown of the BBB in the treated rats. The observation of a dissociation of clinical and MRI findings, especially evidence of Gd-enhancement despite clinical improvement, may be important in the context of interpreting MRI studies in MS patients in treatment trials.

High-dose contrast-enhanced MRI in multiple sclerosis

Contrast-enhanced MRI is effective for assessing disease activity in multiple sclerosis (MS) and may provide an outcome measure for testing the efficacy of treatment in clinical trials. To compare the sensitivity of high-dose gadolinium-HP-DO3A with that of a standard dose of gadolinium-DTPA, we studied 16 patients with relapsing-remitting MS in the acute phase of the disease. Each underwent two MRI examinations within at most 48 h. The initial MRI study was with a standard dose of gadolinium-DTPA (0.1 mmol/kg), and the second one an experimental dose of gadolinium-HP-DO3A (0.3 mmol/kg). No adverse effects were attributed to the contrast media. The high-dose study revealed more enhancing lesions than the standard-dose study (56 vs 38). This difference was found to be more relevant for infratentorial and small lesions. Furthermore, with the higher dose, there was a marked qualitative improvement in the visibility and delineation of the lesions.

Evidence of persistent blood-brain barrier abnormalities in chronic-progressive multiple sclerosis

Brain capillaries were analyzed morphometrically for alterations in organelle distribution and density in biopsy samples of central nervous system tissue from seven patients diagnosed as having chronic progressive multiple sclerosis. Data were expressed as percentage of endothelial cytoplasm occupied by the respective organelles. The density of pinocytotic vesicles in endothelium ranged from 0.53% within normal-appearing parenchyma to 1.2% in gliotic areas. For mitochondria the values ranged from 10.87% in normal areas to 4.72% in the same respective samples. Thus, an inverse correlation between vesicular and mitochondrial content was observed. These findings suggest that endothelial cells in gliotic areas are similar to endothelial cells of the systemic circulation in their mitochondrial content and pinocytotic activity. Interendothelial junctions in capillaries of all areas examined appeared normal. Additional evidence for a continuous blood-brain barrier anomaly in multiple sclerosis was the accumulation of perivascular fibrin, suggesting an increase in microvascular permeability. Perivascular collagen deposits, degenerative changes in pericytes and astrocytic swelling were also indicators of an increase in blood-brain barrier permeability. Taken together with previous data from experimental autoimmune encephalomyelitis, the present findings in chronic silent multiple sclerosis lesions suggest that central nervous system endothelial cells show persistent abnormalities of the blood-brain barrier, even in the absence of active inflammation.

A case with symptoms of vestibular neuronitis caused by an intramedullary lesion

We report on a patient with an intramedullary lesion who showed only symptoms of so-called vestibular neuronitis. From the neurological aspects and MRI findings, the lesion was thought to be localized to the vestibular nerve in the pons. Cerebrospinal fluid testing and MRI findings suggested a diagnosis of multiple sclerosis (MS), although the clinical features were not compatible with MS. This case may shed some light on the aetiology of vestibular neuronitis.

A controlled trial of mitoxantrone in multiple sclerosis: serial MRI evaluation at one year

We present the results of a randomized double-blinded placebo controlled, multicenter trial, of low-dose mitoxantrone (MX), after one year, in 25 patients with relapsing-remitting multiple sclerosis, who had serial enhanced magnetic resonance imaging (MRI). Treatment groups were balanced for age, gender, duration of illness and neurological disability. Five of the 13 MX patients and 10 of the 12 placebo patients had exacerbations during treatment (p < 0.02). The mean change in the extended disability status scale was not significantly different between the MX and placebo treatment groups. Serial Gadolinium-DTPA enhanced MRI detected no significant difference between the MX treated and placebo groups in the mean total number of new, enlarging, or Gadolinium-DTPA enhancing lesions; there was a trend toward a reduction of new, enlarging and Gadolinium-DTPA enhancing lesions in MX patients. Despite this ameliorating effect, the results indicate that serial Gadolinium-DTPA enhanced MRI, performed over one year in a limited number of patients, could not provide conclusive evidence for a role of MX therapy in relapsing-remitting multiple sclerosis.

The role of trauma in the pathogenesis of multiple sclerosis: a review

The suggestion that an alteration of the blood-brain barrier (BBB) is an obligatory step in the pathogenesis of the multiple sclerosis (MS) lesion has been amply confirmed by innumerable magnetic resonance scans. There also exists a large body of clinical, neuropathologic, neuropsychologic, radiologic and experimental evidence that shows that trauma, in particular mild concussive injury to the head, neck or upper back, thus impinging on the brain and spinal cord, may result in an increase in BBB permeability. It is only logical therefore to infer that when such mild trauma to those parts of the body affects MS patients, the resulting alteration of the BBB leads to the formation of new lesions or the enlargement and activation of old ones. In such situations trauma acts as a facilitator of the postulated but still not fully understood pathogenetic mechanism of lesion formation. Because of the extremely poor correlation between site and size of the lesions and clinical manifestations of MS, one cannot expect that every episode of trauma will result in the appearance of new symptoms in an hitherto asymptomatic individual, or the recurrence of old symptoms in an MS patient. It is inappropriate to attempt to prove or disprove a causal relationship between physical trauma and MS exacerbations or clinical onset by means of epidemiologic studies. The unpredictability and variability of the clinical manifestations of the disease, the differences in the genetic and immunologic backgrounds of individuals, as well as in their degree of clinical and pathologic involvement and level of activity, render such investigations pointless.

MRI in acute disseminated encephalomyelitis

A retrospective analysis of CT and MRI studies in 12 patients with a clinical diagnosis of acute disseminated encephalomyelitis (ADEM) was performed. MRI was the definitive modality for the assessment of the lesions of ADEM: all patients had abnormalities consistent with the clinical diagnosis. Ten had abnormalities in the brain, three spinal cord lesions, and three showed evidence of optic neuritis. CT was normal in 6 of the 7 patients in which it was performed.

Ultrastructure of multiple sclerosis

The electron microscopic features of 11 stereotaxic brain biopsies that demonstrated inflammatory primary demyelination consistent both morphologically and clinically with multiple sclerosis are addressed. Degeneration of inner oligodendroglial loops and uniform widening of inner myelin lamellae antedated complete destruction of myelin sheaths. Perivascular lymphocytes, macrophages, and plasma cells were in intimate contact with myelin sheaths. Astrocytes proliferated even away from demyelinated areas. In areas of chronic, established demyelination, oligodendrocyte numbers were greatly decreased, and fields of completely demyelinated axons were seen among astrocytic processes. Axonal injury, evidenced by the formation of axonal swellings, was apparent in maximally affected areas. At the edge of acute lesions with demyelinated axons, oligodendrocytes were preserved morphologically. Thinly myelinated axons indicative of central nervous system-type remyelination by oligodendrocytes were observed primarily at the edges of plaques. An unusual inclusion observed in presumed macrophages was "polelike" bodies 0.04- to 0.7-microns thick. Linearly arrayed, their presumably proteinaceous crystalline substance was moderately electron-dense. Many were membrane-bound and appeared to arise from the endoplasmic reticulum. We conclude that disturbance of the myelinating function of oligodendrocytes may be a critical event in the pathogenesis of multiple sclerosis.

Serial study of neuropsychological performance and gadolinium-enhanced MRI in MS

Many multiple sclerosis patients show cognitive decline, although no definite correlation between brain demyelination at MRI and neuropsychological performance has been found so far. We submitted a group of nine relapsing-remitting, mildly disabled patients to both serial gadolinium-DTPA enhanced MRI and neuropsychological evaluation in a follow up period of three months. Despite the great variability in acute lesions' load, no overall decline in test, performance was found. Furthermore, in selected cases whose test scores declined at follow up, no concordance with the new lesion load was found.

Serial cranial and spinal cord magnetic resonance imaging in multiple sclerosis

Twenty-nine mildly disabled patients with multiple sclerosis underwent serial clinical and magnetic resonance imaging (MRI) evaluations (pre- and postgadolinium cranial and spinal cord MRI) on at least 3 occasions at 13-week intervals and during periods of suspected relapse. Using clinical judgment of the presence of recent active disease as the gold standard, combined MRI studies confirmed the clinical impression of active disease in 93% of follow-up visits (sensitivity) and the absence of active MS in 63% of follow-up visits (specificity). None of the cranial and spinal MRI-detected abnormalities disappeared. Gadolinium administration particularly increased the yield of spinal MRI. Cranial MRI alone detected 80% of the MRI-active visits. Clinical and MRI concordance was significantly better for the presence of recent disease activity than for the anatomical localization of the presumed site of activity. MRI evidence of apparent ongoing disease activity was seen more frequently in patients believed to have active multiple sclerosis in the preceding year (13 of 21) than in patients who had been in clinical remission for at least the 2 preceding years (2 of 8). Although clinical evidence of new disease activity was much less common in patients with active, chronic-progressive disease (1 of 8) than in patients with active, relapsing disease (9 of 13), the proportion of patients with either infrequent relapses, frequent relapses, or slow chronic-progressive disease in the preceding year in whom MRI activity developed and the pattern of this new MRI activity was similar between these types of active patients.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of high-dose methylprednisolone on gadolinium-enhanced magnetic resonance imaging and cerebrospinal fluid measurements in multiple sclerosis

Blood-brain barrier (BBB) disruption is probably the first event in the lesion development in multiple sclerosis (MS). This stage can be visualized by gadolinium-enhanced magnetic resonance (MR) imaging of the brain. Serial MR imaging studies have indicated a continuous spectrum of disease activity with waxing and waning of acute lesions, even in clinically stable MS patients. High-dose intravenous methylprednisolone (MP) has a beneficial clinical effect; reduces gadolinium enhancement, indicating improvement of BBB integrity; and, in MS patients, decreases intrathecal immunoglobulin synthesis with reduction of cerebrospinal fluid (CSF) myelin basic protein (MBP). A correlative triad is noted between gadolinium enhancement, clinical improvement, and decrease of CSF MBP following MP treatment, indicating a relationship between restoration of BBB integrity, clinical improvement and decrease of myelin breakdown. It is not clear whether MP interferes primarily with the process of demyelination or reacts non-specifically with its mediators.

Metabolically dependent blood-brain barrier breakdown in chronic relapsing experimental allergic encephalomyelitis

We have studied chronic relapsing experimental allergic encephalomyelitis (CREAE), a model of immune-mediated demyelination, using gadolinium (Gd)-enhanced magnetic resonance imaging in vivo and the blood-brain barrier (BBB) markers, lanthanum nitrate and Gd nitrate, histologically. In regions of the spinal cord showing Gd enhancement, there was evidence for vesicular transport as a mechanism of BBB breakdown in CREAE, shown by an increased number of endothelial vesicles containing lanthanide (lanthanum or Gd, whichever had been perfused) and deposition of tracer in the perivascular space; tight interendothelial junctions remained intact. Prior perfusion with 2,4-dinitrophenol, a metabolic inhibitor, suppressed the appearance of endothelial vesicles containing lanthanide and tracer in the perivascular space. We conclude that an important contribution to BBB breakdown in CREAE is mediated by a metabolic change in the endothelial cells associated with increased vesicular transport.

Proton MR spectroscopy of gadolinium-enhanced multiple sclerosis plaques

Magnetic resonance (MR) imaging and proton MR spectroscopy were performed in 14 patients with clinically definite multiple sclerosis (MS). Prominent resonances in the 0.5-2.0-ppm region were seen in the spectra of six of nine gadopentetate dimeglumine-enhanced plaques in seven patients. These resonances were presumed to originate in lipids and other myelin breakdown products. Similar resonances were detected in only seven of 21 unenhancing plaques. The more frequent presence of such signals in the gadolinium-enhanced regions indicates that myelin breakdown is often associated with the inflammation that occurs in early stages of MS plaque evolution. It remains uncertain, however, whether active inflammation as indicated by gadolinium enhancement is a necessary precursor of myelin breakdown as detected at MR spectroscopy. Quantitative spectral analysis did not indicate statistically significant differences in N-acetyl aspartate and choline levels relative to creatine plus phosphocreatine between healthy volunteers and MS patients.

Neurogenic bladder due to peripheral neuropathy and a visual disturbance in an elderly man with systemic lupus erythematosus

A 63 year old man with central nervous system lupus with a neurogenic bladder and visual disturbance is described. The diagnosis of neurogenic bladder, attributed to peripheral neuropathy, was made on the basis of cystometrography and clinical symptoms. A brain magnetic resonance imaging scan showed gliosis along the cerebral vessels and the optic nerve. This case shows that systemic lupus erythematosus can be accompanied by a peripheral neurogenic bladder and visual disturbance, and that these symptoms may not improve despite the amelioration of other lupus symptoms on treatment with steroids.

Proton magnetic resonance spectroscopic imaging for metabolic characterization of demyelinating plaques

We used proton magnetic resonance (MR) spectroscopic imaging to determine the serial changes in MR signals from choline, creatine, lactate, and N-acetylaspartate in and around a large demyelinating lesion followed over a period of 8 months. Elevated lactate and choline signals were observed at the first examination 3 days after the onset of symptoms. Reduced N-acetylaspartate signals were observed a few days afterward. The abnormal metabolite signals varied in different regions of the lesion and extended beyond the borders of abnormal signal intensity seen on conventional MR imaging (MRI). On the last examination at 8 months when the lesion appeared much smaller on MRI, choline signals from the center of the lesion were still high, but were falling. Choline signals outside the lesion on MRI had returned to normal as had lactate signals everywhere. Importantly, there was no recovery of N-acetylaspartate signals in or adjacent to the lesion on MRI. This serial study demonstrates the potential of MR spectroscopic imaging for characterizing the chemical pathological evolution of demyelinating lesions in ways that conventional MRI cannot. We propose that abnormal signals from choline can indicate recent regional demyelination, while persistent abnormal signals from N-acetylaspartate can provide an index of irreversible damage in the nervous system.

Multiple sclerosis. Observations and reflections--a personal memoir

The pathogenesis of MS has become better understood as a result of recent advances in several areas, particularly in epidemiology and neuro-imaging. A number of epidemiologically based conclusions need to be revised, most importantly the putative direct relationship between prevalence and latitude, and the concept that epidemics of MS have occurred in some parts of the world. It is now clear that genetic factors play a much more important role in the genesis of the disease than environmental factors, although the latter cannot be ignored. The existence of a genetic susceptibility, coupled with either protective or enhancing factors, which may be genetic or environmental, is recognized as being most important in individuals of northern European origin. Much evidence suggests that the disease is initiated by a viral illness (or possibly a vaccination) at some time before puberty. This first antigenic challenge results in the development of what is called the "MS trait", a systemic condition that may never develop into the actual disease and may be observed as well in the unaffected siblings of MS patients. The trait is almost certainly a manifestation of an alteration of the immune system; its most important effect is to render the blood-brain barrier more vulnerable to a variety of agents that will increase its permeability. In order for MS to involve the central nervous system, loss of integrity of the blood-brain barrier is an obligatory step, an observation which has now been amply confirmed by neuroimaging studies. This effect upon the blood-brain barrier appears to be non-specific, since it may result from such diverse causes as a viral infection, a vaccination, or mild trauma. Edema and inflammation follow, but myelinoclasia is not always a consequence; thus plaque formation may not occur and the initial lesion of MS may disappear without leaving a trace. The actual mechanism of myelinoclasia, and the role played in it by lymphocytes, remain unknown. Although the disease does affect the central nervous system, it may remain asymptomatic for a long time after the actual plaque is formed, even for the person's entire life.

Localized in vivo proton spectroscopy in the brain of patients with multiple sclerosis

Localized proton spectroscopy was performed in 15 patients with acute or chronic multiple sclerosis (MS). Some of the patients were investigated serially, being given a total of 22 spectroscopic investigations. Resonances corresponding to free lipids were observed in six plaques. This was distinctly seen in two plaques at Days 70 and 85 after the occurrence of the plaques. A lesser content of lipids in plaques was observed as early as Day 10 and as late as nearly 1 year after occurrence. The relative concentration of N-acetyl asparate (NAA) was significantly lower in patients than in controls, and the relative concentration of choline (Cho) was significantly higher in patients than in controls. These differences were most pronounced in older plaques. MR spectroscopic demonstration of lipids in a MS plaque probably reflects disintegration of myelin, and a decreased NAA/Cho ratio may be related either to gliosis or to axonal degeneration, which sometimes occurs in longstanding MS.

Serial gadolinium-enhanced magnetic resonance imaging scans in patients with early, relapsing-remitting multiple sclerosis: implications for clinical trials and natural history

Six patients with early, mild, relapsing-remitting multiple sclerosis were studied with monthly gadolinium-enhanced magnetic resonance imaging scans for 8 to 11 months. Numerous enhancing lesions were observed irrespective of clinical activity. Four of the 6 patients had one or more enhancing lesions present on each examination. The other 2 patients had enhancing lesions noted in 7 and 9 of 11 months. In contrast, only two clinical exacerbations were observed during the study period. Neither the exacerbations nor other changes in symptoms or signs correlated with occurrence of the enhancing lesions. Enhancement generally persisted for less than 1 month. The opening of the blood-brain barrier as reflected by gadolinium enhancement on magnetic resonance imaging may represent ongoing disease activity in patients with mild, relapsing-remitting multiple sclerosis who are clinically stable. The frequency of these lesions appears to be sufficient to use as an outcome measure in clinical trials testing clinical efficacy in patients with early, relapsing-remitting multiple sclerosis.

Preliminary clinical trial of gadodiamide injection: a new nonionic gadolinium contrast agent for MR imaging

The safety and efficacy of a newly developed intravenous formulation of the nonionic contrast agent gadolinium diethylenetriaminepentaacetic acid-bis(methylamide), formulated as gadodiamide injection, was investigated. In 30 patients who underwent spin-echo magnetic resonance (MR) imaging before and after contrast agent enhancement, the enhanced images had characteristics judged similar to those of images enhanced by means of available gadolinium compounds. In 15 patients, contrast agent administration was of major diagnostic help, either revealing lesions not apparent without enhancement or providing important lesion characterization. In 12 patients, the lack of abnormal enhancement patterns was important in excluding the presence of disease. In three patients, the contrast agent did not provide information additional to that obtained with the unenhanced T1- and T2-weighted images. No clinically significant changes were observed in vital signs, neurologic status, or laboratory results. The authors conclude that, in this limited series, gadodiamide injection proved to be a safe and useful MR imaging contrast agent for evaluation of the central nervous system and surrounding structures.

Quantitation of blood-brain barrier defect by magnetic resonance imaging and gadolinium-DTPA in patients with multiple sclerosis and brain tumors

In this study quantitation of the degree of deficiency of the blood-brain barrier (BBB) in patients with multiple sclerosis or brain tumors, by using MRI, is shown to be possible. As a measure of permeability of the BBB to Gadolinium-DTPA (Gd-DTPA) the flux per unit of distribution volume per unit of brain mass was used. This quantity was found by introducing the longitudinal relaxation rate (R1) as a measure of concentration of Gd-DTPA in the brain tissue in the mathematical model for the transcapillary transport over the BBB. High accordance between the observed data points and the model was found, and the results were comparable to results obtained from similar studies using positron emission tomography. The improved possibility of quantitating the defect of the BBB by MRI may give new information about pathogenesis or etiology, and leads to improved methods in monitoring the efficacy of treatments in intracranial diseases.

The prospective evaluation of Gd-DTPA in 225 consecutive cranial cases: adverse reactions and diagnostic value

This prospective study evaluates two facets of gadopentetate dimeglumine (Gd-DTPA) enhanced MR imaging in 225 consecutive cranial cases in patients greater than 18 years of age: (i) patient and physician perception of adverse reactions, (ii) diagnostic value of the Gd-DTPA enhanced exam. The 225 cases included 173 head cases, 27 IAC cases, and 25 sella cases. Forty-six percent of the cases were abnormal excluding cases of mild atrophy and ischemic white matter disease judged to be related to aging and not pertinent to the patient's presenting complaint. Concerning adverse reactions, 83% of patients had no complaints. Five percent of the patients had reactions that were judged by the physician to be related to Gd-DTPA. All reactions were minor and required no therapy. In a subset of exams (115) that were blindly and independently interpreted by two board-certified, fellowship-trained radiologists, the Gd-DTPA-enhanced exam resulted in a change in diagnosis in 5%-8% of cases. Additionally, a major benefit of Gd-DTPA administration was the increased diagnostic confidence afforded by the addition of a contrast enhanced exam due to improved lesion characterization and exclusion of additional significant intracranial pathology. In 52%-69% of the abnormal cases, Gd-DTPA provided additional diagnostic information and in 26%-39% the absence of enhancement aided in interpretation. The Gd-DTPA-enhanced exam aids in the diagnosis and characterization of neoplastic disease, acoustic neuroma, subacute infarction, inflammatory disease (meningeal and parenchymal), and certain vascular abnormalities.