Functional response to active and passive ankle movements with clinical correlations in patients with primary progressive multiple sclerosis

Patients with multiple sclerosis (MS) activate a more diffuse cortical network than do healthy subjects when they perform motor tasks. This brain functional reorganisation might contribute to the limiting of disability, but it is unclear whether there is a loss of regional activation in more advanced disease. The aim of this study was to assess whether functional reorganisation diminishes in more disabled patients with primary progressive (PP) MS. The differences in the fMRI response to active and passive movements of the dominant ankle of 13 patients and 16 controls were assessed. The relationships between functional activation and disability and brain lesion load and atrophy were investigated.Patients showed greater fMRI activation than controls with passive movements in the superior temporal gyrus, rolandic operculum, and putamen. The fMRI response to active and passive movements in the ipsilateral inferior frontal gyrus was lower in patients with greater disability and greater brain T2 lesion load, respectively. Furthermore, the fMRI activation with active movements in the contralateral cerebellum was lower in patients with worse mobility. The increased activity with passive movements in regions that participate in sensori-motor integration, such as the putamen, reflects true functional reorganisation, since passive movements induce brain activation through sensory afferents only. The inverse correlation between the fMRI response in regions that are associated with motor control, and clinical or MRI measures of disease progression, suggests that there is a loss of distributed activation in more disabled patients. This may inform future treatment strategies.

Unbinding pathways of an agonist and an antagonist from the 5-HT3 receptor

The binding sites of 5-HT3 and other Cys-loop receptors have been extensively studied, but there are no data on the entry and exit routes of ligands for these sites. Here we have used molecular dynamics simulations to predict the pathway for agonists and antagonists exiting from the 5-HT3 receptor binding site. The data suggest that the unbinding pathway follows a tunnel at the interface of two subunits, which is approximately 8 A long and terminates approximately 20 A above the membrane. The exit routes for an agonist (5-HT) and an antagonist (granisetron) were similar, with trajectories toward the membrane and outward from the ligand binding site. 5-HT appears to form many hydrogen bonds with residues in the unbinding pathway, and experiments show that mutating these residues significantly affects function. The location of the pathway is also supported by docking studies of granisetron, which show a potential binding site for granisetron on the unbinding route. We propose that leaving the binding pocket along this tunnel places the ligands close to the membrane and prevents their immediate reentry into the binding pocket. We anticipate similar exit pathways for other members of the Cys-loop receptor family.

Abnormalities in normal appearing tissues in early primary progressive multiple sclerosis and their relation to disability: a tissue specific magnetisation transfer study

BACKGROUND

Patients with primary progressive multiple sclerosis (PPMS) often develop severe disability despite low levels of abnormality on conventional magnetic resonance imaging (MRI). This may relate to diffuse pathological processes occurring in normal appearing brain tissue (NABT) involving both white matter (NAWM) and grey matter (NAGM). Magnetisation transfer imaging (MTI) is capable of identifying these processes and may be particularly informative when applied to patients with early PPMS.

AIM

To assess the relationship between abnormalities in NABT identified by MTI and disability and other radiological data in patients with early PPMS.

METHODS

We studied 43 patients within 5 years of disease onset and 43 controls. The Expanded Disability Status Scale (EDSS) and the Multiple Sclerosis Functional Composite (MSFC) were scored. Magnetisation transfer ratios (MTR) of NABT, NAWM, and NAGM were calculated and the following MTR parameters were measured: mean, peak height, peak location, and MTR value at the 25th, 50th, and 75th percentiles. Proton density, T2, T1, and gadolinium enhancing lesion loads were also calculated.

RESULTS

Differences were found between patients and controls in mean, peak height, and peak location of NAWM and NAGM (p < or = 0.001). Weak to moderate correlations were found between MTR parameters and disability in both NAWM and NAGM. Strong correlations between MTR parameters and lesion loads were found, particularly in NAWM.

CONCLUSION

MTR abnormalities are seen in NAWM and NAGM in early PPMS and both are associated with disability. NAWM MTR abnormalities are more closely related to conventional MRI measures than those seen in NAGM.

Increasing cord atrophy in early relapsing-remitting multiple sclerosis: a 3 year study

OBJECTIVES

Previous studies have shown that upper cervical cord atrophy (UCCA) occurs in multiple sclerosis (MS), particularly in those disabled and with primary or secondary progressive disease. It is less clear how early it can be detected in relapsing-remitting (RR) MS, and whether early cord atrophy relates to the concurrent or future clinical course.

METHODS

Twenty seven RR MS patients (median disease duration 1.7 years, in all cases <3 years from onset) were recruited along with 20 controls. They were followed for up to 3 years with a yearly assessment of UCCA and clinical function measured by the Expanded Disability Status Scale (EDSS) and MS Functional Composite Score (MSFC). Clinical and MRI correlations were investigated. Statistical models adjusted for covariates including total intracranial volume.

RESULTS

Longitudinal analysis showed a significant decrease in UCCA in patients both within the patient cohort (p < 0.001) and in comparison with controls (p = 0.001). There was a significant increase in EDSS (p = 0.008) but no significant change in MSFC. The rate of UCCA loss did not correlate with clinical change or with change in brain volume.

CONCLUSIONS

In summary, serial UCCA measurement detects the development of spinal cord atrophy in clinically early RR MS.

Sudden unexpected death in infancy: place and time of death

In recent years, many babies who die of Sudden Unexpected Death in Infancy (SUDI) in Northern Ireland are found dead in bed--i.e. co-sleeping--with an adult. In order to assess its frequency autopsy reports between April 1996 and August 2001 were reviewed and linked to temporal factors. The day and month of death, and the place where the baby was found were compared to a reference population of infant deaths between one week of age and the second birthday. Although the rate of SUDI was lower than the UK average, 43 cases of SUDI were identified, and two additional deaths with virtually identical autopsy findings that were attributed to asphyxia caused by suffocation due to overlaying. Thirty-two of the 45 (71%) were less than four months of age. In 30 of the 45 cases (67%) the history stated that the baby was bed sharing with others; 19 died sleeping in an adult bed, and 11 on a sofa or armchair. In 16 of the 30 (53%) there were at least two other people sharing the sleeping surface, and in one case, three. SUDI was twice as frequent at weekends (found dead Saturday-Monday mornings) compared to weekdays (p<0.02), and significantly more common compared to reference deaths (p<0.002). Co-sleeping deaths were also more frequent at weekends. Almost half of all SUDI (49%) occurred in the summer months--more than twice the frequency of reference deaths. While sharing a place of sleep per se may not increase the risk of death, our findings may be linked to factors such as habitual smoking, consumption of alcohol or illicit drugs as reported in case-control studies. In advising parents on safer childcare practices, health professionals must be knowledgeable of current research and when, for example, giving advice on co-sleeping this needs to be person-specific cognisant of the risks within a household. New and better means of targeting such information needs to be researched if those with higher risk life-styles are to be positively influenced.

Cannabinoids in multiple sclerosis (CAMS) study: safety and efficacy data for 12 months follow up

OBJECTIVE

To test the effectiveness and long term safety of cannabinoids in multiple sclerosis (MS), in a follow up to the main Cannabinoids in Multiple Sclerosis (CAMS) study.

METHODS

In total, 630 patients with stable MS with muscle spasticity from 33 UK centres were randomised to receive oral Delta(9)-tetrahydrocannabinol (Delta(9)-THC), cannabis extract, or placebo in the main 15 week CAMS study. The primary outcome was change in the Ashworth spasticity scale. Secondary outcomes were the Rivermead Mobility Index, timed 10 metre walk, UK Neurological Disability Score, postal Barthel Index, General Health Questionnaire-30, and a series of nine category rating scales. Following the main study, patients were invited to continue medication, double blinded, for up to 12 months in the follow up study reported here.

RESULTS

Intention to treat analysis of data from the 80% of patients followed up for 12 months showed evidence of a small treatment effect on muscle spasticity as measured by change in Ashworth score from baseline to 12 months (Delta(9)-THC mean reduction 1.82 (n = 154, 95% confidence interval (CI) 0.53 to 3.12), cannabis extract 0.10 (n = 172, 95% CI -0.99 to 1.19), placebo -0.23 (n = 176, 95% CI -1.41 to 0.94); p = 0.04 unadjusted for ambulatory status and centre, p = 0.01 adjusted). There was suggestive evidence for treatment effects of Delta(9)-THC on some aspects of disability. There were no major safety concerns. Overall, patients felt that these drugs were helpful in treating their disease.

CONCLUSIONS

These data provide limited evidence for a longer term treatment effect of cannabinoids. A long term placebo controlled study is now needed to establish whether cannabinoids may have a role beyond symptom amelioration in MS.

Metabolite changes in early relapsing-remitting multiple sclerosis. A two year follow-up study

Previous in vivo proton magnetic resonance spectroscopic imaging ((1)H-MRSI) studies have found reduced levels of N-acetyl-aspartate (NAA) in multiple sclerosis (MS) lesions, the surrounding normal-appearing white matter (NAWM) and cortical grey matter (CGM), suggesting neuronal and axonal dysfunction and loss. Other metabolites, such as myoinositol (Ins), creatine (Cr), choline (Cho), and glutamate plus glutamine (Glx), can also be quantified by (1)H-MRSI, and studies have indicated that concentrations of these metabolites may also be altered in MS. Relatively little is known about the time course of such metabolite changes. This preliminary study aimed to characterise changes in total NAA (tNAA, the sum of NAA and N-acetyl-aspartyl-glutamate), Cr, Cho, Ins and Glx concentrations in NAWM and in CGM, and their relationship with clinical outcome, in subjects with clinically early relapsing-remitting MS (RRMS). Twenty RRMS subjects and 10 healthy control subjects underwent (1)H-MRSI examinations yearly for two years. Using the LCModel, tNAA, Cr, Cho, Ins and Glx concentrations were estimated both in NAWM and CGM. At baseline, the concentration of tNAA was significantly reduced in the NAWM of the MS patients compared to the control group (-7%, p = 0.003), as well as in the CGM (-8.7%, p = 0.009). NAWM tNAA concentrations tended to recover from baseline, but otherwise tissue metabolite profiles did not significantly change in the MS subjects, or relatively between MS and healthy control subjects. While neuronal and axonal damage is apparent from the early clinical stages of MS, this study suggests that initially it may be partly reversible. Compared with other MR imaging measures, serial (1)H-MRSI may be relatively less sensitive to progressive pathological tissue changes in early RRMS.

Getting the measure of spasticity in multiple sclerosis: the Multiple Sclerosis Spasticity Scale (MSSS-88)

Spasticity is most commonly defined as an inappropriate, velocity dependent, increase in muscle tonic stretch reflexes, due to the amplified reactivity of motor segments to sensory input. It forms one component of the upper motor neuron syndrome and often leads to muscle stiffness and disability. Spasticity can, therefore, be measured through electrophysiological, biomechanical and clinical evaluation, the last most commonly using the Ashworth scale. None of these techniques incorporate the patient experience of spasticity, nor how it affects people's daily lives. Consequently, we set out to construct a rating scale to quantify the perspectives of the impact of spasticity on people with multiple sclerosis. Qualitative methods (in-depth patient interviews and focus groups, expert opinion and literature review) were used to develop a conceptual framework of spasticity impact, and to generate a pool of items with the potential to convert this framework into a rating scale with multiple dimensions. This item pool was administered, in the form of a questionnaire, to a sample of people with multiple sclerosis and spasticity. Guided by Rasch analysis, we constructed and validated a rating scale for each component of the conceptual framework. Decisions regarding item selection were based on the integration and assimilation of seven specific analyses including clinical meaning, ordering of thresholds, fit statistics and differential item functioning. The qualitative phase (17 patient interviews, 3 focus groups) generated 144 potential scale items and a conceptual model with eight components addressing symptoms (muscle stiffness, pain and discomfort and muscle spasms,), physical impact (activities of daily living, walking and body movements) and psychosocial impact (emotional health, social functioning). The first postal survey was sent to 272 people with multiple sclerosis and had a response rate of 88%. Findings supported the development of scales for each component but demonstrated that five item response options were too many. The 144-item questionnaire, reformatted with four-item response options, was administered with four validating instruments to an independent sample of 259 people with multiple sclerosis (response rate 78%). From the responses, an 88-item instrument with eight subscales was developed that satisfied criteria for reliable and valid measurement. Correlations with other measures were consistent with predictions. The 88-item Multiple Sclerosis Spasticity Scale (MSSS-88) is a reliable and valid, patient-based, interval-level measure of the impact of spasticity in multiple sclerosis. It has the potential to advance outcomes measurement in clinical trials and clinical practice, and provides a new perspective in the clinical evaluation of spasticity.

How responsive is the Multiple Sclerosis Impact Scale (MSIS-29)? A comparison with some other self report scales

OBJECTIVES

To compare the responsiveness of the Multiple Sclerosis Impact Scale (MSIS-29) with other self report scales in three multiple sclerosis (MS) samples using a range of methods. To estimate the impact on clinical trials of differing scale responsiveness.

METHODS

We studied three discrete MS samples: consecutive admissions for rehabilitation; consecutive admissions for steroid treatment of relapses; and a cohort with primary progressive MS (PPMS). All patients completed four scales at two time points: MSIS-29; Short Form 36 (SF-36); Functional Assessment of MS (FAMS); and General Health Questionnaire (GHQ-12). We determined: (1) the responsiveness of each scale in each sample (effect sizes): (2) the relative responsiveness of competing scales within each sample (relative efficiency): (3) the differential responsiveness of competing scales across the three samples (relative precision); and (4) the implications for clinical trials (samples size estimates scales to produce the same effect size).

RESULTS

We studied 245 people (64 rehabilitation; 77 steroids; 104 PPMS). The most responsive physical and psychological scales in both rehabilitation and steroids samples were the MSIS-29 physical scale and the GHQ-12. However, the relative ability of different scales to detect change in the two samples was variable. Differing responsiveness implied more than a twofold impact on sample size estimates.

CONCLUSIONS

The MSIS-29 was the most responsive physical and second most responsive psychological scale. Scale responsiveness differs notably within and across samples, which affects sample size calculations. Results of clinical trials are scale dependent.

Magnetization transfer histograms in clinically isolated syndromes suggestive of multiple sclerosis

In established multiple sclerosis, magnetization transfer ratio (MTR) histograms reveal abnormalities of normal-appearing white matter (NAWM) and grey matter (NAGM). The aim of this study was to investigate for such abnormalities in a large cohort of patients presenting with clinically isolated syndromes suggestive of multiple sclerosis. Magnetization transfer imaging was performed on 100 patients (67 women, 33 men, median age 32 years) a mean of 19 weeks (SD 3.8, range 12-33 weeks) after symptom onset with a clinically isolated syndrome and in 50 healthy controls (34 women, 16 men, median age 32.5 years). SPM99 software was used to generate segmented NAWM and NAGM MTR maps. The volumes of T2 lesions, white matter and grey matter were calculated. Eighty-one patients were followed up clinically and with conventional MRI after 3 years (n = 61) or until they developed multiple sclerosis if this occurred sooner (n = 20). Multiple regression analysis was used to investigate differences between patients and controls with age, gender and volume measures as covariates to control for potential confounding effects. The MTR histograms for both NAWM and NAGM showed a reduction in the mean (NAWM, 38.14 versus 38.33, P = 0.001; NAGM 32.29 versus 32.50, P = 0.009; units in pu) and peak location, with a left shift in the histogram. Mean NAWM and NAGM MTR were also reduced in the patients who developed clinically definite multiple sclerosis and multiple sclerosis according to the McDonald criteria but not in the 24 patients with normal T2-weighted brain magnetic resonance imaging (MRI). MTR abnormalities occur in the NAWM and NAGM at the earliest clinical stages of multiple sclerosis.

Capturing the true burden of dystonia on patients: the Cervical Dystonia Impact Profile (CDIP-58)

OBJECTIVES

To develop a new rating scale for measuring the health impact of cervical dystonia (CD) that includes patients' perceptions and complements existing observer dependent clinician rating scales.

METHODS

Scale development was in three stages. In Stage 1, a large pool of items was generated from patient interviews (n = 25), expert opinion, and literature review. In Stage 2, these items were administered by postal survey to people with CD. The resulting data were analyzed using Rasch item analysis to construct, from the item pool, a rating scale that satisfied criteria for rigorous measurement. In Stage 3, the measurement properties of this rating scale were examined in an independent sample of people with CD.

RESULTS

In Stage 1, 150 items concerning the health impact of CD were generated. In Stage 2, 556 people completed questionnaires (87% response rate) and a 58-item rating scale measuring the health impact of CD in eight areas was constructed (CD Impact Profile, CDIP-58). In Stage 3, CDIP-58 data from 391 people (87% response rate) were received. Analyses supported the measurement of eight unidimensional constructs (infit mean square range 0.62 to 1.50), item calibration (33.37 to 67.56), and patient separation statistics (2.59 to 3.38). Items demonstrated stable calibrations in subgroups of people with CD supporting the stability of the CDIP-58.

CONCLUSIONS

The CDIP-58 is a reliable and valid patient-based rating scale measuring the health impact of CD in eight health dimensions.

Multiple sclerosis: diagnosis and the management of acute relapses

Multiple sclerosis is an inflammatory demyelinating disease of the central nervous system that may result in a wide range of neurological symptoms and accumulating disability. Its course is unpredictable resulting in a changing pattern of clinical need. Diagnostic criteria for multiple sclerosis require objective evidence for dissemination in space and time. The diagnostic and management process should follow good practice guidelines with the person at the centre of the process. Appropriate support and information should be available from the time of diagnosis. Continuing education is key in enabling the person to actively participate in their management. In the event of an acute relapse the person should have direct access to the most appropriate local service. Provided medical causes have been excluded, corticosteroid treatment to hasten the recovery from the relapse should be considered. Management of an acute relapse should be comprehensive addressing any medical, functional, or psychosocial sequelae.

Is inflammation important in early PPMS? a longitudinal MRI study

BACKGROUND

Magnetic resonance imaging (MRI) studies in primary progressive multiple sclerosis (PPMS) have shown a reduced frequency of enhancement with the contrast agent gadolinium-DTPA (Gd-DTPA), in comparison with relapsing-remitting multiple sclerosis (RRMS), and it has been suggested that there may be a less important role for inflammation in its pathogenesis. However, the earliest clinical stages of PPMS have not been studied and thus it has not been possible to exclude the existence of an early inflammatory phase.

OBJECTIVE

To study the presence, characteristics, and implications of inflammation in early PPMS.

METHODS

45 patients with a mean disease duration of 3.3 years had triple dose Gd enhanced MRI, expanded disability status scale (EDSS), and multiple sclerosis functional composite (MSFC) assessments at baseline. Repeat MRI was done at 1 and 2 months in 24 patients, and at 6 months in 38.

RESULTS

Enhancing brain lesions were present in 42% of patients at baseline but enhancing cord lesions were uncommon (7%); 85% of enhancing lesions enhanced for one month or less. Patients with enhancing lesions had greater disability (EDSS, p = 0.027; MSFC, p = 0.026) and more MRI abnormalities (greater T2 load, p = 0.008; greater T1 hypointensity load, p = 0.001; and reduced partial brain volume, p = 0.012) than those without enhancement. Enhancement at 6 months was seen in 32% of patients and was restricted to a subset of patients who enhanced at baseline.

CONCLUSIONS

Enhancement is present in some cases of early PPMS and is associated with greater disease impact in terms of both clinical and MRI measures.

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

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

Interferon beta-1b in secondary progressive MS: a combined analysis of the two trials

BACKGROUND

A European (EU) and a North American (NA) placebo-controlled study with interferon beta-1b (IFNB-1b) in secondary progressive multiple sclerosis (SPMS) showed divergent results with regard to their primary outcome of sustained Expanded Disability Status Scale (EDSS) progression, while effects were similar on relapse and MRI-related endpoints. Reasons for this discrepancy were explored in the combined dataset.

METHODS

Baseline characteristics and variability in EDSS assessments were compared. Retrospective combined analyses for time to confirmed progression were performed to assess treatment effects overall and in subgroups defined by pre-study disease activity criteria and other key baseline variables.

RESULTS

The variance of EDSS measurements was 6.5% higher in the NA-SPMS study. The EU study included patients in an earlier phase of SPMS and with more active disease both pre-study (relapses, MRI) as well as on study (EDSS, relapses, and MRI variables as assessed in the placebo groups). The pooled analysis showed an overall risk reduction by about 20% in patients treated with 8 MIU (250 mcg) IFNB-1b for EDSS progression confirmed at 6 months (p = 0.008). Risk reduction by 30% to 40% was found for patients with at least one relapse or change in EDSS by >1 in the 2 years prior to study entry. No other consistent across-studies relation of clinical and MRI variables at baseline to potential treatment response was found.

CONCLUSIONS

Although post hoc, this combined analysis of the two large studies with IFNB-1b in secondary progressive multiple sclerosis suggests that both pronounced disability progression and continuing relapse activity might help in identifying those patients in the secondary progressive phase of the disease who are more likely to benefit from treatment.

A longitudinal study of cognition in primary progressive multiple sclerosis

There are few longitudinal studies of cognition in patients with multiple sclerosis, and the results of these studies remain inconclusive. No serial neuropsychological data of an exclusively primary progressive series are available. Cross-sectional analyses have revealed significant correlations between cognition and magnetic resonance imaging (MRI) parameters in primary progressive multiple sclerosis (PPMS). This study investigated cognitive and MRI change in 99 PPMS patients from five European centres for 2 years. They were assessed at 12 month intervals using the Brief Repeatable Battery, a reasoning test, and a measure of depression. The MRI parameters of T1 hypointensity load, T2 lesion load, and partial brain volume were also calculated at each time point. There were no significant differences between the mean cognitive scores of the patients at year 0 and year 2. However, one-third of the patients demonstrated absolute cognitive decline on individual test scores. Results indicated that initial cognitive status on entry into the study was a good predictor of cognitive ability at 2 years. There was only a small number of significant correlations between changes in cognition and changes on MRI, notably T1 hypointensity load with the two attentional tasks (r = -0.266, P = 0.017; r = -0.303, P = 0.012). It is probable that multiple factors underlie this weak relation between the cognitive and MRI measures.

Identifying brain regions for integrative sensorimotor processing with ankle movements

The objective of this study was to define cortical and subcortical structures activated during both active and passive movements of the ankle, which have a fundamental role in the physiology of locomotion, to improve our understanding of brain sensorimotor integration. Sixteen healthy subjects, all right-foot dominant, performed a dorsi-plantar flexion task of the foot using a custom-made wooden manipulandum, which enabled measurements of the movement amplitude. All subjects underwent a training session, which included surface electromyography, and were able to relax completely during passive movements. Patterns of activation during active and passive movements and differences between functional MRI (fMRI) responses for the two types of movement were assessed. Regions of common activation during the active and passive movements were identified by conjunction analysis. We found that passive movements activated cortical regions that were usually similar in location to those activated by active movements, although the extent of the activations was more limited with passive movements. Active movements of both feet generated greater activation than passive movements in some regions (such as the ipsilateral primary motor cortex) identified in previous studies as being important for motor planning. Common activations during active and passive movements were found not only in the contralateral primary motor and sensory cortices, but also in the premotor cortical regions (such as the bilateral rolandic operculum and contralateral supplementary motor area), and in the subcortical regions (such as the ipsilateral cerebellum and contralateral putamen), suggesting that these regions participate in sensorimotor integration for ankle movements. In future, similar fMRI studies using passive movements have potential to elucidate abnormalities of sensorimotor integration in central nervous system diseases that affect motor function.

Identifying brain regions for integrative sensorimotor processing with ankle movements

The objective of this study was to define cortical and subcortical structures activated during both active and passive movements of the ankle, which have a fundamental role in the physiology of locomotion, to improve our understanding of brain sensorimotor integration. Sixteen healthy subjects, all right-foot dominant, performed a dorsi-plantar flexion task of the foot using a custom-made wooden manipulandum, which enabled measurements of the movement amplitude. All subjects underwent a training session, which included surface electromyography, and were able to relax completely during passive movements. Patterns of activation during active and passive movements and differences between functional MRI (fMRI) responses for the two types of movement were assessed. Regions of common activation during the active and passive movements were identified by conjunction analysis. We found that passive movements activated cortical regions that were usually similar in location to those activated by active movements, although the extent of the activations was more limited with passive movements. Active movements of both feet generated greater activation than passive movements in some regions (such as the ipsilateral primary motor cortex) identified in previous studies as being important for motor planning. Common activations during active and passive movements were found not only in the contralateral primary motor and sensory cortices, but also in the premotor cortical regions (such as the bilateral rolandic operculum and contralateral supplementary motor area), and in the subcortical regions (such as the ipsilateral cerebellum and contralateral putamen), suggesting that these regions participate in sensorimotor integration for ankle movements. In future, similar fMRI studies using passive movements have potential to elucidate abnormalities of sensorimotor integration in central nervous system diseases that affect motor function.

Emergence of thalamic magnetization transfer ratio abnormality in early relapsing-remitting multiple sclerosis

While there is now evidence for thalamic abnormality in established secondary progressive and relapsing-remitting multiple sclerosis (MS), it remains unclear when such abnormality begins. This study investigated the emergence of thalamic abnormality in relapsing-remitting MS by assessing the thalamic magnetization transfer ratio (MTR) in a cohort with clinically early disease. Twenty-three patients with early relapsing-remitting MS (mean age 37; mean disease duration 1.9 years; Expanded Disability Status Scale (EDSS) range 0-3) and 19 healthy controls (mean age 34) were imaged yearly with a magnetization transfer imaging sequence. Twenty-two MS patients and 14 controls completed two-year follow-up. Regions of interest were placed in both thalami and mean thalamic MTR calculated. At baseline, significant differences between patient and control thalamic MTR were not observed. However, at years one and two, the thalamic MTR in patients was significantly lower than control MTR. Although baseline lesion volume did not correlate with baseline thalamic MTR, at year one, an association between baseline lesion volume and year one thalamic MTR emerged. There was also a significant inverse correlation between EDSS and thalamic MTR (r = -0.47, P = 0.02). The study suggests that thalamic involvement occurs within the first five years of MS onset, when most patients are still minimally disabled.

Evaluating neurorehabilitation: lessons from routine data collection

BACKGROUND

Clinical databases are being used increasingly to assess outcomes in healthcare services to provide evidence of clinical effectiveness in routine clinical practice.

OBJECTIVES

To explore the benefits of a database for routine collection of clinical outcomes within an inpatient neurorehabilitation setting; determine the effectiveness of inpatient neurorehabilitation in a range of neurological conditions; and determine variables influencing change in functional outcome.

METHODS

Over a nine year period, demographic and diagnostic characteristics were collected for the 1458 patients admitted consecutively to a neurorehabilitation unit. The level of function was measured on admission and discharge using the Barthel Index (BI) and Functional Independence Measure (FIM). Patient perception of rehabilitation benefit was evaluated using visual analogue scales (VAS).

RESULTS

Of the 1413 patients (mean (SD) age 48 (14.8), range 16 to 87) whose length of stay was more than 10 days (mean 34 (24) range 10 to 184), 282 had stroke, 614 multiple sclerosis, 248 spinal cord injuries, 93 a neuromuscular condition, and 176 other brain pathology. Patients improved in functional ability as measured by both BI and the FIM motor subscale (effect sizes 0.93 to 1.44 and 1.01 to 1.48, respectively). VAS ratings demonstrated high levels of patient perceived benefit. Diagnosis, functional activity score on admission, and length of stay were significant predictors of functional gain, explaining 44% of the variability in the change scores.

CONCLUSIONS

Systematic collection, analysis, and interpretation of standardised clinical outcomes data are feasible within routine clinical practice, and provide evidence that inpatient rehabilitation is effective in improving functional level in neurologically impaired patients. These data complement those of clinical trials and are useful in informing and developing clinical and research practice.

Increasing normal-appearing grey and white matter magnetisation transfer ratio abnormality in early relapsing-remitting multiple sclerosis

Abnormalities within normal-appearing grey and white matter (NAGM and NAWM) occur early in the clinical course of multiple sclerosis (MS) and can be detected in-vivo using the magnetisation transfer ratio (MTR). To better characterize the rates of change in both tissues and to ascertain when such changes begin, we serially studied a cohort of minimally disabled, early relapsing-remitting MS patients, using NAGM and NAWM MTR histograms. Twenty-three patients with clinically definite early relapsing-remitting MS (mean disease duration at baseline 1.9 years), and 19 healthy controls were studied. A magnetisation transfer imaging sequence was acquired yearly for two years. Twenty-one patients and 10 controls completed followup. NAWM and NAGM MTR histograms were derived and mean MTR calculated. A hierarchical regression analysis, adjusting for brain parenchymal fraction,was used to assess MTR change over time. MS NAWM and NAGM MTR were significantly reduced in comparison with controls at baseline and, in patients, both measures decreased further during follow-up: (-0.10 pu/year, p=0.001 and -0.18 pu/year, p<0.001 respectively). The rate of MTR decrease was significantly greater in NAGM than NAWM (p=0.004). Under the assumption that such changes are linear, backward extrapolation of the observed rates of change suggested that NAWM abnormality began before symptom onset. We conclude that increasing MTR abnormalities in NAWM and NAGM are observed early in the course of relapsing-remitting MS. It is now important to investigate whether these measures are predictive of future disability, and consequently, whether MTR could be used as a surrogate marker in therapeutic trials.

Metabolite Changes in Normal-Appearing Gray and White Matter Are Linked With Disability in Early Primary Progressive Multiple Sclerosis

BACKGROUND

Abnormalities in normal-appearing brain tissues may contribute to disability in primary progressive multiple sclerosis (PPMS), where few lesions are seen on conventional imaging.

OBJECTIVES

To evaluate the mechanisms underlying disease progression in the early phase of PPMS by measuring metabolite concentrations in normal-appearing white matter (NAWM) and cortical gray matter (CGM) and to assess their relationship with clinical outcomes.

DESIGN

Case-control study.

SETTING

Tertiary referral hospital. Patients Forty-three consecutive patients within 5 years of onset of PPMS and 44 healthy control subjects.

MAIN OUTCOME MEASURES

Concentrations of choline-containing compounds, phosphocreatine, myo-inositol, total N-acetyl-aspartate (tNAA), and glutamate-glutamine were estimated using proton magnetic resonance spectroscopic imaging. Brain parenchymal, white matter and gray matter fractions and proton density and gadolinium-enhancing lesion loads were calculated. The Expanded Disability Status Scale and Multiple Sclerosis Functional Composite scores were recorded.

RESULTS

In CGM, concentrations of the tNAA (P<.001) and glutamate-glutamine (P = .005) were lower in patients with PPMS than in controls. In NAWM, myo-inositol levels were higher (P = .002) and tNAA levels were lower (P = .005) in patients with PPMS than in controls. The Expanded Disability Status Scale score correlated with the tNAA concentration in CGM (r = -0.44; P = .03) and with myo-inositol (r = 0.41; P = .01) and glutamate-glutamine concentrations (r = 0.41; P = .01) in NAWM. Proton density lesion load correlated negatively with CGM tNAA concentration and positively with NAWM myo-inositol concentration.

CONCLUSION

Metabolite changes, which differ in CGM and NAWM, occur in early PPMS and are linked with disability.

Interferon beta-1b treatment does not induce autoantibodies

BACKGROUND

There is little information regarding the potential of interferon beta (IFNbeta) to induce or exacerbate autoimmune disease. Existing data from uncontrolled studies are contradictory and do not differentiate between autoimmune dysfunction, which is frequent in patients with multiple sclerosis (MS), and untoward drug effects.

OBJECTIVE

To evaluate the impact of IFNbeta on hepatic, thyroid, and other markers of autoimmunity using data from the European placebo-controlled double-blind, multicenter study of IFNbeta-1b in patients with secondary progressive MS (SPMS).

METHODS

Serum samples obtained at baseline and at 6-month intervals for 24 months were analyzed for the following autoantibodies (AAbs): antinuclear (ANA), antimitochondrial (AMA), smooth muscle (SMA), liver kidney microsome (LKM), thyroid microsome (TPO), and human thyroglobulin (TG). AAb status at baseline and during treatment was related to respective laboratory and clinical deviations.

RESULTS

The analysis of AAb data included 355 patients receiving IFNbeta-1b and 353 receiving placebo. There was no difference between treatment groups in de novo AAb positivity. A greater proportion of women were AAb positive at baseline and during treatment. No association was found between liver enzyme elevations and ANA, AMA, or SMA antibody formation in either treatment group. Laboratory-based thyroid alterations during the study were significantly related to TG/TPO status at baseline but were not associated with IFNbeta-1b treatment. Adverse events possibly indicative of other diseases with autoimmune links were not associated with respective AAb status.

CONCLUSION

Interferon beta-1b treatment did not induce autoantibody formation in this population of patients with secondary progressive multiple sclerosis.

Gray and white matter volume changes in early RRMS: A 2-year longitudinal study

BACKGROUND

Brain atrophy, in excess of that seen with normal aging, has been observed early in the clinical course of relapsing-remitting multiple sclerosis (RRMS). Previous work has suggested that at this stage of the disease, gray matter (GM) atrophy progresses more rapidly than the white matter (WM) atrophy.

OBJECTIVES

To characterize the evolution of GM and WM volumes over 2 years, and their associations with lesion loads in a cohort of patients with clinically early RRMS.

METHODS

Twenty-one patients with RRMS (mean age 37.5 years, mean disease duration from symptom onset 2.1 years) and 10 healthy control subjects (mean age 37.1 years) were studied. Tissue volumes, as fractions of total intracranial volumes, were estimated at baseline and 1- and 2-year follow-up. Brain parenchymal fractions (BPF), GM fractions (GMF), and WM fractions (WMF) were estimated. In subjects with MS, brain lesion loads were determined on conventional T2-weighted along with pre- and post-gadolinium (Gd) enhanced T1-weighted images at each timepoint.

RESULTS

A decrease in GMF was observed in subjects with MS vs normal controls over the 2 years of the study (mean -2.1% vs -1.0%, p = 0.044), while no change was seen in WMF over the same period (mean -0.09% vs +0.09%, p = 0.812). However, when the MS cohort was divided in half, dependent upon change in Gd-enhancing lesion load over 2 years (n = 20), a decrease in WMF was seen in the group (n = 10) with the largest decline in Gd volume, whereas WMF increased in the other half (n = 10) concurrent with a net increase in volume of Gd-enhancing lesions (difference between groups: p = 0.034).

CONCLUSIONS

Increasing gray matter but not white matter (WM) atrophy was observed early in the clinical course of relapsing-remitting multiple sclerosis. Fluctuations in inflammatory WM lesions appear to be related to volume changes in WM over this time period.

Magnetic resonance imaging predictors of disability in primary progressive multiple sclerosis: a 5-year study

Magnetic resonance imaging (MRI) has become an accepted tool for monitoring therapeutic trials in relapsing-remitting and secondary progressive multiple sclerosis (MS); it is however unclear whether such MRI markers are equally applicable to primary progressive MS (PPMS). Forty-two patients with PPMS were reviewed five years after commencing a two-year MRI and clinical study. Clinical measures recorded at baseline and five years included both the Expanded Disability Status Scale and the MS functional composite. MRI data collected at baseline and two years included T1 and T2 lesion loads, the number of new brain and cord lesions, and measures of both brain and cord atrophy. The study demonstrated that both the number of new T2 lesions and rate of increase in ventricular volume over two years were modestly predictive of subsequent disease progression and therefore may be useful tools in the testing of new therapeutic agents in PPMS.

Estimation of the macromolecular proton fraction and bound pool T2 in multiple sclerosis

This study used a model for magnetization transfer (MT) to estimate two underlying parameters: the macromolecular proton fraction (f) and the bound pool T2 (T2b) in patients with multiple sclerosis (MS). Sixty patients with clinically definite MS and 27 healthy controls were imaged using: (1) a dual echo fast spin echo sequence, (2) a MT sequence (with ten MT power and offset frequency combinations) and (3) proton density and T1 weighted sequences (for T1 relaxation time estimation). Fourteen normal-appearing white matter (NAWM) regions of interest (ROI) and six normal-appearing gray matter (NAGM) ROIs were outlined in all subjects. Lesions were also contoured in subjects affected by MS. The model was fitted to the data leading to estimates of T2b and f. Results showed that T2b was increased in lesions whereas f was reduced. In NAWM, f was decreased while T2b was only increased in secondary progressive MS. NAWM f correlated modestly with disability. Further studies are needed to investigate the pathological basis of the abnormalities observed.

Self-efficacy predicts self-reported health status in multiple sclerosis

Self-efficacy is a belief that one can competently cope with a challenging situation. If self-efficacy is a strong predictor of health status in multiple sclerosis (MS), it may be an important area to target in clinical practice, as such beliefs may be modifiable. The aim of this study was to examine the predictive value of self-efficacy on self-reported health status in MS. Eighty-nine people with MS completed the Multiple Sclerosis Self-efficacy Scale (MSSE function and control scales), the Multiple Sclerosis Impact Scale (MSIS-29), and the Multiple Sclerosis Walking Scale (MSWS-12) at two time points: 1) admission to an inpatient rehabilitation unit (n = 43) or for steroid treatment for relapses (n = 46); and 2) discharge (rehabilitation group) or six weeks later (steroid group). Multiple regression analyses examined whether baseline and changes in self-efficacy predict changes in self-reported health status. Both baseline and changes in self-efficacy were strong and independent predictors of changes in health status (P-values ranged from 0.025 to < 0.001). That is, pretreatment self-efficacy scores and increases in self-efficacy scores from baseline to follow-up (improvement), were significantly associated with decreases (improvement) in perceived walking ability and physical and psychological impact of MS. The findings suggest that self-efficacy predicts improvement in health status and that self-efficacy would be an important domain to measure and manage actively in education and rehabilitation programs.

Abnormalities of cerebral perfusion in multiple sclerosis

BACKGROUND

Measuring perfusion provides a potential indication of metabolic activity in brain tissue. Studies in multiple sclerosis (MS) have identified areas of decreased perfusion in grey matter (GM) and white matter (WM), but the pattern in clinical subgroups is unclear.

OBJECTIVES

This study investigated perfusion changes in differing MS clinical subgroups on or off beta-interferon therapy using a non-invasive MRI technique (continuous arterial spin labelling) to investigate whether different clinical MS subtypes displayed perfusion changes and whether this could give a further insight into the pathological mechanisms involved.

METHODS

Sixty patients (21 relapsing remitting, 14 secondary progressive, 12 primary progressive, 13 benign) and 34 healthy controls were compared. Statistical parametric mapping (SPM '99) was used to investigate regional variations in perfusion in both GM and WM. Global WM perfusion was derived by segmenting WM from images using T(1) relaxation times.

RESULTS

Regions of lower perfusion in predominantly GM were observed in the primary and secondary progressive cohorts, particularly in the thalamus. Increased WM perfusion was seen in relapsing remitting and secondary progressive cohorts.

CONCLUSIONS

Low GM perfusion could reflect decreased metabolism secondary to neuronal and axonal loss or dysfunction with a predilection for progressive forms of MS. Increased WM perfusion may indicate increased metabolic activity possibly due to increased cellularity and inflammation. Improved methodology and longitudinal studies may enable further investigation of regional and temporal changes, and their relationship with physical and cognitive impairment.

Corticocortical coupling in chronic stroke: Its relevance to recovery

BACKGROUND

The mechanisms behind motor recovery from stroke are not clearly understood. Functional imaging studies have demonstrated task-related brain activation in several motor areas, but few studies have attempted to correlate this with stroke outcome. Moreover, these studies have focused on how motor areas may individually contribute to compensation. Here, the authors investigate whether different cortical areas interact to form dynamic assemblies that may then compensate for disability.

METHODS

The authors investigated corticocortical coherence in 16 healthy subjects and 25 patients with chronic stroke involving one cerebral hemisphere and having varying degrees of motor recovery. Scalp EEG was recorded at rest and while right-handed subjects performed a unimanual grip task. The degree of functional recovery after stroke was assessed using a range of outcome measures.

RESULTS

Compared with healthy subjects, hand-related asymmetries in task-related EEG-EEG coherence were increased between mesial and lateral frontal regions of the affected hemisphere, over mesial frontal regions, and over lateral frontal areas of the unaffected hemisphere when patients with stroke gripped with their affected hand. Mesial hand-related asymmetries in task-related power and coherence were negatively correlated with recovery.

CONCLUSION

Increases in task-related coupling between cortical areas may dynamically compensate for brain damage after stroke. Some of this increased coupling, particularly that over mesial frontal areas, decreases as patients make a functional recovery.

Progressive grey matter atrophy in clinically early relapsing-remitting multiple sclerosis

Brain atrophy appears to occur in patients with multiple sclerosis (MS) in excess of that associated with normal ageing, and may be observed early in the clinical course of the disease. The dynamics and tissue specificity of this process remain unclear This preliminary study explored the evolution of brain grey matter (GM) and white matter (WM) volume loss (as fractions of total intracranial volumes) in 13 subjects with relapsing-remitting MS (mean disease duration 1.9 years at first scan), compared with nine normal control (NC) subjects. Subjects were scanned every six months for 18 months. In MS compared with NC subjects, significant differences in WM fractional volumes were observed at baseline (mean - 5.8%, P = 0.008) but no apparent progressive WM tissue loss was detected. In contrast, while no significant differences in GM fractional volumes were observed at baseline, there was significantly greater time-related volume loss in MS compared with NC subjects over the follow-up period (circa - 0.0086 per year in MS subjects, - 0.0021 per year in the NC subjects, difference P = 0.010). These results suggest that while both GM and WM atrophy are seen early in the clinical course of MS, they may not occur concurrently and may evolve at different rates.

Evidence for grey matter MTR abnormality in minimally disabled patients with early relapsing-remitting multiple sclerosis

OBJECTIVES

To establish whether magnetisation transfer ratio (MTR) histograms are sensitive to change in normal appearing grey matter (NAGM) in early relapsing-remitting multiple sclerosis (RRMS) in the absence of significant disability; and to assess whether grey or white matter MTR measures are associated with clinical measures of impairment in early RRMS METHODS: 38 patients were studied (mean disease duration 1.9 years (range 0.5 to 3.7); median expanded disability status scale (EDSS) 1.5 (0 to 3)), along with 35 healthy controls. MTR was determined from proton density weighted images with and without MT presaturation. SPM99 was used to generate normal appearing white matter (NAWM) and NAGM segments of the MTR map, and partial voxels were minimised with a 10 pu threshold and voxel erosions. Mean MTR was calculated from the tissue segments. Atrophy measures were determined using a 3D fast spoiled gradient recall sequence from 37 patients and 17 controls.

RESULTS

Mean NAGM and NAWM MTR were both reduced in early RRMS (NAGM MTR: 31.9 pu in patients v 32.2 pu in controls; p<0.001; NAWM MTR: 37.9 v 38.3 pu, p = 0.001). Brain parenchymal fraction (BPF) correlated with NAGM MTR, but when BPF was included as a covariate NAGM MTR was still lower in the patients (p = 0.009). EDSS correlated with NAGM MTR (r = 0.446 p = 0.005).

CONCLUSIONS

In early RRMS, grey matter MTR abnormality is apparent. The correlation with mild clinical impairment (in this essentially non-disabled cohort) suggests that NAGM MTR could be a clinically relevant surrogate marker in therapeutic trials.

Improving the evaluation of therapeutic interventions in multiple sclerosis: development of a patient-based measure of outcome

OBJECTIVES

To develop a patient-based, disease-specific measure of the health impact of multiple sclerosis (MS) for use in clinical trials and clinical practice.

DATA SOURCES

People with MS. Members of the MS Society of Great Britain and Northern Ireland.

METHODS

Standard psychometric methods were used to develop the Multiple Sclerosis Impact Scale (MSIS-29) in three stages. Stage 1 (item generation): questionnaire items were generated from 30 patient interviews on the impact of MS on their lives, expert opinion and literature review. Stage 2 (item reduction and scale generation): the questionnaire developed in stage 1 was administered by postal survey to 1530 randomly selected members of the MS Society. Standard item reduction techniques were used to develop a rating scale from the pool of questionnaire items. Stage 3 (psychometric evaluation): the questionnaire was evaluated for data quality, scaling assumptions, acceptability, reliability and validity in a separate postal survey of 1250 MS Society members. Responsiveness was evaluated in 55 people admitted to hospital for rehabilitation and intravenous steroid treatment of MS relapses.

RESULTS

Stage 1 resulted in a 129-item questionnaire. Stage 2 resulted in a 29-item rating scale measuring the physical and psychological impact of MS. The MSIS-29 satisfied all recommended psychometric criteria for rigorous measurement. Data quality was excellent: missing data were low, item test-retest reliability was high and scale scores could be generated for over 98% of respondents. Item descriptive statistics, item convergent and discriminant validity, and factor analysis supported summing items to produce two summary scores. MSIS-29 physical and psychological scale scores showed good variability, low floor and ceiling effects, good internal consistency and test-retest reliability. Correlations with other measures and confirmation of hypotheses about group differences provided evidence for the validity of the MSIS-29 as a measure of the physical and psychological impact of multiple sclerosis. Effect sizes provided preliminary evidence for responsiveness.

CONCLUSIONS

The 29-item MSIS-29 is a rigorous new measure of the physical and psychological impact of MS. All psychometric criteria were satisfied and there is preliminary evidence of responsiveness. The MSIS-29 is particularly appropriate for use in clinical trials to evaluate therapeutic effectiveness from the patient's perspective. Further critical evaluations of the MSIS-29 completed by people with neurologist-confirmed MS in different settings are suggested. Head-to-head comparisons of the psychometric properties of the MSIS-29 and other outcome measures for MS will help to determine the relative advantages of different instruments so that the choice of measures for studies can be evidence based.

The management of multiple sclerosis: current and future therapies

Management of the patient with multiple sclerosis (MS) encompasses a number of distinct, if overlapping, areas. They include anticipation and prevention of problems, symptom control, drug therapies aimed at reducing disease activity and finally, rehabilitation and service delivery. The recent advent of new immunosuppressant treatments for MS is extremely exciting. Beta-interferons (1a and 1b) are now licensed worldwide and glatiramer acetate (Copaxane) is in use in the United States. Many more drugs, including intravenous immunoglobulin, mitoxantrone, methotrexate and cladribine, are undergoing trials and some are showing promising results. Future therapies with monoclonal antibodies and adhesion molecules are also undergoing extensive research. Realistically, however, these new treatments aimed at reducing disease activity will have little impact on existing problems or the degree of disability. Consequently, much of the management of a patient with MS relates to control of the vast array of symptoms. These range from the obvious problems of weakness and spasticity, ataxia and sphincter disturbance, to less common but still important problems such as visual, cognitive, swallowing and respiratory difficulties. Some of the most common, and to the patient most disabling, symptoms are fatigue, thermal sensitivity and pain, areas often neglected by the physician in the face of more obvious physical needs. Much can be done for the patient in all areas. A combination of education, physiotherapy and drug therapy is usually required but occasionally there is a place for more invasive treatments such as intrathecal baclofen administration for severe spasticity or thalamic surgery for cerebellar tremor. A multidisciplinary team approach is essential in the overall management of the patient with MS, particularly when assessing their needs as a basis for both inpatient rehabilitation programs and in the provision of a comprehensive community-based service.

Improving the quality of life of patients with multiple sclerosis: diagnosis

Multiple sclerosis (MS) is the commonest neurological cause of disability in young adults. The clinical course is extremely variable, but typically a relapsing-remitting phase of variable duration is followed by a gradual progression in disability. However, the diagnosis of MS may have an impact that reaches beyond the physical disabilities into many other aspects of life, including career and family. The time of diagnosis is one of the most important in the course of the illness and the way in which investigations are conducted, the timing and manner of imparting the diagnosis, and subsequent support and education may have far-reaching consequences. The diagnostic phase thus presents a difficult management challenge for the neurologist and other health workers attempting to address these issues. This review considers the steps involved in reaching the diagnosis, together with ways in which the overall quality of life of the patient may be maximized during this period.

Elevated white matter myo-inositol in clinically isolated syndromes suggestive of multiple sclerosis

Normal-appearing white matter (NAWM) in established multiple sclerosis has been shown to be abnormal using a variety of magnetic resonance (MR) techniques, including proton MR spectroscopy ((1)H-MRS), although the stage at which these changes first appear is less clear. Using a 1.5 T scanner and single-voxel (1)H-MRS [TR 3000 ms, TE 30 ms, point-resolved spectroscopy (PRESS) localization], we determined NAWM metabolite concentrations in 96 patients a mean of 19 weeks (range 12-28 weeks) after onset of a clinically isolated syndrome (CIS) suggestive of multiple sclerosis and in 44 healthy control subjects. Absolute concentrations of N-acetyl-aspartate, total creatine and phosphocreatine (Cr), choline-containing compounds, glutamate plus glutamine, and myo-inositol (Ins) were estimated automatically using the LCModel. Compared with control subjects, the concentration of Ins was elevated in CIS NAWM (mean 3.31 mM, SD 0.86 versus mean 3.82 mM, SD 1.06; P = 0.001). The increase in Ins was also seen in the patient subgroup with abnormal T2-weighted MRI (mean 3.88 mM, SD 1.10; P = 0.001) and in those who satisfied the McDonald criteria for multiple sclerosis (mean 4.04 mM, SD 1.31; P = 0.001). An increase in Cr was also observed in CIS NAWM (P = 0.023), but other metabolites did not significantly differ between the whole CIS group and control subjects. There was no significant correlation between NAWM Ins and T2 lesion load. The early increase in Ins may reflect a process of pathogenic importance in multiple sclerosis NAWM. Follow-up studies will investigate whether the increase in NAWM Ins is of prognostic importance for future relapses and disability.

Serial magnetization transfer imaging in acute optic neuritis

In serial studies of multiple sclerosis lesions, reductions in magnetization transfer ratio (MTR) are thought to be due to demyelination and axonal loss, with later rises due to remyelination. This study followed serial changes in MTR in acute optic neuritis in combination with clinical and electrophysiological measurements to determine if the MTR changes over time mirror the picture in multiple sclerosis lesions, further validating MTR as a marker of tissue integrity. Twenty-nine patients were recruited who had acute optic neuritis for a median of 13 days (range 7-24 days) since the onset of visual symptoms. A clinical examination and measurement of visual evoked potentials (VEP) was performed on each patient. Their optic nerves were imaged with a fat-saturated fast spin echo (FSE) sequence and a magnetization transfer sequence. Twenty-one had multiple subsequent examinations over the course of 1 year. In addition, 27 control subjects had their optic nerves imaged up to three times over 1 year. A blinded observer segmented the optic nerves from the MTR maps. Lesions were defined on the acute FSE images and, from the coordinates, the ratio of mean lesion MTR : healthy nerve MTR (lesion ratio) was calculated for each dataset. The time-averaged mean MTR in control optic nerves was 47.7 per cent units (pu). In diseased optic nerves, baseline mean MTR was 47.3 pu, with a mean lesion ratio of 0.98. The diseased optic nerve MTR and lesion ratio declined over time with a nadir at about 240 days at a mean MTR value of 44.2 pu and mean lesion ratio of 0.91. Subsequently, diseased optic nerve MTR appeared to rise; after 1 year the diseased optic nerve mean MTR was 45.1 pu (mean lesion ratio 0.93), although the difference was not significant compared with the nadir value. For each 0.01 increase in time-averaged lesion ratio logMAR visual acuity recovery improved by 0.03 (95% CI, 0.002, 0.08, P = 0.02). Time-averaged VEP central field latency was shorter by 6.1 ms (95% CI 1.5, 10.7, P = 0.012) per 1 pu rise in time-averaged diseased optic nerve MTR. The early fall in diseased optic nerve MTR is consistent with demyelination and Wallerian degeneration of transected axons. The late nadir compared with studies of multiple sclerosis lesions may have been due to slow clearance of myelin debris. Remyelination may have influenced subsequent MTR changes. The observations support using MTR to monitor symptomatic demyelinating lesions.

[Diagnosis of multiple sclerosis]

This article prepared by members of International Panel working on new diagnostic criteria of multiple sclerosis (MS) presents and discusses these criteria, which pay special attention to MRI as a method of confirmation of dissemination in space and in time, necessary for MS diagnosis. Also main problems of MS differential diagnosis are discussed as well as significance of other laboratory methods like evoked potentials and cerebrospinal fluid studies. Nevertheless the significance of clinical signs in MS diagnosis are decisive.

Magnetic resonance studies of abnormalities in the normal appearing white matter and grey matter in multiple sclerosis

Magnetic resonance (MR) techniques are of value in following the pathological process of multiple sclerosis in vivo. They are widely applied to monitor the disease natural history and its modification by treatment. However, serial studies of lesion measures have yielded generally disappointing correlations with the development of clinical disability. A potential explanation for this is the presence of abnormalities, beyond the visible lesions, in the normal appearing white matter (NAWM) and grey matter (NAGM). Quantitative structural MR techniques, including measures of magnetisation transfer, diffusion, relaxation times and spectroscopic metabolite concentrations, reveal that there are abnormalities in NAWM and NAGM. These are present from clinical onset and become more pronounced with clinical progression, increasing disability and increasing lesion load. Furthermore, functional MRI (fMRI) studies of motor and visual paradigms has identified a range of responses suggesting that cortical plasticity exists; such modified responses are seen in the earliest stages of disease and in the absence of visible lesions, but are more pronounced with disease progression and increasing lesion load and abnormality in the NAWM. Limited reproducibility and sensitivity to change can pose methodological limitations for MR studies of NAWM and NAGM, especially when follow up intervals are relatively short. Whilst existing quantitative MR measures from normal appearing tissues provide valuable information to understand the natural history and monitor treatment effects in MS, none of them fully or even predominantly accounts for the patient's functional state nor can be relied on as a definitive surrogate measure of treatment effect. Better resolution of the abnormalities is needed especially in grey matter where pathological foci are known to be abundant. Studies correlating structural MR and fMRI parameters with measures of function in well defined anatomical pathways should further elucidate the pathogenic role of abnormality in the normal appearing tissues. In future, new imaging modalities are needed that provide a more specific measure of histopathological and cellular aspects of the disease process in vivo.

Primary progressive multiple sclerosis: a 5-year clinical and MR study

Longitudinal imaging studies of primary progressive multiple sclerosis (PPMS) have shown significant changes in MR measures over 1 to 2 years. Correlation with clinical change over the same period has not been evident; we investigated the possibility that this is because the period of observation was insufficient for these associations to become apparent. Forty-one patients with PPMS were followed prospectively for 5 years. Patients had clinical [Expanded Disability Status Scale (EDSS) and Multiple Sclerosis Functional Composite Measure (MSFC)] and MRI assessment (brain and spinal cord) at baseline, 1, 2 and 5 years. At 5 years, significant deterioration was seen in all clinical and MRI measures (P<0.01, P<0.001 respectively). Associations were seen between increase in EDSS score and decrease in cord area (r=0.31, P<0.05) and between increase in MSFC and both rate of ventricular enlargement (r=0.31, P<0.05) and increase in T2 load (r=0.31, P<0.05). The rates of change of MR measures were not associated with age or disease duration and were more consistent within than between patients. Longer duration of follow-up demonstrates modest associations between change in clinical and MR measures and provides new insights into the pattern of change within and between individuals with PPMS.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Neural correlates of motor recovery after stroke: a longitudinal fMRI study

Recovery of motor function after stroke may occur over weeks or months and is often attributed to cerebral reorganization. We have investigated the longitudinal relationship between recovery after stroke and task-related brain activation during a motor task as measured using functional MRI (fMRI). Eight first-ever stroke patients presenting with hemiparesis resulting from cerebral infarction sparing the primary motor cortex, and four control subjects were recruited. Subjects were scanned on a number of occasions whilst performing an isometric dynamic visually paced hand grip task. Recovery in the patient group was assessed using a battery of outcome measures at each time point. Task-related brain activations decreased over sessions as a function of recovery in a number of primary and non-primary motor regions in all patients, but no session effects were seen in the controls. Furthermore, consistent decreases across sessions correlating with recovery were seen across the whole patient group independent of rate of recovery or initial severity, in primary motor cortex, premotor and prefrontal cortex, supplementary motor areas, cingulate sulcus, temporal lobe, striate cortex, cerebellum, thalamus and basal ganglia. Although recovery-related increases were seen in different brain regions in four patients, there were no consistent effects across the group. These results further our understanding of the recovery process by demonstrating for the first time a clear temporal relationship between recovery and task-related activation of the motor system after stroke.

Spinal cord MRI in clinically isolated optic neuritis

BACKGROUND/METHODS

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

RESULTS

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

CONCLUSIONS

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

Diffusion tensor imaging detects corticospinal tract involvement at multiple levels in amyotrophic lateral sclerosis

BACKGROUND

Histopathological studies of amyotrophic lateral sclerosis (ALS) are of end stage disease. Diffusion tensor imaging (DTI) provides the opportunity to investigate indirectly corticospinal tract pathology of ALS in vivo.

METHODS

DTI was used to study the water diffusion characteristics of the corticospinal tracts in 21 patients with ALS and 14 normal controls. The authors measured the fractional anisotropy (FA) and mean diffusivity (MD) along the pyramidal tracts from the internal capsules down to the pyramids. A mixed model regression analysis was used to compare FA and MD between the ALS and control groups.

RESULTS

FA showed a downward linear trend from the cerebral peduncles to the pyramids and was lower in the ALS group than controls at multiple levels of the corticospinal tract. At the internal capsules, FA was higher on the right. MD showed an upward trend, progressing caudally from the internal capsules to the pyramids. MD was higher at the level of the internal capsule in the ALS group, but caudally this difference was not maintained. No correlations were found between clinical markers of disability and water diffusion indices.

CONCLUSIONS

These findings provide insights into the pathological processes of ALS. Differences in diffusion characteristics at different anatomical levels may relate to underlying tract architecture or the distribution of pathological damage in ALS. Further development may permit monitoring of progression and treatment of disease.

Evidence-based measurement in multiple sclerosis: the psychometric properties of the physical and psychological dimensions of three quality of life rating scales

The selection of measures of quality of life used in clinical trials of multiple sclerosis (MS) should be evidence-based. Head-to-head comparison of measures facilitates the selection of measures. The aim of the study was to compare the psychometric properties of the physical and psychological dimensions in three measures of quality of life to aid choice of the most appropriate scale for use in clinical trials of MS. One hundred and twenty-one people with MS (rehabilitation = 57; steroids = 64) completed a selection of health measures before and after treatment. The psychometric properties of three measures of physical function (MSIS-29 physical, SF-36 physical functioning, FAMS mobility) and three measures of psychological function (MSIS-29 psychological, SF-36 mental health, FAMS emotional well-being) were compared by examining data quality, scaling assumptions, acceptability, reliability, validity and responsiveness. Physical (0.63-0.71) and psychological (0.70-0.75) scales were substantially correlated indicating they measure related constructs. The MSIS-29 physical and psychological scales satisfied all criteria for internal consistency reliability (physical = 0.91; psychological = 0.89) and validity. The SF-36 physical scale had a notable floor effect (20%). The FAMS mobility scale had lower reliability (alpha = 0.78) compared to other measures. The MSIS-29 physical (effect size = 0.91) and psychological (effect size = 0.62) scales were the most responsive. In these three samples, the MSIS-29 had better measurement properties for combined physical and psychological health than the SF-36 and the FAMS.

Diffusion tractography based group mapping of major white-matter pathways in the human brain

Tractography uses diffusion tensor imaging data to trace white matter pathways in vivo within the brain. We have constructed group maps that represent three major white matter tracts-the anterior callosal fibers, optic radiations, and pyramidal tracts-in a group of 21 volunteers. For each individual tract the fast marching tractography (FMT) algorithm was used to generate a VSC (voxel scale connectivity) map in native space. Using SPM99 these maps were transformed into a standard reference frame and three group mapping techniques were investigated: the first averaged the individual VSC maps, the second produced maps that demonstrate intersubject tract variability and degree of overlap, and the third used an SPM analysis to construct a statistical image that represents the group effect. The group maps reconstructed for each tract under investigation conform well to known anatomy and are consistent with data derived from postmortem human brains. Greater intersubject variability is found around the terminal projections of the tracts adjacent to cerebral cortex, whereas the "core" of each tract is characterized by lower variability. No significant differences were found between the left and right side of the pyramidal tracts and optic radiations. The group mapping techniques utilize the VSC maps in different but complementary ways. In the future, group mapping could investigate in vivo white matter differences between normal subjects and patients affected by neurological and psychiatric diseases.

Non-invasive mapping of connections between human thalamus and cortex using diffusion imaging

Evidence concerning anatomical connectivities in the human brain is sparse and based largely on limited post-mortem observations. Diffusion tensor imaging has previously been used to define large white-matter tracts in the living human brain, but this technique has had limited success in tracing pathways into gray matter. Here we identified specific connections between human thalamus and cortex using a novel probabilistic tractography algorithm with diffusion imaging data. Classification of thalamic gray matter based on cortical connectivity patterns revealed distinct subregions whose locations correspond to nuclei described previously in histological studies. The connections that we found between thalamus and cortex were similar to those reported for non-human primates and were reproducible between individuals. Our results provide the first quantitative demonstration of reliable inference of anatomical connectivity between human gray matter structures using diffusion data and the first connectivity-based segmentation of gray matter.

Interferon beta in multiple sclerosis: experience in a British specialist multiple sclerosis centre

BACKGROUND

The efficacy of interferon beta (IFN beta) is well established in relapsing-remitting multiple sclerosis (MS). However, the use of this drug in clinical practice is complex, especially because it is only partially effective, its long term efficacy and side effects are unknown, its efficacy may be abrogated by the development of neutralising antibodies, compliance is variable, and its cost effectiveness is controversial.

OBJECTIVES AND METHODS

Analysis of a prospectively followed up series of 101 MS patients treated with IFN beta was undertaken to: (1) monitor the outcome of IFN beta treatment in clinical practice; (2) compare the immunogenicity of the three commercial IFN beta preparations available; (3) assess the proportion of patients fulfilling the current guidelines of the Association of British Neurologists for stopping IFN beta therapy.

RESULTS

During a median treatment period of 26 months (range 2-85), the relapse rate decreased by 41%. Although the reduction in the relapse rate was similar for all three commercial products, none of the Avonex treated patients were relapse free, compared with 19% of the Betaferon treated and 27% of the Rebif treated patients (p=0.02). Neutralising antibodies were not detected in Avonex treated patients (0 of 18), compared with 12 of 32 (38%) Betaferon treated and 10 of 23 (44%) Rebif treated patients (p=0.02). Forty of 101 (40%) patients satisfied the current (2001) Association of British Neurologists criteria for stopping IFN beta treatment at some stage during their treatment.

CONCLUSION

IFN beta is effective in reducing the relapse rate in patients with relapsing-remitting MS in routine clinical practice. However, after a median treatment duration of 26 months, 40% of initially relapsing-remitting MS patients seem to have ongoing disease activity, presenting as disabling relapses or insidious progression.

Preliminary magnetic resonance study of the macromolecular proton fraction in white matter: a potential marker of myelin?

We report on a new quantitative magnetization transfer (MT) technique that allows for the in vivo estimation of the macromolecular proton fraction (f) and the bound pool T2 relaxation time (T2b), whilst permitting whole brain coverage. In this pilot study, five subjects with multiple sclerosis (MS) and five healthy controls were studied. Both f and T2b were significantly different between MS lesions and normal control white matter (WM). Relationships between f and T1 relaxation time [Spearmans rank correlation coefficient (r(s)) = -0.97, P < 0.001] and f and the magnetization transfer ratio (MTR; r(s) = 0.80, P < 0.001) were observed. Compared with MTR, f and T2b have the potential advantage of relative independence from MT acquisition protocol while offering more pathologically specific information. In particular, f may provide a more direct indication of myelin content in WM.