Performance Measures and Plasma Biomarker Levels in Patients with Multiple Sclerosis after 14 Days of Fampridine Treatment: An Explorative Study.

Peripheral cytokine levels may serve as biomarkers for treatment response and disease monitoring in patients with multiple sclerosis (pwMS). The objectives were to assess changes in plasma biomarkers in PwMS after 14 days of fampridine treatment and to explore correlations between changes in performance measures and plasma biomarkers. We included 27 PwMS, 14 women and 13 men, aged 52.0 ± 11.6 years, with a disease duration of 17 ± 8.5 years, and an Expanded Disability Status Scale of 6 [IQR 5.0/6.5]. Gait and hand function were assessed using performance tests completed prior to fampridine and after 14 days of treatment. Venous blood was obtained, and chemiluminescence analysis conducted to assess plasma cytokines and neurodegenerative markers. All performance measures demonstrated improvements. Biomarkers showed decreased tumor necrosis factor (TNF) receptor-2 levels. Associations were found between change scores in (i) Six Spot Step Test and Interleukin (IL)-2, IL-8, and IL-17 levels; (ii) timed 25-foot walk and interferon-γ, IL-2, IL-8, TNF-α, and neurofilament light levels, and (iii) 12-Item Multiple Sclerosis Walking Scale and IL-17 levels. The associations may reflect increased MS-related inflammatory activity rather than a fampridine-induced response or that a higher level of inflammation induces a better response to fampridine.

Fampridine for gait imbalance in patients with multiple sclerosis (MS): a systematic review and meta-analysis.

BACKGROUND: Gait imbalance is one of the frequent complications in subjects with multiple sclerosis (MS). Fampridine (4-aminopyridine) is a potassium-channel blocker that is administered for gait imbalance in MS. Different studies showed the effects of fampridine on gait status based on various tests in subjects with MS. Some showed significant improvement after treatment, and others did not. So, we designed this systematic review, and meta-analysis to estimate the pooled effects of fampridine on gait status in patients with MS. METHODS: The main goal is the evaluation of times of different gait test pre and post fampridine treatment. Two independent expert researchers conducted a systematic and comprehensive search in PubMed, Scopus, EMBASE, Web of Science, and Google Scholar and also gray literature, including references of the references and conference abstracts. The search was done on September 16, 2022. Before-after studies trials reporting scores of the walking tests. We extracted data regarding the total number of participants, first author, publication year, country of origin, mean age, Expanded Disability Status Scale (EDSS), and the results of walking tests. RESULTS: The literature search revealed 1963 studies; after deleting duplicates, 1098 studies remained. Seventy-seven full texts were evaluated. Finally, 18 studies were included for meta-analysis, while most of them were not placebo-controlled trials. The most frequent country of origin was Germany, and the mean age and EDSS ranged between 44 and 56 years and 4 and 6, respectively. The studies were published between 2013 and 2019. The pooled standardized mean difference (SMD) (after-before) of the MS Walking Scale (MSWS-12) was - 1.97 (95%CI: - 1.7, - 1.03) (I2 = 93.1%, P < 0.001). The pooled SMD (after-before) of the six-minute walk test (6MWT) was 0.49 (95%CI: 0.22, - 0.76) (I2 = 0%, P = 0.7). The pooled SMD (after-before) of T Timed 25-Foot Walk (T25FW) was - 0.99(95%CI: - 1.52, - 0.47) (I2 = 97.5%, P < 0.001). CONCLUSION: This systematic review and meta-analysis show that fampridine improves gait imbalance in patients with MS.

Fampridine in multiple sclerosis patients with acute phase of cervical transverse myelitis: a double-blind, randomized placebo-controlled trial.

BACKGROUND: Fampridine is a potassium channel blocker drug used to improve walking ability in patients with multiple sclerosis (MS). We evaluated the effect of fampridine in patients with MS in the acute phase of transverse myelitis. METHODS: In a randomized, placebo-controlled trial, 30 patients who had their first episode of cervical myelitis with quadriparesis presentation, with the final diagnosis of MS, were randomly divided into two equal groups. The intervention group received intravenous methylprednisolone (IVMP) for 7 days plus fampridine. The placebo group received IVMP for 7 days plus placebo. To compare the treatment results, we compared the Barthel index (BI) scores of the groups at the start of the trial and the 21st day after the start of treatment. RESULTS: There was no significant difference in baseline characteristics between the intervention and placebo groups in terms of mean age, sex, and mean admission BI (p > 0.05). Mean (SD) admission BI in placebo and intervention groups was 27.20 (7.341) and 27.87(5.78), respectively (p = 0.784). The measured mean (SD) BI after treatment was 48.73 (15.54) in the placebo and 64.93 (11.81) in the intervention group (p = 0.003) after 3 weeks. CONCLUSION: Using fampridine plus IVMP in the acute phase of transverse myelitis in MS patients improved the disease's symptoms and increased the daily activity ability of patients.

Effects of 4-Aminopyridine on Combined Nerve and Muscle Injury and Bone Loss.

PURPOSE: Musculoskeletal injuries are common, and peripheral nerve injury (PNI) causes significant muscle and bone loss within weeks. After PNI, 4-aminopyridine (4-AP) improves functional recovery and muscle atrophy. However, it is unknown whether 4-AP has any effect on isolated traumatic muscle injury and PNI-induced bone loss. METHODS: A standardized crush injury was performed on the sciatic nerve and muscles in mice, and the mice were assigned to receive normal saline or 4-AP treatment daily for 21 days. The postinjury motor and sensory function recovery was assessed, injured muscles were processed for histomorphometry, and the tibial bone was scanned for bone density. RESULTS: 4-Aminopyridine significantly accelerated the postinjury motor and sensory function recovery, improved muscle histomorphometry, increased muscle satellite cell numbers, and shifted muscle fiber types after combined nerve and muscle injury. Importantly, the 4-AP treatment significantly reduced PNI-induced bone loss. In contrast, in the case of isolated muscle injury, 4-AP had no effect on functional recovery and bone density, but it improved muscle-specific histomorphometry to a limited extent. CONCLUSIONS: These findings demonstrate the potential beneficial effects of 4-AP on the recovery of muscle morphology and bone density after combined muscle and nerve injury. CLINICAL RELEVANCE: Nerve injuries frequently involve muscle and result in rapid muscle and bone atrophy. In this scenario, 4-AP, in addition to accelerating nerve functional recovery, might work as an adjunctive agent to improve the recovery of injured muscle and attenuate PNI-induced bone loss.

Chronic Pharmacological Increase of Neuronal Activity Improves Sensory-Motor Dysfunction in Spinal Muscular Atrophy Mice.

Dysfunction of neuronal circuits is an important determinant of neurodegenerative diseases. Synaptic dysfunction, death, and intrinsic activity of neurons are thought to contribute to the demise of normal behavior in the disease state. However, the interplay between these major pathogenic events during disease progression is poorly understood. Spinal muscular atrophy (SMA) is a neurodegenerative disease caused by a deficiency in the ubiquitously expressed protein SMN and is characterized by motor neuron death, skeletal muscle atrophy, as well as dysfunction and loss of both central and peripheral excitatory synapses. These disease hallmarks result in an overall reduction of neuronal activity in the spinal sensory-motor circuit. Here, we show that increasing neuronal activity by chronic treatment with the FDA-approved potassium channel blocker 4-aminopyridine (4-AP) improves motor behavior in both sexes of a severe mouse model of SMA. 4-AP restores neurotransmission and number of proprioceptive synapses and neuromuscular junctions (NMJs), while having no effects on motor neuron death. In addition, 4-AP treatment with pharmacological inhibition of p53-dependent motor neuron death results in additive effects, leading to full correction of sensory-motor circuit pathology and enhanced phenotypic benefit in SMA mice. Our in vivo study reveals that 4-AP-induced increase of neuronal activity restores synaptic connectivity and function in the sensory-motor circuit to improve the SMA motor phenotype.SIGNIFICANCE STATEMENT Spinal muscular atrophy (SMA) is a neurodegenerative disease, characterized by synaptic loss, motor neuron death, and reduced neuronal activity in spinal sensory-motor circuits. However, whether these are parallel or dependent events is unclear. We show here that long-term increase of neuronal activity by the FDA-approved drug 4-aminopyridine (4-AP) rescues the number and function of central and peripheral synapses in a SMA mouse model, resulting in an improvement of the sensory-motor circuit and motor behavior. Combinatorial treatment of pharmacological inhibition of p53, which is responsible for motor neuron death and 4-AP, results in additive beneficial effects on the sensory-motor circuit in SMA. Thus, neuronal activity restores synaptic connections and improves significantly the severe SMA phenotype.

A Phase 3, double-blind, placebo-controlled efficacy and safety study of ADS-5102 (Amantadine) extended-release capsules in people with multiple sclerosis and walking impairment.

BACKGROUND: ADS-5102, a delayed-release, extended-release (DR/ER) amantadine, improved walking speed in MS in a Phase 2 trial. OBJECTIVE: The aim of this study was to present primary results of a Phase 3, double-blind, ADS-5102 trial (INROADS) for walking speed. METHODS: Adult participants with MS and walking impairment, not currently using amantadine or dalfampridine, underwent 4-week placebo run-in before randomization 1:1:1 to placebo, 137 or 274 mg/day ADS-5102 for 12 weeks. Primary outcome was the proportion of responders (20% increase in Timed 25-Foot Walk (T25FW) speed) for 274 mg ADS-5102 versus placebo at end of double-blind (Study Week 16). Additional measures included Timed Up and Go (TUG), 2-Minute Walk Test (2MWT), and 12-item Multiple Sclerosis Walking Scale (MSWS-12). RESULTS: In total, 558 participants were randomized and received double-blind treatment. Significantly more participants responded with 274 mg ADS-5102 (21.1%) versus placebo (11.3%). Mean T25FW speed also significantly improved (0.19 ft/s) versus placebo (0.07 ft/s). Other measures were not significant using prespecified hierarchical testing procedure. Adverse events led to discontinuation for 3.8% (placebo), 6.4% (137 mg ADS-5102), and 20.5% (274 mg ADS-5102). CONCLUSION: INROADS met its primary endpoint, showing a significantly greater proportion of participants with meaningful improvement in walking speed for 274 mg ADS-5102 versus placebo. Numeric dose response was seen for some secondary efficacy outcomes and adverse events.

The efficacy of combining topiramate and 4-aminopyridine to reduce relapses and interictal progression in two cases of episodic ataxia type 2.

BACKGROUND: Episodic ataxia type 2 is an autosomal dominant channelopathy, caused by genetic variants in the voltage-dependent calcium channel a-1 subunit (CACNA1A), which is characterized by intermittent episodes of vertigo and ataxia. A slow progression of cerebellar signs is commonly observed in the course of the disease. Treatment with the carbonic anhydrase inhibitor acetazolamide is recommended. METHODS: We report the cases of two patients with EA-2 and migraine, linked to a novel CACNA1A mutation associated with disabling ictal and interictal disease, which did not respond to acetazolamide. RESULTS: A 30-year-old woman and a 50-year-old man, who was a ski instructor, reported disabling episodes of rotatory vertigo and progressive interictal ataxia. In both cases, the disease progressed despite treatment with acetazolamide. The concomitant use of topiramate and 4-aminopyridine significantly reduced the frequency and severity of relapses and migraine and improved the interictal cerebellar progression in both cases. CONCLUSIONS: We propose combined applications of topiramate and 4-aminopyridine in refractory cases and those with poor tolerance to acetazolamide and also in those with frequent associated migraine. The effectiveness of this combination of drugs for treating intermittent ataxic episodes and interictal signs in EA-2 has not been previously reported.

3,4-diaminopyridine treatment for Lambert-Eaton myasthenic syndrome in adults: a meta-analysis of randomized controlled trials.

BACKGROUND: Lambert-Eaton myasthenic syndrome (LEMS) is a rare autoimmune disorder of neuromuscular transmission. The objective was to examine the efficacy and safety of 3,4-diaminopyridine (3,4-DAP) in patients with LEMS. METHODS: We searched several databases to identify relevant studies, including PubMed, EMBASE, Web of Science, MEDLINE, Cochrane Neuromuscular Disease Group Specialized Register and the Cochrane Central Register of Controlled Trials(CENTRAL). The primary outcome, quantitative myasthenia gravis (QMG) score and the secondary outcome, compound muscle action potentials (CMAP) amplitude were pooled by meta-analysis. RESULTS: Six randomised controlled trials (RCTs) involving 115 patients with LEMS were included. QMG score showed a significant decrease (improvement) of 2.76 points (95 % CI, -4.08 to -1.45, p < 0.001) after treatment with 3, 4-DAP. Moreover, the overall mean CMAP amplitude improved significantly in LEMS patients with 3, 4-DAP treatment, compared with placebo treatment (mean difference 1.34 mV, 95 % CI, 0.98 to 1.70, p < 0.001). The overall assessment of all included trials showed a low risk of bias and low heterogeneity. CONCLUSIONS: The pooled results of RCTs demonsrated with moderate to high evidence that 3,4-DAP has a significant effect on LEMS treatment, with improvements in muscle strength score and CMAP amplitude.

A Novel KCNA2 Variant in a Patient with Non-Progressive Congenital Ataxia and Epilepsy: Functional Characterization and Sensitivity to 4-Aminopyridine.

Kv1.2 channels, encoded by the KCNA2 gene, are localized in the central and peripheral nervous system, where they regulate neuronal excitability. Recently, heterozygous mutations in KCNA2 have been associated with a spectrum of symptoms extending from epileptic encephalopathy, intellectual disability, and cerebellar ataxia. Patients are treated with a combination of antiepileptic drugs and 4-aminopyridine (4-AP) has been recently trialed in specific cases. We identified a novel variant in KCNA2, E236K, in a Serbian proband with non-progressive congenital ataxia and early onset epilepsy, treated with sodium valproate. To ascertain the pathogenicity of E236K mutation and to verify its sensitivity to 4-AP, we transfected HEK 293 cells with Kv1.2 WT or E236K cDNAs and recorded potassium currents through the whole-cell patch-clamp. In silico analysis supported the electrophysiological data. E236K channels showed voltage-dependent activation shifted towards negative potentials and slower kinetics of deactivation and activation compared with Kv1.2 WT. Heteromeric Kv1.2 WT+E236K channels, resembling the condition of the heterozygous patient, confirmed a mixed gain- and loss-of-function (GoF/LoF) biophysical phenotype. 4-AP inhibited both Kv1.2 and E236K channels with similar potency. Homology modeling studies of mutant channels suggested a reduced interaction between the residue K236 in the S2 segment and the gating charges at S4. Overall, the biophysical phenotype of E236K channels correlates with the mild end of the clinical spectrum reported in patients with GoF/LoF defects. The response to 4-AP corroborates existing evidence that KCNA2-disorders could benefit from variant-tailored therapeutic approaches, based on functional studies.

Predicting responsiveness to fampridine in gait-impaired patients with multiple sclerosis.

BACKGROUND AND PURPOSE: Fampridine leads to significant improvements in walking in many people with multiple sclerosis (PwMS). However, a relevant proportion of PwMS does not respond to fampridine and predictors of initial drug responsiveness are unknown. METHODS: Drug response to prolonged-release (PR)-fampridine was assessed in 55 PwMS using the timed 25-foot walk (T25FW), 6-min walk test (6MWT) and 12-item multiple sclerosis walking scale as outcome parameters. Patients were treated with PR-fampridine and placebo for 6 weeks each in a randomized, double-blind, placebo-controlled trial with crossover design (NCT01576354). Possible predictors of drug responsiveness were investigated by multiple correlation analysis and binary logistic regression models. An additional longitudinal analysis followed the drug responses of 32 patients treated with PR-fampridine over 3 years to identify potential predictors of long-term drug responsiveness. RESULTS: Severity of walking disability was positively correlated with enhanced responses to PR-fampridine. The strongest single predictor of drug responsiveness was poor 6MWT performance at baseline, which was positively correlated with enhanced drug response in the 6MWT (R = -0.541; P < 0.001). A multivariable logistic regression model including 6MWT and T25FW baseline performances predicted PR-fampridine responder status with an accuracy of 85.5% (specificity, 90.0%; sensitivity, 73.3%), with a threshold of 211 m in the 6MWT best separating responders from non-responders. Enhanced drug responsiveness after 3 years correlated with decline in walking endurance during this period (R = -0.634; P = 0.001). CONCLUSIONS: Initial walking impairment is a good predictor of therapeutic responsiveness to PR-fampridine. Valid predictors of patients' responsiveness to PR-fampridine are essential for patient stratification and optimization of multiple slcerosis treatment.

Effect of patients' expectations on clinical response to fampridine treatment.

INTRODUCTION: Patient expectation of treatment outcome is one of the primary mechanisms underlying the placebo effect. In multiple sclerosis trials with symptomatic treatments, a robust placebo effect is observed, which might be related to patient expectations. The aim of this study was to evaluate whether patient expectations regarding fampridine treatment influence the clinical response after 4 weeks and 6 months of treatment. MATERIALS AND METHODS: We designed and carried out a prospective study from June 2015 to August 2017. Before treatment, patients completed a questionnaire including a scale evaluating their expectations regarding the treatment. The effect of baseline positive expectancy on the response status after 4 weeks and 6 months of treatment was analyzed through univariable and, when applicable, multivariable analysis. RESULTS: A total of 47 consecutive patients were included in the study. At week 4, 37 (78.7%) patients were classified as responders; a one-point increase in the positive expectancy questionnaire was significantly associated with a fourfold increase in the likelihood of being a responder [OR = 4.020 (95% CI 1.082-14.933); p = 0.038]. At 6 months, 43 patients completed follow-up. The number of responders decreased to 28; at this point, positive expectancy at baseline was no longer associated with response status. CONCLUSION: Baseline positive expectancy regarding fampridine was determinant of the clinical response after 4 weeks of treatment. However, in the long term, fampridine efficacy was not dependent on expectations prior to treatment.

3,4-diaminopyridine reverses paralysis in botulinum neurotoxin-intoxicated diaphragms through two functionally distinct mechanisms.

Botulinum neurotoxins (BoNTs) are exceedingly potent neurological poisons that prevent neurotransmitter release from peripheral nerve terminals by cleaving presynaptic proteins required for synaptic vesicle fusion. The ensuing neuromuscular paralysis causes death by asphyxiation. Although no antidotal treatments exist to block toxin activity within the nerve terminal, aminopyridine antagonists of voltage-gated potassium channels have been proposed as symptomatic treatments for botulism toxemia. However, clinical evaluation of aminopyridines as symptomatic treatments for botulism has been inconclusive, in part because mechanisms responsible for reversal of paralysis in BoNT-poisoned nerve terminals are not understood. Here we measured the effects of 3,4-diaminopyridine (DAP) on phrenic nerve-elicited diaphragm contraction and end-plate potentials at various times after intoxication with BoNT serotypes A, B, or E. We found that DAP-mediated increases in quantal content promote neurotransmission from intoxicated nerve terminals through two functionally distinguishable mechanisms. First, DAP increases the probability of neurotransmission at non-intoxicated release sites. This mechanism is serotype-independent, becomes less effective as nerve terminals become progressively impaired, and remains susceptible to ongoing intoxication. Second, DAP elicits persistent production of toxin-resistant endplate potentials from nerve terminals fully intoxicated by BoNT/A, but not serotypes B or E. Since this effect appears specific to BoNT/A intoxication, we propose that DAP treatment enables BoNT/A-cleaved SNAP-25 to productively engage in fusogenic release by increasing the opportunity for low-efficiency fusion events. These findings have important implications for DAP as a botulism therapeutic by defining conditions under which DAP may be clinically effective in reversing botulism symptoms.

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.

Interventions for eye movement disorders due to acquired brain injury.

BACKGROUND: Acquired brain injury can cause eye movement disorders which may include: strabismus, gaze deficits and nystagmus, causing visual symptoms of double, blurred or 'juddery' vision and reading difficulties. A wide range of interventions exist that have potential to alleviate or ameliorate these symptoms. There is a need to evaluate the effectiveness of these interventions and the timing of their implementation. OBJECTIVES: We aimed to assess the effectiveness of any intervention and determine the effect of timing of intervention in the treatment of strabismus, gaze deficits and nystagmus due to acquired brain injury. We considered restitutive, substitutive, compensatory or pharmacological interventions separately and compared them to control, placebo, alternative treatment or no treatment for improving ocular alignment or motility (or both). SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (containing the Cochrane Eyes and Vision Trials Register) (2017, Issue 5), MEDLINE Ovid, Embase Ovid, CINAHL EBSCO, AMED Ovid, PsycINFO Ovid, Dissertations & Theses (PQDT) database, PsycBITE (Psychological Database for Brain Impairment Treatment Efficacy), ISRCTN registry, ClinicalTrials.gov, Health Services Research Projects in Progress (HSRProj), National Eye Institute Clinical Studies Database and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). The databases were last searched on 26 June 2017. No date or language restrictions were used in the electronic searches for trials. We manually searched the Australian Orthoptic Journal, British and Irish Orthoptic Journal, and ESA, ISA and IOA conference proceedings. We contacted researchers active in this field for information about further published or unpublished studies. SELECTION CRITERIA: We included randomised controlled trials (RCTs) of any intervention for ocular alignment or motility deficits (or both) due to acquired brain injury. DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies and extracted data. We used standard methods expected by Cochrane. We employed the GRADE approach to interpret findings and assess the quality of the evidence. MAIN RESULTS: We found five RCTs (116 participants) that were eligible for inclusion. These trials included conditions of acquired nystagmus, sixth cranial nerve palsy and traumatic brain injury-induced ocular motility defects. We did not identify any relevant studies of restitutive interventions.We identified one UK-based trial of a substitutive intervention, in which botulinum toxin was compared with observation in 47 people with acute sixth nerve palsy. At four months after entry into the trial, people given botulinum toxin were more likely to make a full recovery (reduction in angle of deviation within 10 prism dioptres), compared with observation (risk ratio 1.19, 95% CI 0.96 to 1.48; low-certainty evidence). These same participants also achieved binocular single vision. In the injection group only, there were 2 cases of transient ptosis out of 22 participants (9%), and 4 participants out of 22 (18%) with transient vertical deviation; a total complication rate of 24% per injection and 27% per participant. All adverse events recovered. We judged the certainty of evidence as low, downgrading for risk of bias and imprecision. It was not possible to mask investigators or participants to allocation, and the follow-up between groups varied.We identified one USA-based cross-over trial of a compensatory intervention. Oculomotor rehabilitation was compared with sham training in 12 people with mild traumatic brain injury, at least one year after the injury. We judged the evidence from this study to be very low-certainty. The study was small, data for the sham training group were not fully reported, and it was unclear if a cross-over study design was appropriate as this is an intervention with potential to have a permanent effect.We identified three cross-over studies of pharmacological interventions for acquired nystagmus, which took place in Germany and the USA. These studies investigated two classes of pharmacological interventions: GABAergic drugs (gabapentin, baclofen) and aminopyridines (4-aminopyridines (AP), 3,4-diaminopyridine (DAP)). We judged the evidence from all three studies as very low-certainty because of small numbers of participants (which led to imprecision) and risk of bias (they were cross-over studies which did not report data in a way that permitted estimation of effect size).One study compared gabapentin (up to 900 mg/day) with baclofen (up to 30 mg/day) in 21 people with pendular and jerk nystagmus. The follow-up period was two weeks. This study provides very low-certainty evidence that gabapentin may work better than baclofen in improving ocular motility and reducing participant-reported symptoms (oscillopsia). These effects may be different in pendular and jerk nystagmus, but without formal subgroup analysis it is unclear if the difference between the two types of nystagmus was chance finding. Quality of life was not reported. Ten participants with pendular nystagmus chose to continue treatment with gabapentin, and one with baclofen. Two participants with jerk nystagmus chose to continue treatment with gabapentin, and one with baclofen. Drug intolerance was reported in one person receiving gabapentin and in four participants receiving baclofen. Increased ataxia was reported in three participants receiving gabapentin and two participants receiving baclofen.One study compared a single dose of 3,4-DAP (20 mg) with placebo in 17 people with downbeat nystagmus. Assessments were made 30 minutes after taking the drug. This study provides very low-certainty evidence that 3,4-DAP may reduce the mean peak slow-phase velocity, with less oscillopsia, in people with downbeat nystagmus. Three participants reported transient side effects of minor perioral/distal paraesthesia.One study compared a single dose of 4-AP with a single dose of 3,4-DAP (both 10 mg doses) in eight people with downbeat nystagmus. Assessments were made 45 and 90 minutes after drug administration. This study provides very low-certainty evidence that both 3,4-DAP and 4-AP may reduce the mean slow-phase velocity in people with downbeat nystagmus. This effect may be stronger with 4-AP. AUTHORS' CONCLUSIONS: The included studies provide insufficient evidence to inform decisions about treatments specifically for eye movement disorders that occur following acquired brain injury. No information was obtained on the cost of treatment or measures of participant satisfaction relating to treatment options and effectiveness. It was possible to describe the outcome of treatment in each trial and ascertain the occurrence of adverse events.

Healthcare resource use and costs of multiple sclerosis patients in Germany before and during fampridine treatment.

BACKGROUND: Multiple sclerosis (MS) patients often suffer from gait impairment and fampridine is indicated to medically improve walking ability in this population. Patient characteristics, healthcare resource use, and costs of MS patients on fampridine treatment for 12 months in Germany were analyzed. METHODS: A retrospective claims database analysis was conducted including MS patients who initiated fampridine treatment (index date) between July 2011 and December 2013. Continuous insurance enrollment during 12 months pre- and post-index date was required, as was at least 1 additional fampridine prescription in the fourth quarter after the index date. Patient characteristics were evaluated and pre- vs post-index MS-related healthcare utilization and costs were compared. RESULTS: A total of 562 patients were included in this study. The mean (standard deviation [SD]) age was 50.5 (9.8) years and 63% were female. In the treatment period, almost every patient had at least 1 MS-related outpatient visit, 24% were hospitalized due to MS, and 79% utilized MS-specific physical therapy in addition to the fampridine treatment. Total MS-related healthcare costs were significantly higher in the fampridine treatment period than in the period prior to fampridine initiation (€17,392 vs €10,960, P < 0.001). While this difference was driven primarily by prescription costs, MS-related inpatient costs were lower during fampridine treatment (€1,333 vs €1,565, P < 0.001). CONCLUSIONS: Physical therapy is mainly used concomitant to fampridine treatment. While healthcare costs were higher during fampridine treatment compared to the pre-treatment period, inpatient costs were lower. Further research is necessary to better understand the fampridine influence.

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.

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.

Update on the Pharmacotherapy of Cerebellar Ataxia and Nystagmus.

Pharmacological treatment of cerebellar ataxias and cerebellar nystagmus still remains difficult. The efficacy of most of the agents recommended in the past for symptomatic or even causative therapy could not be proven in larger state-of-the art clinical trials. Exceptions are (a) 4-aminopyridine (4-AP) for episodic ataxia type 2 (EA2): one observational and one randomized controlled trial showed a significant effect on the number of attacks of ataxia and quality of life; (b) aminopyridines in cerebellar downbeat nystagmus (DBN): two randomized controlled trials and several observational studies demonstrate a significant improvement of the intensity of DBN, visual acuity, and postural imbalance. In both diseases the sustained-release form is evidently also efficient; (c) 4-AP in cerebellar gait ataxia: evidence comes from two observational studies. (d) chlorzoxazone in DBN which, however, was so far demonstrated in only one observational study; (e) the modified amino acid acetyl-DL-leucine: evidently effective in cerebellar ataxias, shown in three observational studies, one on patients with Niemann-Pick type C; its mode of action has to be evaluated in animal models and on a cellular/electrophysiological level. There are ongoing randomized placebo-controlled trials on EA2 with 4-AP versus acetazolamide (EAT-2-TREAT), cerebellar gait ataxia with 4-AP (FACEG), and a multinational trial on cerebellar ataxia with acetyl-DL-leucine (ALCAT).

Prolonged-release fampridine and walking and balance in MS: randomised controlled MOBILE trial.

BACKGROUND: Mobility impairment is a common disability in MS and negatively impacts patients' lives. OBJECTIVE: Evaluate the effect of prolonged-release (PR) fampridine (extended-release dalfampridine in the United States) on self-assessed walking disability, dynamic/static balance and safety in patients with MS. METHODS: MOBILE was a randomised, double-blind, exploratory, placebo-controlled trial. Patients with progressive/relapsing-remitting MS and Expanded Disability Status Scale score of 4.0-7.0 were treated with PR-fampridine or placebo twice daily for 24 weeks. Efficacy endpoints included change from baseline in the 12-item MS Walking Scale (MSWS-12), Timed Up and Go (TUG) test and Berg Balance Scale (BBS). RESULTS: 132 patients were randomised at 24 sites in six countries. PR-fampridine therapy resulted in greater median improvements from baseline in MSWS-12 score, TUG speed and BBS total score versus placebo over 24 weeks. A higher proportion of patients receiving PR-fampridine versus placebo experienced significant improvements at MSWS-12 improvement thresholds ⩾7 (p = 0.0275), ⩾8 (p = 0.0153) and ⩾9 points (p = 0.0088) and TUG speed thresholds ⩾10% (p = 0.0021) and ⩾15% (p = 0.0262). PR-fampridine was well tolerated. CONCLUSIONS: PR-fampridine therapy resulted in early and sustained improvements in broad measures of walking and balance over six months.

Prolonged-release fampridine in multiple sclerosis: Improved ambulation effected by changes in walking pattern.

BACKGROUND: Prolonged-release fampridine (PR-fampridine, 4-aminopyridine) increases walking speed in the timed 25-foot walk test (T25FW) in some patients (timed-walk responders) with multiple sclerosis (MS). OBJECTIVE: To explore the effects of PR-fampridine on different aspects of walking function and to identify associated gait modifications in subjects with MS. METHODS: In this prospective, randomized, placebo-controlled, double-blind, phase II study (FAMPKIN; clinicaltrials.gov, NCT01576354), subjects received a 6-week course of oral placebo or PR-fampridine treatment (10 mg, twice daily) before crossing over. Using 3D-motion-analysis, kinematic and kinetic parameters were assessed during treadmill walking (primary endpoint). Clinical outcome measures included T25FW, 6-minute walk test (6MWT), and balance scales. Physical activity in everyday life was measured with an accelerometer device. RESULTS: Data from 55 patients were suitable for analysis. Seventeen subjects were timed-walk responders under PR-fampridine. For the total study population and for responders, a significant increase in walking speed (T25FW) and distance (6MWT) was observed. Gait pattern changes were found at the single-subject level and correlated with improvements in the T25FW and 6MWT. Physical activity was increased in responders. CONCLUSION: PR-fampridine improves walking speed, endurance, and everyday physical activity in a subset of subjects with MS and leads to individual modifications of the gait pattern.