Building an evidence base for multiple sclerosis management: support for physiotherapy.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to A J Thompson.
Explore the source record for details and available documents.
OBJECTIVES: With increasing evidence that permanent tissue damage occurs early in the course of multiple sclerosis, it is important that treatment trials include patients in the earliest stages of the disease. For many patients with multiple sclerosis the first presentation is a clinically isolated syndrome. Not all patients with a clinically isolated syndrome develop multiple sclerosis, however, and treatment of all such patients would be unwarranted. A single abnormal brain MRI identifies patients at a higher risk for the early development of multiple sclerosis, but current criteria are limited by either poor specificity (T2 lesions) or sensitivity (contrast enhancing lesions). The aim of the study was to assess the positive predictive value, sensitivity, and specificity of MRI indices for the development of multiple sclerosis after 1 year from two MRI examinations obtained 3 months apart. METHODS: MRI examinations were performed in 68 patients with a clinically isolated syndrome, with a clinical assessment after 1 year. RESULTS: Contrast enhancing lesions at both time points were the most predictive indices for developing multiple sclerosis (positive predictive value 70%) but had low sensitivity (39%). The combination of T2 lesions at baseline with new T2 lesions at follow up had the best overall positive predictive value (53%), sensitivity (83%), and specificity (76%). In patients with T2 lesions at baseline, the presence or absence of new T2 lesions at follow up significantly altered the risk of multiple sclerosis within 1 year (55% and 5% respectively, p<0.001). Multiple sclerosis also developed in 10% of patients with a normal baseline MRI. CONCLUSIONS: Serial imaging in patients with clinically isolated syndromes improved the positive predictive value, sensitivity, and specificity of MRI for the development of early multiple sclerosis and also identified patients at a lower risk of early multiple sclerosis than would have been expected from their abnormal baseline MRI. Selection of patients with clinically isolated syndromes for therapeutic intervention or clinical trials may benefit from serial MRI, to target those at greatest risk of early development of multiple sclerosis.
Atrophy of the spinal cord is known to occur in multiple sclerosis but the cause and the timing of its onset are not clear. Recent evidence suggests that atrophy may start to occur early in the disease. The aim was to determine whether atrophy of the spinal cord could be detected in vivo using MRI techniques, in patients presenting with a clinically isolated syndrome, which in many cases is the earliest clinical stage of multiple sclerosis. The cross sectional area of the spinal cord was measured in 43 patients presenting with a clinically isolated syndrome and 15 matched controls. T2 weighted imaging of the brain was also performed to determine the number and volume of high signal lesions consistent with disseminated demyelination. Both patients and controls were restudied after 1 year. The spinal cord area was significantly smaller in the 74% of patients with an abnormal brain MRI at presentation than in controls (mean areas 73.9 mm(2) and 78.1 mm(2) respectively, p=0.03). No significant difference was found in the spinal cord area between controls and patients with normal baseline brain imaging. The annual rate of change in patients did not differ significantly from controls. In conclusion, the finding of a smaller cord area in the subgroup of patients with clinically isolated syndrome with the highest risk of developing multiple sclerosis-that is, with an abnormal brain MRI, suggests that atrophy has developed in some patients with multiple sclerosis even before their first clinical symptoms. However, the lack of a detectable change in cord area over 1 year of follow up contrasts strikingly with the results of an earlier study of patients with relapsing-remitting multiple sclerosis, suggesting that the rate of atrophy increases as the disease becomes more established.
OBJECTIVES: Routine data collection is now considered mandatory. Therefore, staff rated clinical scales that consist of multiple items should have the minimum number of items necessary for rigorous measurement. This study explores the possibility of developing a short form Barthel index, suitable for use in clinical trials, epidemiological studies, and audit, that satisfies criteria for rigorous measurement and is psychometrically equivalent to the 10 item instrument. METHODS: Data were analysed from 844 consecutive admissions to a neurological rehabilitation unit in London. Random half samples were generated. Short forms were developed in one sample (n=419), by selecting items with the best measurement properties, and tested in the other (n=418). For each of the 10 items of the BI, item total correlations and effect sizes were computed and rank ordered. The best items were defined as those with the lowest cross product of these rank orderings. The acceptability, reliability, validity, and responsiveness of three short form BIs (five, four, and three item) were determined and compared with the 10 item BI. Agreement between scores generated by short forms and 10 item BI was determined using intraclass correlation coefficients and the method of Bland and Altman. RESULTS: The five best items in this sample were transfers, bathing, toilet use, stairs, and mobility. Of the three short forms examined, the five item BI had the best measurement properties and was psychometrically equivalent to the 10 item BI. Agreement between scores generated by the two measures for individual patients was excellent (ICC=0.90) but not identical (limits of agreement=1.84+/-3.84). CONCLUSIONS: The five item short form BI may be a suitable outcome measure for group comparison studies in comparable samples. Further evaluations are needed. Results demonstrate a fundamental difference between assessment and measurement and the importance of incorporating psychometric methods in the development and evaluation of health measures.
Explore the source record for details and available documents.
As short-term MRI studies are increasingly being used to monitor disease activity in multiple sclerosis (MS) it is vital to establish if short-term MRI activity is predictive of long term clinical outcome. We followed up after 5 years a group of 10 benign (relapsing-remitting MS with a disease duration > 10 years and EDSS < or = 3) and 10 early relapsing-remitting patients who previously had monthly serial MRI scans for 6 months. In the early relapsing-remitting group median EDSS at entry to the initial serial study was three and in the benign group 2.5. At 5-year follow up, five of these 20 patients had developed a definite deterioration in EDSS. The median number of new enhancing lesions detected originally in the group that had deteriorated was 11 (7-17) compared to 0 (0-5) new enhancing lesions, for those who had not deteriorated (P < 0.05). There was a trend towards a higher baseline T2 lesion load in the group with a definite change in EDSS but this was not significant This study suggests that short-term measurement of the number of gadolinium enhancing lesions may predict long term outcome in relapsing-remitting MS.
Gadolinium enhanced magnetic resonance imaging detects focal blood-brain barrier breakdown in new inflammatory multiple sclerosis lesions, but such lesions do not correlate with disease progression. To explore whether the latter might relate to subtle but widespread blood-brain barrier (BBB) breakdown with low grade inflammation mediating tissue damage, quantitative techniques were used to detect subtle gadolinium enhancement within otherwise normal-appearing white matter and within lesions not showing visible enhancement. T1-weighted imaging was performed prior to and at 5, 20 and 40 min following injection of 0.3 mmol/kg gadopentate dimeglumine in 33 patients with multiple sclerosis and five healthy control subjects. In healthy controls, a significant increase in white matter signal 5 min following contrast injection was observed (1.8%, P < 0.0005); the signal returned to baseline values by 20 min. In multiple sclerosis patients, a non-significant trend was noted for signal to remain elevated in normal-appearing white matter at the 20 and 40 min post-contrast time points; this was most apparent in primary progressive multiple sclerosis. Significant increases in signal intensity were noted at all time points post contrast in apparent non-enhancing lesions. The transient post contrast signal increase in controls is likely due to intravascular gadopentate dimeglumine. The persistent increases in signal intensity in non-enhancing lesions suggest more widespread abnormalities in BBB than is visually apparent, but substantiation of BBB leakage in normal appearing white matter will require further study using more sensitive methods.
Pathological changes in the normal-appearing white matter in multiple sclerosis are well recognised, but their relationship to pathology in focal lesions is not well understood. Magnetic resonance diffusion imaging is sensitive to abnormalities in the integrity, size and geometry of water spaces in brain tissue. This study investigated the anatomical distribution of normal-appearing white matter diffusion abnormalities and their relationship to diffusion in focal lesions in multiple sclerosis (MS). The average apparent diffusion coefficient (ADCav) was measured by three-axis echoplanar diffusion imaging in normal-appearing white matter regions and lesions throughout the brain in 40 patients, and in white matter in 14 matched controls. The correlation between the ADCav in normal-appearing white matter and lesions was determined. In controls and patients, diffusion was highest in the corpus callosum. Patients had a higher mean ADCav than controls in widespread regions including the corpus callosum, cerebellar, temporal and occipital normal-appearing white matter. Mean normal-appearing white matter ADCav correlated strongly with mean lesion ADCav (r = 0.67, P < 0.001). This study demonstrates that water diffusion is elevated in widespread areas of normal-appearing white matter in MS, and is correlated with diffusion in lesions. These findings suggest that the pathogenetic mechanisms causing tissue damage in lesions and normal-appearing white matter are at least partly linked.
Memory tests were often developed for healthy populations. The accuracy of these measures is reduced when administered to patients with neurological diseases, who may experience physical and/or cognitive symptoms. Also, methodological factors, for example, spanning the ability spectrum, and content/format artefacts, may contribute to a decline in test precision. The aim of this study was to develop a new test of memory, which addresses these issues. The new memory test comprises assessments of recall, paired association, and recognition, at a Task Familiarisation stage and two difficulty levels, for both the verbal and spatial modalities. It was administered to 85 healthy individuals and 100 patients with multiple sclerosis (MS). All patients were able to attempt each task of the new assessment and there was no influence of visual integrity or manual dexterity on memory test performance, supporting the applicability of the tasks to patients with multiple sclerosis. Both the standardisation and validation samples demonstrated a wide range of scores on each section of the new test suggesting that the measure spanned an acceptably broad range of abilities. It seems probable, therefore, that the new assessment offers a more exact measure of verbal and spatial recall, paired association, and recognition memory.
OBJECTIVE: Patients with nontraumatic spinal cord lesions account for between one fourth and one half of all spinal cord injuries. In the management of this group of patients, an understanding of factors influencing functional improvement is essential to help define the most appropriate rehabilitation programme. Although it is possible to predict accurately the functional outcome for an individual patient with a complete traumatic spinal cord injury, few studies have looked at prognostic factors in patients with nontraumatic spinal cord disease. The aim of this study was to determine which, and how well, factors assessed on admission to a rehabilitation unit relate to functional improvement in this group. METHODS: The study sample consists of 100 patients with an incomplete nontraumatic spinal cord lesion who underwent inpatient neurorehabilitation. Possible prognostic factors were sought by identifying those variables with a significant difference in the Functional Independence Measure (FIM) motor change score above and below the median. A step-wise multiple regression analysis was then performed to determine which variables influenced functional outcome. RESULTS: Patients with larger functional gains had significantly lower disability scores on admission, a shorter time between symptom onset and rehabilitation, and a longer length of stay. They were more likely to have a cervical lesion and evidence of neurologic recovery. Multiple regression analysis demonstrated that the FIM motor score on admission and the time between symptom onset and rehabilitation predicted 54% of the variance of the FIM motor score gain. CONCLUSIONS: This finding suggests that early rehabilitation is an important factor in securing a good outcome.
BACKGROUND AND PURPOSE: In patients with multiple sclerosis (MS), reduced magnetization transfer ratios (MTRs) have been reported in white matter that appears normal on studies obtained with conventional imaging techniques. The stage in the disease when this first becomes detectable is unclear. The purpose of this study was to measure the MTR of normal-appearing white matter (NAWM) and lesions in patients with clinically isolated syndromes (CIS), many of whom are at the earliest stages of MS, and to determine the prognostic value of any observed changes. METHODS: Twenty-seven CIS patients and 13 matched control subjects were studied. The mean MTR was measured from 10 regions of NAWM and, when present, from lesions. The patients were followed-up clinically for a median of 12 months. RESULTS: There was no significant difference in the mean MTR between NAWM in control subjects (38.5% units) and that in CIS patients (38.4% units). After 12 months' follow-up, MS developed in 26% of the patients. The MTR of NAWM in these patients did not differ from that of the other patients or the control subjects. CONCLUSION: The reduced MTR in NAWM, described in established MS, was not detectable in patients with CIS. MTR did not provide prognostic information for this short period of follow-up.
The murine 5-HT(3A) receptor subunit is expressed as either of two splice variants which are differentially regulated in vivo. The difference resides in a six-amino acid sequence within the cytoplasmic loop between transmembrane regions 3 and 4, which is present in the long form but not the short form. No physiological roles have yet been ascribed to the two splice variants. Whole cell patch clamp recording from transfected HEK 293 cells stably expressing either long or short form receptors showed very similar responses under control conditions. However, inclusion of 1 mM cAMP (activator of protein kinase A) in the patch pipette caused an initial increase in the desensitization rate of the long form, but a decrease in the short form. With the addition of 100 nM phorbol 12-myristate 13-acetate (PMA; activator of protein kinase C) to the pipette solution, responses elicited with 1 microM 5-HT revealed an increase in the current amplitude in the long but not the short form of the receptor. Over a longer time period, inclusion of PMA in the patch-pipette caused a faster run down of peak current amplitude in response to 30 microM 5-HT in the long form but did not affect the short form; there was no observed long-term effects of cAMP. We conclude that the long and short forms of the 5-HT(3) receptor are differentially modulated by agents that activate PKA and PKC. These different patterns of modulation could have markedly divergent consequences on receptor function.
OBJECTIVE: To investigate the variation in T1 and T2 relaxation times of normal appearing white matter (NAWM) and lesions in multiple sclerosis (MS) throughout the brain. BACKGROUND: The magnetic resonance imaging (MRI) sequence fast FLAIR (fluid attenuated inversion recovery) has demonstrated overall increased lesion detection when compared to conventional or fast spin echo (FSE) but fewer lesions in the posterior fossa and spinal cord. The reasons for this are unknown, but may be due to variations in the T1 and T2 relaxation times within NAWM and MS lesions. METHOD: Ten patients and 10 controls underwent MRI of the brain which involved FSE, fast FLAIR and the measurement of T1 and T2 relaxation times. RESULTS: Of 151 lesions analysed (22 infra-tentorial, 129 supra-tentorial), eight were missed by the fast FLAIR sequence. T1 and T2 relaxation times in normal controls were longer in the infra-tentorial, than supra-tentorial, region. Patient NAWM relaxation times were prolonged compared with control values in both regions. Lesions demonstrated longer relaxation times than either control white matter or patient NAWM in both regions, however this difference was less marked infra-tentorially. The eight posterior fossa lesions not visible on the fast FLAIR sequence were characterised by short T1 and T2 relaxation times which overlapped with the patient NAWM for both T1 and T2 and with control values for T2 relaxation times. CONCLUSION: Both lesion and NAWM relaxation time characteristics vary throughout the brain. The T1 and T2 relaxation times of infra-tentorial lesions are closer to the relaxation times of local NAWM than supra-tentorial lesions, resulting in reduced contrast between posterior fossa lesions and the background NAWM. Consequently the characteristics of some lesions overlap with those of NAWM resulting in reduced conspicuity. By utilising this information, it may be possible to optimise fast FLAIR sequences to improve infra-tentorial lesion detection.
PURPOSE: To determine the outcome in severe Guillain-Barre syndrome following combined neurological and rehabilitation management using standardized disability and handicap measures and to identify the factors which affect this outcome. METHODS: A retrospective study was performed of 24 patients with Guillain-Barre Syndrome admitted over a 3 year period to the neurological rehabilitation unit of the National Hospital for Neurology and Neurosurgery. Queen Square, London. Disability and handicap on admission and discharge were measured using the modified Barthel Index (BI), Functional Independence Measure (FIM). Environmental Status Scale (ESS) and Handicap Assessment Scale (HAS). Data was collected to identify any factors affecting outcome; age at onset, time to nadir, duration of ventilation, total in-patient stay, duration of stay at the neurological rehabilitation unit, symptoms, signs and electrophysiological findings. RESULTS: The majority of patients had multiple problems. Outcome was related to the duration of rehabilitation. The mean modified BI score and the FIM score increased whereas ESS scores and HAS scores decreased, these changes were compatible with a reduction in disability and handicap. CONCLUSIONS: Significant improvement in function occurred during rehabilitation. These changes can be demonstrated using standardized outcome measures.
OBJECTIVE: To assess the potential of registered volumetric MRI in measuring rates of atrophy in MS. BACKGROUND: Pathologic and imaging studies suggest that the development of permanent neurologic impairment in MS is associated with progressive brain and spinal cord atrophy. Atrophy has been suggested as a potential marker of disease progression. Conventional atrophy measurements requiring manual outlining are time-consuming and subject to reproducibility problems. Registration of serial MRI may offer a useful alternative in that cerebral losses may be measured directly from automated subtraction of brain volumes. METHODS: Twenty-six patients with MS and 26 age- and gender-matched controls had two volumetric brain MR studies 1 year apart. Baseline brain and ventricular volumes were measured using semiautomated techniques, and follow-up scans were registered to baseline. Rates of cerebral atrophy were calculated directly from the registered scans. RESULTS: Baseline brain volumes in the MS group were smaller (mean difference 78 mL [95% CI 13 to 143; p = 0.02]) and ventricular volumes greater (mean difference 12 mL [95% CI 6 to 18; p < 0.001]) than controls. The rate of cerebral atrophy in the MS group (0.8% per year) was over twice that of controls (0.3%), and the rate of ventricular enlargement was five times greater than the controls (1.6 versus 0.3 mL/year). CONCLUSION: Progressive cerebral atrophy is an important feature of MS. Registration-based measurements are sensitive and reproducible, allowing progressive atrophy to be detected within 1 year and may have potential as a marker of progression in monitoring therapeutic trials.
Neuropsychological deficits and the relationship to brain pathology were examined in 13 primary progressive (PP) and 12 secondary progressive (SP) multiple sclerosis patients with a similar duration of the progressive phase and comparable physical disability. A battery of neuropsychological tests to assess attention, short-term and working memory was administered to the patients, and their performance was compared to that of 20 healthy controls matched for age and premorbid IQ. Total cerebral lesion load on T2-weighted magnetic resonance imaging was measured in the patients. Both PP and SP patients performed significantly worse than controls in most of the neuropsychological tests. There were only subtle differences between SP and PP on the working memory task although magnetic resonance imaging lesion load was significantly higher in SP than in PP patients. In this exploratory study only subtle differences in cognitive impairment were detected between SP and PP patients matched for physical disability and relevant illness features. The results also suggest that the severity of cognitive impairment cannot be fully explained by the extent of abnormalities detected on conventional T2-weighted magnetic resonance images, and that other pathological abnormalities such as in normal-appearing white matter are likely to be involved.
OBJECTIVE: To determine the relation of neurology and neuropsychology to everyday competence. DESIGN: The association of these three domains was investigated using a single case multiple baseline design with two phases. Phase A comprised 6 weeks that coincided with an inpatient admission. Phase B comprised 3 months spent at home. A battery of visual spatial tests was completed every fortnight during the A phase and at the end of the B phase. Two new tests of relevant neurologic function with control data were developed and used weekly during the A phase and at the end of the B phase. The first test recorded the speed, accuracy, and efficiency of her walking, and the second test recorded her depth perception. SETTING: Tertiary care center. PARTICIPANT: A 35-year-old woman who suffered a venous sinus thrombosis with visual disorientation syndrome. RESULTS: During Phase A, she achieved significant functional gains in mobility, dressing, bathing, and domestic tasks, in the context of unchanging psychometric test scores and static relevant neurologic function. During Phase B, she achieved few functional gains, despite improvements in neurologic status, demonstrated by depth perception. CONCLUSIONS: Everyday function can progress without improvement in neurologic and cognitive status.
1H magnetic resonance spectroscopy (MRS) provides a unique tool to detect and quantify brain metabolites. In multiple sclerosis it can be used to investigate axonal loss or dysfunction through measurement of N-acetyl aspartate (NAA), a neuronal marker. Previous studies in adults have reported variable effects of aging on metabolite concentrations but have predominantly focused on changes in the elderly. This study has examined a younger adult age group to provide a reference database more applicable to the multiple sclerosis population. Single voxel (1)H MRS was carried out in 44 subjects between 22 and 62 years of age. Sixteen subjects underwent repeat examination after one year. Absolute concentrations of NA (the sum of NAA and N-acetyl aspartate glutamate), NAA, creatine/phosphocreatine (Cr), choline containing compounds (Cho) and myo-inositol (mI) were measured. NA, NAA and mI concentrations did not correlate with age but there were significant correlations between age and Cr (r = 0.43, p = 0.004) and Cho (r = 0.38, p = 0. 011) concentrations. No significant differences in metabolite concentrations were seen over one year. This study provides evidence that age-related changes of metabolite concentrations occur even in a young to middle aged adult population. This emphasizes the need to perform absolute quantification of metabolite concentrations rather than ratios and the importance of age-matching in (1)H MRS studies of multiple sclerosis.