Dose comparison trial of sustained-release fampridine in multiple sclerosis

4-aminopyridine attenuates inflammation and apoptosis and increases angiogenesis to promote skin regeneration following a burn injury in mice

Severe thermal skin burns are complicated by inflammation and apoptosis, which delays wound healing and contributes to significant morbidity. Diverse treatments demonstrate limited success in mitigating these processes to accelerate healing. Agents that alter cell behavior to improve healing would alter treatment paradigms. We repurposed 4-aminopyridine (4-AP), a drug approved by the US FDA for multiple sclerosis, to treat severe burns in mice (10-week-old C57BL/6 J male mice weighing 25 ± 3 g). We found that 4-AP, in the early stages of burn healing, significantly reduced the expression of pro-inflammatory cytokines IL1β and TNFα while increasing the expression of anti-inflammatory markers CD206, ARG-1, and IL10. We demonstrated increased intracellular calcium effects of 4-AP through Orai1-pSTAT6 signaling, where 4-AP significantly mitigated inflammatory effects by promoting M2 macrophage differentiation in in-vitro macrophages and post-skin burn tissues. 4-AP attenuated apoptosis, with decreases in apoptotic markers BAX, caspase-9, and caspase-3 and increases in anti-apoptotic markers BCL2 and BCL-XL. Furthermore, 4-AP promoted angiogenesis through increases in the expression of CD31, VEGF, and eNOS. Together, these likely contributed to accelerated burn wound closure, as demonstrated in increased keratinocyte proliferation (K14) and differentiation (K10) markers. In the later stages of burn healing, 4-AP increased TGFβ and FGF levels, which are known to mark the transformation of fibroblasts to myofibroblasts. This was further demonstrated by an increased expression of α-SMA and vimentin, as well as higher levels of collagen I and III, MMP 3, and 9 in mice treated with 4-AP. Our findings support the idea that 4-AP may have a novel, clinically relevant therapeutic use in promoting burn wound healing.

4-aminopyridine attenuates inflammation and apoptosis and increases angiogenesis to promote skin regeneration following a burn injury

Severe thermal skin burns are complicated by inflammation and apoptosis, which delays wound healing and contributes to significant morbidity. Diverse treatments demonstrate limited success with mitigating these processes to accelerate healing. Agents that alter cell behavior to improve healing would alter treatment paradigms. We repurposed 4-aminopyridine (4-AP), a drug approved by the US FDA for multiple sclerosis, to treat severe burns. We found that 4-AP, in the early stages of burn healing, significantly reduced the expression of pro-inflammatory cytokines IL1β and TNFα while increasing the expression of anti-inflammatory markers CD206, ARG-1, and IL10. 4-AP attenuated apoptosis, with decreases in apoptotic markers BAX, caspase-9, and caspase-3 and increases in anti-apoptotic markers BCL2 and BCL-XL. Furthermore, 4-AP promoted angiogenesis through increases in the expression of CD31, VEGF, and eNOS. Together, these likely contributed to accelerated burn wound closure, as demonstrated in increased keratinocyte proliferation (K14) and differentiation (K10) markers. In the later stages of burn healing, 4-AP increased TGFβ and FGF levels, which are known to mark the transformation of fibroblasts to myofibroblasts. This was further demonstrated by an increased expression of α-SMA and vimentin, as well as higher levels of collagen I and III, MMP 3, and 9 in animals treated with 4-AP. Our findings support the idea that 4-AP may have a novel, clinically relevant therapeutic use in promoting burn wound healing.

Providing meaningful interpretation of performance outcome measures by co-calibration with patient-reported outcomes through the Rasch model: illustration with multiple sclerosis measures

Performance outcome (PerfO) measures are based on tasks performed by patients in a controlled environment, making their meaningful interpretation challenging to establish. Co-calibrating PerfO and patient-reported outcome (PRO) measures of the same target concept allow for interpretation of the PerfO with the item content of the PRO. The Rasch model applied to the discretized PerfO measure together with the PRO items allows expressing parameters related to the PerfO measure in the PRO metric for it to be linked to the PRO responses. We applied this approach to two PerfO measures used in multiple sclerosis (MS) for walking and manual ability: the Timed 25-Foot Walk (T25FW) and the 9-Hole Peg Test (9HPT). To determine meaningful interpretation of these two PerfO measures, they were co-calibrated with two PRO measures of closely related concepts, the MS walking scale - 12 items (MSWS-12) and the ABILHAND, using the data of 2,043 subjects from five global clinical trials in MS. The probabilistic relationships between the PerfO measures and the PRO metrics were used to express the response pattern to the PRO items as a function of the unit of the PerfOs. This example illustrates the promises of the co-calibration approach for the interpretation of PerfO measures but also highlights the challenges associated with it, mostly related to the quality of the PRO metric in terms of coverage of the targeted concept. Co-calibration with PRO measures could also be an adequate solution for interpretation of digital sensor measures whose meaningfulness is also often questioned.

Bupropion-Induced Myoclonus: Case Report and Review of the Literature

Bupropion is an atypical antidepressant agent approved for treating major depressive disorders and prescribed for smoking cessation, attention deficit hyperactive disorder (ADHD), and sexual dysfunction. In a few cases, bupropion was associated with myoclonus. We present a case of a 58-year-old male, a heavy smoker seeking smoking cessation, was prescribed bupropion 150 mg twice daily. The subject doubled the dosage without medical advice. After 3 days of the increased dosage, he started to experience abnormal movements in his upper limbs associated with diffuse facial twitching. Neuroimaging, electrodiagnostic studies, and laboratory exams were unremarkable. Bupropion was discontinued, and clonazepam was initiated. The subject fully recovered within 24 hours. To the authors' knowledge, only 8 cases of bupropion-induced myoclonus were reported in the literature. Bupropion discontinuation was the most common management. All individuals except 2 cases fully recovered after bupropion withdrawal. The mechanism of bupropion is probably associated with the serotoninergic pathway.

Patient and Clinician Perspectives of Physical Therapy for Walking Difficulties in Multiple Sclerosis

Gait speed is frequently the primary efficacy endpoint in clinical trials of interventions targeting mobility in people with multiple sclerosis (MS). However, it is unclear whether increased gait speed is a meaningful outcome for people living with MS. The purpose of this study was to identify the most important aspects of mobility for people with MS and physical therapists and to explore how patients and clinicians perceive whether physical therapy has been effective. Forty-six people with MS and 23 physical therapy clinicians participated in a focus group, one-on-one interview, or electronic survey. The focus group and interview data were transcribed and coded to identify themes. Free-text survey responses were also coded, and multiple-choice options were analyzed for frequency. Among people with MS, falls and difficulties getting out into the community were identified as highly important mobility limitations. Clinicians also identified falls and safety as a priority. Walking speed was infrequently described as a problem, and although gait speed is often measured by clinicians, improving gait speed is rarely a treatment goal. Despite their emphasis on safety, clinicians lacked certainty about how to objectively measure improvements in safety. People with MS evaluated physical therapy effectiveness based on the ease by which they can do things and acknowledged that "not getting worse" is a positive outcome. Clinicians evaluated effectiveness based on the amount of change in objective outcome measures and by patient and caregiver reports of improved function. These findings indicate that gait speed is not of major importance to people with MS or physical therapy clinicians. People with MS want to be able to walk further and without an assistive device, and they want to avoid falls. Clinicians want to maximize safety while improving functional ability. Clinicians and patients may differ in their expected outcomes from physical therapy.

Multiple sclerosis: Motor dysfunction

Multiple sclerosis is a chronic neurological disease characterized by inflammation and degeneration within the central nervous system. Over the course of the disease, most MS patients successively accumulate inflammatory lesions, axonal damage, and diffuse CNS pathology, along with an increasing degree of motor disability. While the pharmacological approach to MS targets inflammation to decrease relapse rates and relieve symptoms, disease-modifying therapy and immunosuppressive medications may not prevent the accumulation of pathology in most patients leading to long-term motor disability. This has been met with recent interest in promoting plasticity-guided concepts, enhanced by neurophysiological and neuroimaging approaches to address the preservation of motor function.

Amifampridine safety and efficacy in spinal muscular atrophy ambulatory patients: a randomized, placebo-controlled, crossover phase 2 trial

BACKGROUND

Spinal muscular atrophy (SMA) is an autosomal recessive disease where a deficient amount of SMN protein leads to progressive lower motor neuron degeneration. SMN-enhancing therapies are now available. Yet, fatigue and signs of impaired neuromuscular junction (NMJ) transmission could contribute to SMA phenotype. Amifampridine prolongs presynaptic NMJ terminal depolarization, enhancing neuromuscular transmission.

METHODS

SMA-001 was a phase 2, 1:1 randomized, double-blind, placebo-controlled crossover study. Ambulatory (walking unaided at least 30 m) SMA Type 3 patients, untreated with SMN-enhancing medications, entered a run-in phase where amifampridine was titrated up to an optimized stable dose. Patients achieving at least three points improvement in Hammersmith Functional Motor Score Expanded (HFMSE) were randomized to amifampridine or placebo, alternatively, in the 28-day double-blind crossover phase. Safety was evaluated by adverse events (AE) collection. Primary efficacy measure was the HFMSE change from randomization. Secondary outcomes included timed tests and quality of life assessment. Descriptive analyses and a mixed effects linear model were used for statistics.

RESULTS

From 14 January 2019, 13 patients, mean age 34.5 years (range 18-53), with 5/13 (38.5%) females, were included. No serious AE were reported. Transient paresthesia (33.3%) was the only amifampridine-related AE. Six patients for each treatment sequence were randomized. Amifampridine treatment led to a statistically significant improvement in HFMSE (mean difference 0.792; 95% CI from 0.22 to 1.37; p = 0.0083), compared to placebo, but not in secondary outcomes.

DISCUSSION

SMA-001 study provided Class II evidence that amifampridine was safe and effective in treating ambulatory SMA type 3 patients.

CLINICAL TRIAL REGISTRATION

NCT03781479; EUDRACT 2017-004,600-22.

4-Aminopyridine Induces Nerve Growth Factor to Improve Skin Wound Healing and Tissue Regeneration

The discovery of ways to enhance skin wound healing is of great importance due to the frequency of skin lesions. We discovered that 4-aminopyridine (4-AP), a potassium channel blocker approved by the FDA for improving walking ability in multiple sclerosis, greatly enhances skin wound healing. Benefits included faster wound closure, restoration of normal-appearing skin architecture, and reinnervation. Hair follicle neogenesis within the healed wounds was increased, both histologically and by analysis of K15 and K17 expression. 4-AP increased levels of vimentin (fibroblasts) and alpha-smooth muscle actin (α-SMA, collagen-producing myofibroblasts) in the healed dermis. 4-AP also increased neuronal regeneration with increased numbers of axons and S100⁺ Schwann cells (SCs), and increased expression of SRY-Box Transcription Factor 10 (SOX10). Treatment also increased levels of transforming growth factor-β (TGF-β), substance P, and nerve growth factor (NGF), important promoters of wound healing. In vitro studies demonstrated that 4-AP induced nerve growth factor and enhanced proliferation and migration of human keratinocytes. Thus, 4-AP enhanced many of the key attributes of successful wound healing and offers a promising new approach to enhance skin wound healing and tissue regeneration.

Case ReportPaclitaxel-loaded TPGS2k/Gelatin-grafted Cyclodextrin/Hyaluronic acid-grafted Cyclodextrin nanoparticles for oral bioavailability and targeting enhancement

The clinical applications of paclitaxel (PTX), a natural compound with broad-spectrum antitumor effects, have been markedly limited owing to its poor oral bioavailability and lack of targeting ability. Recently, several drug carriers, such as TPGS_2k, gelatin (Gel), cyclodextrin (CD), and hyaluronic acid (HA), have been identified as promising enhancers of drug efficacy. Therefore, Gel-grafted CD (GEL-CD) and HA-grafted CD (HA-CD) were synthesized via grafting, and PTX-loaded TPGS_2k/GEL-CD/HA-CD nanoparticles (TGHC-PTX-NPs) were successfully prepared using the ultrasonic crushing method. The mean particles size, polydispersity index, and Zeta potential of TGHC-PTX-NPs were 253.57 ± 2.64 nm, 0.13 ± 0.03, and 0.087 ± 0.005 mV, respectively. TGHC-PTX-NPs with an encapsulation efficiency of 61.77 ± 0.47% and a loading capacity of 6.86 ± 0.32% appeared round and uniformly dispersed based on transmission electron microscopy. In vitro release data revealed that TGHC-PTX-NPs had good sustained-release properties. Further, TGHC-PTX-NPs had increased the targeted uptake by HeLa cells as HA can specifically bind to the CD44 receptor at the cell surface, and its intestinal absorption is related to caveolin-mediated endocytosis. The pharmacokinetic results indicated that TGHC-PTX-NPs significantly enhanced the absorption of PTX in vivo compared to the PTX suspension, with a relative bioavailability of 227.21%. Such findings indicate the potential of TGHC-PTX-NPs for numerous clinical applications.

Dalfampridine for Mobility Limitations in People With Multiple Sclerosis May Be Augmented by Physical Therapy: A Non-randomized Two-Group Proof-of-Concept Pilot Study

Purpose: To demonstrate proof-of-concept for a combined physical therapy and pharmacological intervention and obtain preliminary estimates of the therapeutic efficacy of a motor-relearning physical therapy intervention with and without concurrent dalfampridine treatment on gait speed in people with mobility limitations due to multiple sclerosis (MS).

Methods: Using a non-randomized, two-group design, 4 individuals with MS newly prescribed dalfampridine as part of their routine medical care, and 4 individuals with MS not taking dalfampridine completed a 3-week drug run-in or no-treatment baseline, respectively. After 3 weeks, all participants commenced physical therapy twice weekly for 6 weeks. Participants taking dalfampridine took the medication for the study duration. The physical therapy program comprised functional strengthening, gait training, balance training, and dual-task training. The primary outcome was Timed 25-foot Walk (T25FW) at the end of the 6-week physical therapy program.

Results: For the 4 participants taking dalfampridine, average improvement in T25FW on drug only was 12.8% (95% CI 1.2 to 24.4%). During the 6-week physical therapy phase, both groups significantly improved T25FW, but the effect tended to favor the group taking dalfampridine (mean difference = −0.93 s, 95% CI −1.9 to 0.07 s, p = 0.064, d = 1.6). Whereas the physical therapy group had average T25FW improvement of 10.8% (95% CI 1.0 to 20.5%), the physical therapy plus dalfampridine group demonstrated average improvement of 20.7% (95% CI 3.8 to 37.6%).

Conclusions: Further research is warranted to examine whether dalfampridine for mobility impairment may be augmented by physical therapy in people with MS.

Failed, Interrupted, or Inconclusive Trials on Neuroprotective and Neuroregenerative Treatment Strategies in Multiple Sclerosis: Update 2015-2020

In the recent past, a plethora of drugs have been approved for the treatment of multiple sclerosis (MS). These therapeutics are mainly confined to immunomodulatory or immunosuppressive strategies but do not sufficiently address remyelination and neuroprotection. However, several neuroregenerative agents have shown potential in pre-clinical research and entered Phase I to III clinical trials. Although none of these compounds have yet proceeded to approval, understanding the causes of failure can broaden our knowledge about neuroprotection and neuroregeneration in MS. Moreover, most of the investigated approaches are characterised by consistent mechanisms of action and proved convincing efficacy in animal studies. Therefore, learning from their failure will help us to enforce the translation of findings acquired in pre-clinical studies into clinical application. Here, we summarise trials on MS treatment published since 2015 that have either failed or were interrupted due to a lack of efficacy, adverse events, or for other reasons. We further outline the rationale underlying these drugs and analyse the background of failure to gather new insights into MS pathophysiology and optimise future study designs. For conciseness, this review focuses on agents promoting remyelination and medications with primarily neuroprotective properties or unconventional approaches. Failed clinical trials that pursue immunomodulation are presented in a separate article.

Dalfampridine improves slowed processing speed in multiple sclerosis patients with mild motor disability: post hoc analysis of a randomized controlled trial

Objective

To evaluate baseline characteristics predictive of improving information processing speed in multiple sclerosis (MS) and the relationship between cognitive and motor response to dalfampridine (DA) treatment.

Methods

This is a post hoc analysis of a randomized, double-blind, placebo-controlled trial in patients with MS randomized to receive DA 10 mg or placebo twice daily for 12 consecutive weeks. Here, we include only data from 71 patients in the arm treated with DA. According to the median value of Symbol Digit Modalities Test (SDMT) response, patients were categorized as "full responders" (FR) or "partially responders" (PR).

Results

There was higher possibility of being FR in the presence of a baseline lower Expanded Disability Status Scale [odds ratio (OR) 0.69; 95% confidence interval (CI) 0.5-0.97, p = 0.034], a higher Multiple Sclerosis Functional Composite value (OR 1.37; 95%CI 1.05-1.8, p = 0.022), a lower Timed 25-Foot Walk Test (OR 0.76; 95% CI 0.6-0.98, p = 0.033), and a lower 9-Hole Peg Test with dominant hand (OR 0.92; 95% CI 0.86-0.99, p = 0.029). FR group did not show any significant improvement of motor performance compared with PR group.

Conclusion

The current analysis shows that in MS patients with cognitive deficit, the greatest improvement in SDMT provided by DA was observed in patients with milder motor impairment; cognitive and motor responses to treatments are not related.

Trial registration

EU Clinical Trials Register; ID 2013-002558-64 (https://www.clinicaltrialsregister.eu/ctr-search/search?query=2013-002558-64).

Neuroprotective Properties of 4-Aminopyridine

As an antagonist of voltage-gated potassium (Kv) channels, 4-aminopyridine (4-AP) is used as symptomatic therapy in several neurologic disorders. The improvement of visual function and motor skills and relieve of fatigue in patients with MS have been attributed to 4-AP. Its prolonged release formulation (fampridine) has been approved for the symptomatic treatment of walking disability in MS. The beneficial effects were explained by the blockade of axonal Kv channels, thereby enhancing conduction along demyelinated axons. However, an increasing body of evidence suggests that 4-AP may have additional properties beyond the symptomatic mode of action. In this review, we summarize preclinical and clinical data on possible neuroprotective features of 4-AP.

[Efficacy and safety of Kinezia (fampridine) in the complex therapy of multiple sclerosis]

OBJECTIVE

To analyze the efficacy and safety of fampridine** (Valenta Pharm, Russia) in the complex therapy of multiple sclerosis (MS).

MATERIAL AND METHODS

One hundred and twenty-six patients with MS were double blind randomized to receive fampridine (n=60) or placebo (n=66). Fampridine was administered in prolonged-release form (film-coated tablets, 10 mg) at a dose of 10 mg (1 tablet) 2 times a day, for 24 weeks. The placebo group was treated in the same way. From the 12th week, all patients in the placebo group were transferred to therapy with fampridine, 10 mg 2 times a day, for another 12 weeks. Concomitant standard therapy for MS was allowed in both groups (concomitant disease-modifying medications and other treatment). The primary outcome in the study was the proportion of patients with reduced t25fw test time (determining walking speed on a 25-foot path) on at least two out of three visits compared to baseline. The mean change in Multiple Sclerosis Functional Composite (MSFC) scores from baseline was assessed at visits 4-7 (8-24 weeks).

RESULTS

The proportion of patients with reduced t25fw test time compared to the baseline level was 31.7% in the fampridine group, which is higher than in the placebo group - 3.0% (p<0.001). The overall result of the Multiple Sclerosis Functional Composite (MSFC) reflected a gradual improvement in the patient's condition during treatment period. The dynamics of MSFC result relative to the baseline level significantly differed (p<0.05) between the fampridine and placebo groups in favor of the fampridine group during all treatment periods. In the fampridine group, adverse events (AE) associated with disorders of the nervous system were more common: headache, dizziness, and coordination disorders.

CONCLUSIONS

Fampridine improves walking performance in MS patients. The Russian product fampridine has demonstrated a favorable safety profile.

A cross-sectional comparison of performance, neurophysiological and MRI outcomes of responders and non-responders to fampridine treatment in multiple sclerosis - An explorative study

OBJECTIVE

To compare baseline physical and cognitive performance, neurophysiological, and magnetic resonance imaging (MRI) outcomes and examinetheir interrelationship inparticipants with Multiple Sclerosis (MS), already established aseither responder or non-responder to Fampridine treatment, andto examine associationswiththe expanded disability status scale (EDSS) and 12-item MS walking scale (MSWS-12).

METHODS

Baseline data from an explorative longitudinal observational study were analyzed. Participants underwent the Timed 25-Foot Walk Test (T25FW), Six Spot Step Test (SSST), Nine-Hole Peg Test, Five Times Sit-to-Stand Test, Symbol Digit Modalities Test (SDMT), neurophysiological testing, including central motor conduction time (CMCT), peripheral motor conduction time (PMCT), motor evoked potential (MEP) amplitudesand electroneuronographyof the lower extremities, and brain MRI (brain volume, number and volume of T2-weighted lesions and lesion load normalized to brain volume).

RESULTS

41 responders and 8 non-responders were examined. There were no intergroup differences inphysical performance, cognitive, neurophysiological, andMRI outcomes (p > 0.05).CMCT was associated withT25FW, SSST, EDSS, and MSWS-12,(p < 0.05). SDMT was associated with the number and volume of T2-weighted lesions, and lesion load normalized to brain volume (p < 0.05).

CONCLUSION

No differences were identified between responders and non-responders to Fampridine treatment regarding physical and cognitive performance, neurophysiological or MRI outcomes. The results call for cautious interpretation and further large-scale studies are needed to expand ourunderstanding of underlying mechanisms discriminating Fampridine responders and non-responders.CMCT may be used as a marker of disability and walking impairment, while SDMT was associated with white matter lesions estimated by MRI. ClinicalTrials.gov identifier: NCT03401307.

Aminopiridines in the treatment of multiple sclerosis and other neurological disorders

Symptomatic treatment has a great relevance for the management of patients with neurologic diseases, since it reduces disease burden and improves quality of life. Aminopyridines (APs) are a group of potassium (K+) channel blocking agents that exert their activity both at central nervous system level and on neuromuscular junction. This review describes the use of APs for the symptomatic treatment of neurological conditions. We will describe trials leading to the approval of the extended-release 4-aminopyridine for MS and evidence in support of the use in other neurological diseases.

Pharmacotherapy in multiple sclerosis-induced cognitive impairment: A systematic review and meta-analysis

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS) commonly complicated by cognitive impairment. Unfortunately, no medical therapy has been proved to improve cognitive problems in these patients. This meta-analysis investigated the effectiveness of different categories of drugs on the minimal assessment of cognitive function in MS (MACFIMS)-related tasks outcome in MS patients. To this end, a systematic evaluation was conducted using PubMed, Google Scholar, and Scopus databases. Among a total of 128 publications, 31 studies met our inclusion criteria, and 22 included in the meta-analysis. We found that symbol digit modalities test (SDMT), paced auditory serial addition test (PASAT), controlled oral word association test (COWAT), and California verbal learning test (CVLT) were the most frequently reported tasks in included studies. The frequently reported drugs were classified into five main groups of acetylcholine esterase inhibitors, CNS stimulants, fampridine, herbal remedies, and miscellaneous. Overall heterogeneity of the studies was modest. The treatments did not affect cognitive function in any of the tasks (p>0.05). However, in subgroup analysis, we found significant improvement in SDMT task outecomes after treatment by fampridine (0.283 SMD, 95%CI, 0.015 to 0.550, p = 0.039, I2=11.7%). Our meta-analysis highlighted that the currently proposed therapeutic agents had no beneficial effects on the alleviation of MS-induced cognitive impairment.

Clinical assessment, management, and rehabilitation of walking impairment in MS: an expert review

INTRODUCTION

One of the most common and life-altering consequences of Multiple Sclerosis (MS) is walking impairment. The distance, speed, and Gait pattern functions are components of the International Classification of Functioning, Disability, and Health (ICF) and are also predictors of dependency in terms of daily living activities in patients with MS (pwMS).

AREAS COVERED

This article provides an overview of walking impairment in pwMS, with focus on the assessment of gait and the rehabilitation approaches.

EXPERT OPINION

The authors recommend that pwMS undergo gait assessment integrating the ICF perspective using validated clinical outcome measures that cover spatiotemporal gait parameters. Moreover, assessment of walking speed with short walking capacity tests such as the timed 25-foot walk (T25FW) or the 10-m walk test (10 MWT) and tests for walking distance with middle distance tests such as the 2-min walk test (2MWT) and the 6-min walk test (6MWT). This review further highlights strategies that may restore walking function including pharmacological symptomatic treatment and non-pharmacological rehabilitation approaches such as exercise and task-specific training providing an appraisal of mobility targeted therapies to be considered when planning multidisciplinary comprehensive-care of pwMS. Finally, new and novel strategies such as motor imagery and rhythmic auditory stimulation have been developed to improve walking speed and distance in pwMS.

Efficacy and safety of fampridine for walking disability in multiple sclerosis

Fampridine is the only drug approved for the treatment of walking impairment in multiple sclerosis. Around a third of the patients on treatment obtained an improvement in walking speed during the development phase. The effects are clinically significant, appear soon after the start of the treatment and are long-lasting, but disappear soon after the drug is withdrawn. In the real-world setting, the number of patients with a significant response to the treatment seems to be higher (around 70%). The tolerance is good, with mild to moderate, and transient adverse events. The most commonly reported are insomnia, headache, fatigue, back pain, dizziness, nausea and balance disorders. The main contraindications are a history of seizures, renal impairment and concomitant treatment with OCT2 inhibitors.

Lack of effect on ambulation of dalfampridine-ER (4-AP) treatment in adult SMA patients

SMA is a genetically determined motor system disorder that results in muscle weakness, selective motor neuron death, muscle atrophy, and impaired functional mobility. In SMA model systems, long-term treatment with 4-aminopyridine (4-AP) has been shown to improve motor function. To assess tolerability and preliminary efficacy of 4-AP on walking ability, endurance and EMG in adult ambulatory SMA patients, we conducted a double blind, placebo control, crossover pilot study with dalfampridine (4-AP, 10 mg BID). The study is comprised of a short-term (2 weeks) treatment arm with 1-week washout and a long-term (6 weeks) treatment arm with a 2-week washout. The primary outcome measure, for which the study was powered, was the 6 min walk test (6MWT, distance and percent fatigue); secondary outcome measures were the Hammersmith Functional Motor Scale Expanded (HFMSE), Manual Muscle Testing (MMT), Myometry with Hand held Dynamometry, HHD) and Quantitative Gait Analyses. We performed electrophysiology, including CMAP and H-reflex, during the short-term treatment trial. The mean age of the 11 participants enrolled was 37.7 ± 11.9 years; 54.5% were male. Dalfampridine was safe and well tolerated and no patient suffered a serious adverse event related to treatment. We observed no statistically significant positive effects of dalfampridine treatment on our primary functional motor outcome (6MWT distance, fatigue). Dalfampridine had a positive effects on H-reflex and H/M ratio but not on CMAP amplitude. The effect on the H-reflex is of interest, as it suggests dalfampridine may enhance neuronal activity, an effect observed in SMA Drosophila and mouse models at doses (mg/kg) not recommended for clinical use. Larger studies with dalfampridine in SMA patients are needed to confirm our findings, especially in light of studies in other populations showing drug effects in only a subset of patients.

Personalized Template-Based Step Detection From Inertial Measurement Units Signals in Multiple Sclerosis

Background: Objective gait assessment is key for the follow-up of patients with progressive multiple sclerosis (pMS). Inertial measurement units (IMUs) provide reliable and yet easy quantitative gait assessment in routine clinical settings. However, to the best of our knowledge, no automated step-detection algorithm performs well in detecting severely altered pMS gait. Method: This article elaborates on a step-detection method based on personalized templates tested against a gold standard. Twenty-two individuals with pMS and 10 young healthy subjects (HSs) were instructed to walk on an electronic walkway wearing synchronized IMUs. Templates were derived from the IMU signals by using Initial and Final Contact times given by the walkway. These were used to detect steps from other gait trials of the same individual (intra-individual template-based detection, IITD) or another participant from the same group (pMS or HS) (intra-group template-based detection, IGTD). All participants were seen twice with a 6-month interval, with two measurements performed at each visit. Performance and accuracy metrics were computed, along with a similarity index (SId), which was computed as the mean distance between detected steps and their respective closest template. Results: For HS participants, both the IITD and the IGTD algorithms had precision and recall of 1.00 for detecting steps. For pMS participants, precision and recall ranged from 0.94 to 1.00 for IITD and 0.85 to 0.95 for IGTD depending on the level of disability. The SId was correlated with performance and the accuracy of the result. An SId threshold of 0.957 (IITD) and 0.963 (IGTD) could rule out decreased performance (F-measure ≤ 0.95), with negative predictive values of 0.99 and 0.96 with the IITD and IGTD algorithms. Also, the SId computed with the IITD and IGTD algorithms could distinguish individuals showing changes at 6-month follow-up. Conclusion: This personalized step-detection method has high performance for detecting steps in pMS individuals with severely altered gait. The algorithm can be self-evaluating with the SI, which gives a measure of the confidence the clinician can have in the detection. What is more, the SId can be used as a biomarker of change in disease severity occurring between the two measurement times.

Interventions for preventing falls in people with multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is one of the most prevalent diseases of the central nervous system with recent prevalence estimates indicating that MS directly affects 2.3 million people worldwide. Fall rates of 56% have been reported among people with MS in a recent meta-analysis. Clinical guidelines do not outline an evidence-based approach to falls interventions in MS. There is a need for synthesised information regarding the effectiveness of falls prevention interventions in MS.

OBJECTIVES

The aim of this review was to evaluate the effectiveness of interventions designed to reduce falls in people with MS. Specific objectives included comparing: (1) falls prevention interventions to controls and; (2) different types of falls prevention interventions.

SEARCH METHODS

We searched the Trials Register of the Cochrane Multiple Sclerosis and Rare Diseases of the CNS Group, Cochrane Central Register of Controlled Trials (2018 Issue 9); MEDLINE (PubMed) (1966 to 12 September 2018); Embase (EMBASE.com) (1974 to 12 September 2018); Cumulative Index to Nursing and Allied Health Literature (EBSCOhost) (1981 to 12 September 2018); Latin American and Caribbean Health Science Information Database (Bireme) (1982 to 12 September 2018); ClinicalTrials.gov; and World Health Organization International Clinical Trials Registry Platform; PsycINFO (1806 to 12 September 2018; and Physiotherapy Evidence Database (1999 to 12 September 2018).

SELECTION CRITERIA

We selected randomised controlled trials or quasi-randomised trials of interventions to reduce falls in people with MS. We included trials that examined falls prevention interventions compared to controls or different types of falls prevention interventions. Primary outcomes included: falls rate, risk of falling, number of falls per person and adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors screened studies for selection, assessed risk of bias and extracted data. We used a rate ratio (RaR) and 95% confidence interval to compare falls rate between groups. For risk of falling, we used a risk ratio (RR) and 95% CI based on the number of fallers in each group.

MAIN RESULTS

A total of 839 people with MS (12 to 177 individuals) were randomised in the 13 included trials. The mean age of the participants was 52 years (36 to 62 years). The percentage of women participants ranged from 59% to 85%. Studies included people with all types of MS. Most trials compared an exercise intervention with no intervention or different types of falls prevention interventions. We included two comparisons: (1) Falls prevention intervention versus control and (2) Falls prevention intervention versus another falls prevention intervention. The most common interventions tested were exercise as a single intervention, education as a single intervention, functional electrical stimulation and exercise plus education. The risk of bias of the included studies mixed, with nine studies demonstrating high risk of bias related to one or more aspects of their methodology. The evidence was uncertain regarding the effects of exercise versus control on falls rate (RaR of 0.68; 95% CI 0.43 to 1.06; very low-quality evidence), number of fallers (RR of 0.85; 95% CI 0.51 to 1.43; low-quality evidence) and adverse events (RR of 1.25; 95% CI 0.26 to 6.03; low-quality evidence). Data were not available on quality of life outcomes comparing exercise to control. The majority of other comparisons between falls interventions and controls demonstrated no evidence of effect in favour of either group for all primary outcomes. For the comparison of different falls prevention interventions, the heterogeneity of intervention types across studies prohibited the pooling of data. In relation to secondary outcomes, there was evidence of an effect in favour of exercise interventions compared to controls for balance function with a SMD of 0.50 (95% CI 0.09 to 0.92), self-reported mobility with a SMD of 16.30 (95% CI 9.34 to 23.26) and objective mobility with a SMD of 0.28 (95% CI 0.07 to 0.50). Secondary outcomes were not assessed under the GRADE criteria and results must be interpreted with caution.

AUTHORS' CONCLUSIONS

The evidence regarding the effects of interventions for preventing falls in MS is sparse and uncertain. The evidence base demonstrates mixed risk of bias, with very low to low certainty of the evidence. There is some evidence in favour of exercise interventions for the improvement of balance function and mobility. However, this must be interpreted with caution as these secondary outcomes were not assessed under the GRADE criteria and as the results represent data from a small number of studies. Robust RCTs examining the effectiveness of multifactorial falls interventions on falls outcomes are needed.

Effects of Fampridine in People with Multiple Sclerosis: A Systematic Review and Meta-analysis

BACKGROUND

Prolonged-release (PR) fampridine is a potassium channel blocker used as a symptomatic treatment for walking disability in patients with multiple sclerosis (MS). Its clinical effects in such patients have not been systematically reviewed, and may be more wide-ranging than expected.

OBJECTIVES

To summarize the evidence on the effects of PR fampridine in patients with MS.

METHODS

A systematic search of Pubmed, Scopus (including EMBASE), and PsycINFO (completed in 01/2019) was carried out to identify randomized controlled trials (RCT) that compared PR fampridine to placebo. When appropriate, data were pooled using a random-effects model, and standardized mean differences (SMD) were computed. Study quality was assessed using the Downs and Black checklist. PRISMA guidelines were followed. All retrieved functional outcomes were categorized according to the International Classification of Functioning, Disability and Health (ICF).

RESULTS

A total of 706 articles were screened for inclusion. Twenty RCTs involving 2616 patients met the eligibility criteria. Most studies were of good-to-excellent quality. PR fampridine administration resulted in significant benefits in relation to walking short distances (SMD: 1.23 (95% IC 0.65-1.81)) and perceived walking capacity (0.64 (0.27-1.02)). Its effects on muscle strength and middle-distance walking were not significant (0.53 (- 0.04 to 1.10) and 0.31 (- 0.18 to 0.80), respectively). No effect on higher-level cognitive functions (- 0.07 (- 0.58 to 0.45)) or hand and arm use (0.16 (- 0.33 to 0.64)) was observed. Individual studies reported effects on other outcomes across the ICF domains.

CONCLUSIONS

There is strong evidence that PR fampridine exerts strong effects on the ability to walk short distances and on perceived walking capacity. Other effects of PR fampridine according to the ICF are possible but still unclear.

4-aminopyridine – the new old drug for the treatment of neurodegenerative diseases

In this review are described the preclinical and clinical pharmacological data as well as new therapeutic indications for the use of 4-aminopyridine. 4-aminopyridine is a potassium (K+) channel blocker that has a long history and various application areas. It is a chemical agent developed in 1963 as a bird poison. The first approval for clinical application of 4-aminopyridine was in 70’s in Bulgaria, since anesthetists in that country have confirmed its effect as reversal agent for nondepolarizing myorelaxants. The Bulgarian pharmaceutical company Sopharma commersialized 4-aminopyridine under the trade name Pymadin. Since then 4-aminopyridine was extensively studied and in 2010 is approved in the USA for the treatment of walking disabilities in patients with multiple sclerosis. In recent years, data from clinical trials indicated that K-channel blockade may prove to be an appropriate strategy to overcome disturbances in nerve impulses conduction associated with demyelination of the central nervous system.

Effect of dalfampridine on information processing speed impairment in multiple sclerosis

Objective

To test a possible benefit of dalfampridine on information processing speed (IPS), a key function for cognitive impairment (CogIm) in multiple sclerosis (MS).

Methods

In this randomized, double-blind, placebo-controlled trial, we included patients with a score on the Symbol Digit Modalities Test (SDMT) under the 10th percentile of the reference value. Patients were randomized in a 2:1 ratio to receive dalfampridine 10 mg or placebo twice daily for 12 weeks. They underwent a comprehensive neuropsychological evaluation at screening (T0), at the end of treatment (T1), and after a 4-week follow-up (T2). The primary endpoint was improvement in SDMT.

Results

Out of 208 patients screened, 120 were randomized to receive either dalfampridine (n = 80) or placebo (n = 40). At T1, the dalfampridine group presented an increase of SDMT scores vs placebo group (mean change 9.9 [95% confidence interval (CI) 8.5–11.4] vs 5.2 [95% CI 2.8–7.6], p = 0.0018; d = 0.60 for raw score; and 0.8 [95% CI 0.6–1] vs 0.3 [95% CI 0.0–0.5], p = 0.0013; d = 0.61 for z scores; by linear mixed model with robust standard error). The improvement was not sustained at T2. A beneficial effect of dalfampridine was observed in the Paced Auditory Serial Addition Test and in cognitive fatigue.

Conclusion

Dalfampridine could be considered as an effective treatment option for IPS impairment in MS.

Trial registration

2013-002558-64 EU Clinical Trials Register.

Classification of evidence

This study provides Class I evidence that for patients with MS with low scores on the SDMT, dalfampridine improves IPS.

Evaluating dalfampridine for the treatment of relapsing-remitting multiple sclerosis: does it add to the treatment armamentarium?

Introduction: Multiple sclerosis (MS) is a demyelinating disease, causing axonal damage and disability. Dalfampridine (DAL) is an extended-release formulation of 4-aminopyridine (4AP) and broad-spectrum voltage-dependent potassium channel blocker that is reported to improve motor, visual and cognitive functions. Furthermore, it is presently the only approved drug for walking impairment in MS. Areas covered: Herein, the authors evaluate DAL as a relapsing-remitting MS treatment, reporting and commenting on all aspects of the drug including its chemistry, safety, pharmacokinetics, and cost-effectiveness. A bibliographic search was performed on PubMed using the terms 'dalfampridine OR fampridine OR 4-aminopyridine'. Expert opinion: Evidence from post-marketing studies suggests that DAL, consistent with the effects of 4AP, may not only improve walking speed, but also arm function, fatigue, mood and cognition through restored nerve conduction in central nervous system demyelinated areas. Long-term safety data confirm that the approved dose of 10 mg twice daily is generally well tolerated. However, despite the reported efficacy, the extent of the benefits is limited in real life activities, although significant improvements have been demonstrated in the clinical setting. Patients often complain of side effects (such as cramps and painful paraesthesia) or lack of efficacy. Also, its considerably higher pricing in comparison to 4AP represents an important limitation.

Nonwalking response to fampridine in patients with multiple sclerosis in a real-world setting

Objectives

Mobility impairments constitute a long-term burden in patients with multiple sclerosis (MS). Currently there is evidence that the drug fampridine may improve nonwalking symptoms in MS patients. The main objective of this study is to analyze whether participants showing a beneficial walking response to fampridine, also show a positive response in nonwalking assessments in a real-world clinical setting.

Methods

Subjects enrolled were part of a study analyzing gait parameters, for which response to treatment with fampridine was monitored after a period of 2 weeks. Neurologists then decided whether patients were responders to fampridine (RF) according to their global impression of patients' gait improvement. As nonwalking outcomes, we included the nine-hole peg test (9-HPT), the EuroQoL five dimensions questionnaire (EQ-5D) for quality of life, The Würzburger Fatigue Inventory for MS (WEIMuS), the Center for Epidemiologic Studies depression scale (CES-D), and the Paced Auditory Serial Addition Test (PASAT). Minimal clinically important difference (MCID) was evaluated for each test.

Results

A total of 189 participants were included: 122 were women (64.55%), with a mean age of 53.55 (±10.83). RFs showed significant improvement in all of the nonwalking outcomes (p < 0.05), except for a nonsignificant improvement in nondominant upper limb function and PASAT; the largest score improvement was seen in the physical and cognitive sections of the WEIMuS (25.69% and 29.81%, respectively, p < 0.001).

Conclusion

We provide evidence that physician's global judgement of walking improvement is a reliable measure for determining response to fampridine in nonwalking parameters, with fatigue showing the greatest score improvement after 2 weeks.

Value of gait analysis for measuring disease severity using inertial sensors in patients with multiple sclerosis: protocol for a systematic review and meta-analysis

BACKGROUND

Gait impairment is a hallmark of multiple sclerosis (MS) which significantly endangers the quality of life of the individual. Inertial measurement units (IMUs) are small, light wearable sensors that can be used in routine neurological practice. InertiaLocoGraphy (ILG), the quantification of gait with IMUs, has proven useful to detect early changes in MS undetectable with standard stopwatch-timed measures. Still, whether such markers are useful for evaluating the severity of the disease remains unknown. Therefore, the correlation between ILG and disease progression would be worth exploring.

METHODS

We will search MEDLINE via PubMed, Cochrane, and EMBASE electronic databases to identify articles published before May 2, 2018 that measure gait using IMUs in MS patients. In addition, grey literature will be searched. Inclusion criteria will be adults with a clinical diagnosis of MS and gait measured by using inertial sensors. We will exclude from the meta-analysis articles that do not provide sufficient data for evaluating the correlations between ILG parameters and disease severity as measured by at least one of the six following tests: the Expanded Disability Status Scale (EDSS), the Multiple Sclerosis Walking Scale-12 (MSWS), the Multiple Sclerosis Severity Score (MSSS), the Multiple Sclerosis Impact Scale (MSIS-29), the Multiple Sclerosis Functional Composite (MSFC), and the Timed 25-ft Walk Test (T25FW). Extracted data from included articles will be presented descriptively, and effect sizes will be computed based on the recommendations from the Cochrane Collaboration handbook and RevMan software.

DISCUSSION

Identifying changes in disease state throughout the course of MS is essential for optimal care. Current clinical and performance tests allow for identifying advanced gait alteration but lack sensitivity to detect subtle gait change. IMUs can be easily used in clinical practice to quantify gait in MS patients. Nevertheless, whether these outcomes are clinically relevant is uncertain because no study has evaluated their correlation with disease severity across different settings. This systematic review and meta-analysis would bring insight into the potential of this outcome as a marker of disease evolution.

SYSTEMATIC REVIEW REGISTRATION

This review was registered with the International Prospective Register of Systematic Reviews on May 2, 2018 (Registration: CRD42018092651). Both the search strategy and study protocol are available at https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=92651 .

Case Report: Combining Dalfampridine with Multicomponent Exercise and Gait Training in a Person with Multiple Sclerosis

Background

Dalfampridine extended release (D-ER) improves gait speed in some people with multiple sclerosis (MS), but many patients who take D-ER demonstrate only small improvements of questionable clinical significance. Physical therapy (PT) may augment the treatment effects of D-ER on the nervous system and improve clinical outcomes. This case report describes the successful use of D-ER combined with multicomponent PT in a patient who did not have a clinically important change in gait speed with D-ER alone.

Methods

A 59-year-old woman with a 6-year history of relapsing-remitting MS was prescribed D-ER by her neurologist. After 3 weeks of D-ER therapy (10 mg twice daily), she demonstrated only a 7.1% improvement in the Timed 25-Foot Walk test. She then commenced PT consisting of two 40-minute sessions per week for 6 weeks while continuing D-ER therapy. Training focused on gait, balance, coordination, functional strengthening, and dual-task performance.

Results

After 6 weeks of D-ER + PT, she had a further 14.6% improvement in Timed 25-Foot Walk gait speed, for a total improvement of 20.7%, which elevated her above the clinically meaningful threshold of 20%. Similar patterns of improvement were also observed for self-selected gait speed in single- and dual-task conditions. Improvements in fast and dual-task gait speed were retained 3 weeks later.

Conclusions

For this patient, combining PT with D-ER therapy improved gait speed more than the use of D-ER alone. Further investigation of D-ER + PT or PT as an alternative to D-ER in patients with submeaningful medication response is warranted.

Restoring Axonal Function with 4-Aminopyridine: Clinical Efficacy in Multiple Sclerosis and Beyond

The oral potassium channel blocker 4-aminopyridine has been used in various neurological conditions for decades. Numerous case reports and studies have supported its clinical efficacy in ameliorating the clinical presentation of certain neurological disorders. However, its short half-life, erratic drug levels, and safety-related dose restrictions limited its use as a self-compounded drug in clinical practice. This changed with the introduction of a prolonged-release formulation, which was successfully tested in patients with multiple sclerosis. It was fully approved by the US FDA in January 2010 but initially received only conditional approval from the European Medicines Agency (EMA) in July 2011. After additional clinical studies, this conditional approval was changed to unrestricted approval in August 2017. This article reviews and discusses these recent studies and places aminopyridines and their clinical utility into the context of a broader spectrum of neurological disorders, where clinical efficacy has been suggested. In 2010, prolonged-release 4-aminopyridine became the first drug specifically licensed to improve walking in patients with multiple sclerosis. About one-third of patients across disease courses benefit from this treatment. In addition, various reports indicate clinical efficacy beyond multiple sclerosis, which may broaden its use in clinical practice.

ADSTEP: Preliminary Investigation of a Multicomponent Walking Aid Program in People With Multiple Sclerosis

OBJECTIVE

To evaluate the effect of the Assistive Device Selection, Training and Education Program (ADSTEP) on falls and walking and sitting activity in people with multiple sclerosis (PwMS).

DESIGN

Randomized controlled trial.

SETTING

Veterans affairs medical center.

PARTICIPANTS

PwMS (N=40) using a walking aid at baseline who had fallen in the previous year.

INTERVENTIONS

Participants were randomly assigned to ADSTEP or control. ADSTEP had 6 weekly, 40-minute, 1-on-1 sessions with a physical therapist, starting with walking aid selection and fitting, followed by task-oriented progressive gait training. Control was usual medical care with the option of ADSTEP after the study.

MAIN OUTCOME MEASURES

The following were assessed at baseline, intervention completion, and 3 months later: falls, timed Up and Go, timed 25-foot walk, 2-minute walk, Four Square Step Test, International Physical Activity Questionnaire, Quebec User Evaluation of Satisfaction with Assistive Technologies, Multiple Sclerosis Walking Scale-12, Activities-Specific Balance Confidence Scale, and Multiple Sclerosis Impact Scale-29. Effect on these outcomes was estimated by a 2-by-2 repeated measures general linear model.

RESULTS

Fewer ADSTEP than control participants fell (χ²=3.96, P<.05. number needed to treat =3.3). Time spent sitting changed significantly differently with ADSTEP than with control from baseline to intervention completion (F=11.16, P=.002. ADSTEP: reduced 87.00±194.89min/d; control: increased 103.50±142.21min/d; d=0.88) and to 3-month follow-up (F=9.25, P=.004. ADSTEP: reduced 75.79±171.57min/d; control: increased 84.50±149.23min/d; d=0.79). ADSTEP yielded a moderate effect on time spent walking compared to control at 3-month follow-up (P>.05. ADSTEP 117.53±148.40min/d; control 46.43±58.55min/d; d=0.63).

CONCLUSIONS

ADSTEP prevents falls, reduces sitting, and may increase walking in PwMS.

Therapies for mobility disability in persons with multiple sclerosis

INTRODUCTION

Mobility disability is one of the most widespread and impactful consequences of multiple sclerosis (MS). Disease modifying drugs (DMDs) may delay the progression of disability over time; however, there is minimal evidence supporting the efficacy of DMDs for reversing mobility disability or restoring ambulatory function in persons with MS. Areas covered: This review outlines symptomatic pharmacologic and non-pharmacologic therapeutic approaches that target mobility disability with the goal of restoring and improving walking function. First, the efficacy of dalfampridine, currently the only Food and Drug Administration approved symptomatic pharmacologic agent that improves walking in persons with MS is described. Next, a review of the efficacy of non-pharmacologic therapies for improving walking, including exercise training, physical therapy, and gait training is given. Last, guidance on future research on mobility in MS is provided by emphasizing the importance of combinatory treatment approaches that include multiple intervention modalities, as the best treatment plan likely involves a comprehensive, multidisciplinary approach. Expert commentary: There has been an increased effort to develop symptom-specific treatments in MS that directly target mobility disability; however, more research is needed to determine the efficacy of these rehabilitative strategies alone and together for improving walking in persons with MS.

Balance, gait, and falls in multiple sclerosis

Multiple sclerosis (MS) is a chronic disease of the central nervous system (CNS) and the most widespread nontraumatic cause of disability in young adults around the world. MS occurs in people of all ages, races, and ethnicities. MS is characterized by clinical symptoms resulting from lesions in the brain, spinal cord, or optic nerves that can affect balance, gait, and fall risk. Lesions accumulate over time and occur in different areas of the CNS causing symptoms that include weakness, spasticity, and fatigue, as well as changes in sensation, coordination, vision, cognition, and bladder function. Thus, it is not surprising that imbalance, gait dysfunction, and falls are common in people with MS. The overwhelming majority have abnormalities of postural control and gait even early in the disease course. In all, 50-80% have balance and gait dysfunction and over 50% fall at least once each year. Balance dysfunction in MS is conceptualized as three interrelated problems: decreased ability to maintain position, limited and slowed movement towards limits of stability, and delayed responses to postural displacements and perturbations. In addition, functional balance performance may be affected by impaired dual-task integration. Walking changes in MS include reduced gait speed, impaired walking balance, and reduced walking-related physical activity. Falls in people with MS are associated with injuries, reduced participation, and increased fear of falling. A wide and growing range of rehabilitation and medical interventions are available to address the changes in balance, gait, and fall risk associated with MS.

Multiple Sclerosis and Clinical Gait Analysis before and after Fampridine: A Systematic Review

BACKGROUND

Gait impairment is one of the most disabling symptoms in people with multiple sclerosis (PwMS). Fampridine, has demonstrated a positive effect on gait speed in PwMS after 14 days of treatment but the long-term effects have not yet been demonstrated. This study reviews the long-term effects of fampridine on gait in PwMS.

SUMMARY

This systematic review was conducted according to the PRISMA statement. Studies were considered long term if treatment exceeded 28 days. From the 498 studies identified, 18 (2,200 patients) fulfilled all eligibility criteria. Only 3 studies followed-up patients for >1 year and one of these showed a non-significant improvement in the gait speed. Key Messages: Fampridine seems to be beneficial at improving gait speed in PwMS in the long term. Further long-term studies are needed on related gait and functional parameters.

Fampridine Prolonged Release: A Review in Multiple Sclerosis Patients with Walking Disability

Oral fampridine prolonged release (PR) [Fampyra^®] is a lipid-soluble selective potassium channel blocker that is approved in the EU for the improvement of walking in adult multiple sclerosis (MS) patients with walking disability (expanded disability status scale score of 4-7). In clinical trials (MS-F203 and MS-F204) using an objective measure of walking improvement [the timed 25-foot walk (T25FW)], more than one-third of patients receiving fampridine PR achieved a consistent on-treatment improvement in walking speed (i.e. became TW responders) over 9-14 weeks of treatment. Fampridine PR recipients who fulfilled the definition of TW responder had mean improvements of ≈25% from baseline in T25FW walking speed. In a clinical trial (ENHANCE) that used a patient-rated measure of walking improvement [12-item MS walking scale (MSWS-12)], a significantly greater proportion of fampridine PR recipients than placebo recipients achieved a ≥8-point improvement on the MSWS-12 with 24 weeks of treatment. Where reported, adverse events were mostly mild or moderate in severity, and generally consistent with the underlying disease or mechanism of action of fampridine PR. Fampridine PR is a useful treatment option to consider in adult MS patients with walking disability.

Fampridine response in MS patients with gait impairment in a real-world setting: Need for new response criteria?

OBJECTIVE

The primary objective of this real-world study was to describe the response to fampridine and changes of gait parameters in multiple sclerosis (MS) patients' walking disability (Expanded Disability Status Scale (EDSS): 4-7) after treatment with fampridine for 2 weeks as recommended by the European Medicines Agency (EMA) and compare it with the overall physician's judgement.

METHODS

A total of 211 adult MS patients were analyzed using a multimodal gait assessment including the timed 25-foot walk test (T25FW), 2-minute walking test (2-MWT), 12-item Multiple Sclerosis Walking Scale (MSWS-12), the GAITRite electronic walkway system, and the patients' clinical global impression (CGI). Multimodal gait assessment was compared with the clinician's impression of overall improvement after 2 weeks.

RESULTS

In total, 189 subjects were included, of which 133 (70.37%) were responders to fampridine (RF), according to physician's judgement. Looking at independent multimodal gait assessment, RFs showed improvement of 12.60% in the T25FW, 19.25% in the 2-MWT, 21.12% in the MSWS-12, and 6.54% in their Functional Ambulation Profile (FAP) score. The combination of the T25FW and the MSWS-12 would offer the best sensitivity and specificity for determining response to fampridine according to both neurologists' and patients' classification.

CONCLUSION

This study provides new information on the use of fampridine in a real-world setting with a large patient sample on the potential benefit of using more definitive responder criteria to fampridine for the clinical setting.

Validity of the timed 25-foot walk as an ambulatory performance outcome measure for multiple sclerosis

The Multiple Sclerosis Outcome Assessments Consortium (MSOAC) includes representatives from advocacy organizations, Food and Drug Administration (FDA), European Medicines Agency (EMA), National Institute of Neurological Disorders and Stroke (NINDS), academic institutions, and industry partners along with persons living with multiple sclerosis (MS). One of the MSOAC goals is acceptance and qualification by regulators of performance outcomes that are highly reliable and valid, practical, cost-effective, and meaningful in MS. This article addresses the history, application, and psychometric properties of one such MSOAC metric of ambulation or walking namely, the timed 25-foot walk (T25FW). The T25FW has strong reliability over both brief and long periods of time in MS across a large range of disability levels. The outcome of walking speed from the T25FW has obvious real-world relevance and has correlated strongly with other measures of walking and lower extremity function. The T25FW is responsive for capturing intervention effects in pharmacological and rehabilitation trials and has an established value for capturing clinically meaningful change in ambulation. Directions for future research involve validating clinically meaningful improvements on the T25FW as well as determining whether 20% change is clinically meaningful across the disability spectrum. Researchers might further consider synchronizing accelerometers and motion sensors with the T25FW for capturing walking speed in everyday life and the patient's real environment.

Impact of fampridine on quality of life: clinical benefit in real-world practice

Objectives

To assess the effectiveness and tolerability of fampridine in patients with multiple sclerosis (MS) in real clinical practice and to analyse adherence to treatment and general satisfaction of patients in terms of quality of life (QOL).

Methods

Patients who started treatment with fampridine from May 2014 to October 2014 were included. Primary and secondary outcomes were Timed 25-Foot Walk (T25FW) and MS Walking Scale-12 (MSWS-12) respectively, measured at baseline and 2 weeks, 3 and 6 months. Adherence was measured by the Morisky-Green questionnaire, patient satisfaction with a visual analogue scale (VAS) and QOL with improvement in mobility, self-care, daily activities, pain/discomfort or anxiety/depression.

Results

30 patients (46.7% women) of mean age 39 years, mean MS duration 13.7 years, mean Expanded Disability Status Scale score 5.8, 57% with relapsing-remitting MS were included. 22 patients (73%) continued to take treatment throughout the study period. Two weeks after treatment initiation all measures improved significantly from baseline (T25FW: -7.5 s, p<0.05; MSWS-12: -36.7, p<0.05). At 6 months, walking speed and self-perceived walking ability were significantly improved (T25FW: -3.8 s, p<0.05; MSWS-12: -30.0, p<0.05). Adverse events were reported by 30% of patients. Seizures were registered in one patient. 70% of patients were adherent with treatment. Median (IQR) general satisfaction VAS score was 8 (7-9). Patients reported an improvement in mobility (70%), anxiety/depression (33.3%), self-care (23.3%), daily activities (23.3%) and pain/discomfort (3.3%).

Conclusions

Fampridine is effective and safe in patients with MS in real clinical practice up to 6 months. Adherence to treatment was suboptimal but patients' general satisfaction was high and fampridine improved several items of QOL.

Quantification of postural stability in minimally disabled multiple sclerosis patients by means of dynamic posturography: an observational study

BACKGROUND

Multiple Sclerosis (MS) is a widespread progressive neurologic disease with consequent impairments in daily activities. Disorders of balance are frequent and equilibrium tests are potentially useful to quantify disability and to verify treatment effectiveness. The fair sensitivity of the widely used not-perturbed tests to detect balance disturbances in MS patients have prompted the development of mechatronic systems capable to impose known equilibrium perturbations, in order to challenge the balance control and, consequently, to better assess the level of impairment. We sought to clarify whether the proposed perturbed-test is capable to discriminate healthy subjects from patients with MS, even in mild or in the absence of clinically evident balance disturbances.

METHODS

We assessed balance performances of 17 adults with MS and 13 age-matched healthy controls (HC) using both perturbed (PT) and not-perturbed (NPT) postural tests by means of a 3 Degree Of Freedom (DOF) rotational mechatronic platform. Participants stood barefoot on the platform in standing position and their center of pressure (CoP) was gathered by using a pressure matrix. Each trial lasted 30 s and was carried out with and without visual stimuli. Several postural indices were computed for each trial. Correlations between postural indices and clinical scales were analyzed.

RESULTS

No significant differences were found between groups for all indices when subjects performed NPTs. Conversely, significant differences in postural indices between MS and HC emerged during PTs. Additionally, PTs revealed significant differences between patients without any cerebellar impairment (cerebellar EDSS subscore equal to 0) and HC. The discrimination capability of PTs was confirmed by the ROC analysis. No significant change of the selected metrics occurred in HC when NPTs were performed with eyes closed, while indices presented a significant worsening in MS subjects.

CONCLUSIONS

Not-perturbed tests showed lower sensitivity than perturbed ones in the identification of equilibrium impairments in minimally disabled MS patients. However, not-perturbed tests allow to better evaluate the influence of visual flow disturbances on balance control in MS. In conclusion, our findings proved that the use of the novel tests based on a 3DOF mechatronic device represents an effective tool to investigate early balance disturbances in MS.

Experience with fampridine in clinical practice: analysis of a possible marker of clinical response

PURPOSE OF THE STUDY

Approximately 85% of patients with multiple sclerosis experience reduced mobility, which negatively affects quality of life. Fampridine is the first symptomatic treatment aimed at improving gait. We analyzed effectiveness and tolerance in clinical practice. We also sought a prevalent gait pattern in responders as a potential clinical response marker.

MATERIAL AND METHODS

Six-month prospective study of fampridine in patients with multiple sclerosis. Response was evaluated using the Timed 25-Foot Walk Test (T25FW) and the 12-Item Multiple Sclerosis Walking Scale (MSWS-12). Response was defined as increased gait speed (≥20%) and decreased MSWS-12 score (≥4 points).

RESULTS

Fifty-five patients (67.3% women; mean age, 51.7 [11.1] years) with a baseline Expanded Disability Status Scale (EDSS) score of 5.8. Gait pattern was paraparetic (40%), hemiparetic (21.8%) and ataxic (38.2%). Of all patients, 70.9% demonstrated clinical benefit based on response criteria established, at the 14-d follow-up, 61.8% at 3 months and 45.5% at 6 months. A similar response pattern was observed in the MSWS-12. A significant decrease in the mean (SD) EDSS score was observed in responders at 6 months (6.1 [0.9] vs. 5.64 [0.1], p < 0.05). Adverse effects were recorded in 50.9%, although most were mild-moderate and resolved completely. We did not identify a prevalent gait pattern among responders. After a washout period, some patients received fampridine a second time obtaining response recovery.

CONCLUSIONS

In our patients' cohort, fampridine proved clinical benefit, being safe and well tolerated in most cases. We did not identify a gait pattern that was predictive of clinical response.

Early effect of dalfampridine in patients with MS: A multi-instrumental approach to better investigate responsiveness

BACKGROUND

4-aminopyridine (4-AP) is a potassium-channel blocker able to enhance walking speed in MS improving the action potentials of demyelinated axons on which internodal potassium channels are exposed.

OBJECTIVE

to study early 4-AP effect with clinical, subjective, neurophysiological and neuroradiological tools.

METHODS

Clinical (Timed 25-Foot Walk - T25FW, Timed Up-And-Go - TUG), subjective (MS Walking Scale-12 - MSWS-12), neurophysiological (Motor Evoked Potentials - MEPs) and imaging (Diffusion Tensor Imaging - DTI) evaluations were performed before (T0) and after (T1) 14days of 4-AP treatment. MEPs were recorded from Abductor Hallucis of both legs. A Tract-Based-Spatial-Statistics (TBSS) was performed on DTI.

RESULTS

We found a significant difference between T0 and T1 for T25FW, TUG, MSWS-12 (p≤0.001) in the whole patients' sample (23 subjects, median EDSS 6.0) and decrease of Central Motor Conduction Time and increase of mean Amplitude (Amp) at T1 (p=0.008 and p=0.006). We also recorded a significant difference of T25FW, TUG, MSWS-12 and Amp in clinical responder (CR) patients (CR: amelioration >20% at T25FW). TBSS showed a significant Mean and Radial Diffusivity reduction in the corticospinal tracts (p<0.05) of the whole group of patients; this reduction was also found in the CR subgroup.

CONCLUSION

Neurophysiological and neuroradiological parameters were modified in MS patients treated with 4-AP, and most of them reported a subjective improvement of their motor performances after treatment. The use of clinical, subjective, neurophysiological and neuroradiological tools could help to better explore MS patients responsiveness to 4-AP.

The e-MSWS-12: improving the multiple sclerosis walking scale using item response theory

BACKGROUND

The Multiple Sclerosis Walking Scale (MSWS-12) is the predominant patient-reported measure of multiple sclerosis (MS) -elated walking ability, yet it had not been analyzed using item response theory (IRT), the emerging standard for patient-reported outcome (PRO) validation. This study aims to reduce MSWS-12 measurement error and facilitate computerized adaptive testing by creating an IRT model of the MSWS-12 and distributing it online.

METHODS

MSWS-12 responses from 284 subjects with MS were collected by mail and used to fit and compare several IRT models. Following model selection and assessment, subpopulations based on age and sex were tested for differential item functioning (DIF).

RESULTS

Model comparison favored a one-dimensional graded response model (GRM). This model met fit criteria and explained 87 % of response variance. The performance of each MSWS-12 item was characterized using category response curves (CRCs) and item information. IRT-based MSWS-12 scores correlated with traditional MSWS-12 scores (r = 0.99) and timed 25-foot walk (T25FW) speed (r =  -0.70). Item 2 showed DIF based on age (χ ² = 19.02, df = 5, p < 0.01), and Item 11 showed DIF based on sex (χ ² = 13.76, df = 5, p = 0.02).

CONCLUSIONS

MSWS-12 measurement error depends on walking ability, but could be lowered by improving or replacing items with low information or DIF. The e-MSWS-12 includes IRT-based scoring, error checking, and an estimated T25FW derived from MSWS-12 responses. It is available at https://ms-irt.shinyapps.io/e-MSWS-12 .