Highlights
- •Two weeks of Fampridine treatment did not improve kinematic gait quality.
- •Gait function/performance improved following two weeks of Fampridine treatment.
- •No Fampridine induced improvements were detected in spatiotemporal parameters.
- •Changes in kinematic gait quality and gait function/performance did not correlate.
Abstract
Background
Fampridine has shown to improve walking speed, motor control, and balance in patients with multiple sclerosis. However, potential fampridine-induced changes in gait quality and underlying mechanisms, evaluated by three-dimensional gait analysis, are poorly examined.
The aim was to examine if two weeks of fampridine treatment would improve gait quality (using Gait Profile Score and Gait Variable Scores from three-dimensional gait analysis) and gait function (using performance-based tests, spatiotemporal parameters, and self-perceived gait function).
Methods
14 participants with multiple sclerosis were included (9 women and 5 men, age 53.6 ± 12.8 years, disease duration 21 ± 9.1 years) in this cohort study. Tests were completed prior to fampridine and after 14 (± 1) days of treatment. Three-dimensional gait analyses were completed, and kinematic measures were calculated for overall gait quality using Gait Profile Score, and for joint-specific variables, Gait Variable Scores. Gait function was assessed using spatiotemporal parameters, performance-based tests, and a patient-reported outcome measure. Student’s paired t-test/Wilcoxon signed rank test were used to compare baseline and follow-up variables. Sample size calculation for Gait Profile Score required at least 9 participants.
Findings
No fampridine-induced improvements in gait quality were demonstrated. For gait function, improvements were found in performance-based tests (Timed 25-Foot Walk: −11.5%; Six Spot Step Test: −13.9%; 2-Minute Walk Test: 18.2%) and self-perceived gait function (12-itemMS Walking Scale: –35.2%).
Interpretation
Although two weeks of fampridine treatment in patients with multiple sclerosis improved gait function, there was no change in overall kinematic quality of gait.
Trial registration:
This work was collected as a part of a registered clinical trial (MUST): ClinicalTrials.gov NCT03847545
Keywords
1. Introduction
Multiple sclerosis (MS) is a chronic inflammatory, demyelinating disease of the central nervous system and the most frequent neurological disease affecting young adults (
Filippi et al., 2018
). MS causes a variety of clinical manifestations including muscle weakness, spasticity, paresis, and sensory deficits (- Filippi M.
- Bar-Or A.
- Piehl F.
- et al.
Multiple sclerosis.
Nat. Rev. Dis. Prim. 2018; 4 ([published Online First: 2018/11/10]): 43https://doi.org/10.1038/s41572-018-0041-4
Pau et al., 2014
), resulting in functional limitations such as reduced walking speed, endurance, and poor balance. Gait limitations is a main cause of disability in patients with MS (- Pau M.
- Coghe G.
- Atzeni C.
- et al.
Novel characterization of gait impairments in people with multiple sclerosis by means of the gait profile score.
J. Neurol. Sci. 2014; 345 ([published Online First: 2014/07/31]): 159-163https://doi.org/10.1016/j.jns.2014.07.032
Larocca, 2011
), and up to 76% of patients require a walking aid or wheelchair at some stage (- Larocca N.G.
Impact of walking impairment in multiple sclerosis: perspectives of patients and care partners.
The Patient. 2011; 4 ([published Online First: 2011/07/20]): 189-201https://doi.org/10.2165/11591150-000000000-00000
Kister et al., 2013
).- Kister I.
- Chamot E.
- Salter A.R.
- et al.
Disability in multiple sclerosis: a reference for patients and clinicians.
Neurology. 2013; 80 ([published Online First: 2013/02/22]): 1018-1024https://doi.org/10.1212/WNL.0b013e3182872855
Fampridine is presently the only medical drug used to alleviate gait function in MS (
Ahdab et al., 2019
). It enhances signal conduction in demyelinated axons by blocking voltage-dependent potassium channels (- Ahdab R.
- Shatila M.M.
- Shatila A.R.
- et al.
Cortical excitability measures may predict clinical response to fampridine in patients with multiple sclerosis and gait impairment.
Brain Sci. 2019; 9 (published Online First: 2019/12/11)https://doi.org/10.3390/brainsci9120357
Hayes, 2007
). Clinical studies demonstrate improved walking speed (- Hayes K.C.
Fampridine-SR for multiple sclerosis and spinal cord injury.
Expert. Rev. Neurother. 2007; 7 ([published Online First: 2007/05/12]): 453-461https://doi.org/10.1586/14737175.7.5.453
Filli et al., 2018
; - Filli L.
- Sutter T.
- Easthope C.S.
- et al.
Profiling walking dysfunction in multiple sclerosis: characterisation, classification and progression over time.
Sci. Rep. 2018; 8 ([published Online First: 2018/03/23]): 4984https://doi.org/10.1038/s41598-018-22676-0
Goodman et al., 2010
; Jensen et al., 2014
; Zörner et al., 2016
), walking endurance (- Zörner B.
- Filli L.
- Reuter K.
- et al.
Prolonged-release fampridine in multiple sclerosis: improved ambulation effected by changes in walking pattern.
Mult. Scler. 2016; 22 ([published Online First: 2016/01/15]): 1463-1475https://doi.org/10.1177/1352458515622695
Filli et al., 2018
; - Filli L.
- Sutter T.
- Easthope C.S.
- et al.
Profiling walking dysfunction in multiple sclerosis: characterisation, classification and progression over time.
Sci. Rep. 2018; 8 ([published Online First: 2018/03/23]): 4984https://doi.org/10.1038/s41598-018-22676-0
Zörner et al., 2016
), coordination (- Zörner B.
- Filli L.
- Reuter K.
- et al.
Prolonged-release fampridine in multiple sclerosis: improved ambulation effected by changes in walking pattern.
Mult. Scler. 2016; 22 ([published Online First: 2016/01/15]): 1463-1475https://doi.org/10.1177/1352458515622695
Jensen et al., 2014
; Jensen et al., 2016
), balance (- Jensen H.B.
- Nielsen J.L.
- Ravnborg M.
- et al.
Effect of slow release-Fampridine on muscle strength, rate of force development, functional capacity and cognitive function in an enriched population of MS patients. A randomized, double blind, placebo controlled study.
Mult. Scler. Relat. Disord. 2016; 10 (published Online First: 2016/12/07): 137-144https://doi.org/10.1016/j.msard.2016.07.019
Hupperts et al., 2016
; - Hupperts R.
- Lycke J.
- Short C.
- et al.
Prolonged-release fampridine and walking and balance in MS: randomised controlled MOBILE trial.
Mult. Scler. 2016; 22 ([published Online First: 2015/04/30]): 212-221https://doi.org/10.1177/1352458515581436
Jensen et al., 2014
), self-perceived gait function (Goodman et al., 2009
; Hupperts et al., 2016
), and Functional Ambulation Profile (FAP) Score (- Hupperts R.
- Lycke J.
- Short C.
- et al.
Prolonged-release fampridine and walking and balance in MS: randomised controlled MOBILE trial.
Mult. Scler. 2016; 22 ([published Online First: 2015/04/30]): 212-221https://doi.org/10.1177/1352458515581436
Allart et al., 2015
; - Allart E.
- Benoit A.
- Blanchard-Dauphin A.
- et al.
Sustained-released fampridine in multiple sclerosis: effects on gait parameters, arm function, fatigue, and quality of life.
J. Neurol. 2015; 262 ([published Online First: 2015/06/05]): 1936-1945https://doi.org/10.1007/s00415-015-7797-1
Rodriguez-Leal et al., 2018
) (a composite value of selected spatiotemporal parameters) (- Rodriguez-Leal F.A.
- Haase R.
- Thomas K.
- et al.
Fampridine response in MS patients with gait impairment in a real-world setting: need for new response criteria?.
Mult. Scler. 2018; 24 ([published Online First: 2017/07/26]): 1337-1346https://doi.org/10.1177/1352458517720043
Givon et al., 2009
) in a subset of patients with MS. However, the effect of fampridine on neuromechanical changes of gait, including the overall ‘quality of gait’, in patients with MS has not been examined.- Givon U.
- Zeilig G.
- Achiron A.
Gait analysis in multiple sclerosis: characterization of temporal-spatial parameters using GAITRite functional ambulation system.
Gait Posture. 2009; 29 ([published Online First: 2008/10/28]): 138-142https://doi.org/10.1016/j.gaitpost.2008.07.011
Three-dimensional gait analysis (3DGA) is an established method for objective quantification of kinematic, kinetic, and spatiotemporal parameters (
Benedetti et al., 1999
; - Benedetti M.G.
- Piperno R.
- Simoncini L.
- et al.
Gait abnormalities in minimally impaired multiple sclerosis patients.
Mult. Scler. 1999; 5 ([published Online First: 1999/10/12]): 363-368https://doi.org/10.1177/135245859900500510
Martin et al., 2006
) and is considered the gold standard for gait analysis (- Martin C.L.
- Phillips B.A.
- Kilpatrick T.J.
- et al.
Gait and balance impairment in early multiple sclerosis in the absence of clinical disability.
Mult. Scler. 2006; 12 ([published Online First: 2006/11/08]): 620-628https://doi.org/10.1177/1352458506070658
Cameron and Wagner, 2011
). The Gait Profile Score (GPS) is a summary measure of 3DGA that evaluates the overall quality of gait by comparing nine kinematic variables, described as Gait Variable Scores (GVS), relative to normative data. A higher GPS/GVS implies a larger deviation from a hypothetical “normal” gait and a greater level of impairment (- Cameron M.H.
- Wagner J.M.
Gait abnormalities in multiple sclerosis: pathogenesis, evaluation, and advances in treatment.
Curr. Neurol. Neurosci. Rep. 2011; 11 ([published Online First: 2011/07/23]): 507-515https://doi.org/10.1007/s11910-011-0214-y
Baker et al., 2009
). GPS and/or GVS have been applied in previous studies involving patients with MS (- Baker R.
- McGinley J.L.
- Schwartz M.H.
- et al.
The gait profile score and movement analysis profile.
Gait Posture. 2009; 30 ([published Online First: 2009/07/28]): 265-269https://doi.org/10.1016/j.gaitpost.2009.05.020
Andreopoulou et al., 2019
; - Andreopoulou G.
- Mahad D.J.
- Mercer T.H.
- et al.
Test-retest reliability and minimal detectable change of ankle kinematics and spatiotemporal parameters in MS population.
Gait Posture. 2019; 74 ([published Online First: 2019/09/29]): 218-222https://doi.org/10.1016/j.gaitpost.2019.09.015
Coghe et al., 2015
; - Coghe G.
- Pau M.
- Corona F.
- et al.
Walking improvements with nabiximols in patients with multiple sclerosis.
J. Neurol. 2015; 262 ([published Online First: 2015/08/05]): 2472-2477https://doi.org/10.1007/s00415-015-7866-5
Morel et al., 2017
; - Morel E.
- Allali G.
- Laidet M.
- et al.
Gait profile score in multiple sclerosis patients with low disability.
Gait Posture. 2017; 51 ([published Online First: 2016/10/25]): 169-173https://doi.org/10.1016/j.gaitpost.2016.10.013
Pau et al., 2014
; - Pau M.
- Coghe G.
- Atzeni C.
- et al.
Novel characterization of gait impairments in people with multiple sclerosis by means of the gait profile score.
J. Neurol. Sci. 2014; 345 ([published Online First: 2014/07/31]): 159-163https://doi.org/10.1016/j.jns.2014.07.032
Pau et al., 2018
) and are considered feasible, reliable (- Pau M.
- Corona F.
- Coghe G.
- et al.
Quantitative assessment of the effects of 6 months of adapted physical activity on gait in people with multiple sclerosis: a randomized controlled trial.
Disabil. Rehabil. 2018; 40 ([published Online First: 2017/01/14]): 144-151https://doi.org/10.1080/09638288.2016.1244291
Andreopoulou et al., 2019
; - Andreopoulou G.
- Mahad D.J.
- Mercer T.H.
- et al.
Test-retest reliability and minimal detectable change of ankle kinematics and spatiotemporal parameters in MS population.
Gait Posture. 2019; 74 ([published Online First: 2019/09/29]): 218-222https://doi.org/10.1016/j.gaitpost.2019.09.015
Pau et al., 2014
), and responsive in this population (- Pau M.
- Coghe G.
- Atzeni C.
- et al.
Novel characterization of gait impairments in people with multiple sclerosis by means of the gait profile score.
J. Neurol. Sci. 2014; 345 ([published Online First: 2014/07/31]): 159-163https://doi.org/10.1016/j.jns.2014.07.032
Pau et al., 2014
).- Pau M.
- Coghe G.
- Atzeni C.
- et al.
Novel characterization of gait impairments in people with multiple sclerosis by means of the gait profile score.
J. Neurol. Sci. 2014; 345 ([published Online First: 2014/07/31]): 159-163https://doi.org/10.1016/j.jns.2014.07.032
The literature on fampridine-induced 3DGA changes in patients with MS, only include two publications on the same study: One demonstrating changes on kinematic variables (
Zörner et al., 2016
) and one on kinetic variables (- Zörner B.
- Filli L.
- Reuter K.
- et al.
Prolonged-release fampridine in multiple sclerosis: improved ambulation effected by changes in walking pattern.
Mult. Scler. 2016; 22 ([published Online First: 2016/01/15]): 1463-1475https://doi.org/10.1177/1352458515622695
Weller et al., 2020
). The study however, was performed during treadmill walking and the analysis included only a few kinematic variables, thus not allowing an interpretation of overall kinematic quality of gait (- Weller D.
- Lörincz L.
- Sutter T.
- et al.
Fampridine-induced changes in walking kinetics are associated with clinical improvements in patients with multiple sclerosis.
J. Neurol. Sci. 2020; 416 ([published Online First: 2020/06/20])116978https://doi.org/10.1016/j.jns.2020.116978
Zörner et al., 2016
). The use of GPS/GVS, in combination with performance-based tests and self-perceived gait function, may help evaluate neuromechanical changes of fampridine on overall quality of gait.- Zörner B.
- Filli L.
- Reuter K.
- et al.
Prolonged-release fampridine in multiple sclerosis: improved ambulation effected by changes in walking pattern.
Mult. Scler. 2016; 22 ([published Online First: 2016/01/15]): 1463-1475https://doi.org/10.1177/1352458515622695
The aims of this study were to test the hypothesis that both gait quality (using GPS based on nine different GVS readings) and gait function (using performance-based tests, spatiotemporal variables, and self-perceived gait function) would improve in patients with MS after two weeks of fampridine treatment. Further, we hypothesized that changes in GPS would be associated with changes in performance-based tests and self-perceived gait function.
2. Methods
2.1 Participants and setting
The present cohort study (without a separate control group) is part of a larger explorative, prospective observational cohort study (the MUST study) conducted at Odense University Hospital, Denmark from December 2018 to October 2021, in which participants were offered fampridine in a start-up period before evaluating its potential clinical impact. Therefore, the current sample includes both fampridine responders and non-responders (Trial registration: ClinicalTrials.gov NCT03847545). Data for the current sub-study were collected between May 2019 and May 2021 and are reported here according to the STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) statement (
Vandenbroucke et al., 2007
). The study was approved by the National Committee on Health Research Ethics (S-20170203) and the Danish Data Protection Agency (2012-58-0018) and was conducted in accordance with the Declaration of Helsinki. Prior to testing, participants received oral and written information about the study and provided written informed consent.- Vandenbroucke J.P.
- von Elm E.
- Altman D.G.
- et al.
Strengthening the reporting of observational studies in epidemiology (STROBE): explanation and elaboration.
Ann. Intern. Med. 2007; 147 ([published Online First: 2007/10/17]): W163-W194https://doi.org/10.7326/0003-4819-147-8-200710160-00010-w1
Eligible participants were recruited from the outpatient MS Clinic at Odense University Hospital. Inclusion criteria were a diagnosis of MS according to the McDonald 2010 criteria (
Polman et al., 2011
), age > 18 years, and an Expanded Disability Status Score (EDSS) between 4 and 7. Finally, participants should comply with clinical guidelines for receiving fampridine based on clinical symptoms and neurological evaluations. Exclusion criteria were history of epilepsy, MS attacks or acute decrease of functional capacity within 60 days, change in immunomodulatory treatment within 60 days, cancer within five years, clinically significant systemic disease, concomitant treatment with cimetidine, carvedilol, propranolol or metformin, and previous operations in the back or lower extremities.- Polman C.H.
- Reingold S.C.
- Banwell B.
- et al.
Diagnostic criteria for multiple sclerosis: 2010 revisions to the McDonald criteria.
Ann. Neurol. 2011; 69 ([published Online First: 2011/03/10]): 292-302https://doi.org/10.1002/ana.22366
The participants included in the MUST study were randomly allocated to the present sub-study involving 3DGA (computerised at a sequence of 1:1) resulting in an extra test day at the test-site for each visit. The randomization procedure was done to reduce the number of time-consuming procedures and adhere to the sample size calculation (Section 2.3). Assessments were performed at baseline (T0), prior to starting fampridine, and at follow-up (T1) after 14 (±1) days of 10 mg fampridine® (Biogen, Cambridge, MA, USA) twice daily. Both T0 and T1 consisted of two consecutive days, one including the performance-based tests and one including 3DGA. Walking aids were used as required and kept identical for the individual tests at T0 and T1. At T0 baseline characteristics was collected, including age, gender, height and weight (from which Body Mass Index (BMI) was calculated), disease duration, and EDSS.
2.2 Outcome measures
2.2.1 Gait quality using 3D gait analysis
Kinematic data were acquired using a Vicon T40 motion analysis system (Vicon, Oxford, UK) consisting of eight cameras sampling at 100 Hz. Prior to testing, relevant anthropometric measures were collected for the individual participant, followed by montage of 24 reflective markers and estimation of joint angles based on the modified Plug-In Gait model (
Davis et al., 1991
).Participants walked barefooted at their normal self-selected walking speed, but were asked to adjust this at the follow-up visit if the self-selected walking-speed exceeded ±5% difference between the two visits. Data from five full gait cycles (unilateral heel-strike to heel-strike) for the dominant side (allowing suitable rest time between trials) at each visit were used for analyses. One assessor with 5 years of experience with this method (first study author) was responsible for marker placement, collecting the gait data, and data processing.
Both GPS and the nine individual GVS were used to evaluate gait quality and potential kinematic changes at joint level, respectively according to Baker et al. 2009 (
Baker et al., 2009
). GPS is the root mean square (RMS) difference between the data of relevant kinematic variables of an individual participant and the averaged data from a reference group comprised of people without gait limitations. GVS refers to the RMS difference of the kinematic variables at each joint level: pelvic tilt, obliquity and rotation; hip flexion-extension, adduction-abduction, and rotation; knee flexion-extension; ankle dorsiflexion; and foot progression (- Baker R.
- McGinley J.L.
- Schwartz M.H.
- et al.
The gait profile score and movement analysis profile.
Gait Posture. 2009; 30 ([published Online First: 2009/07/28]): 265-269https://doi.org/10.1016/j.gaitpost.2009.05.020
Baker et al., 2009
). For normative data, we used an age-matched reference group collected in our own lab (n: 29; Gender: 14 men/15 woman, age (mean (SD)): 50.5 years (10.3); BMI: 25.1 (3.0)).- Baker R.
- McGinley J.L.
- Schwartz M.H.
- et al.
The gait profile score and movement analysis profile.
Gait Posture. 2009; 30 ([published Online First: 2009/07/28]): 265-269https://doi.org/10.1016/j.gaitpost.2009.05.020
We processed the raw data using used Vicon Nexus Software (version 2.9.2 or later) and Vicon Polygon Software (version 4.4.5 or later) and subsequently analysed GPS and GVS using a custom-made MatLab script.
2.2.2 Gait function
Gait function was evaluated using spatiotemporal parameters captured during the 3DGA, performance-based tests, and a patient-reported measure. The Timed 25-Foot Walk (T25FW) measures short-distance walking speed and was performed according to the Multiple Sclerosis Functional Composite (
Fischer et al., 2001
). The Six Spot Step Test (SSST) evaluates ambulatory function and involves criss-cross walking across a rectangular course as quickly as possible while kicking five blocks out of circles marked on the floor (Nieuwenhuis et al., 2006
). In the 2-min Walk Test (2MWT) (- Nieuwenhuis M.M.
- Van Tongeren H.
- Sørensen P.S.
- et al.
The six spot step test: a new measurement for walking ability in multiple sclerosis.
Mult. Scler. 2006; 12 ([published Online First: 2006/08/12]): 495-500https://doi.org/10.1191/1352458506ms1293oa
Gijbels et al., 2011
), participants walked laps on a 20-m lane for 2 min, and the total distance travelled was recorded. Self-perceived impact of MS on gait function was measured using the 12-item MS Walking Scale (MSWS-12), a questionnaire evaluating gait limitations due to MS during the past two weeks (Hobart et al., 2003
). All included measuring tools are considered reliable and valid for the current patient group (- Hobart J.C.
- Riazi A.
- Lamping D.L.
- et al.
Measuring the impact of MS on walking ability: the 12-item MS walking scale (MSWS-12).
Neurology. 2003; 60 ([published Online First: 2003/01/15]): 31-36https://doi.org/10.1212/wnl.60.1.31
Callesen et al., 2019
; - Callesen J.
- Richter C.
- Kristensen C.
- et al.
Test-retest agreement and reliability of the six spot step test in persons with multiple sclerosis.
Mult. Scler. 2019; 25 ([published Online First: 2017/12/21]): 286-294https://doi.org/10.1177/1352458517745725
Gijbels et al., 2011
; Motl et al., 2017
; - Motl R.W.
- Cohen J.A.
- Benedict R.
- et al.
Validity of the timed 25-foot walk as an ambulatory performance outcome measure for multiple sclerosis.
Mult. Scler. 2017; 23 ([published Online First: 2017/02/17]): 704-710https://doi.org/10.1177/1352458517690823
Pilutti et al., 2013
; - Pilutti L.A.
- Dlugonski D.
- Sandroff B.M.
- et al.
Further validation of multiple sclerosis walking scale-12 scores based on spatiotemporal gait parameters.
Arch. Phys. Med. Rehabil. 2013; 94 ([published Online First: 2012/09/11]): 575-578https://doi.org/10.1016/j.apmr.2012.08.214
Scalzitti et al., 2018
).- Scalzitti D.A.
- Harwood K.J.
- Maring J.R.
- et al.
Validation of the 2-minute talk test with the 6-minute walk test and other functional measures in persons with multiple sclerosis.
Int. J. MS Care. 2018; 20 ([published Online First: 2018/08/29]): 158-163https://doi.org/10.7224/1537-2073.2017-046
2.3 Statistical analysis
Statistical analyses were performed using Stata/BE 17.0 (StataCorp LLC, College Station, TX, USA).
Sample size calculation for the present analysis was performed a priori using previously reported GPS values on a comparable MS population (GPS mean ± SD) 9.1° ± 1.3° (
Andreopoulou et al., 2019
) and a minimal clinically important difference of 1.6° GPS, originally defined in a sample of children (- Andreopoulou G.
- Mahad D.J.
- Mercer T.H.
- et al.
Test-retest reliability and minimal detectable change of ankle kinematics and spatiotemporal parameters in MS population.
Gait Posture. 2019; 74 ([published Online First: 2019/09/29]): 218-222https://doi.org/10.1016/j.gaitpost.2019.09.015
Baker et al., 2012
). As no SD was reported for the original paper, we generalised the between-individual SD to the standard deviation of the change scores as SD = 1.3°. Based on a paired design, alpha = 0.05, 80% statistical power, assumption of Gaussian distribution of change scores, and attainment of minimal clinically important difference, a minimum of 9 participants were needed to reject the null hypothesis of no change from T0 to T1.- Baker R.
- McGinley J.L.
- Schwartz M.
- et al.
The minimal clinically important difference for the gait profile score.
Gait Posture. 2012; 35 ([published Online First: 2012/01/10]): 612-615https://doi.org/10.1016/j.gaitpost.2011.12.008
Gaussian distribution for included data was investigated using normal probability plots and the Shapiro-Wilk test. To investigate changes between T0 and T1, we used Student's paired t-test with 95% confidence intervals (parametric) and Wilcoxon signed rank test with median values and bootstrap confidence intervals (95% BCa) (non-parametric).
To compare characteristics of the included participants with MS to, those of the patients who were randomized to perform 3DGA but declined, we used Student's unpaired t-test (parametric) and Wilcoxon rank sum test (non-parametric).
Due to the small sample size, we had no hypothesis for the specific form of association between GPS change scores and change scores of the performance-based measures and self-perceived gait function. Therefore, both Pearson's product-moment correlation coefficient r and Spearman's rank-order correlation coefficient ρ (rho) are reported. For kinematic and spatiotemporal data, the results for the dominant side are reported.
3. Results
Of the 71 patients with MS invited to participate in the larger cohort study (MUST), 16 declined. During the screening process, further 8 patients did not meet inclusion criteria. Of the remaining 47 participants, 26 were randomly allocated to 3DGA and 14 of these accepted the extra visit associated with the 3DGA; these 14 participants were included in the current sub-study (Fig. 1). No differences in characteristics were detected between the 14 included participants and the 12 patients who were randomized to 3DGA but declined (Table 1). All included participants completed both visits. The average age was 54 years, the majority were women, were overweight, and had an EDSS score between 4 and 6. The proportion using a walking aid during testing varied from 21% to 43% (Table 1).
Fig. 1Flowchart.
Show full caption
Illustration of the inclusion and the progress of all participants for the current sub-study on three-dimensional gait analysis (3DGA).
Table 1Baseline characteristics of included participants and patients that declined to perform 3DGA.
| Characteristics | Performed 3DGA (n = 14) | Declined 3DGA (n = 12) | p-value |
|---|---|---|---|
| Age, years | 53.6 (12.8) | 58.7 (12.9) | 0.18 |
| Females, n (%) | 9 (64) | 6 (50) | 1.00 |
| BMI, kg/m2 | 26.2 (3.9) | NA | NA |
| Disease duration, years | 21 (9.1) | 20.8 (10.1) | 0.95 |
| EDSS | 5.2 (0.8) | 5.6 (0.9) | 0.43 |
| Patients using walking aids during tests, n (%): | |||
| 3DGA | 4 (28.6) | NA | NA |
| T25FW | 3 (21.4) | 4 (33.3) | 0.53 |
| SSST | 3 (21.4) | 5 (41.7) | 0.27 |
| 2MWT | 6 (42.9) | 6 (50.0) | 0.73 |
Values are reported as mean (SD) or n (%).
3DGA: Three-dimensional gait analysis; EDSS: Expanded Disability Status Score; T25FW: Timed 25-Foot Walk; SSST: Six Spot Step Test; 2MWT: 2-min Walk Test; NA; not applicable.
We found no improvements in gait quality in terms of GPS or any kinematic changes at joint level by means of GVS (p > 0.05), following two weeks of fampridine treatment (Table 2a). However, we found significant improvement of gait function according to performance-based tests: T25FW, SSST, and 2MWT (p < 0.003) and self-perceived gait function: MSWS-12 (p < 0.001) (Table 2b). No significant changes were seen in the spatiotemporal parameters (p > 0.05) (Table 2b).
Table 2aGait quality at baseline (T0) and 14-day follow-up (T1) for 14 patients with multiple sclerosis.
| Gait quality variables | T0 | T1 | Change [95% CI] | % change | p-value |
|---|---|---|---|---|---|
| Overall GPS (degrees) | 8.50 (7.61/8.96) | 7.90 (7.39/9.35) | −0.21 [−0.72; 0.29] | −2.47 | 0.456 |
| GVS – dominant side (degrees) | |||||
| Pelvic tilt | 3.82 (2.71/7.10) | 5.24 (3.34/6.23) | 0.06[−1.35; 1.46] | 1.57 | 0.931 |
| Pelvic obliquity | 2.24 (1.85/2.76) | 2.05 (1.37/2.39) | −0.22 [−0.49; 0.04] | −9.82 | 0.094 |
| Pelvic rotation | 4.45 (3.70/5.76) | 5.38 (3.95/5.98) | 0.22 [−0.43; 0.86] | 4.94 | 0.482 |
| Hip flexion-extension | 9.18 (8.08/11.87) | 9.47 (7.69/12.74) | 0.31[−0.80; 1.42] | 3.38 | 0.561 |
| Hip abduction-adduction | 4.38 (3.41/4.95) | 4.15 (2.71/5.24) | −0.22 [−0.80; 0.35] | −5.02 | 0.410 |
| Hip rotation | 7.89 (6.32/11.82) | 7.11 (5.61/9.57) | −1.03 [−3.16; 1.10] | −13.05 | 0.316 |
| Knee flexion-extension | 13.25 (10.80/14.86) | 12.28 (8.38/15.03) | −0.99 [−2.14; 0.17] | −7.47 | 0.087 |
| Ankle dorsi flexion | 8.88 (7.08/10.23) | 8.68 (6.64/10.75) | −0.30 [−1.09; 1.01]* | −3.38 | 0.510 |
| Foot progression | 7.36 (5.12/8.50) | 6.96 (6.20/9.32) | 0.25 [−0.91; 1.41] | 3.40 | 0.648 |
Table 2bGait function at baseline (T0) and 14-day follow-up (T1) for 14 patients with multiple sclerosis.
| Gait function variables | T0 | T1 | Change [95% CI] | % change | p-value |
|---|---|---|---|---|---|
| Performance-based test and PROM | |||||
| T25FW (s) | 6.30 (5.35/7.05) | 5.58 (4.55/6.50) | −0.82 [−1.16; –0.47] | −11.51 | <0.001 |
| SSST (s) | 11.87 (3.87) | 10.22 (2.75) | −1.65 [−2.65; −0.49]* | −13.90 | 0.002 |
| 2MWT (m) | 126.80 (25.71) | 149.84 (36.98) | 23.04 [14.03; 28.00]* | 18.17 | 0.001 |
| MSWS-12 (points) | 63.84 (13.44) | 41.37 (18.69) | −22.47 [−29.17; −4.17]* | −35.17 | <0.001 |
| Spatiotemporal parameters – dominant side | |||||
| Walking speed (m/s) | 0.94 (0.20) | 0.94 (0.19) | 0.00 [−0.01; 0.02] | 0.00 | 0.664 |
| Cadence (steps/min) | 105.17 (8.90) | 104.35 (9.48) | −0.82 [–2.50; 0.86] | –0.78 | 0.311 |
| Step length (m) | 0.54 (0.08) | 0.55 (0.08) | 0.01 [−0.00; 0.03] | 1.85 | 0.113 |
| Step width (m) | 0.17 (0.04) | 0.17 (0.04) | 0.00 [−0.01; 0.01] | 0.00 | 0.874 |
| Stride length (m) | 1.07 (0.16) | 1.08 (0.16) | 0.02 [−0.01; 0.04] | 0.93 | 0.160 |
Values at T0 and T1 are mean (SD) or median (IQR). Change scores are mean [95% CI] if normally distributed or median [95% BCa] (followed by *) if non-normally distributed.
GPS: Gait Profile Score; GVS: Gait Variable Scores; T25FW: Timed 25-Foot Walk; SSST: Six Spot Step Test; 2MWT: 2-min Walk Test; MSWS-12: 12-item MS Walking Scale; IQR: interquartile range; SD: standard deviation.
No significant correlations were detected between change in GPS and changes in the performance-based tests or self-perceived gait function (p > 0.05), see Fig. 2.
Fig. 2Scatterplots of associations.
Show full caption
Scatterplots of associations between change in GPS and change in (A) T25FW, (B) SSST, (C) 2MWT and (D) MSWS-12 for 14 patients with multiple sclerosis.
r: Pearson correlation coefficient; rho: Spearman's rank correlation coefficient; GPS: Gait Profile Score; T25FW: Timed 25-Foot Walk; SSST: Six Spot Step Test; 2MWT: 2-min Walk Test; MSWS-12: 12-Item MS Walking Scale.
4. Discussion
4.1 Main findings
This is the first study examining potential fampridine-induced improvements in gait quality using a gait summary measure in patients with MS. The study represents a pragmatic clinical approach where participants were offered fampridine in a start-up period before evaluating its potential clinical impact. Therefore, the current study represents a sample including both fampridine responders and non-responders. Contrary to our hypothesis, we found no significant group mean improvements in gait quality and joint specific kinematic scores following fampridine treatment. However, improvements in the performance-based tests and self-perceived gait function confirmed our hypothesis of improved gait function. We found no significant associations between gait quality (GPS) and measures of gait function, consequently rejecting our hypothesis. Fampridine-induced changes thus appear to be restricted to performance-based gait variables and self-perceived gait function. As the underlying neuromechanical joint specific kinematic deviations (GVS) and overall quality of gait (GPS) showed no difference, the walking strategy remains unaltered i.e. MS-related gait limitations remain unchanged despite better function after two weeks of fampridine treatment.
4.2 Quality of gait
Compared to a median GPS of 4.8° in our age-matched reference group (data not shown), the participants with MS in the present study showed impaired gait quality at baseline, with a median GPS of 9.39° (IQR: 8.30°/9.82°), which is comparable with a GPS of 9.1° reported in a previous study on patients with MS (
Andreopoulou et al., 2019
). Thus, the observed lack of fampridine-induced change in gait quality cannot be ascribed to a flooring effect.- Andreopoulou G.
- Mahad D.J.
- Mercer T.H.
- et al.
Test-retest reliability and minimal detectable change of ankle kinematics and spatiotemporal parameters in MS population.
Gait Posture. 2019; 74 ([published Online First: 2019/09/29]): 218-222https://doi.org/10.1016/j.gaitpost.2019.09.015
A previous study demonstrated a minor fampridine-induced improvement in kinematic knee ROM of 2° during treadmill walking (
Zörner et al., 2016
). Together with current results of no improvements in GVS and GPS, this finding indicates that the kinematic strategy of patients with MS remains unaltered after a period of fampridine treatment. In contrast, a significant improvement of 10% (corresponding to 1.34° in the GPS) was found in patients with MS following one month of medical treatment for spasticity (nabiximols) (- Zörner B.
- Filli L.
- Reuter K.
- et al.
Prolonged-release fampridine in multiple sclerosis: improved ambulation effected by changes in walking pattern.
Mult. Scler. 2016; 22 ([published Online First: 2016/01/15]): 1463-1475https://doi.org/10.1177/1352458515622695
Coghe et al., 2015
); the median GPS (12.25°) was considerably poorer than that in the current study (9.39°), so direct comparisons especially of the difference in treatment outcome should be made with caution. Furthermore, no anchor-based MS-specific minimal clinically important change is defined for the GPS, and whether the observed change was clinically relevant, can be questioned. Fampridine-induced changes have been observed in some walking kinetics during treadmill walking, albeit on single patient and not group level, and not versus placebo (- Coghe G.
- Pau M.
- Corona F.
- et al.
Walking improvements with nabiximols in patients with multiple sclerosis.
J. Neurol. 2015; 262 ([published Online First: 2015/08/05]): 2472-2477https://doi.org/10.1007/s00415-015-7866-5
Weller et al., 2020
). Interestingly, the sub-group of patients displaying kinetic changes, also exhibited improvements in clinical walking tests. Thus, indicating that improvements in gait kinetics potentially influences gait performance, measured by clinical walking tests (- Weller D.
- Lörincz L.
- Sutter T.
- et al.
Fampridine-induced changes in walking kinetics are associated with clinical improvements in patients with multiple sclerosis.
J. Neurol. Sci. 2020; 416 ([published Online First: 2020/06/20])116978https://doi.org/10.1016/j.jns.2020.116978
Weller et al., 2020
).- Weller D.
- Lörincz L.
- Sutter T.
- et al.
Fampridine-induced changes in walking kinetics are associated with clinical improvements in patients with multiple sclerosis.
J. Neurol. Sci. 2020; 416 ([published Online First: 2020/06/20])116978https://doi.org/10.1016/j.jns.2020.116978
Compared to controls, patients with MS have demonstrated reduced velocity, cadence, and step length as well as increased base of support (
Givon et al., 2009
). To the best of our knowledge, only two studies (- Givon U.
- Zeilig G.
- Achiron A.
Gait analysis in multiple sclerosis: characterization of temporal-spatial parameters using GAITRite functional ambulation system.
Gait Posture. 2009; 29 ([published Online First: 2008/10/28]): 138-142https://doi.org/10.1016/j.gaitpost.2008.07.011
Allart et al., 2015
; - Allart E.
- Benoit A.
- Blanchard-Dauphin A.
- et al.
Sustained-released fampridine in multiple sclerosis: effects on gait parameters, arm function, fatigue, and quality of life.
J. Neurol. 2015; 262 ([published Online First: 2015/06/05]): 1936-1945https://doi.org/10.1007/s00415-015-7797-1
Rodriguez-Leal et al., 2018
) have examined changes in spatiotemporal parameters in patients with MS following fampridine treatment. Both studies (- Rodriguez-Leal F.A.
- Haase R.
- Thomas K.
- et al.
Fampridine response in MS patients with gait impairment in a real-world setting: need for new response criteria?.
Mult. Scler. 2018; 24 ([published Online First: 2017/07/26]): 1337-1346https://doi.org/10.1177/1352458517720043
Allart et al., 2015
; - Allart E.
- Benoit A.
- Blanchard-Dauphin A.
- et al.
Sustained-released fampridine in multiple sclerosis: effects on gait parameters, arm function, fatigue, and quality of life.
J. Neurol. 2015; 262 ([published Online First: 2015/06/05]): 1936-1945https://doi.org/10.1007/s00415-015-7797-1
Rodriguez-Leal et al., 2018
) evaluated the Functional Ambulation Profile (FAP) score, which is composite value of gait based on selected spatiotemporal parameters (- Rodriguez-Leal F.A.
- Haase R.
- Thomas K.
- et al.
Fampridine response in MS patients with gait impairment in a real-world setting: need for new response criteria?.
Mult. Scler. 2018; 24 ([published Online First: 2017/07/26]): 1337-1346https://doi.org/10.1177/1352458517720043
Givon et al., 2009
). A significant positive change in FAP score was detected in both studies although one based the conclusion on group-level analysis (- Givon U.
- Zeilig G.
- Achiron A.
Gait analysis in multiple sclerosis: characterization of temporal-spatial parameters using GAITRite functional ambulation system.
Gait Posture. 2009; 29 ([published Online First: 2008/10/28]): 138-142https://doi.org/10.1016/j.gaitpost.2008.07.011
Rodriguez-Leal et al., 2018
) and the other used a categorical responder criterion threshold of 15% (- Rodriguez-Leal F.A.
- Haase R.
- Thomas K.
- et al.
Fampridine response in MS patients with gait impairment in a real-world setting: need for new response criteria?.
Mult. Scler. 2018; 24 ([published Online First: 2017/07/26]): 1337-1346https://doi.org/10.1177/1352458517720043
Allart et al., 2015
). The latter additionally evaluated the spatiotemporal parameters separately, finding significant improvements in walking speed, cadence, and step-length (- Allart E.
- Benoit A.
- Blanchard-Dauphin A.
- et al.
Sustained-released fampridine in multiple sclerosis: effects on gait parameters, arm function, fatigue, and quality of life.
J. Neurol. 2015; 262 ([published Online First: 2015/06/05]): 1936-1945https://doi.org/10.1007/s00415-015-7797-1
Allart et al., 2015
). Compared to our study, participants in both studies were more impaired at baseline according to clinical performance tests. Furthermore, unlike our study, the two previous studies did not match walking speed between sessions (- Allart E.
- Benoit A.
- Blanchard-Dauphin A.
- et al.
Sustained-released fampridine in multiple sclerosis: effects on gait parameters, arm function, fatigue, and quality of life.
J. Neurol. 2015; 262 ([published Online First: 2015/06/05]): 1936-1945https://doi.org/10.1007/s00415-015-7797-1
Allart et al., 2015
; - Allart E.
- Benoit A.
- Blanchard-Dauphin A.
- et al.
Sustained-released fampridine in multiple sclerosis: effects on gait parameters, arm function, fatigue, and quality of life.
J. Neurol. 2015; 262 ([published Online First: 2015/06/05]): 1936-1945https://doi.org/10.1007/s00415-015-7797-1
Rodriguez-Leal et al., 2018
), potentially introducing a biasing factor on gait variables (including spatiotemporal parameters and joint kinematics).- Rodriguez-Leal F.A.
- Haase R.
- Thomas K.
- et al.
Fampridine response in MS patients with gait impairment in a real-world setting: need for new response criteria?.
Mult. Scler. 2018; 24 ([published Online First: 2017/07/26]): 1337-1346https://doi.org/10.1177/1352458517720043
4.3 Gait performance
In contrast to measures of gait quality, significant improvements were seen on performance-based measures after fampridine treatment with the MSWS-12 showing the largest percentage improvement (−22.5 points/−35.2%). This positive change is substantial compared to most previous studies (
Brambilla et al., 2016
; - Brambilla L.
- Rossi Sebastiano D.
- Aquino D.
- et al.
Early effect of dalfampridine in patients with MS: a multi-instrumental approach to better investigate responsiveness.
J. Neurol. Sci. 2016; 368 ([published Online First: 2016/08/20]): 402-407https://doi.org/10.1016/j.jns.2016.06.019
Lo et al., 2015
; - Lo A.C.
- Ruiz J.A.
- Koenig C.M.
- et al.
Effects of dalfampridine on multi-dimensional aspects of gait and dexterity in multiple sclerosis among timed walk responders and non-responders.
J. Neurol. Sci. 2015; 356 ([published Online First: 2015/07/04]): 77-82https://doi.org/10.1016/j.jns.2015.06.008
Rodriguez-Leal et al., 2018
) and represents an improvement larger than the defined minimal clinically important change from the patient's and therapist's perspectives (10.4 points and 11.4 points, respectively) (- Rodriguez-Leal F.A.
- Haase R.
- Thomas K.
- et al.
Fampridine response in MS patients with gait impairment in a real-world setting: need for new response criteria?.
Mult. Scler. 2018; 24 ([published Online First: 2017/07/26]): 1337-1346https://doi.org/10.1177/1352458517720043
Baert et al., 2014
).- Baert I.
- Freeman J.
- Smedal T.
- et al.
Responsiveness and clinically meaningful improvement, according to disability level, of five walking measures after rehabilitation in multiple sclerosis: a European multicenter study.
Neurorehabil. Neural Repair. 2014; 28 ([published Online First: 2014/02/08]): 621-631https://doi.org/10.1177/1545968314521010
The 2MWT also showed a large improvement (18.2%). Despite its strong discriminatory ability, the 2MWT has rarely been used to examine the effect of fampridine at group level, but a change of 14.8% was reported in a study on the response to fampridine (
Rodriguez-Leal et al., 2018
). Although the previous study differed slightly in baseline EDSS characteristics and the participants covered a shorter distance in the 2MWT (- Rodriguez-Leal F.A.
- Haase R.
- Thomas K.
- et al.
Fampridine response in MS patients with gait impairment in a real-world setting: need for new response criteria?.
Mult. Scler. 2018; 24 ([published Online First: 2017/07/26]): 1337-1346https://doi.org/10.1177/1352458517720043
Rodriguez-Leal et al., 2018
), both that study and our study obtained the minimally clinical important change value of 9.6 m (patient perspective) and 6.8 m (therapist perspective) (- Rodriguez-Leal F.A.
- Haase R.
- Thomas K.
- et al.
Fampridine response in MS patients with gait impairment in a real-world setting: need for new response criteria?.
Mult. Scler. 2018; 24 ([published Online First: 2017/07/26]): 1337-1346https://doi.org/10.1177/1352458517720043
Baert et al., 2014
).- Baert I.
- Freeman J.
- Smedal T.
- et al.
Responsiveness and clinically meaningful improvement, according to disability level, of five walking measures after rehabilitation in multiple sclerosis: a European multicenter study.
Neurorehabil. Neural Repair. 2014; 28 ([published Online First: 2014/02/08]): 621-631https://doi.org/10.1177/1545968314521010
The current improvements of −11.5% in T25FW and − 13.9% in SSST are in line with previously reported results in patients with MS (
Jensen et al., 2014
; Lo et al., 2015
). Notably, the group mean change does not reach the defined clinical relevancy of 20% for the T25FW (- Lo A.C.
- Ruiz J.A.
- Koenig C.M.
- et al.
Effects of dalfampridine on multi-dimensional aspects of gait and dexterity in multiple sclerosis among timed walk responders and non-responders.
J. Neurol. Sci. 2015; 356 ([published Online First: 2015/07/04]): 77-82https://doi.org/10.1016/j.jns.2015.06.008
Hobart et al., 2013
), which is often considered the response criterion for continued treatment with fampridine (- Hobart J.
- Blight A.R.
- Goodman A.
- et al.
Timed 25-foot walk: direct evidence that improving 20% or greater is clinically meaningful in MS.
Neurology. 2013; 80 ([published Online First: 2013/03/29]): 1509-1517https://doi.org/10.1212/WNL.0b013e31828cf7f3
Hobart et al., 2013
; - Hobart J.
- Blight A.R.
- Goodman A.
- et al.
Timed 25-foot walk: direct evidence that improving 20% or greater is clinically meaningful in MS.
Neurology. 2013; 80 ([published Online First: 2013/03/29]): 1509-1517https://doi.org/10.1212/WNL.0b013e31828cf7f3
Jensen et al., 2014
). Similarly, SSST does not reach the threshold of >19% change for it to be considered a real change exceeding the measurement variability (Callesen et al., 2019
). These thresholds however, may have been defined in patients with MS who display a higher level of gait limitations since their basis test results (mean T25FW: 8 to 45 s (- Callesen J.
- Richter C.
- Kristensen C.
- et al.
Test-retest agreement and reliability of the six spot step test in persons with multiple sclerosis.
Mult. Scler. 2019; 25 ([published Online First: 2017/12/21]): 286-294https://doi.org/10.1177/1352458517745725
Hobart et al., 2013
); SSST: 5.6 to 61.1 s (- Hobart J.
- Blight A.R.
- Goodman A.
- et al.
Timed 25-foot walk: direct evidence that improving 20% or greater is clinically meaningful in MS.
Neurology. 2013; 80 ([published Online First: 2013/03/29]): 1509-1517https://doi.org/10.1212/WNL.0b013e31828cf7f3
Callesen et al., 2019
) are substantially inferior to those demonstrated in our sample (mean T25FW: 6.3 s; mean SSST: 11.9 s). The case-mix of responders and non-responders in the current study may also explain the failure to achieve the thresholds for the T25FW and SSST.- Callesen J.
- Richter C.
- Kristensen C.
- et al.
Test-retest agreement and reliability of the six spot step test in persons with multiple sclerosis.
Mult. Scler. 2019; 25 ([published Online First: 2017/12/21]): 286-294https://doi.org/10.1177/1352458517745725
We found no association between improvement in gait quality and improvement in gait function. In view of the large and significant improvements seen in the functional tests and self-perceived gait function, the lack of change in gait quality is not due to a lack of response to fampridine. Instead, the positive fampridine effect on gait function is perhaps a result of improved signal conduction that results in a faster muscular response, rather than a direct effect on the movement pattern and thus kinematic gait quality evaluated by GPS and GVS. Improved gait quality would theoretically include a change in the MS patient's neuromechanical movement strategy, which most likely requires more than the short-term alteration of signal conduction in demyelinated axons that fampridine offers. The current lack of change in gait quality could thus be a consequence of both the short intervention and the isolated biochemical impact of fampridine. Future studies with longer intervention periods, possibly supplemented with targeted gait rehabilitation, are warranted to evaluate the potential influence of fampridine treatment on gait quality in patients with MS.
4.4 Strengths and limitations
Our study provides useful new clinical data on fampridine's effect on kinematic gait quality to add to its known impact on gait function in patients with MS. A further strength is that our GPS calculations were based on data from an able-bodied, age-matched reference group that were collected in our own laboratory. In addition, despite Baker et al. 2009 previously documented a weak correlation between GPS and walking speed (rho = −0.28) (
Baker et al., 2009
), we chose to match walking speed between sessions to fully eliminate its potential influence on kinematic variables (- Baker R.
- McGinley J.L.
- Schwartz M.H.
- et al.
The gait profile score and movement analysis profile.
Gait Posture. 2009; 30 ([published Online First: 2009/07/28]): 265-269https://doi.org/10.1016/j.gaitpost.2009.05.020
Filli et al., 2018
).- Filli L.
- Sutter T.
- Easthope C.S.
- et al.
Profiling walking dysfunction in multiple sclerosis: characterisation, classification and progression over time.
Sci. Rep. 2018; 8 ([published Online First: 2018/03/23]): 4984https://doi.org/10.1038/s41598-018-22676-0
The present study has some methodological limitations. First, the pragmatic clinical approach entailed the inclusion of a sample including both fampridine responders and non-responders. This ruled out a randomized controlled trial approach, and thus also a causal investigation. The non-controlled and un-blinded design raises the possibilities of placebo effect, performance bias, and recall bias, all of which could influence the results. However, fampridine has previously been tested against placebo, and the extensive body of literature supporting a positive fampridine effect on gait function during a two-week trial (
Allart et al., 2015
; - Allart E.
- Benoit A.
- Blanchard-Dauphin A.
- et al.
Sustained-released fampridine in multiple sclerosis: effects on gait parameters, arm function, fatigue, and quality of life.
J. Neurol. 2015; 262 ([published Online First: 2015/06/05]): 1936-1945https://doi.org/10.1007/s00415-015-7797-1
Goodman et al., 2009
; Goodman et al., 2010
; Lo et al., 2015
; - Lo A.C.
- Ruiz J.A.
- Koenig C.M.
- et al.
Effects of dalfampridine on multi-dimensional aspects of gait and dexterity in multiple sclerosis among timed walk responders and non-responders.
J. Neurol. Sci. 2015; 356 ([published Online First: 2015/07/04]): 77-82https://doi.org/10.1016/j.jns.2015.06.008
Zörner et al., 2016
) supports the current results.- Zörner B.
- Filli L.
- Reuter K.
- et al.
Prolonged-release fampridine in multiple sclerosis: improved ambulation effected by changes in walking pattern.
Mult. Scler. 2016; 22 ([published Online First: 2016/01/15]): 1463-1475https://doi.org/10.1177/1352458515622695
Although the sample size was defined a priori, this was based on a minimally clinically important GPS difference derived from children, as a MS-specific anchor-based difference was not available. In addition, the small sample size potentially reduces generalizability to the larger MS population. However, even though only 14, out of the 26 participants who were randomly allocated to 3DGA, accepted to perform this examination, a sub-group analysis of those randomized but not willing to undergo 3DGA yielded no difference in patient characteristics, suggesting high external validity.
5. Conclusions
In this prospective cohort study, improved gait function was observed in patients with MS following fampridine treatment according to performance-based tests and self-perceived gait function. However, no improvement in the kinematic quality of gait was seen. This may indicate that the impact of a two-week fampridine treatment is limited to improved signal conduction that leads to better gait performance.
Author contribution
Conception or design of the work: All.
Coordinating the study: MT, AHL, HHN.
Data collection: MT.
Data-analysis: MT, AHL.
Interpretation of data: MT, AHL, HHN, KLL.
Writing – drafting the work: MT, AHL, HHN, KLL.
Writing – Revision and editing of the work: All.
Final approval of the version to be published: All.
Declaration of Competing Interest
The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:
Helle Hvilsted Nielsen reports a relationship with Biogen that includes: consulting or advisory, speaking and lecture fees, and travel reimbursement. Helle Hvilsted Nielsen reports a relationship with Roche that includes: consulting or advisory, speaking and lecture fees, and travel reimbursement. Helle Hvilsted Nielsen reports a relationship with Sanofi Genzyme that includes: consulting or advisory, speaking and lecture fees, and travel reimbursement. Helle Hvilsted Nielsen reports a relationship with Merck & Co Inc. that includes: consulting or advisory, speaking and lecture fees, and travel reimbursement. Helle Hvilsted Nielsen reports a relationship with Novartis that includes: consulting or advisory, speaking and lecture fees, and travel reimbursement. Helle Hvilsted Nielsen reports a relationship with Teva Pharmaceutical Industries Ltd. that includes: consulting or advisory, speaking and lecture fees, and travel reimbursement. Henrik Boye Jensen reports a relationship with Biogen that includes: consulting or advisory, speaking and lecture fees, and travel reimbursement. Henrik Boye Jensen reports a relationship with Roche that includes: consulting or advisory, speaking and lecture fees, and travel reimbursement. Henrik Boye Jensen reports a relationship with Sanofi Genzyme that includes: consulting or advisory, speaking and lecture fees, and travel reimbursement. Henrik Boye Jensen reports a relationship with Merck & Co Inc. that includes: consulting or advisory, speaking and lecture fees, and travel reimbursement. Henrik Boye Jensen reports a relationship with Novartis that includes: consulting or advisory, speaking and lecture fees, and travel reimbursement. Henrik Boye Jensen reports a relationship with Teva Pharmaceutical Industries Ltd. that includes: consulting or advisory, speaking and lecture fees, and travel reimbursement.
Acknowledgements
This work was funded by The University of Southern Denmark , The Region of Southern Denmark [grant number: 17/33583 , 18/51851 ], Lounkaer Foundation, Augustinus' Foundation [grant number: 18-0217 ], The Danish Multiple Sclerosis Society [grant number: A35607 ], Lily Benthine Lund's Foundation [grant number: 5652 ], The Society of Multiple Sclerosis Patients on Funen, The of Chief Physician Committee Research Foundation [grant number: 70-A3228 ], The Promotion of Medical Science Foundation [grant number: 18-L-0369 ]. The study sponsors have no involvement in in the study or influence on the reporting of the results.
We thank Dennis Brandborg Nielsen for software engineering assistance. Cecilie Dollerup Skov, Line Weis Andersen, and Gro Gynther Borges for the assistance with data collection. We thank Simon Bang Mohr Kristensen and Claire Gudex, BRIDGE, for statistical assistance and for proof-reading respectively. Furthermore, we wish to thank OPEN – Open Patient data Explorative Network.
Finally, the authors would like to express their gratitude for the participants who volunteered to participate in the present study.
References
- Cortical excitability measures may predict clinical response to fampridine in patients with multiple sclerosis and gait impairment.Brain Sci. 2019; 9 (published Online First: 2019/12/11)https://doi.org/10.3390/brainsci9120357
- Sustained-released fampridine in multiple sclerosis: effects on gait parameters, arm function, fatigue, and quality of life.J. Neurol. 2015; 262 ([published Online First: 2015/06/05]): 1936-1945https://doi.org/10.1007/s00415-015-7797-1
- Test-retest reliability and minimal detectable change of ankle kinematics and spatiotemporal parameters in MS population.Gait Posture. 2019; 74 ([published Online First: 2019/09/29]): 218-222https://doi.org/10.1016/j.gaitpost.2019.09.015
- Responsiveness and clinically meaningful improvement, according to disability level, of five walking measures after rehabilitation in multiple sclerosis: a European multicenter study.Neurorehabil. Neural Repair. 2014; 28 ([published Online First: 2014/02/08]): 621-631https://doi.org/10.1177/1545968314521010
- The gait profile score and movement analysis profile.Gait Posture. 2009; 30 ([published Online First: 2009/07/28]): 265-269https://doi.org/10.1016/j.gaitpost.2009.05.020
- The minimal clinically important difference for the gait profile score.Gait Posture. 2012; 35 ([published Online First: 2012/01/10]): 612-615https://doi.org/10.1016/j.gaitpost.2011.12.008
- Gait abnormalities in minimally impaired multiple sclerosis patients.Mult. Scler. 1999; 5 ([published Online First: 1999/10/12]): 363-368https://doi.org/10.1177/135245859900500510
- Early effect of dalfampridine in patients with MS: a multi-instrumental approach to better investigate responsiveness.J. Neurol. Sci. 2016; 368 ([published Online First: 2016/08/20]): 402-407https://doi.org/10.1016/j.jns.2016.06.019
- Test-retest agreement and reliability of the six spot step test in persons with multiple sclerosis.Mult. Scler. 2019; 25 ([published Online First: 2017/12/21]): 286-294https://doi.org/10.1177/1352458517745725
- Gait abnormalities in multiple sclerosis: pathogenesis, evaluation, and advances in treatment.Curr. Neurol. Neurosci. Rep. 2011; 11 ([published Online First: 2011/07/23]): 507-515https://doi.org/10.1007/s11910-011-0214-y
- Walking improvements with nabiximols in patients with multiple sclerosis.J. Neurol. 2015; 262 ([published Online First: 2015/08/05]): 2472-2477https://doi.org/10.1007/s00415-015-7866-5
- A gait analysis data collection and reduction technique.Hum. Mov. Sci. 1991; 10: 575-587https://doi.org/10.1016/0167-9457(91)90046-Z
- Multiple sclerosis.Nat. Rev. Dis. Prim. 2018; 4 ([published Online First: 2018/11/10]): 43https://doi.org/10.1038/s41572-018-0041-4
- Profiling walking dysfunction in multiple sclerosis: characterisation, classification and progression over time.Sci. Rep. 2018; 8 ([published Online First: 2018/03/23]): 4984https://doi.org/10.1038/s41598-018-22676-0
- Multiple Sclerosis Functional Composite (MSFC): Administration and Scoring Manual.2001
- Comparison of the 2- and 6-minute walk test in multiple sclerosis.Mult. Scler. 2011; 17: 1269-1272https://doi.org/10.1177/1352458511408475
- Gait analysis in multiple sclerosis: characterization of temporal-spatial parameters using GAITRite functional ambulation system.Gait Posture. 2009; 29 ([published Online First: 2008/10/28]): 138-142https://doi.org/10.1016/j.gaitpost.2008.07.011
- Sustained-release oral fampridine in multiple sclerosis: a randomised, double-blind, controlled trial.Lancet. 2009; 373: 732-738https://doi.org/10.1016/S0140-6736(09)60442-6
- A phase 3 trial of extended release oral dalfampridine in multiple sclerosis.Ann. Neurol. 2010; 68: 494-502https://doi.org/10.1002/ana.22240
- Fampridine-SR for multiple sclerosis and spinal cord injury.Expert. Rev. Neurother. 2007; 7 ([published Online First: 2007/05/12]): 453-461https://doi.org/10.1586/14737175.7.5.453
- Measuring the impact of MS on walking ability: the 12-item MS walking scale (MSWS-12).Neurology. 2003; 60 ([published Online First: 2003/01/15]): 31-36https://doi.org/10.1212/wnl.60.1.31
- Timed 25-foot walk: direct evidence that improving 20% or greater is clinically meaningful in MS.Neurology. 2013; 80 ([published Online First: 2013/03/29]): 1509-1517https://doi.org/10.1212/WNL.0b013e31828cf7f3
- Prolonged-release fampridine and walking and balance in MS: randomised controlled MOBILE trial.Mult. Scler. 2016; 22 ([published Online First: 2015/04/30]): 212-221https://doi.org/10.1177/1352458515581436
- Changes in cognition, arm function and lower body function after slow-release Fampridine treatment.Mult. Scler. 2014; 20: 1872-1880https://doi.org/10.1177/1352458514533844
- Effect of slow release-Fampridine on muscle strength, rate of force development, functional capacity and cognitive function in an enriched population of MS patients. A randomized, double blind, placebo controlled study.Mult. Scler. Relat. Disord. 2016; 10 (published Online First: 2016/12/07): 137-144https://doi.org/10.1016/j.msard.2016.07.019
- Disability in multiple sclerosis: a reference for patients and clinicians.Neurology. 2013; 80 ([published Online First: 2013/02/22]): 1018-1024https://doi.org/10.1212/WNL.0b013e3182872855
- Impact of walking impairment in multiple sclerosis: perspectives of patients and care partners.The Patient. 2011; 4 ([published Online First: 2011/07/20]): 189-201https://doi.org/10.2165/11591150-000000000-00000
- Effects of dalfampridine on multi-dimensional aspects of gait and dexterity in multiple sclerosis among timed walk responders and non-responders.J. Neurol. Sci. 2015; 356 ([published Online First: 2015/07/04]): 77-82https://doi.org/10.1016/j.jns.2015.06.008
- Gait and balance impairment in early multiple sclerosis in the absence of clinical disability.Mult. Scler. 2006; 12 ([published Online First: 2006/11/08]): 620-628https://doi.org/10.1177/1352458506070658
- Gait profile score in multiple sclerosis patients with low disability.Gait Posture. 2017; 51 ([published Online First: 2016/10/25]): 169-173https://doi.org/10.1016/j.gaitpost.2016.10.013
- Validity of the timed 25-foot walk as an ambulatory performance outcome measure for multiple sclerosis.Mult. Scler. 2017; 23 ([published Online First: 2017/02/17]): 704-710https://doi.org/10.1177/1352458517690823
- The six spot step test: a new measurement for walking ability in multiple sclerosis.Mult. Scler. 2006; 12 ([published Online First: 2006/08/12]): 495-500https://doi.org/10.1191/1352458506ms1293oa
- Novel characterization of gait impairments in people with multiple sclerosis by means of the gait profile score.J. Neurol. Sci. 2014; 345 ([published Online First: 2014/07/31]): 159-163https://doi.org/10.1016/j.jns.2014.07.032
- Quantitative assessment of the effects of 6 months of adapted physical activity on gait in people with multiple sclerosis: a randomized controlled trial.Disabil. Rehabil. 2018; 40 ([published Online First: 2017/01/14]): 144-151https://doi.org/10.1080/09638288.2016.1244291
- Further validation of multiple sclerosis walking scale-12 scores based on spatiotemporal gait parameters.Arch. Phys. Med. Rehabil. 2013; 94 ([published Online First: 2012/09/11]): 575-578https://doi.org/10.1016/j.apmr.2012.08.214
- Diagnostic criteria for multiple sclerosis: 2010 revisions to the McDonald criteria.Ann. Neurol. 2011; 69 ([published Online First: 2011/03/10]): 292-302https://doi.org/10.1002/ana.22366
- Fampridine response in MS patients with gait impairment in a real-world setting: need for new response criteria?.Mult. Scler. 2018; 24 ([published Online First: 2017/07/26]): 1337-1346https://doi.org/10.1177/1352458517720043
- Validation of the 2-minute talk test with the 6-minute walk test and other functional measures in persons with multiple sclerosis.Int. J. MS Care. 2018; 20 ([published Online First: 2018/08/29]): 158-163https://doi.org/10.7224/1537-2073.2017-046
- Strengthening the reporting of observational studies in epidemiology (STROBE): explanation and elaboration.Ann. Intern. Med. 2007; 147 ([published Online First: 2007/10/17]): W163-W194https://doi.org/10.7326/0003-4819-147-8-200710160-00010-w1
- Fampridine-induced changes in walking kinetics are associated with clinical improvements in patients with multiple sclerosis.J. Neurol. Sci. 2020; 416 ([published Online First: 2020/06/20])116978https://doi.org/10.1016/j.jns.2020.116978
- Prolonged-release fampridine in multiple sclerosis: improved ambulation effected by changes in walking pattern.Mult. Scler. 2016; 22 ([published Online First: 2016/01/15]): 1463-1475https://doi.org/10.1177/1352458515622695
Article Info
Publication History
Published online: November 16, 2022
Accepted:
November 15,
2022
Received:
May 25,
2022
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