A cohort study of functional electrical stimulation in people with multiple sclerosis demonstrating improvements in quality of life and cost-effectiveness.

OBJECTIVE: The objective of this study was to determine the impact on health-related quality of life of functional electrical stimulation used to improve walking in people with multiple sclerosis and to explore cost-effectiveness. DESIGN: A retrospective analysis of patient records was conducted. SETTING: This study used outpatient therapy service as the study setting. SUBJECTS: Data from 82 consecutive patients with multiple sclerosis attending for set up with functional electrical stimulation were analysed. INTERVENTIONS: Patients were seen at baseline, three and six months for support in use of functional electrical stimulation, and data were collected at baseline and six months. MAIN MEASURES: The EQ-5D-5L and walking speed were collected at baseline and six months after using functional electrical stimulation. The Psychosocial Impact of Assistive Device Scale was collected at six months. EQ-5D-3L utilities were derived and cost-effectiveness analysis was completed utilizing a five-year time horizon and methodology published by National Institute for Health and Care Excellence. RESULTS: Significant differences (P < 0.001) were seen in walking speed (baseline 0.670 m/s; with stimulation 0.768 m/s) and maintained over six months (0.772 m/s with stimulation). EQ-5D data significantly improved over six months (baseline 0.486, six months 0.596, P < 0.001) and meaningful mean scores were seen in all aspects of the Psychosocial Impact of Assistive Device Scale. However, there were no correlations between measures. In the cost utility analysis, compared to standard care, functional electrical stimulation was more expensive and more effective with an incremental cost-effectiveness ratio of £6137. CONCLUSION: Functional electrical stimulation is a cost-effective treatment to improve walking speed and health-related quality of life in people with multiple sclerosis.

The high cost of spasticity in multiple sclerosis to individuals and society.

BACKGROUND: Spasticity is an extremely common, distressing and disabling symptom of multiple sclerosis. Limited data suggest the associated health care costs correlate with increasing severity and place a high economic burden on individuals, health care systems and society. OBJECTIVE: The aim of this study was to quantify the impact of multiple sclerosis spasticity on health care resources and the associated costs at different levels of severity in people with multiple sclerosis in the United Kingdom. METHODS: An online survey was carried out to understand the resources used in the management of spasticity in multiple sclerosis. The questionnaire asked health care specialists to estimate their involvement and the resource use associated with different levels of spasticity, and the survey outputs were used to derive the resource costs. RESULTS: The level and cost of care substantially increased with the degree of spasticity. Key factors contributing to high annual costs per patient were home care, hospital admissions and high-cost items, such as hospital beds. CONCLUSIONS: Based on the survey results, it can be assumed that managing spasticity early and effectively could result in substantial cost savings, in addition to the improvements in health-related quality of life.

Evaluation of the cognitive benefits of intrathecal baclofen pump implantation in people with intractable multiple sclerosis related spasticity.

BACKGROUND: Spasticity is a common problematic symptom in Multiple Sclerosis with over one third of patients failing first line therapies. Intrathecal baclofen is a safe and efficacious option for treatment resistant spasticity. Anecdotally patients report improved concentration/cognitive performance when switching to intrathecal baclofen (ITB) from systemic medications. AIM: To explore whether subjects who proceed with ITB pump implantation for spasticity management and reduce oral anti-spasticity agents will have improved cognitive function. METHODS: Subjects were admitted for trial of ITB via lumbar puncture and subsequent pump implantation. Spasticity and cognitive measures before ITB trial and 3 months post implant were recorded. Paired t-test or Wilcoxon Signed Ranks test was used for within subject change and effect sizes (Cohen's dz) were calculated. Subgroup analysis of those on ≥2, or ≤ 1 spasticity medications at baseline was performed. RESULTS: 27 subjects with MS completed per protocol. Mean age 46 years [26 - 56], disease duration 15 years [6 - 26], RRMS = 3, SPMS = 17 and PPMS=7. The majority were on multiple spasticity medications. Spasticity scores significantly improved post pump implant. Mean ITB dose at 3 months was 143 mcg / day and 19 discontinued all other treatments for spasticity. There was no deterioration on any cognitive or mood measure. An improvement of moderate effect size was found in Backwards Digit Span (d=0.41, p=0.059) and HADS - anxiety (d=0.37, p=0.097). Fatigue Severity Scale score decreased substantially (d=0.81, p=0.005). Small improvements in Symbol Digit Modalities Test score (d=0.24) and Sustained Attention to Response Task response time (d=0.23) were non-significant. Performance on other measures did not change. Effect sizes were larger in subgroup on ≥2 oral spasticity medications at baseline, compared to the group on ≤1 medication (SDMT, d=0.42 vs d=0.07; Backwards digit span 0.45 vs 0.28; HADS-anxiety 0.39 vs 0.32; HADS-depression d=0.32 vs 0.05 and FSS, d= 1.14 vs 0.42). CONCLUSIONS: In a pilot study exploring the impact of ITB on cognition, spasticity scores improved universally and beneficial effects on some measures of fatigue, anxiety, auditory attention and verbal working memory were found. Improvement of speed of processing in those withdrawing higher doses of oral medication was also demonstrated suggesting that switching to ITB has added cognitive and psychological benefits for people with MS.

Rehabilitation in practice: Spasticity management.

This series of articles for rehabilitation in practice aims to cover a knowledge element of the rehabilitation medicine curriculum. Nevertheless they are intended to be of interest to a multidisciplinary audience. The competency addressed in this article is 'The trainee consistently demonstrates a knowledge of the pathophysiology of various specific impairments including spasticity'. Spasticity is an extremely common feature of chronic neurological conditions and, if badly managed, it can result in pain, contractures and pressure sores, all of which can impact on function. It is therefore essential that a multidisciplinary management strategy is in place to help the individual manage their particular situation through education with timely access to interventions including instigation of a physical management programme and medication such as baclofen, tizanidine, dantrolene, benzodiazepines and gabapentin. Further treatment options for focal spasticity are botulinum toxin and phenol nerve blocks or intrathecal baclofen or phenol for predominant lower limb spasticity. Ongoing assessment with the use of appropriate outcome measures can both guide choice of treatment and monitor efficacy.

Evaluation of the impact of intrathecal baclofen on the walking ability of people with Multiple Sclerosis related spasticity.

BACKGROUND: Spasticity is a frequent and disabling symptom in people with Multiple Sclerosis (MS). Intrathecal baclofen (ITB) is an effective but infrequently used treatment in ambulant people. OBJECTIVE: To evaluate the impact of ITB on ambulation in people with moderate to severe MS related spasticity. METHODS: Data was collected prospectively regarding spasticity and ambulation at baseline, after ITB trial via lumbar puncture, 3 months and annually thereafter. RESULTS: 30 subjects; Mean age 47.9 (26-64), 67% female, mean EDSS 6.5 [6.5-7.5]. Reduction in mean Ashworth score (pre 1.44: post 0.98, p<0.001) and Penn spasm score (pre 3: post 1; p<0.001) was shown. 20 people (67%) proceeded with implantation; lower limb MRC power was predictive of proceeding to pump (OR 2.98; 95% CI 1.01 - 8.7; p <0.05). In those proceeding to implantation there was no difference in 10mTW at 1 year (ANOVA (F(3,24) = 2.6, p=0.13). Currently, 15 (75%) remain ambulatory (mean 3.75 years, range 1-9). After implant, 17 (85%) discontinued all oral anti-spasticity treatments conferring other benefits. CONCLUSION: Ambulation in people with MS can be preserved for several years whilst effectively treating spasticity with ITB with careful patient selection; ITB should not be considered a last resort.

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.

Spinal cord atrophy and disability in MS: a longitudinal study.

OBJECTIVE: To assess whether it is possible to measure changes in cord cross-sectional area during a 1-year period in patients with MS reliably. BACKGROUND: Involvement of the spinal cord in MS is extremely common and an important element in the development of disability. Although little relation has been shown between the cord lesion load and disability, a strong correlation between spinal cord atrophy and the expanded disability status scale (EDSS) has been demonstrated in cross-sectional studies. METHOD: A highly reproducible semiautomated technique that measures the cross-sectional area of the cord at the C2 level was applied to 13 healthy control subjects and 28 patients serially. RESULTS: This study confirms that patients have significantly smaller cords than control subjects at baseline (control subjects: mean 80.95 mm2, patients: mean 71.25 mm2, p = 0.01) and demonstrates that patients have a significant loss in cord cross-sectional area during 12 months, which was not seen in control subjects (p < 0.001). This reduction in cord size was most marked in the primary progressive patients who had a mean cord cross-sectional area loss of 3.52 mm2 (5.2%) and least in the secondary progressive (-0.26 mm2, 0.7%) and benign patients (-0.41 mm2, 0.8%). The baseline cord cross-sectional area correlated strongly with the EDSS (r = -0.52, p = 0.005) and with disease duration (r = -0.75, p < 0.001); however, there was no significant difference in cord area (p = 0.69) or change in cord area (p = 0.51) between those patients with a definite increase in EDSS and those without. CONCLUSION: This study demonstrates, for the first time, that it is possible to measure changes in cord cross-sectional area over time. The serial measurement of spinal cord atrophy may thus make an important contribution to the evaluation of therapeutic efficacy, especially in primary progressive disease.

Progressive cerebral atrophy in MS: a serial study using registered, volumetric MRI.

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.

Primary and transitional progressive MS: a clinical and MRI cross-sectional study.

BACKGROUND: Ten percent of patients with MS have a progressive course from onset with no history of relapses or remissions. A smaller subgroup follow a similar progressive course but have a single relapse at some point (transitional progressive [TP] MS). To date these patients have been excluded from receiving licensed treatments for MS and from most therapeutic trials. OBJECTIVE: To document the clinical and MRI characteristics of a large cohort of progressive patients, including 158 with primary progressive (PP) MS and 33 with TPMS. Data from a small reference group of 20 patients with secondary progressive (SP) MS are also presented for reference. METHODS: Patients were recruited from six European centers. All underwent a clinical assessment including scoring on the Expanded Disability Status Scale (EDSS) and MRI of the brain and spinal cord. RESULTS: The men-to-women ratio was 81:77 (51% men) in the PP group, 14:19 (42% men) in the TP group, and 5:15 (25% men) in the SP group. The mean age at disease onset was significantly higher in the PP group than it was in the other two groups (PP 40.2 years, TP 34.9 years, SP 28.7 years). On MRI the PP group had lower mean brain T2 and T1 hypointensity lesion loads than the SP group (T2 12.02 versus 27.74 cm3, p = 0.001; T1 4.34 versus 7.04 cm3, p = 0.015). The SP and TP cohorts had significantly more T2-weighted lesions in the spinal cord than the PP patients, and the SP cohort had the greatest degree of atrophy. There was a correlation in the PP and TP patients between EDSS score and brain and spinal cord atrophy (r = 0.3, 0.2, p < or = 0.006) but not with brain lesion load. The PP and TP patients who presented with spinal cord pathology had significantly lower brain T2 and T1 lesion loads than those with non-spinal cord presentations (p = 0.002). CONCLUSIONS: The monitoring of disease progression in PPMS is difficult, although measures of atrophy correlate with the EDSS and appear most promising. This study increases our understanding of this unique patient group, which will be further expanded with the acquisition of serial data.

Interleukin 1 genotypes in multiple sclerosis and relationship to disease severity.

We studied the association between clinical outcome in MS and allelic variants single nucleotide polymorphisms (SNPs) of interleukin-1alpha (IL-1alpha), IL-1beta and a variable number tandem repeat (VNTR) in IL-1 receptor antagonist (IL-1RN). A total of 377 patients with MS were studied. Significant associations between IL-1 genotypes and clinical outcome were found using logistic regression after correction for gender, onset age and disease duration. The same trends were subsequently demonstrated in a second independent group of 67 primary progressive patients. Our results suggest that genetically determined immunomodulation mediated by IL-1 influences long-term prognosis in multiple sclerosis (MS).

Factors affecting functional outcome in patients with nontraumatic spinal cord lesions after inpatient rehabilitation.

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.

Acanthocytosis and neurological disorders.

Acanthocytosis occurs because of ultrastructural abnormalities of the erythrocyte membranous skeleton resulting in reduced membrane fluidity. At least three hereditary neurological conditions are associated with it, although as yet the pathogenesis of the neurological features is unknown. In abetalipoproteinaemia, an autosomal recessive condition, vitamin E deficiency results in a progressive spinocerebellar syndrome associated with peripheral neuropathy and retinitis pigmentosa. Neuroacanthocytosis is also probably an autosomal recessive condition and is characterised by chorea, orofaciolingual dyskinesia, dysarthria, areflexia, seizures and dementia. McLeod syndrome is an X-linked recessive disorder usually presenting in males as a benign myopathy with areflexia, in association with a particular abnormality of expression of Kell blood group antigens. However, occasionally the neurological features are more severe and indistinguishable from those of neuroacanthocytosis. Recent advances in molecular genetics may assist better understanding of the disease mechanisms and the search for more effective treatments.

Imaging of the spinal cord and brain in multiple sclerosis: a comparative study between fast FLAIR and fast spin echo.

Recent reports have suggested that fluid attenuated inversion recovery (FLAIR) is a technique superior to conventional (CSE) or fast spin echo (FSE) T2-weighted sequences in detecting intrinsic lesions both in the brain and spinal cord. We report our experience of an inversion recovery prepared FSE, which we refer to as fast FLAIR, in a comparative study of ten patients with clinically definite multiple sclerosis (MS) who underwent cervical cord and brain imaging with both FSE and fast FLAIR. The results showed that in the cerebral hemispheres fast FLAIR detected more lesions than FSE (P < 0.001). However, FSE detected more lesions than fast FLAIR in the posterior fossa (P = 0.02) and in the cord fast FLAIR was much inferior detecting only 2 of 33 lesions seen on FSE. Estimating the T2 relaxation times of lesions in each of three areas (periventricular, posterior fossa, cervical cord) showed that the T2 value of posterior fossa and cervical cord lesions was significantly lower than that of periventricular lesions, suggesting that the lesion composition is different and consequently their imaging appearances are different. In conclusion, although fast FLAIR improves the detection of MS lesions in the cerebral hemispheres, its substantially lower sensitivity in the posterior fossa and spinal cord is a potentially important limitation to its use as a tool for the diagnosis of MS and for monitoring therapies. Further studies are needed to elucidate the mechanisms underlying the loss of sensitivity.

Problems in designing and recruiting to therapeutic trials in primary progressive multiple sclerosis.

Patients with primary progressive multiple sclerosis have atypical clinical and magnetic resonance imaging (MRI) characteristics which present unique problems in designing and recruiting to therapeutic trials. The first randomised controlled therapeutic trial specifically for primary progressive multiple sclerosis is now underway. Although only an exploratory phase II study, it has provided further insight into difficulties in diagnosis, classification and choice of clinical and MRI outcome measures. Patients with primary progressive multiple sclerosis have a wide differential diagnosis and do not readily conform to the Poser criteria. They may therefore present diagnostic uncertainty, particularly as their classification often relies on a retrospective history. This was highlighted during the recruitment to this study of interferon-beta1a. Of the 138 patients referred with a definite diagnosis of primary progressive multiple sclerosis only 50 were enrolled in the study. Of the 88 patients not included, 50% either did not have primary progressive multiple sclerosis, or the diagnosis was not secure. Outcome measures pose particular problems. Clinically the focus must be on progression, and the measure should be both responsive and reliable. In relation to MRI, the currently recommended measures for therapeutic trials in relapsing/remitting and secondary progressive multiple sclerosis show little change in primary progressive multiple sclerosis, and therefore more pathologically specific MRI measures are required. Strict clinical guidelines and further developments in clinical and MRI measures are required to facilitate future therapeutic trials in primary progressive multiple sclerosis.

Rehabilitation of incomplete spinal cord pathology: factors affecting prognosis and outcome.

To determine the factors affecting the outcome of patients with incomplete spinal cord lesions, a retrospective study was performed of all such patients (n = 49) admitted to the neurorehabilitation unit of the National Hospital for Neurology and Neurosurgery, London, over a 2-year period. Disability on admission and discharge as measured by the Functional Independence Measure (FIM), change in disability, presence or absence of neurological recovery, patient age, level of the lesion and length of inpatient stay were the main outcome measures. Data were complete on 39 patients. There were 20 patients with cervical myelopathy, 15 with intrinsic cord abnormalities including syrinxes, 7 with spinal cord infarcts and 7 with other conditions such as tropical spastic paraparesis and hereditary paraparesis. Age ranged from 17 to 88 years (mean 53). Mean duration of stay was 40 days and the duration was related to the diagnosis. Nineteen of the patients made some neurological improvement, while all but one improved on the FIM. This functional gain did not correlate with the patients' age, initial disability or level of the lesion, but was related to the length of stay in the unit, and neurological improvement. We conclude that the needs of patients with progressive incomplete spinal cord lesions due to neurological disease differ from those of patients with acute traumatic spinal cord lesions and are best managed in a neurological rehabilitation unit. Efficacy appears to be related to neurological recovery and the duration of rehabilitation. This study underlines the value of combined neurological and rehabilitation expertise in the management of this patient group and the need to incorporate both disciplines in planning service provision.

1H magnetic resonance spectroscopy of normal appearing white matter in primary progressive multiple sclerosis.

Recent magnetic resonance imaging (MRI) and pathological studies have indicated that axonal loss is a major contributor to disease progression in multiple sclerosis. 1H magnetic resonance spectroscopy (MRS), through measurement of N-acetyl aspartate (NAA), a neuronal marker, provides a unique tool to investigate this. Patients with primary progressive multiple sclerosis have few lesions on conventional MRI, suggesting that changes in normal appearing white matter (NAWM), such as axonal loss, may be particularly relevant to disease progression in this group. To test this hypothesis NAWM was studied with MRS, measuring the concentration of N-acetyl derived groups (NA, the sum of NAA and N-acetyl aspartyl glutamate). Single-voxel MRS using a water-suppressed PRESS sequence was carried out in 24 patients with primary progressive multiple sclerosis and in 16 age-matched controls. Ratios of metabolite to creatine concentration (Cr) were calculated in all subjects, and absolute concentrations were measured in 18 patients and all controls. NA/Cr (median 1.40, range 0.86-1.91) was significantly lower in NAWM in patients than in controls (median 1.70, range 1.27-2.14; P = 0.006), as was the absolute concentration of NA (patients, median 6.90 mM, range 4.62-10.38 mM; controls, median 7.77 mM, range 6.60-9.71 mM; P = 0.032). There was no significant difference in the absolute concentration of creatine between the groups. This study supports the hypothesis that axonal loss occurs in NAWM in primary progressive multiple sclerosis and may well be a mechanism for disease progression in this group.

Variations in T1 and T2 relaxation times of normal appearing white matter and lesions in multiple sclerosis.

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.

Reproducibility of magnetic resonance imaging measurements of spinal cord atrophy: the role of quality assurance.

A sensitive magnetic resonance imaging (MRI) method to measure spinal cord cross-sectional area with the potential to monitor disease progression has recently been developed. As changes in cord area due to disease are usually small, assessment of the reliability of the methodology is essential in serial studies of spinal cord atrophy. The aim of this study was to institute and evaluate a protocol of quality assurance to determine long-term reproducibility of serial studies. Serial MRI of the spinal cord was carried out in five healthy volunteer controls over 1 year. Cross-sectional spinal cord areas were measured in a total of 46 scans. The mean coefficient of variation of all subjects over one year was 1.35%. The intra-observer coefficient of variation for same scan analysis was 0.63%. This study has confirmed high reliability of our serial data over one year and the on-going quality assurance protocol enables continuing evaluation of the reproducibility of results in serial studies. Quality assurance is an essential and practical component of all serial MRI studies, without which the clinical implications of change cannot be reliably evaluated.