Volumes of brain atrophy and plaques correlated with neurological disability in secondary progressive multiple sclerosis

MRI features and disability in multiple sclerosis: A systematic review and meta-analysis

BACKGROUND

In this systematic review and meta-analysis, we aimed to investigate the correlation between disability in patients with Multiple sclerosis (MS) measured by the Expanded Disability Status Scale (EDSS) and brain Magnetic Resonance Imaging (MRI) features to provide reliable results on which characteristics in the MRI can predict disability and prognosis of the disease.

METHODS

A systematic literature search was performed using three databases including PubMed, Scopus, and Web of Science. The selected peer-reviewed studies must report a correlation between EDSS scores and MRI features. The correlation coefficients of included studies were converted to the Fisher's z scale, and the results were pooled.

RESULTS

Overall, 105 studies A total of 16,613 patients with MS entered our study. We found no significant correlation between total brain volume and EDSS assessment (95 % CI: -0.37 to 0.08; z-score: -0.15). We examined the potential correlation between the volume of T1 and T2 lesions and the level of disability. A positive significant correlation was found (95 % CI: 0.19 to 0.43; z-score: 0.31), (95 % CI: 0.17 to 0.33; z-score: 0.25). We observed a significant correlation between white matter volume and EDSS score in patients with MS (95 % CI: -0.37 to -0.03; z-score: -0.21). Moreover, there was a significant negative correlation between gray matter volume and disability (95 % CI: -0.025 to -0.07; z-score: -0.16).

CONCLUSION

In conclusion, this systematic review and meta-analysis revealed that disability in patients with MS is linked to extensive changes in different brain regions, encompassing gray and white matter, as well as T1 and T2 weighted MRI lesions.

The signal intensity variation of multiple sclerosis (MS) lesions on magnetic resonance imaging (MRI) as a potential biomarker for patients' disability: A feasibility study

Introduction

Although many lesion-based MRI biomarkers in multiple sclerosis (MS) patients were investigated, none of the previous studies dealt with the signal intensity variations (SIVs) of MS lesions. In this study, the SIVs of MS lesions on direct myelin imaging and standard clinical sequences as possible MRI biomarkers for disability in MS patients were assessed.

Methods

Twenty seven MS patients were included in this prospective study. IR-UTE, FLAIR, and MPRAGE sequences were employed on a 3T scanner. Regions of interest (ROIs) were manually drawn within the MS lesions, and the cerebrospinal fluid (CSF) and signal intensity ratios (SIR) were calculated from the derived values. Variations coefficients were determined from the standard deviations (Coeff 1) and the absolute differences (Coeff 2) of the SIRs. Disability grade was assessed by the expanded disability status scale (EDSS). Cortical/gray matter, subcortical, infratentorial, and spinal lesions were excluded.

Results

The mean diameter of the lesions was 7.8 ± 1.97 mm, while the mean EDSS score was 4.5 ± 1.73. We found moderate correlations between the EDSS and Coeff 1 and 2 on IR-UTE and MPRAGE images. Accordingly, Pearson's correlations on IR-UTE were R = 0.51 (p = 0.007) and R = 0.49 (p = 0.01) for Coeff 1 and 2, respectively. For MPRAGE, Pearson's correlations were R = 0.5 (p = 0.008) and R = 0.48 (p = 0.012) for Coeff 1 and 2, respectively. For FLAIR, only poor correlations could be found.

Conclusion

The SIVs of MS lesions on IR-UTE and MPRAGE images, assessed by Coeff 1 and 2, could be used as novel potential MRI biomarkers for patients' disability.

A brain extraction algorithm for infant T2 weighted magnetic resonance images based on fuzzy c-means thresholding

It is challenging to extract the brain region from T2-weighted magnetic resonance infant brain images because conventional brain segmentation algorithms are generally optimized for adult brain images, which have different spatial resolution, dynamic changes of imaging intensity, brain size and shape from infant brain images. In this study, we propose a brain extraction algorithm for infant T2-weighted images. The proposed method utilizes histogram partitioning to separate brain regions from the background image. Then, fuzzy c-means thresholding is performed to obtain a rough brain mask for each image slice, followed by refinement steps. For slices that contain eye regions, an additional eye removal algorithm is proposed to eliminate eyes from the brain mask. By using the proposed method, accurate masks for infant T2-weighted brain images can be generated. For validation, we applied the proposed algorithm and conventional methods to T2 infant images (0–24 months of age) acquired with 2D and 3D sequences at 3T MRI. The Dice coefficients and Precision scores, which were calculated as quantitative measures, showed the highest values for the proposed method as follows: For images acquired with a 2D imaging sequence, the average Dice coefficients were 0.9650 ± 0.006 for the proposed method, 0.9262 ± 0.006 for iBEAT, and 0.9490 ± 0.006 for BET. For the data acquired with a 3D imaging sequence, the average Dice coefficient was 0.9746 ± 0.008 for the proposed method, 0.9448 ± 0.004 for iBEAT, and 0.9622 ± 0.01 for BET. The average Precision was 0.9638 ± 0.009 and 0.9565 ± 0.016 for the proposed method, 0.8981 ± 0.01 and 0.8968 ± 0.008 for iBEAT, and 0.9346 ± 0.014 and 0.9282 ± 0.019 for BET for images acquired with 2D and 3D imaging sequences, respectively, demonstrating that the proposed method could be efficiently used for brain extraction in T2-weighted infant images.

Correlation between the clinical disability and T1 hypointense lesions' volume in cerebral magnetic resonance imaging of multiple sclerosis patients: A systematic review and meta-analysis

BACKGROUND

To evaluate the correlation between T1 hypointense lesions' mean volume on cerebral MRI with disability level of patients with multiple sclerosis.

METHODS

We included studies testing the desired outcome in adult patients diagnosed with RRMS or SPMS. In Feb 2021, we searched PubMed, Embase, CENTRAL, and Web of Science to find relevant studies. All included studies were assessed for the risk of bias using a tailored version of the Quality in Prognosis Studies (QUIPS) tool. Extracted correlation coefficients were converted to the Fisher's z scale, and a meta-analysis using a random-effects model was performed on the results.

RESULTS

We included 27 studies (1919 participants). Meta-analysis revealed a correlation coefficient of 0.32 (95% CI 0.26-0.37) between T1 hypointense lesions' mean volume and EDSS score.

DISCUSSION

The correlation between T1 hypointense lesions' mean volume and EDSS was interpreted as low to slightly moderate. The certainty of the evidence was judged to be high.

Estrogen- and progesterone-mediated structural neuroplasticity in women: evidence from neuroimaging

There is substantial evidence that the ovarian sex hormones, estrogen and progesterone, which vary considerably over the course of the human female lifetime, contribute to changes in brain structure and function. This structured, quantitative literature reviews aims to summarize neuroimaging literature addressing physiological variation in brain macro- and microstructure across an array of hormonal transitions including the menstrual cycle, use of hormonal contraceptives, pregnancy, and menopause. Twenty-five studies reporting structural neuroimaging of women, addressing variation across hormonal states, were identified from a structured search of PUBMED and were systematically reviewed. Although the studies are heterogenous with regard to methodology, overall the results point to overlapping areas of hormone related effects on brain structure particularly affecting the structures of the limbic system. These findings are in keeping with functional data that point to a role for estrogen and progesterone in mediating emotional processing.

Association between MRI parameters and the MS severity scale: a 12 year follow-up study

BACKGROUND

Several magnetic resonance imaging (MRI) parameters are known to be associated with short-term outcome in multiple sclerosis (MS) patients. MS-related disability typically progresses over decades, stressing the need for longer follow-up studies. Until now, these studies are relatively sparse and, therefore, the predictive value of MRI parameters for clinical disability remains largely unknown.

OBJECTIVE

To assess the predictive value of brain MRI parameters, which are obtained during the first 3.3 years of the study for overall disease severity as measured by the MS Severity Score (MSSS) after 12.2 years follow-up.

METHODS

Forty-six MS patients were included in the study. MRI parameters included both lesion loads and atrophy measures. Average and change parameters were calculated for MRI parameters and subsequently used as independent variables in regression models, while MSSS was the dependent variable.

RESULTS

Follow-up (FU) was obtained in 43/46 patients (94%) and median expanded disability status scale (EDSS) score increased significantly from 2.5 to 4.0. At last FU median MSSS was 4.3 (range 2.2-6.9). In univariate analyses, both change and cross-sectional T1-hypointense lesion load and ventricular atrophy measures were associated with MSSS. A multiple regression model included the change parameter of hypointense T1-lesion load (BHLL). This model explained 20% of variance in MSSS, which increased to 34% when type of disease (relapsing remitting or secondary progressive), age, and sex were entered additionally.

CONCLUSION

MRI measures of axonal loss are associated with higher overall disease severity in MS patients.

Cerebral MRI abnormalities and their association with neuropsychiatric manifestations in SLE: a population‐based study

OBJECTIVE

To evaluate the volumetric brain magnetic resonance imaging (MRI) findings in a population-based sample of systemic lupus erythematosus (SLE) patients and to detect a possible relationship between cerebral MRI abnormalities and specific neuropsychiatric (NP) manifestations.

METHODS

The study population consisted of patients with SLE (n = 43) in Pirkanmaa Health Care District, Finland and of a sex- and age-stratified reference group from the general population (n = 43). In addition to a clinical neurological investigation, all subjects received a detailed neuropsychological assessment and an MRI study. Volumetric measures of cerebral atrophy as well as T1- and T2-weighted lesions were obtained. SLE activity was assessed by the European Consensus Lupus Activity Measure (ECLAM) index, and accumulated NP abnormalities were measured by the Systemic Lupus International Collaborating Clinics (SLICC) damage index. A cumulative lifetime dose of glucocorticoids was determined from the patientrecords.

RESULTS

Compared with controls, SLE patients had increased volumes of both T1- and T2-weighted lesions (p = 0.019 and p<0.0001, respectively) and increased cerebral atrophy (p<0.001). All the measured MRI parameters were statistically significantly higher in NPSLE than in non-NPSLE patients. In SLE patients, cerebral atrophy was associated with cognitive dysfunction, epileptic seizures, and cerebrovascular disease; T1-weighted lesions were associated with epileptic seizures and T2-weighted lesions with cognitive dysfunction. All MRI parameters correlated significantly with the SLICC index but not with the ECLAM index. A positive correlation was found between a cumulative dose of glucocorticoids and cerebral atrophy in SLE patients.

CONCLUSION

MRI abnormalities, including brain atrophy and T1- and T2-weighted lesions, are significantly more common in patients with SLE than in the general population and they are related to specific NP manifestations. Our findings also provide support for the organic aetiology of cognitive dysfunction in SLE.

[Multiple sclerosis]

Multiple sclerosis is the most common chronic inflammatory disease of myelin with interspersed lesions in the white matter of the central nervous system. Magnetic resonance imaging (MRI) plays a key role in the diagnosis and monitoring of white matter diseases. This article focuses on key findings in multiple sclerosis as detected by MRI.

Once-weekly 22microg subcutaneous IFN-beta-1a in secondary progressive MS: a 3-year follow-up study on brain MRI measurements and serum MMP-9 levels

OBJECTIVE

To study the effect of weekly injected subcutaneous interferon (IFN)-beta-1a 22 microg on the extent of brain lesions on magnetic resonance imaging (MRI) and the level of serum matrix metalloproteinase (MMP)-9 in patients with secondary progressive multiple sclerosis (SPMS).

SUBJECTS AND METHODS

All the 28 Finnish patients participating in the Nordic multicentre trial on the clinical efficacy of weekly IFN-beta-1a (Rebif) 22 microg in SPMS were studied neurologically and by volumetric MRI during a 3-year follow-up. The levels of MMP-9 in serum were measured over the 3-year study.

RESULTS

There was no obvious effect on the number of contrast medium-enhancing lesions, the volume of T1 or T2 lesions or level of serum MMP-9, nor was any effect detected on the relapse rate and the Expanded Disability Status Scale (EDSS). Brain atrophy progression was not affected by the treatment.

CONCLUSION

The lack of effect on MRI, clinical outcomes or the levels of MMP-9 indicates that subcutaneous administration of low-dose low-frequency IFN-beta-1a is insufficient in controlling either the inflammatory constitutes or the neurodegenerative changes of advanced SPMS.

Cell surface adhesion molecules and cytokine profiles in primary progressive multiple sclerosis

OBJECTIVE

We evaluated the utility of adhesion molecule (AM) and cytokine/chemokine expressions in blood and cerebrospinal fluid (CSF) as markers of disease activity in primary progressive multiple sclerosis (PPMS).

METHODS

The expressions of AMs and the levels of 17 cytokines in patients with PPMS (n = 25) were compared with those in secondary progressive MS (SPMS) (n = 18) and controls (n =11) and correlated with the volumes of focal and atrophic changes on MRI.

RESULTS

The expressions of very late activation antigen 4 (VLA-4), lymphocyte function-associated antigen 1 (LFA-1) and intercellular adhesion molecule 1 (ICAM-1) in blood and CSF were higher in PPMS than in controls. Comparison between PPMS and SPMS showed higher levels of ICAM-1 in blood and CSF in PPMS, while the level of the vascular adhesion molecule (VCAM-1) was higher only in blood. There was no difference in the levels of cytokines in serum or CSF between PPMS and SPMS or controls, but evidence suggesting intrathecal synthesis of interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) was found in PPMS. The expressions of CSF VLA-4 in PPMS correlated with the total volume of cerebral lesions and the number of diffuse brain lesions in MRI, while the amount of LFA-1 in CSF correlated with the number of spinal T2 lesions. The level of serum MIP-1beta correlated with the T2 lesion load and EDSS score in PPMS.

CONCLUSIONS

The upregulated expressions of AMs in blood and CSF and evidence for intrathecal synthesis of MCP-1 and IL-8 in PPMS indicate the importance of inflammatory changes in the pathogenesis of PPMS.

Cerebellar cortical atrophy in experimental autoimmune encephalomyelitis

Brain atrophy measured by MRI is an important correlate with clinical disability and disease duration in multiple sclerosis (MS). Unfortunately, neuropathologic mechanisms which lead to this grey matter atrophy remain unknown. The objective of this study was to determine whether brain atrophy occurs in the mouse model, experimental autoimmune encephalomyelitis (EAE). Postmortem high-resolution T2-weighted magnetic resonance microscopy (MRM) images from 32 mouse brains (21 EAE and 11 control) were collected. A minimum deformation atlas was constructed and a deformable atlas approach was used to quantify volumetric changes in neuroanatomical structures. A significant decrease in the mean cerebellar cortex volume in mice with late EAE (48-56 days after disease induction) as compared to normal strain, gender, and age-matched controls was observed. There was a direct correlation between cerebellar cortical atrophy and disease duration. At an early time point in disease, 15 days after disease induction, cerebellar white matter lesions were detected by both histology and MRM. These data demonstrate that myelin-specific autoimmune responses can lead to grey matter atrophy in an otherwise normal CNS. The model described herein can now be used to investigate neuropathologic mechanisms that lead to the development of gray matter atrophy in this setting.

Magnetic resonance imaging measures of brain atrophy in multiple sclerosis

Magnetic resonance imaging (MRI) has been widely used to diagnose and monitor multiple sclerosis (MS). Although MRI-visible lesions are a key feature of MS, they are thought to correlate poorly with clinical progression. Neurodegeneration is increasingly being recognized as an important factor in the pathogenesis of MS, and MRI measures of brain atrophy have been suggested as surrogate markers of neuroaxonal loss and disease progression. This pathology may be more relevant to the progression of disability than focal inflammation. A number of MRI-based methods have been developed for the measurement of global and regional brain atrophy. Natural-history studies of MS and clinically isolated syndromes suggestive of MS have observed atrophy in these subjects above that seen in controls, over periods ranging from three months to years. Brain atrophy has also been incorporated as an outcome measure in therapeutic trials of disease-modifying treatments. This paper considers neuroaxonal loss and the pathological basis of brain atrophy, methods developed to quantify brain atrophy, the findings of natural-history and therapeutic studies, the relationship of brain atrophy to disability and cognition, and the future research directions and clinical applications of brain atrophy measurements.

Clinical-magnetic resonance imaging correlations in multiple sclerosis

Conventional magnetic resonance imaging (MRI) has routinely been used to improve the accuracy of multiple sclerosis (MS) diagnosis and monitoring, detect the effects of disease-modifying therapy, and refine the utility of clinical assessments. However, conventional MRI measures, such as the use of lesion volume and count of gadolinium-enhancing and T2 lesions, have insufficient sensitivity and specificity to reveal the true degree of pathological changes occurring in MS. Newer metrics of MRI analysis, including T1-weighted hypointense lesions (black holes) and central nervous system (CNS) atrophy measures, are able to capture a more global picture of the range of tissue alterations caused by inflammation, demyelination, axonal loss, and neurodegeneration. There is mounting evidence that these MRI measures correlate well with existing and developing neurological impairment and disability. In so doing, these MRI techniques can help elucidate the mechanisms underlying the pathophysiology and natural history of MS. The current understanding is that T1 black holes and CNS atrophy more accurately reflect the neurodegenerative and destructive components of the MS disease process. Therefore, the short and long-term studies that aim to measure the degree and severity of the neurodegenerative MS disease process should incorporate these MRI metrics as part of their standard routine MRI protocols.

The measurement and clinical relevance of brain atrophy in multiple sclerosis

Brain atrophy has emerged as a clinically relevant component of disease progression in multiple sclerosis. Progressive loss of brain tissue bulk can be detected in vivo in a sensitive and reproducible manner by MRI. Clinical studies have shown that brain atrophy begins early in the disease course. The increasing amount of data linking brain atrophy to clinical impairments suggest that irreversible tissue destruction is an important determinant of disease progression to a greater extent than can be explained by conventional lesion assessments. In this review, we will summarise the proposed mechanisms contributing to brain atrophy in patients with multiple sclerosis. We will critically discuss the wide range of MRI-based methods used to quantify regional and whole-brain-volume loss. Based on a review of current information, we will summarise the rate of atrophy among phenotypes for multiple sclerosis, the clinical relevance of brain atrophy, and the effect of disease-modifying treatments on its progression.

Measurement of Brain and Spinal Cord Atrophy by Magnetic Resonance Imaging as a Tool to Monitor Multiple Sclerosis

Evaluation of brain and spinal cord atrophy by magnetic resonance imaging (MRI) has become an increasingly important component of understanding the multiple sclerosis (MS) disease process. These destructive aspects of the disease develop early in the disease course. A growing body of data links brain and spinal cord atrophy to clinical impairment more closely than can be linked with conventional measures of overt lesions. Thus, irreversible tissue damage may be a key factor leading to disease progression. In this review, the authors present the proposed mechanisms leading to central nervous system (CNS) atrophy. They describe the available MRI-based techniques to measure regional and global atrophy of the brain and spinal cord. They compare the rate of atrophy among MS phenotypes and summarize the emerging data linking atrophy to neurological and neuropsychological impairment. Finally, they discuss the effect of disease-modifying immunotherapies on the rate of CNS atrophy in patients with MS. Future research to clarify the etiology and pathophysiology of brain and spinal cord atrophy should provide new targets for therapeutic development.

Imaging of multiple sclerosis: role in neurotherapeutics

Magnetic resonance imaging (MRI) plays an ever-expanding role in the evaluation of multiple sclerosis (MS). This includes its sensitivity for the diagnosis of the disease and its role in identifying patients at high risk for conversion to MS after a first presentation with selected clinically isolated syndromes. In addition, MRI is a key tool in providing primary therapeutic outcome measures for phase I/II trials and secondary outcome measures in phase III trials. The utility of MRI stems from its sensitivity to longitudinal changes including those in overt lesions and, with advanced MRI techniques, in areas affected by diffuse occult disease (the so-called normal-appearing brain tissue). However, all current MRI methodology suffers from limited specificity for the underlying histopathology. Conventional MRI techniques, including lesion detection and measurement of atrophy from T1- or T2-weighted images, have been the mainstay for monitoring disease activity in clinical trials, in which the use of gadolinium with T1-weighted images adds additional sensitivity and specificity for areas of acute inflammation. Advanced imaging methods including magnetization transfer, fluid attenuated inversion recovery, diffusion, magnetic resonance spectroscopy, functional MRI, and nuclear imaging techniques have added to our understanding of the pathogenesis of MS and may provide methods to monitor therapies more sensitively in the future. However, these advanced methods are limited by their cost, availability, complexity, and lack of validation. In this article, we review the role of conventional and advanced imaging techniques with an emphasis on neurotherapeutics.

Sensitivity and reproducibility of a new fast 3D segmentation technique for clinical MR-based brain volumetry in multiple sclerosis

Fast, reliable and easy-to-use methods to quantify brain atrophy are of increasing importance in clinical studies on neuro-degenerative diseases. Here, ILAB 4, a new volumetry software that uses a fast semi-automated 3D segmentation of thin-slice T1-weighted 3D MR images based on a modified watershed transform and an automatic histogram analysis was evaluated. It provides the cerebral volumes: whole brain, white matter, gray matter and intracranial cavity. Inter- and intra-rater reliability and scan-rescan reproducibility were excellent in measuring whole brain volumes (coefficients of variation below 0.5%) of volunteers and patients. However, gray and white matter volumes were more susceptible to image quality. High accuracy of the absolute volume results (+/-5 ml) were shown by phantom and preparation measurements. Analysis times were 6 min for processing of 128 slices. The proposed technique is reliable and highly suitable for quantitative studies of brain atrophy, e.g., in multiple sclerosis.

Increased serum matrix metalloproteinase 9 levels in systemic lupus erythematosus patients with neuropsychiatric manifestations and brain magnetic resonance imaging abnormalities

OBJECTIVE

To evaluate whether serum matrix metalloproteinase 9 (MMP-9) levels are associated with neuropsychiatric manifestations, particularly cognitive dysfunction, as evaluated by neuropsychological testing and brain magnetic resonance imaging (MRI) abnormalities in patients with systemic lupus erythematosus (SLE).

METHODS

MMP-9 determinations were made in 44 patients with SLE and 43 healthy controls who underwent a clinical neurologic and neuropsychological investigation in order to identify neuropsychiatric manifestations. Cerebral MRI scans with volumetric estimation of intracranial cerebrospinal fluid spaces, T1-weighted lesions, and T2-weighted lesions were performed for all subjects. SLE activity was assessed by the European Consensus Lupus Activity Measure (ECLAM) index, and accumulated neuropsychiatric abnormality was assessed by the Systemic Lupus International Collaborating Clinics (SLICC)/American College of Rheumatology damage index.

RESULTS

No significant difference was found in serum MMP-9 levels between the overall group of SLE patients and controls. However, SLE patients who had at least 1 neuropsychiatric manifestation (NPSLE patients) had significantly higher serum MMP-9 concentrations than did SLE patients without neuropsychiatric syndromes (P = 0.009). Among patients with NPSLE, those with cognitive deficits had significantly higher concentrations of serum MMP-9 than did those with normal cognitive function (P = 0.027). Furthermore, serum MMP-9 levels had a significant positive correlation with the volumes of T1-weighted and T2-weighted lesions in the brain MRI (P = 0.031 and P = 0.015, respectively). The concentration of serum MMP-9 correlated significantly with the SLICC index but not with the ECLAM index.

CONCLUSION

Elevated levels of serum MMP-9 in patients with SLE may reflect neuropsychiatric involvement, particularly cognitive dysfunction. The serum MMP-9 concentration may be associated with small- vessel cerebral vasculopathy and increased risk of cerebral ischemic events in patients with SLE.

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

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

Urodynamic findings in primary progressive multiple sclerosis are associated with increased volumes of plaques and atrophy in the central nervous system

OBJECTIVE

Voiding dysfunction is more frequent in primary progressive multiple sclerosis (PPMS) than in other subtypes of MS. We investigated whether lower urinary tract disorders are reflected in the extent of changes in brain and spinal cord detected by magnetic resonance imaging (MRI).

METHODS

Micturition symptoms and specific urodynamic findings in 24 patients with PPMS were related to MRI abnormalities as analysed by segmentation and volumetric analysis.

RESULTS

Urgency and urge incontinence were the most frequent urinary symptoms (83 and 75 %), while detrusor sphincter dyssynergia (DSD) (71%), detrusor hyperreflexia (58%) and obstruction (58%) were the most common micturition dysfunctions. Comparison between patients with detrusor hyperreflexia and those with normal bladder function revealed higher volumes of T2-weighted plaques in the brains of former (P = 0.01). In patients with hypotonic bladder the total brain volume was smaller (P = 0.02) and the number of thoracic plaques in T2-weighted images higher (P = 0.02) compared to patients with normal bladder function. Furthermore, DSD was associated with a higher volume of T2-weighted plaques in the brain (P = 0.02).

CONCLUSIONS

Voiding dysfunction in PPMS is associated with increasing brain and spinal cord abnormalities. Urodynamic investigation is, however, needed for specific definition of micturition disturbances and should be made before therapeutic decisions.

Volumetric quantitation by MRI in primary progressive multiple sclerosis: volumes of plaques and atrophy correlated with neurological disability

In primary progressive multiple sclerosis (PPMS) abnormalities in brain magnetic resonance imaging (MRI) differ from abnormalities in other subtypes of multiple sclerosis (MS). It was investigated whether the extent of brain and spinal cord MRI abnormalities is reflected in the neurological disability in PPMS. Focal and diffuse changes and atrophy in central nervous system (CNS) in patients with PPMS (n = 28) and healthy controls (n = 20) were assessed by semi-automatic MRI segmentation and volumetric analysis. The measurements were related to neurological disability as expressed by the expanded disability status scale (EDSS), the regional functional scoring system (RFSS), the arm index and the ambulation index. Plaques in T1- and/or T2-weighted images were seen in all brains, while spinal plaques were detected in 23 of 28 patients (82%). The total volumes of brain and spinal cord were significantly smaller in patients than in controls (P = 0.001 and 0.000, respectively). The volumes of T1 or T2 lesions in the brain correlated to the ambulation index (r = 0.51, P = 0.005 and r = 0.53, P = 0.004, respectively). No correlations were detected between MRI measurements and total EDSS score, but relative brain atrophy correlated inversely with the total RFSS scores, poor arm index and higher cerebral disturbances (r = -0.53, P = 0.004; r = -0.53, P = 0.004; and r = -0.52, P = 0.005, respectively). Although the number of spinal T2 lesions correlated with sensory disturbances (r = 0.60, P = 0.001), no correlations were found between EDSS subscores and spinal cord atrophy. These findings show that marked atrophy of brain and spinal cord detected by volumetric quantitation correlates with neurological disability. This observation indicates the importance of neurodegenerative events in PPMS.

High-dose immunosuppressive therapy and autologous peripheral blood stem cell transplantation for severe multiple sclerosis

There were 26 patients enrolled in a pilot study of high-dose immunosuppressive therapy (HDIT) for severe multiple sclerosis (MS). Median baseline expanded disability status scale (EDSS) was 7.0 (range, 5.0-8.0). HDIT consisted of total body irradiation, cyclophosphamide, and antithymocyte globulin (ATG) and was followed by transplantation of autologous, granulocyte colony-stimulating factor (G-CSF)-mobilized CD34-selected stem cells. Regimen-related toxicities were mild. Because of bladder dysfunction, there were 8 infectious events of the lower urinary tract. One patient died from Epstein-Barr virus (EBV)-related posttransplantation lymphoproliferative disorder (PTLD) associated with a change from horse-derived to rabbit-derived ATG in the HDIT regimen. An engraftment syndrome characterized by noninfectious fever with or without rash developed in 13 of the first 18 patients and was associated in some cases with transient worsening of neurologic symptoms. There were 2 significant adverse neurologic events that occurred, including a flare of MS during mobilization and an episode of irreversible neurologic deterioration after HDIT associated with fever. With a median follow-up of 24 (range, 3-36) months, the Kaplan-Meier estimate of progression (>/= 1.0 point EDSS) at 3 years was 27%. Of 12 patients who had oligoclonal bands in the cerebrospinal fluid at baseline, 9 had persistence after HDIT. After HDIT, 4 patients developed new enhancing lesions on magnetic resonance imaging of the brain. The estimate of survival at 3 years was 91%. Important clinical issues in the use of HDIT and stem cell transplantation for MS were identified; however, modifications of the initial approaches appear to reduce treatment risks. This was a heterogeneous high-risk group, and a phase 3 study is planned to fully assess efficacy.

Interventions for the prevention of brain atrophy in multiple sclerosis : current status

The assessment of brain volume changes on serial magnetic resonance imaging (MRI) scans can provide an objective measure of the neurodegenerative component of multiple sclerosis (MS) pathology. Results from placebo-controlled and crossover clinical trials indicate that immunomodulating (e.g. recombinant interferon-beta [IFNbeta]-1a [Rebif] and IFNbeta-1b [Betaferon] and glatiramer acetate [Copaxone]) and immunosuppressive (e.g. cladribine and alemtuzumab) treatments for relapsing-remitting (RR) and secondary progressive MS lack substantial efficacy in preventing the development of brain atrophy, despite the marked effects of these treatments on clinical and MRI outcomes of disease activity. A modest but significant treatment effect on brain atrophy has been reported for patients with RRMS only in one trial of IFNbeta-1a (Avonex) and in another study of long-term corticosteroid therapy.Failure to find a significant treatment benefit in preventing brain atrophy might be the result of inadequate trial designs, including their relatively short durations, which may not be adequate to reveal beneficial effects in a chronic disease like MS. Alternatively, such a failure might indicate that treatments proven to be effective in reducing MS-related inflammation are unable to act with the same efficacy on the most severe and disabling pathological substrates of the disease. The modest correlation between MRI enhancement frequency and brain atrophy observed in the placebo groups of several trials also fits with the concept that the suppression of inflammatory activity in MS is not fully and rapidly associated with a similar effect on the global neurodegenerative process of the disease.

Accuracy and reproducibility of manual and semiautomated quantification of MS lesions by MRI

PURPOSE

To evaluate the accuracy, reproducibility, and speed of two semiautomated methods for quantifying total white matter lesion burden in multiple sclerosis (MS) patients with respect to manual tracing and to other methods presented in recent literature.

MATERIALS AND METHODS

Two methods involving the use of MRI for semiautomated quantification of total lesion burden in MS patients were examined. The first method, geometrically constrained region growth (GEORG), requires user specification of lesion location. The second technique, directed multispectral segmentation (DMSS), requires only the location of a single exemplar lesion. Test data sets included both clinical MS data and MS brain phantoms.

RESULTS

The mean processing times were 60 minutes for manual tracing, 10 minutes for region growth, and 3 minutes for directed segmentation. Intra- and interoperator coefficients of variation (CVs) were 5.1% and 16.5% for manual tracing, 1.4% and 2.3% for region growth, and 1.5% and 5.2% for directed segmentation. The average deviations from manual tracing were 9% for region growth and 5.7% for directed segmentation.

CONCLUSION

Both semiautomated methods were shown to have a significant advantage over manual tracing in terms of speed and precision. The accuracy of both methods was acceptable, given the high variability of the manual results.

Issues and practices in multiple sclerosis

The objective of this roundtable discussion of experts in the field of multiple sclerosis (MS) was to summarize the current understanding of MS and its therapeutic options. The experts discussed subjects ranging from the etiology of MS to the current standards for patient care. Specific topics included the subtypes of MS, with a focus on the benign subtype, brain atrophy, the role of magnetic resonance imaging or "neuroimaging studies," disease-modifying therapies, biological markers as indicators of drug efficacy, and combination therapies. In addition, the experts speculated as to what will be available in the near future for the improved diagnosis and management of MS. This review summarizes the main points of this discussion and is intended to serve as a reference for neurologists involved in the care of patients with MS.

Early intervention with immunomodulatory agents in the treatment of multiple sclerosis

Multiple sclerosis (MS) is a lifelong neurologic disease leading to moderate or severe disability in the majority of affected patients. Studies of the natural history of MS suggest that 90% of patients with relapsing-remitting MS eventually develop secondary progressive (SP) disease. Magnetic resonance imaging (MRI) studies have consistently shown a high frequency of new T2 lesions and new gadolinium enhancing lesions even in the absence of clinical relapse. Lesion burden on T2 MRI increases by 5% to 10% per year and both axonal transection and cerebral atrophy are present at the earliest stages of RR MS. A wealth of evidence suggests that MS is a disease process that is continuously active, and that irreversible damage occurs early in the disease. Despite knowledge of the natural history and the availability of treatments that reduce relapse rates, decrease the accumulation of disability, and decrease surrogate measures of disease activity, only 60% of eligible patients have been treated with immunomodulating agents. This paper reviews the available evidence suggesting that immunomodulatory therapy modifies the natural history of MS and presents an argument for early intervention in the treatment of MS.

Inflammation and atrophy in multiple sclerosis: MRI associations with disease course

Brain atrophy may be a useful surrogate marker of axonal loss and disease progression in multiple sclerosis (MS). Several studies have suggested that inflammatory disease activity is a risk factor for atrophy in the early stages of the disease, but may become less important later in the disease course. We aimed to investigate the relationships between atrophy and active inflammation at different stages of the disease course using brain volume measurements from magnetic resonance imaging (MRI) in patients with both relapsing-remitting (RR) (n=95) and secondary progressive (SP) (n=76) MS. Conventional dual echo and three-dimensional magnetization-prepared rapid-acquisition gradient echo imaging were performed in all patients and in 31 healthy controls. Supratentorial and infratentorial brain, and lateral ventricular volumes were determined using modern design stereology. Patients with SP MS had smaller supratentorial (p=0.003) and infratentorial brain volumes (p=0.0003), and larger lateral ventricles (p=0.02) than patients with RR MS. RR MS patients with T(1)-enhancing lesions had smaller supratentorial (p=0.02) and infratentorial (p=0.002) brain volumes and larger ventricles (p=0.002) than those without enhancing lesions. SP MS patients with enhancing lesions also had significantly larger lateral ventricles (p=0.03). Categorical analysis showed that more RR MS patients with enhancing lesions had smaller supratentorial brain (p=0.005), or larger lateral ventricular (p=0.028) volumes, and more SP MS patients with enhancing lesions had increased lateral ventricle volumes (p=0.013), than patients without enhancements. The number of enhancing lesions was significantly correlated with lateral ventricular volumes in both RR MS (r=0.39, p=0.0001) and SP MS (r=0.46, p<0.0001). Our data shows that the presence of active inflammation on a single MRI in the course of RR and SP MS, is associated with a higher risk and higher level of brain atrophy. These findings emphasise the important long-term relationship between inflammation and atrophy in MS and provide additional support for the strategy of early anti-inflammatory treatment to protect tissue integrity.

Quantitative diffusion weighted magnetic resonance imaging, cerebral atrophy, and disability in multiple sclerosis

OBJECTIVES

To investigate the relations between quantitative diffusion coefficient MRI histograms, clinical variables, and cerebral atrophy.

METHODS

Twenty two patients with clinically definite multiple sclerosis and 11 healthy volunteers were studied. Histograms of apparent diffusion coefficient (ADC) from a volume of interest that included multiple slices encompassing the lateral ventricles were processed from diffusion weighted MRI. In addition, total lesion load was measured on T2 weighted dual echo images, and cerebral volume from 3D magnetisation prepared rapid acquisition gradient echo scans. All patients underwent neurological assessment, including disability on the expanded disability status scale (EDSS).

RESULTS

Histograms from the patient group showed a reduced peak height and a "right shift" compared with healthy controls. Peak height of the diffusion histogram correlated with both EDSS (r=-0.54, p=0.0101) and disease duration (r=-0.52, p=0.0140), but not with age. Brain volume correlated with peak height of the ADC histogram (r=0.55, p=0.0129), but not with disability. Total lesion load also correlated moderately with EDSS (r=0.46, p=0.03).

CONCLUSIONS

This study shows for the first time that quantitative MRI measures of diffusion correlate with clinical variables (disability, disease duration) and cerebral atrophy in multiple sclerosis. Cerebral atrophy and fixed neurological deficit may be attributed to axonal loss, which would be expected to have a significant effect on ADC. Extension of this method to more patients and longitudinal studies will further elucidate its sensitivity, reproducibility, and potential role in clinical practice and treatment trials.

Intra-observer, inter-observer and inter-scanner variations in brain MRI volume measurements in multiple sclerosis

INTRODUCTION

Measurement of brain volume on magnetic resonance imaging (MRI) scans is regarded as an objective marker of multiple sclerosis (MS) severity with the potential to monitor treatment efficacy accurately. This study was performed to assess the variability of brain MRI volume measurements.

PATIENTS AND METHODS

We studied nine patients with relapsing-remitting MS, who were imaged on two occasions (separated by an interval of 24 h) using two different MR scanners and fast fluid-attenuated inversion recovery (fast-FLAIR) sequences. The whole brain volume computed from each image was measured three times by three observers using a seed-growing technique based on signal intensity thresholding. Intra-observer, inter-observer and inter-scanner variabilities were expressed as coefficients of variations (COVs). The inter-scanner variability included not only the intra-observer variation but also the repositioning variability and the variation in observed brain volume caused by different scanner hardware and sequence implementations.

RESULTS

There was no statistically significant difference in patients' brain volume values between observers (P=0.82) or between scanners (P=0.30). The mean intra-observer COV was 1.2% (s.e.=0.4%), the mean inter-observer COV was 1.8% (s.e.=0.8%) and the mean inter-scanner COV was 2.4% (s.e.=1.2%). The intra-observer variance was not statistically different from those found between observers (P=0.83) or scanners (P=0.44).

CONCLUSION

The intra-observer variability in brain volume measurements found in this study was within the range of intra-observer variability found in previous studies. This study shows that the use of different observers and MR scanners has only a small influence on the measured brain volume and does not affect the reproducibility of this measurement greatly.

Why treat early multiple sclerosis patients?

Class 1 clinical trials demonstrated that immunomodulatory treatments (interferon beta and glatiramer acetate) reduce the disease activity and the accumulation of disability in relapsing remitting multiple sclerosis. Moreover interferon beta-1b also had similar positive effects in secondary progressive multiple sclerosis. The magnitude of these clinical effects was modest, but the reduction of inflammatory activity, as revealed by magnetic resonance imaging, was marked. Converging evidence from new pathological studies and new magnetic resonance techniques, characterized by increased pathological specificity, has shown that already in the early phases of the disease inflammatory activity determines irreversible axonal damage. Moreover, the amount of inflammatory activity at the clinical presentation of the disease has some value in predicting long-term disability. Taken together, these data indicate that patients may benefit from early treatment; the positive results of the Controlled High Risk Subjects Avonex Multiple Sclerosis Prevention Study support this conclusion.