Treatment with 4-aminopyridine improves upper limb tremor of a patient with multiple sclerosis: a video case report

Inborn Errors of Metabolism with Ataxia: Current and Future Treatment Options

A number of hereditary ataxias are caused by inborn errors of metabolism (IEM), most of which are highly heterogeneous in their clinical presentation. Prompt diagnosis is important because disease-specific therapies may be available. In this review, we offer a comprehensive overview of metabolic ataxias summarized by disease, highlighting novel clinical trials and emerging therapies with a particular emphasis on first-in-human gene therapies. We present disease-specific treatments if they exist and review the current evidence for symptomatic treatments of these highly heterogeneous diseases (where cerebellar ataxia is part of their phenotype) that aim to improve the disease burden and enhance quality of life. In general, a multimodal and holistic approach to the treatment of cerebellar ataxia, irrespective of etiology, is necessary to offer the best medical care. Physical therapy and speech and occupational therapy are obligatory. Genetic counseling is essential for making informed decisions about family planning.

Movement Disorders in Multiple Sclerosis: An Update

Background:

Multiple sclerosis (MS), a subset of chronic primary inflammatory demyelinating disorders of the central nervous system, is closely associated with various movement disorders. These disorders may be due to MS pathophysiology or be coincidental. This review describes the full spectrum of movement disorders in MS with their possible mechanistic pathways and therapeutic modalities.

Methods:

The authors conducted a narrative literature review by searching for ‘multiple sclerosis’ and the specific movement disorder on PubMed until October 2021. Relevant articles were screened, selected, and included in the review according to groups of movement disorders.

Results:

The most prevalent movement disorders described in MS include restless leg syndrome, tremor, ataxia, parkinsonism, paroxysmal dyskinesias, chorea and ballism, facial myokymia, including hemifacial spasm and spastic paretic hemifacial contracture, tics, and tourettism. The anatomical basis of some of these disorders is poorly understood; however, the link between them and MS is supported by clinical and neuroimaging evidence. Treatment options are disorder-specific and often multidisciplinary, including pharmacological, surgical, and physical therapies.

Discussion:

Movements disorders in MS involve multiple pathophysiological processes and anatomical pathways. Since these disorders can be the presenting symptoms, they may aid in early diagnosis and managing the patient, including monitoring disease progression. Treatment of these disorders is a challenge. Further work needs to be done to understand the prevalence and the pathophysiological mechanisms responsible for movement disorders in MS.

Prolonged-release fampridine for the treatment of myoclonus after cervical myelitis: a case report

Prolonged-release fampridine (PR-FAM), a potassium channel blocker, is approved for improving walking ability in patients with multiple sclerosis (MS). Beyond this, positive effects on other MS symptoms like fatigue, cognition, and tremor have been described. To our knowledge, a positive effect of PR-FAM on spinal myoclonus has not been described so far. Here, we report a 32-year-old female with myoclonus after cervical myelitis affecting both hands which markedly improved after administration of PR-FAM. Treatments used before such as carbamazepine or levetiracetam had to be withdrawn because of intolerable side effects or lack of efficacy. The positive effect of PR-FAM could be confirmed by transient suspension. PR-FAM may be considered as a treatment option in refractory spinal myoclonus after myelitis in selected cases.

Vestibular rehabilitation in multiple sclerosis: study protocol for a randomised controlled trial and cost-effectiveness analysis comparing customised with booklet based vestibular rehabilitation for vestibulopathy and a 12 month observational cohort study of the symptom reduction and recurrence rate following treatment for benign paroxysmal positional vertigo

Background

Symptoms arising from vestibular system dysfunction are observed in 49–59% of people with Multiple Sclerosis (MS). Symptoms may include vertigo, dizziness and/or imbalance. These impact on functional ability, contribute to falls and significant health and social care costs. In people with MS, vestibular dysfunction can be due to peripheral pathology that may include Benign Paroxysmal Positional Vertigo (BPPV), as well as central or combined pathology. Vestibular symptoms may be treated with vestibular rehabilitation (VR), and with repositioning manoeuvres in the case of BPPV. However, there is a paucity of evidence about the rate and degree of symptom recovery with VR for people with MS and vestibulopathy. In addition, given the multiplicity of symptoms and underpinning vestibular pathologies often seen in people with MS, a customised VR approach may be more clinically appropriate and cost effective than generic booklet-based approaches. Likewise, BPPV should be identified and treated appropriately.

Methods/ design

People with MS and symptoms of vertigo, dizziness and/or imbalance will be screened for central and/or peripheral vestibulopathy and/or BPPV. Following consent, people with BPPV will be treated with re-positioning manoeuvres over 1–3 sessions and followed up at 6 and 12 months to assess for any re-occurrence of BPPV. People with central and/or peripheral vestibulopathy will be entered into a randomised controlled trial (RCT). Trial participants will be randomly allocated (1:1) to either a 12-week generic booklet-based home programme with telephone support or a 12-week VR programme consisting of customised treatment including 12 face-to-face sessions and a home exercise programme. Customised or booklet-based interventions will start 2 weeks after randomisation and all trial participants will be followed up 14 and 26 weeks from randomisation. The primary clinical outcome is the Dizziness Handicap Inventory at 26 weeks and the primary economic endpoint is quality-adjusted life-years. A range of secondary outcomes associated with vestibular function will be used.

Discussion

If customised VR is demonstrated to be clinically and cost-effective compared to generic booklet-based VR this will inform practice guidelines and the development of training packages for therapists in the diagnosis and treatment of vestibulopathy in people with MS.

Trial registration

ISRCTN Number: 27374299

Date of Registration 24/09/2018

Protocol Version 15 25/09/2019

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-020-01983-y.

Tremor in Multiple Sclerosis-An Overview and Future Perspectives

Tremor is an important and common symptom in patients with multiple sclerosis (MS). It constituted one of the three core features of MS triad described by Charcot in the last century. Tremor could have a drastic impact on patients' quality of life. This paper provides an overview of tremor in MS and future perspectives with a particular emphasis on its epidemiology (prevalence: 25-58%), clinical characteristics (i.e., large amplitude 2.5-7 Hz predominantly postural or intention tremor vs. exaggerated physiological tremor vs. pseudo-rhythmic activity arising from cerebellar dysfunction vs. psychogenic tremor), pathophysiological mechanisms (potential implication of cerebellum, cerebello-thalamo-cortical pathways, basal ganglia, and brainstem), assessment modalities (e.g., tremor rating scales, Stewart-Holmes maneuver, visual tracking, digitized spirography and accelerometric techniques, accelerometry-electromyography coupling), and therapeutic options (i.e., including pharmacological agents, botulinum toxin A injections; deep brain stimulation or thalamotomy reserved for severe, disabling, or pharmaco-resistant tremors). Some suggestions are provided to help overcome the unmet needs and guide future therapeutic and diagnostic studies in this complex disorder.

Dalfampridine to Improve Balance in Multiple Sclerosis: Substudy from a Randomized Placebo-Controlled Trial

This was a substudy of a randomized, double-blind, placebo-controlled trial originally designed to explore the effect of dalfampridine on information processing speed (2013-002558-64 EU Clinical Trials Register) in patients with multiple sclerosis (MS). A total of 120 patients were originally randomized in a 2:1 ratio to receive dalfampridine 10 mg or placebo twice daily for 12 weeks. Here, we sought to explore the effect of dalfampridine on static balance in single-task and dual-task conditions in a subgroup of 41 patients. They underwent static posturography in quiet standing (single-task) and while performing the Stroop test (dual-task) at randomization (baseline), after 12 weeks and after a 4-week wash-out period. Baseline characteristics of active group (n = 27) did not differ from those of placebo group (n = 14). Dalfampridine treatment was associated with better balance control than placebo in both single-task (F = 4.80, p = 0.034) and dual-task (F = 6.42, p = 0.015) conditions, with small-to-moderate effect sizes (Cohen's f2 = 0.122-0.162). The beneficial effect of dalfampridine was not retained 4 weeks after its discontinuation. The rate of accidental falls per month did not differ between the two groups (p = 0.12). Our preliminary findings suggest that dalfampridine can be considered a potential option to treat balance impairment due to MS. Larger sample sizes are needed to verify if the beneficial effect of dalfampridine on balance can be translated into a reduced risk of accidental falls.

Current Opinions and Consensus for Studying Tremor in Animal Models

Tremor is the most common movement disorder; however, we are just beginning to understand the brain circuitry that generates tremor. Various neuroimaging, neuropathological, and physiological studies in human tremor disorders have been performed to further our knowledge of tremor. But, the causal relationship between these observations and tremor is usually difficult to establish and detailed mechanisms are not sufficiently studied. To overcome these obstacles, animal models can provide an important means to look into human tremor disorders. In this manuscript, we will discuss the use of different species of animals (mice, rats, fruit flies, pigs, and monkeys) to model human tremor disorders. Several ways to manipulate the brain circuitry and physiology in these animal models (pharmacology, genetics, and lesioning) will also be discussed. Finally, we will discuss how these animal models can help us to gain knowledge of the pathophysiology of human tremor disorders, which could serve as a platform towards developing novel therapies for tremor.

Upper Limb Intention Tremor in Multiple Sclerosis: An Evidence-Based Review of Assessment and Treatment

Background

To present the current knowledge on the characteristics, assessment, and treatment of upper limb intention tremor to inform and improve future intervention studies in patients with multiple sclerosis (MS), we conducted a literature review for articles on upper limb intention tremor in patients with MS.

Methods

Two reviewers conducted searches in PubMed, Web of Science, and MEDLINE (Ovid). Relevant articles, sorted on inclusion criteria, were examined for descriptions and assessments of upper limb intention tremor, and intervention studies were evaluated based on treatment type.

Results

Eight descriptive studies were found reporting on the incidence and severity of tremor, impairments, and lesion load. Ten studies focused on measurement of tremor using various assessments. Intervention studies included eight articles using a diverse set of noninvasive techniques mainly showing transient reduction in tremor amplitude and temporary increase in function. Eighteen studies on pharmacologic interventions were found, with most displaying positive outcomes and mediation of tremor; others showed little to no benefit. Surgical interventions included 17 studies on thalamotomy and 20 on deep brain stimulation. Most studies showed tremor improvement after surgery; however, most sample sizes were small, and interventions were highly invasive, with potential adverse effects resulting from surgery.

Conclusions

The literature on upper limb intention tremor in MS is relatively sparse. More studies are required to determine mechanism of action and to provide more suitable and sustainable interventions to decrease upper limb intention tremor and improve quality of life of individuals with MS.

[What is new in symptomatic MS treatment: Part 1-introduction and methodical approach, ataxia and tremor]

The symptomatic treatment of multiple sclerosis (MS) nowadays is of similar importance as immunotherapy within a comprehensive concept of therapy of this chronic disease, since it contributes considerably to the reduction of disabilities in activities of daily living as well as social and occupational life. Moreover, symptomatic treatment is of great importance for amelioration of quality of life. Since our last survey of symptomatic MS treatment in 2004 and publication of the guidelines of the German Neurological Society and the Klinisches Kompetenznetz Multiple Sklerose (KKN‑MS) in 2014 several developments within the topics of mobility, bladder and sexual function, vision, fatigue, cognition and rehabilitation took place. These new findings together with further aspects of disease measures and overall treatment strategies of the respective symptoms, as well as treatment goals are introduced in a series of six individual contributions. Here, the topic will be introduced, the methodical approach will be explained, and the treatment of ataxia and tremor will be discussed.

Effect of Fampridine-PR (prolonged released 4-aminopyridine) on the manual functions of patients with Multiple Sclerosis

BACKGROUND

Persons with MS (PwMS) commonly present ambulatory and manual dysfunctions. While ambulation is recognized as important to PwMS, manual dysfunction is only lately gaining attention. Fampridine-PR was approved for MS ambulatory impairments. Anecdotal evidences indicate possible therapeutic effects on manual function.

OBJECTIVE

To comprehensively assess the effect of Fampridine-PR on manual functions of PwMS.

METHODS

Twenty six PwMS with ambulatory and manual dysfunction assessed before, 1 and 3months after treatment with Fampridine-PR, applying Timed 25-Foot Walk (T25FW) for ambulation while manual functions were evaluated by several tools addressing the International Classification of Functioning (ICF) concepts. This includes hand grip and pinch strength, 9 Hole Peg Test (9HPT), Arthritis Hand Function Test (AHFT), activities of daily life (ADL) tests, ABILHAND questionnaire and Computerized Penmanship Evaluation Tool (ComPET).

RESULTS

Fampridine-PR increased dominant hand grip and pinch strength 1month following treatment initiation by 12% and 10% (p<0.05), respectively. 9HPT improved by 11.3% after 3months of treatment (p<0.05%) and ABILHAND improved by 16% and 31% (p<0.05%) after 1 and 3months of treatment. Mean stroke duration in air of the name writing task improved by 21% (p<0.05) following 3months of treatment. T25FW results were similar to previous reports.

CONCLUSION

The results of this pilot study suggest that Fampridine-PR improves manual function of PwMS. Methods herein indicate that an integrative approach may be useful for evaluation of manual function in MS and in additional neurological diseases.

Symptomatic management in multiple sclerosis

Multiple sclerosis (MS) is the commonest cause of disability in young adults. While there is increasing choice and better treatments available for delaying disease progression, there are still, very few, effective symptomatic treatments. For many patients such as those with primary progressive MS (PPMS) and those that inevitably become secondary progressive, symptom management is the only treatment available. MS related symptoms are complex, interrelated, and can be interdependent. It requires good understanding of the condition, a holistic multidisciplinary approach, and above all, patient education and empowerment.

The differential diagnosis and treatment of tremor

BACKGROUND

Essential tremor is the most common type of tremor, with a prevalence of 0.4% in the overall population and 4-7% in persons over age 65. In general, tremor is so common that patients with tremor are frequently treated not only by neurologists, but also by physicians from other specialties.

METHOD

This review is based on publications retrieved by a selective PubMed search and on guidelines from Germany and abroad.

RESULTS

Particular tremor syndromes are usually diagnosed on the basis of their typical clinical presentation and whatever accompanying manifestations may be present. Ancillary tests are usually unnecessary. Unilateral rest tremor accompanied by rigidity and bradykinesia is typical of Parkinson's disease. Essential tremor is a bilateral postural tremor. The most common cause of intention tremor is multiple sclerosis. Mild tremor syndromes can often be treated satisfactorily with drugs. In case of severe tremor, which is rarer, a stereotactic operation can be considered. The usual outcome of such procedures is the complete suppression of tremor.

CONCLUSION

Most patients with tremor can be given a precise diagnosis and offered specific treatment. It is important for the physician to inform the patient about the expected course of tremor over time, its possible genetic causes, and the various available treatments.

Consensus paper: management of degenerative cerebellar disorders

Treatment of motor symptoms of degenerative cerebellar ataxia remains difficult. Yet there are recent developments that are likely to lead to significant improvements in the future. Most desirable would be a causative treatment of the underlying cerebellar disease. This is currently available only for a very small subset of cerebellar ataxias with known metabolic dysfunction. However, increasing knowledge of the pathophysiology of hereditary ataxia should lead to an increasing number of medically sensible drug trials. In this paper, data from recent drug trials in patients with recessive and dominant cerebellar ataxias will be summarized. There is consensus that up to date, no medication has been proven effective. Aminopyridines and acetazolamide are the only exception, which are beneficial in patients with episodic ataxia type 2. Aminopyridines are also effective in a subset of patients presenting with downbeat nystagmus. As such, all authors agreed that the mainstays of treatment of degenerative cerebellar ataxia are currently physiotherapy, occupational therapy, and speech therapy. For many years, well-controlled rehabilitation studies in patients with cerebellar ataxia were lacking. Data of recently published studies show that coordinative training improves motor function in both adult and juvenile patients with cerebellar degeneration. Given the well-known contribution of the cerebellum to motor learning, possible mechanisms underlying improvement will be outlined. There is consensus that evidence-based guidelines for the physiotherapy of degenerative cerebellar ataxia need to be developed. Future developments in physiotherapeutical interventions will be discussed including application of non-invasive brain stimulation.

The node of Ranvier in CNS pathology

Healthy nodes of Ranvier are crucial for action potential propagation along myelinated axons, both in the central and in the peripheral nervous system. Surprisingly, the node of Ranvier has often been neglected when describing CNS disorders, with most pathologies classified simply as being due to neuronal defects in the grey matter or due to oligodendrocyte damage in the white matter. However, recent studies have highlighted changes that occur in pathological conditions at the node of Ranvier, and at the associated paranodal and juxtaparanodal regions where neurons and myelinating glial cells interact. Lengthening of the node of Ranvier, failure of the electrically resistive seal between the myelin and the axon at the paranode, and retraction of myelin to expose voltage-gated K⁺ channels in the juxtaparanode, may contribute to altering the function of myelinated axons in a wide range of diseases, including stroke, spinal cord injury and multiple sclerosis. Here, we review the principles by which the node of Ranvier operates and its molecular structure, and thus explain how defects at the node and paranode contribute to neurological disorders.

Oral dalfampridine improves standing balance detected at static posturography in multiple sclerosis

We report a 14-week post-marketing experience on 20 patients with multiple sclerosis (MS) who started prolonged-release (PR) oral dalfampridine 10 mg twice daily according to European Medicine Agency criteria. They underwent serial static posturography assessments and the dizziness handicap inventory (DHI) to investigate whether PR dalfampridine could impact standing balance and self-reported perception of balance. The incidence of accidental falls per person per month was also recorded throughout the study. Eight (40%) patients, who had a relevant improvement in walking speed, were defined as treatment responders. They showed a significant improvement of standing balance (with respect to pretreatment assessment) when contrasted with 12 (60%) nonresponders (F [4,15] = 3.959, P = 0.027). No significant changes in DHI score, as well as in its functional, physical, and emotional subscales, were found in both responders and nonresponders at the end of study (all P values are ≥0.2). Treatment response did not affect the incidence of accidental falls. Future studies based on larger sample sizes, and with longer followup, are required to confirm the beneficial effect of PR dalfampridine on standing balance.

The treatment of tremor

Tremor is a hyperkinetic movement disorder characterized by rhythmic oscillations of one or more body parts. It can be disabling and may impair quality of life. Various etiological subtypes of tremor are recognized, with essential tremor (ET) and Parkinsonian tremor being the most common. Here we review the current literature on tremor treatment regarding ET and head and voice tremor, as well as dystonic tremor, orthostatic tremor, tremor due to multiple sclerosis (MS) or lesions in the brainstem or thalamus, neuropathic tremor, and functional (psychogenic) tremor, and summarize main findings. Most studies are available for ET and only few studies specifically focused on other tremor forms. Controlled trials outside ET are rare and hence most of the recommendations are based on a low level of evidence. For ET, propranolol and primidone are considered drugs of first choice with a mean effect size of approximately 50 % tremor reduction. The efficacy of topiramate is also supported by a large double-blind placebo-controlled trial, while other drugs have less supporting evidence. With a mean effect size of about 90 % deep brain stimulation in the nucleus ventralis intermedius or the subthalamic nucleus may be the most potent treatment; however, there are no controlled trials and it is reserved for severely affected patients. Dystonic limb tremor may respond to anticholinergics. Botulinum toxin improves head and voice tremor. Gabapentin and clonazepam are often recommended for orthostatic tremor. MS tremor responds only poorly to drug treatment. For patients with severe MS tremor, thalamic deep brain stimulation has been recommended. Patients with functional tremor may benefit from antidepressants and are best be treated in a multidisciplinary setting. Several tremor syndromes can already be treated with success. But new drugs specifically designed for tremor treatment are needed. ET is most likely covering different entities and their delineation may also improve treatment. Modern study designs and long-term studies are needed.