The treatment of tremor

Managing multiple sclerosis in individuals aged 55 and above: a comprehensive review

Multiple Sclerosis (MS) management in individuals aged 55 and above presents unique challenges due to the complex interaction between aging, comorbidities, immunosenescence, and MS pathophysiology. This comprehensive review explores the evolving landscape of MS in older adults, including the increased incidence and prevalence of MS in this age group, the shift in disease phenotypes from relapsing-remitting to progressive forms, and the presence of multimorbidity and polypharmacy. We aim to provide an updated review of the available evidence of disease-modifying treatments (DMTs) in older patients, including the efficacy and safety of existing therapies, emerging treatments such as Bruton tyrosine kinase (BTKs) inhibitors and those targeting remyelination and neuroprotection, and the critical decisions surrounding the initiation, de-escalation, and discontinuation of DMTs. Non-pharmacologic approaches, including physical therapy, neuromodulation therapies, cognitive rehabilitation, and psychotherapy, are also examined for their role in holistic care. The importance of MS Care Units and advance care planning are explored as a cornerstone in providing patient-centric care, ensuring alignment with patient preferences in the disease trajectory. Finally, the review emphasizes the need for personalized management and continuous monitoring of MS patients, alongside advocating for inclusive study designs in clinical research to improve the management of this growing patient demographic.

The Optimal Targeting for Focused Ultrasound Thalamotomy Differs between Dystonic and Essential Tremor: A 12-Month Prospective Pilot Study

BACKGROUND

Magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy is increasingly used to treat drug-resistant essential tremor (ET). Data on MRgFUS thalamotomy in dystonic tremor (DT) are anecdotal.

OBJECTIVES

To investigate efficacy, safety, and differences in target coordinates of MRgFUS thalamotomy in DT versus ET.

METHODS

Ten patients with DT and 35 with ET who consecutively underwent MRgFUS thalamotomy were followed for 12 months. Although in both groups the initial surgical planning coordinates corresponded to the ventralis intermediate (Vim), the final target could be modified intraoperatively based on clinical response.

RESULTS

Tremor significantly improved in both groups. The thalamic lesion was significantly more anterior in DT than ET. Considering both ET and DT groups, the more anterior the lesion, the lower the odds ratio for adverse events.

CONCLUSIONS

MRgFUS thalamotomy is safe and effective in DT and ET. Compared to classical Vim coordinates used for ET, more anterior targeting should be considered for DT.

Radiofrequency thalamotomy for tremor produces focused and predictable lesions shown on magnetic resonance images

Radiofrequency thalamotomy is a neurosurgical management option for medically-refractory tremor. In this observational study, we evaluate the MRI features of the resultant lesion, their temporal dynamics, and how they vary depending on surgical factors. We report on lesion characteristics including size and location, as well as how these vary over time and across different MRI sequences. Data from 12 patients (2 essential tremor, 10 Parkinson's disease) who underwent unilateral radiofrequency thalamotomy for tremor were analysed. Lesion characteristics were compared across five structural sequences. Volumetric analysis of lesion features was performed at early (<5 weeks) and late (>5 months) timepoints by manual segmentation. Lesion location was determined after registration of lesions to standard space. All patients showed tremor improvement (clinical global impressions scale) postoperatively. Chronic side-effects included balance disturbances (n = 4) and worsening mobility due to parkinsonism progression (n = 1). Early lesion features including a necrotic core, cytotoxic oedema and perilesional oedema were best demarcated on T2-weighted sequences. Multiple lesions were associated with greater cytotoxic oedema compared with single lesions (T2-weighted mean volume: 537 ± 112 mm³ versus 302 ± 146 mm³, P = 0.028). Total lesion volume reduced on average by 90% between the early and late scans (T2-weighted mean volume: 918 ± 517 versus 75 ± 50 mm³, t = 3.592, P = 0.023, n = 5), with comparable volumes demonstrated at ∼6 months after surgery. Lesion volumes on susceptibility-weighted images were larger than those of T2-weighted images at later timepoints. Radiofrequency thalamotomy produces focused and predictable lesion imaging characteristics over time. T2-weighted scans distinguish between the early lesion core and oedema characteristics, while lesions may remain more visible on susceptibility-weighted images in the months following surgery. Scanning patients in the immediate postoperative period and then at 6 months is clinically meaningful for understanding the anatomical basis of the transient and permanent effects of thalamotomy.

Sodium Oxybate in Alcohol-Responsive Essential Tremor of Voice: An Open-Label Phase II Study

BACKGROUND

Essential tremor of voice (ETv) is characterized by involuntary oscillations of laryngeal and upper airway muscles, causing rhythmic alterations in pitch and loudness during both passive breathing and active laryngeal tasks, such as speaking and singing. Treatment of ETv is challenging and typically less effective compared with treatment of ET affecting extremities.

OBJECTIVE

We conducted a proof-of-concept, open-label phase II study to examine the efficacy and central effects of sodium oxybate in patients with alcohol-responsive ETv.

METHODS

All subjects received 1.0 to 1.5 g of oral sodium oxybate and underwent brain functional magnetic resonance imaging. The primary endpoint was the number of patients (% from total) with reduced ETv symptoms by at least 10% at about 40 to 45 minutes after sodium oxybate intake based on the combined visual analog scale score of ETv symptom severity. The secondary endpoint included changes in brain activity after sodium oxybate intake compared to baseline.

RESULTS

Sodium oxybate reduced ETv symptoms on average by 40.8% in 92.9% of patients. Drug effects were observed about 40 to 45 minutes after intake, lasting about 3.5 hours, and gradually wearing off by the end of the fifth hour. The central effects of sodium oxybate were associated with normalized activity in the cerebellum, inferior/superior parietal lobules, inferior frontal gyrus, and insula and re-established functional relationships between these regions.

CONCLUSIONS

Sodium oxybate showed high efficacy in ETv patients, with a likely central action on disorder pathophysiology. Sodium oxybate may be an effective novel oral drug for treatment of alcohol-responsive ETv patients. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Tackling the neurological manifestations in Wilson's disease - currently available treatment options

INTRODUCTION

Wilson's disease (WD) is a potentially treatable, inherited disorder resulting from impaired copper metabolism. Pathological copper accumulation causes a range of symptoms, most commonly hepatic and a wide spectrum of neurological symptoms including tremor, dystonia, chorea, parkinsonism, dysphagia, dysarthria, gait and posture disturbances. To reduce copper overload, anti-copper drugs are used that improve liver function and neurological symptoms in up to 85% of patients. However, in some WD patients, treatment introduction leads to neurological deterioration, and in others, neurological symptoms persist with no improvement or improvement only after several years of treatment, severely affecting the patient's quality of life.

AREAS COVERED

This review appraises the evidence on various pharmacological and non-pharmacological therapies, neurosurgical procedures and liver transplantation for the management of neurological WD symptoms. The authors also discuss the neurological symptoms of WD, causes of deterioration and present symptomatic treatment options.

EXPERT OPINION

Based on case and series reports, current recommendations and expert opinion, WD treatment is focused mainly on drugs leading to negative copper body metabolism (chelators or zinc salts) and copper-restricted diet. Treatment of WD neurological symptoms should follow general recommendations of symptomatic treatment. Patients should be always considered individually, especially in the case of severe, disabling neurological symptoms.

β-Adrenoceptor Blockade Moderates Neuroinflammation in Male and Female EAE Rats and Abrogates Sexual Dimorphisms in the Major Neuroinflammatory Pathways by Being More Efficient in Males

Our previous studies showed more severe experimental autoimmune encephalomyelitis (EAE) in male compared with female adult rats, and moderating effect of propranolol-induced β-adrenoceptor blockade on EAE in females, the effect associated with transcriptional stimulation of Nrf2/HO-1 axis in spinal cord microglia. This study examined putative sexual dimorphism in propranolol action on EAE severity. Propranolol treatment beginning from the onset of clinical EAE mitigated EAE severity in rats of both sexes, but to a greater extent in males exhibiting higher noradrenaline levels and myeloid cell β₂-adrenoceptor expression in spinal cord. This correlated with more prominent stimulatory effects of propranolol not only on CX3CL1/CX3CR1/Nrf2/HO-1 cascade, but also on Stat3/Socs3 signaling axis in spinal cord microglia/myeloid cells (mirrored in the decreased Stat3 and the increased Socs3 expression) from male rats compared with their female counterparts. Propranolol diminished the frequency of activated cells among microglia, increased their phagocyting/endocyting capacity, and shifted cytokine secretory profile of microglia/blood-borne myeloid cells towards an anti-inflammatory/neuroprotective phenotype. Additionally, it downregulated the expression of chemokines (CCL2, CCL19/21) driving T-cell/monocyte trafficking into spinal cord. Consequently, in propranolol-treated rats fewer activated CD4+ T cells and IL-17+ T cells, including CD4+IL17+ cells coexpressing IFN-γ/GM-CSF, were recovered from spinal cord of propranolol-treated rats compared with sex-matched saline-injected controls. All the effects of propranolol were more prominent in males. The study as a whole disclosed that sexual dimorphism in multiple molecular mechanisms implicated in EAE development may be responsible for greater severity of EAE in male rats and sexually dimorphic action of substances affecting them. Propranolol moderated EAE severity more effectively in male rats, exhibiting greater spinal cord noradrenaline (NA) levels and myeloid cell β₂-adrenoceptor (β₂-AR) expression than females. Propranolol affected CX3CR1/Nrf2/HO-1 and Stat3/Socs3 signaling axes in myeloid cells, favored their anti-inflammatory/neuroprotective phenotype and, consequently, reduced Th cell reactivation and differentiation into highly pathogenic IL-17/IFN-γ/GM-CSF-producing cells.

Botulinum toxin for motor disorders

Botulinum neurotoxins are a group of biological toxins produced by the gram-negative bacteria Clostridium botulinum. After intramuscular injection, they produce dose-related muscle relaxation, which has proven useful in the treatment of a large number of motor and movement disorders. In this chapter, we discuss the utility of botulinum toxin treatment in three major and common medical conditions related to the dysfunction of the motor system, namely dystonia, tremor, and spasticity. A summary of the existing literature is provided along with different techniques of injection including those recommended by the authors.

Computational study and validation of a novel passive hand tremor attenuator

Tremors are a prevalent movement disorder due to a nervous system condition that leads to involuntary muscle movements observed in patients. This paper converts the tremorous anatomical human arm model to a single degree of freedom (SDOF) forced vibration problem. The mathematical modelling with Euler-Lagrange's equation is performed for the SDOF human arm model with two different potential vibration absorbers. A computational study is conducted on MATLAB Simulink by MathWorks Inc. (Natick, MA) to compare two absorbers, and the results are verified on the multibody dynamics simulation solution software, MSC Adams by Hexagon AB. It is concluded that the T beam-shaped vibration absorber represented a higher amplitude reduction, up to 80%, compared to the inertial mass absorber, which had an amplitude reduction of 65% over the range of frequencies. Experiments conducted with the T beam absorber prototype also support the computational findings. Future research focuses on designing an ergonomic wearable device with a proposed T-beam absorber that can passively attenuate the tremor at various frequencies.

Deep brain stimulation for arm tremor: A randomized trial comparing two targets

OBJECTIVE

Deep brain stimulation (DBS) of the thalamic ventral intermediate nucleus (VIM) effectively suppresses arm tremor. Uncontrolled studies suggest the posterior subthalamic area (PSA) may be superior. We compared the intra-individual efficacy of VIM- versus PSA-DBS on tremor suppression and arm function.

METHODS

We performed a randomized, double-blind, crossover trial at Oslo University Hospital in patients (18-80 years) with isolated or combined action tremor affecting at least one arm. Four-contact DBS leads were implanted (bi- or unilaterally) with a trajectory to cover the VIM (upper two contacts) and PSA (lower two contacts). Patients were randomized (1:1 ratio) post-surgery to: Group 1, VIM-stimulation months 0-3 (period 1), then PSA-stimulation months 4-6 (period 2); Group 2, PSA-stimulation first, then VIM-stimulation. Primary endpoint was the difference in improvement from baseline to the end of the VIM- versus PSA-period in the sum of the dominant arm tremor scores of the Fahn-Tolosa-Marin Tremor Rating Scale (FTMTRS), items 5/6 + 10-14.

RESULTS

Forty-five patients were randomized to Group 1 (n = 23) or 2 (n = 22). In the primary endpoint per-protocol analysis (mixed model, n = 40), mean difference in the sum FTMTRS score improvement for the dominant arm was -2.65 points (95% CI -4.33 to -0.97; p = 0.002). The difference in favour of PSA stimulation was highly significant in period 2, but not period 1.

INTERPRETATION

Our randomized trial demonstrated that PSA stimulation provided superior tremor suppression compared with VIM stimulation. A period effect reducing tremor for up to three months in both groups was most likely attributed to a post-surgery stun effect. This article is protected by copyright. All rights reserved.

First experience of thalamotomy by focused ultrasound under MR-guided navigation in the treatment of tremor. Neuroimaging follow-up. Case report and literature review

The authors describe dynamic MRI and clinical data after non-invasive treatment of tremor in the upper extremity. Thalamotomy by high-intensity focused ultrasound under MR-guided navigation was performed. A 57-year-old patient with Parkinson's disease underwent treatment with focused ultrasound. MRI of the brain was performed 1 and 48 hours, 47 days, 3 and 6 months later. Features of natural course of focal brain changes after treatment, data of MR tractography necessary for correction of target zone are described. The authors conclude that MR changes are characterized by presence of a focus in the area of focused exposure. Peak severity is observed on the second day after procedure with subsequent regression. MR-based analysis of predictors is promising to forecast treatment outcomes.

Role of Directional Configuration in Deep Brain Stimulation for Essential Tremor: A Single Center Experience

Background

Traditionally, the standard of care for medication refractory essential tremor has been to utilize omnidirectional deep brain stimulation of the ventral intermediate nucleus. The advent of directional stimulation allows for spatial restriction of the stimulation on selected targets without involving the neighboring structures, thereby limiting off-target side effects and improving clinical utility.

Methods

We performed a retrospective review of patients between February 2017 and September 2019 who had received ventral intermediate nucleus deep brain stimulation that allowed for directional programming (specifically Abbott/St. Jude). Initial and final major programming sessions post-operatively (approximately 30- and 90-days post-surgery) were examined to determine frequency and reason for use of directional programming.

Results

A total of 33 total patients were identified. A little over half were males (58%, N = 19), with an average age of 68 years old (SD 9.3) at the time of surgery, and a disease duration of almost 30 years (27.2, SD 19) with a wide range from 2-62 years. After initial programming, over 50% (17 of 33) of patients were using directional configurations. This increased to 85% (28 of 33) at the 90-day programming. Reasons for conversion to directional configuration included avoidance of side effects (specifically, muscle contractions (9/33), paresthesia (5/33), dysarthria (1/33) and gait ataxia (1/33)) or improved tremor control (12/33).

Discussion

Our single-center experience suggests that in the large majority of cases, directional leads were utilized and offered advantages in tremor control or side effect avoidance.

Geospatial Analysis of Persons with Movement Disorders Living in Underserved Regions

Background

Movement disorders persons from underserved areas have increased barriers to access tertiary care. There is currently limited data on the geographic and demographic profile of movement disorders persons from underserved areas.

Methods

A retrospective chart review of the geographic and demographic profile of consecutive cases seen between 2002-2017 at the University of Florida Norman Fixel Institute for Neurological Diseases (UF-NFIND) was performed. Information collected included age, sex, diagnosis, zip code, treatment received, and insurance information. The distances between each person's home residence and the nearest movement disorders center of excellence (MDC) as well as the distance to the UF-NFIND were calculated using ArcGIS 10.3.

Results

A total of 5.2% (355/6867) of the sample population were identified as a Medicaid/self-pay population and classified as underserved. The most common diagnoses were tic disorder (19.2%), dystonia (18.3%), and Parkinson's disease (14.3%). In underserved persons, the median distances from their homes to the UF-NFIND (82.19 [45.79-176.93] km) vs. their nearest MDC (63.34 [26.91-121.43] km) were significantly different (p < 0.001).

Discussion

Underserved persons in our study travelled further to receive subspecialty care at UF-NFIND than closer MDCs. Potential reasons for underutilization of closer care could possibly include research opportunities, availability of specific treatments or procedures, insurance restrictions, and limited specialist availability. Despite this observation, underserved persons were underrepresented at our institution compared to the proportion of Medicaid/uninsured patients in Florida. Our results highlight the need for increased awareness of care options for underserved movement disorders populations.

Managing Essential Tremor

Essential tremor is one of the most common tremor syndromes. According to the recent tremor classification, tremor as a symptom is defined as an involuntary, rhythmic, oscillatory movement of a body part and is classified along two axes: axis 1-defining syndromes based on the clinical features such as historical features, tremor characteristics, associated signs, and laboratory tests; and axis 2-classifying the etiology (Bhatia et al., Mov Disord 33:75-87, 2018). The management of this condition has two major approaches. The first is to exclude treatable etiologies, as particularly during the onset of this condition the presentation of a variety of etiologies can be with monosymptomatic tremor. Once the few etiologies with causal treatments are excluded, all further treatment is symptomatic. Shared decision-making with enabling the patient to knowledgeably choose treatment options is needed to customize the management. Mild to moderate tremor severity can sometimes be controlled with occupational treatment, speech therapy of psychotherapy, or adaptation of coping strategy. First-line pharmacological treatments include symptomatic treatment with propranolol, primidone, and topiramate. Botulinum toxin is for selected cases. Invasive treatments for essential tremor should be considered for severe tremors. They are generally accepted as the most powerful interventions and provide not only improvement of tremor but also a significant improvement of life quality. The current standard is deep brain stimulation (DBS) of the thalamic and subthalamic region. Focused ultrasound thalamotomy is a new therapy attracting increasing interest. Radiofrequency lesioning is only rarely done if DBS or focused ultrasound is not possible. Radiosurgery is not well established. We present our treatment algorithm.

Topiramate-Responsive Tremor in a Novel Pathogenic Variant of SPG15 Patient

Hereditary spastic paraplegia (HSP) is group of a rare neurodegenerative disorder with both genetically and clinically diverse neurologic features. Indeed, disease progression is varying greatly within the different forms and current treatment modalities are exclusively symptomatic for HSP. Tremor in HSP patients is only mentioned with rare case reports, so treatment option is lack in clinical ground. We reported a case of a HSP-15 girl with a previously reported novel mutation of SPG15 complained of a life disturbing tremor and topiramate as a drug therapy for tremor in our HSP patient.

MR Imaging of the Brain in Neurologic Wilson Disease

BACKGROUND AND PURPOSE

Neurologic Wilson disease is an inherited disease characterized by a copper metabolic disorder that causes damage to many organs, especially the brain. Few studies report the relationships between these neurologic symptoms and MR imaging of the brain. Therefore, we investigated the correlation of brain abnormalities in patients with neurologic Wilson disease with their clinical symptoms, age of onset, and lag time to diagnosis.

MATERIALS AND METHODS

A cohort of 364 patients was recruited in China between January 2003 and December 2017. Age of onset, lag time until diagnosis, and neurologic symptoms were recorded, and cranial MR imaging was performed. Patients were divided into groups within each of these factors for correlation analysis with the MR imaging brain scans.

RESULTS

Abnormal signals in the MR imaging brain scans were seen in all 364 cases. Affected regions included the putamen, pons, midbrain, and thalamus, while the medulla and occipital lobe were unaffected. The putamen was the most frequently damaged brain region in this study. With the age of onset younger than 10 years, cranial MR imaging scans showed only impairment in the putamen. Patients with a longer lag time before diagnosis were more likely to have impairment in the pons, midbrain, and cortex. Among neurologic symptoms of Wilson disease, torsion spasm is associated with the midbrain and cortex, and choreoathetosis is related to the caudate nucleus.

CONCLUSIONS

Abnormalities in the putamen, pons, midbrain, and thalamus are part of the neuroimaging spectrum of Wilson disease. There is a significant correlation between the site of brain injury and diagnosis lag time.

Treatment of essential tremor: current status

Essential tremor is the most common cause of tremor involving upper limbs, head and voice. The first line of treatment for limb tremor is pharmacotherapy with propranolol or primidone. However, these two drugs reduce the tremor severity by only half. In medication refractory and functionally disabling tremor, alternative forms of therapy need to be considered. Botulinum toxin injections are likely efficacious for limb, voice and head tremor but are associated with side effects. Surgical interventions include deep brain stimulation; magnetic resonance-guided focused ultrasound and thalamotomy for unilateral and deep brain stimulation for bilateral procedures. Recent consensus classification for essential tremor has included a new subgroup, ‘Essential tremor plus’, who have associated subtle neurological ‘soft signs’, such as dystonic posturing of limbs and may require a different treatment approach. In this review, we have addressed the current management of essential tremor with regard to different anatomical locations of tremor as well as different modalities of treatment.

SLC6A4 Repeat and Single-Nucleotide Polymorphisms Are Associated With Depression and Rest Tremor in Parkinson's Disease: An Exploratory Study

Introduction: Level of serotonin is mainly regulated by the serotonin reuptake transporter encoded by SLC6A4. The promoter region of SLC6A4 bears a repeat polymorphism 5-HTTLPR and a single nucleotide polymorphism rs25531. We have previously studied the association between these two variants and sporadic PD. The objective of the current study was to determine whether the SLC6A4 polymorphisms were associated with key motor and non-motor symptoms of PD.

Methods: A total of 370 PD patients of Han Chinese were included. Associations between the SLC6A4 polymorphisms and PD symptoms including depression, intellectual impairment, tremor and rigidity were analyzed.

Results: 5-HTTLPR was associated with depression in PD patients and presence of the LL genotype was protective against the depression risk. The rs25531 was associated with rest tremor in PD and the A allele serves as a recessive risk allele. No associations were found in the two polymorphisms with respect to intellectual impairment and rigidity in the cohort.

Conclusion: The current study reveals two PD symptoms associated with SLC6A4 polymorphisms, and provides new insight into how serotonergic system genetically participates in the symptomatic progression of PD. Further study is warranted in additional populations.

Simulated Tremor Propagation in the Upper Limb: From Muscle Activity to Joint Displacement

Although tremor is the most common movement disorder, there are few non-invasive treatment options. Creating effective tremor suppression devices requires a knowledge of where tremor originates mechanically (which muscles) and how it propagates through the limb (to which degrees of freedom, DOF). To simulate tremor propagation, we created a simple model of the upper limb, with tremorogenic activity in the 15 major superficial muscles as inputs and tremulous joint displacement in the 7 major DOF as outputs. The model approximated the muscle excitation-contraction dynamics, musculoskeletal geometry, and mechanical impedance of the limb. From our simulations, we determined fundamental principles for tremor propagation: 1) The distribution of tremor depends strongly on musculoskeletal dynamics. 2) The spreading of tremor is due to inertial coupling (primarily) and musculoskeletal geometry (secondarily). 3) Tremorogenic activity in a given muscle causes significant tremor in only a small subset of DOF, though these affected DOF may be distant from the muscle. 4) Assuming uniform distribution of tremorogenic activity among muscles, tremor increases proximal-distally, and the contribution from muscles increases proximal-distally. 5) Although adding inertia (e.g. with weighted utensils) is often used to suppress tremor, it is possible to increase tremor by adding inertia to the wrong DOF. 6) Similarly, adding viscoelasticity to the wrong DOF can increase tremor. Based solely on the musculoskeletal system, these principles indicate that tremor treatments targeting muscles should focus first on the distal muscles, and devices targeting DOF should focus first on the distal DOF.

Cerebellar repetitive transcranial magnetic stimulation for patients with essential tremor

INTRODUCTION

The possibility of repetitive transcranial magnetic stimulation (rTMS) as an alternative therapy for essential tremor (ET) patients has emerged. However, its effect on medicated ET patients is lacking. The aim of this pilot study was to investigate the effect of cerebellar low-frequency rTMS as an "add-on" treatment.

METHODS

In this single-blinded, randomized, sham-controlled pilot study, patients with ET were randomized into two groups, one receiving real-rTMS and the other sham-rTMS. For 5 days, 1200 stimulations per day were applied to the bilateral cerebellar hemispheres at an intensity of 90% of the resting motor threshold (RMT) with a frequency of 1-Hz. Motor evoked potentials (MEPs) and the Fahn-Tolosa-Marin tremor rating scales (TRS) were measured before, immediately, and 4 weeks after the completion of the rTMS procedures. All patients continued taking medications during all procedures.

RESULTS

Among 22 patients, 12 and 10 patients were randomized into the real- and sham-rTMS groups, respectively. Repeated analysis of variance (ANOVA) measurements showed that the total TRS, TRS-A and B were changed both in real and sham-rTMS groups without interaction between time and group. TRS-C and MEPs, were not significantly changed at each follow-up point in either the real or sham-rTMS sessions.

CONCLUSION

We conclude that cerebellar low-frequency rTMS is safe, but has no significant effect as an "add-on" therapy in patients with ET.

The Comprehensive Management of Cerebellar Ataxia in Adults

PURPOSE OF REVIEW

In this review, we present the multidisciplinary approach to the management of the many neurological, medical, social, and emotional issues facing patients with cerebellar ataxia.

RECENT FINDINGS

Our holistic approach to treatment, developed over the past 25 years in the Massachusetts General Hospital Ataxia Unit, is centered on the compassionate care of the patient and their family, empowering them through engagement, and including the families as partners in the healing process. We present the management of ataxia in adults, beginning with establishing an accurate diagnosis, followed by treatment of the multiple symptoms seen in cerebellar disorders, with a view to maximizing quality of life and effectively living with the consequences of ataxia. We discuss the importance of a multidisciplinary approach to the management of ataxia, including medical and non-medical management and the evidence base that supports these interventions. We address the pharmacological treatment of ataxia, tremor, and other associated movement disorders; ophthalmological symptoms; bowel, bladder, and sexual symptoms; orthostatic hypotension; psychiatric and cognitive symptoms; neuromodulation, including deep brain stimulation; rehabilitation including physical therapy, occupational therapy and speech and language pathology and, as necessary, involving urology, psychiatry, and pain medicine. We discuss the role of palliative care in late-stage disease. The management of adults with ataxia is complex and a team-based approach is essential.

Cost-Effectiveness of Magnetic Resonance-Guided Focused Ultrasound for Essential Tremor

BACKGROUND

Radiofrequency thalamotomy and deep brain stimulation are current treatments for moderate to severe medication-refractory essential tremor. However, they are invasive and thus carry risks. Magnetic resonance-guided focused ultrasound is a new, less invasive surgical option. The objective of the present study was to determine the cost-effectiveness of magnetic resonance-guided focused ultrasound compared with standard treatments in Canada.

METHODS

We conducted a cost-utility analysis using a Markov cohort model. We compared magnetic resonance-guided focused ultrasound with no surgery in people ineligible for invasive neurosurgery and with radiofrequency thalamotomy and deep brain stimulation in people eligible for invasive neurosurgery. In the reference case analysis, we used a 5-year time horizon and a public payer perspective and discounted costs and benefits at 1.5% per year.

RESULTS

Compared with no surgery in people ineligible for invasive neurosurgery, magnetic resonance-guided focused ultrasound cost $21,438 more but yielded 0.47 additional quality-adjusted life years, producing an incremental cost-effectiveness ratio of $45,817 per quality-adjusted life year gained. In people eligible for invasive neurosurgery, magnetic resonance-guided focused ultrasound was slightly less effective but much less expensive compared with the current standard of care, deep brain stimulation. The results were sensitive to assumptions regarding the time horizon, cost of magnetic resonance-guided focused ultrasound, and probability of recurrence.

CONCLUSIONS

In people ineligible for invasive neurosurgery, the incremental cost-effectiveness ratio of magnetic resonance-guided focused ultrasound versus no surgery is comparable to many other tests and treatments that are widely adopted in high-income countries. In people eligible for invasive neurosurgery, magnetic resonance-guided focused ultrasound is also a reasonable option. © 2018 International Parkinson and Movement Disorder Society.

Botulinum Toxin for the Treatment of Hand Tremor

The aim of this study is to review our longitudinal experience with onabotulinumtoxinA (onaBoNT-A) injections for medically refractory hand tremor. We performed a retrospective review of our database of patients treated with onaBoNT-A for hand tremor evaluated between 2010 and 2018 in at least 2 sessions with follow-up. The majority were injected into the forearm flexors (FF), although treatment was individualized. During the specified period, 91 patients (53 essential tremor, 31 dystonic tremor, 6 Parkinson's disease tremor, and 1 cerebellar outflow tremor) met our inclusion criteria. The mean age (SD) was 64.8 years (12.8), and mean duration of follow-up was 29.6 months (25.1) with mean of 7.7 (6.3) treatment visits. FF were injected in 89 (97.8%) patients, exclusively in 74 (81.3%), and 15 (16.5%) were injected in FF and other muscles. EMG guidance was used in 5 patients (5.5%). On a 0⁻4 "peak effect" rating scale (0 = no effect, 4 = marked improvement in severity and function), 80.2% and 85.7% of patients reported moderate or marked improvement (score 3 or 4) at their first and last follow-up visit, respectively. There was no statistically significant difference in the outcomes between first and last visit: average "peak effect" rating score (3.2 versus 3.4), "global" rating score (3.0 versus 3.2), latency of response (4.5 versus 3.8 days), and total duration of response (12.7 versus 12.8 weeks), except onaBoNT-A dose (65.0 versus 78.6 U/limb, p = 0.002). Of 1095 limb injections, there were 134 (12.2%) non-disabling and transient (mean 36 days) adverse events (132 limb weakness, 2 pain). OnaBoNT-A injections are safe and effective in the treatment of hand tremor.

Functional lesional neurosurgery for tremor: a systematic review and meta-analysis

BACKGROUND

This work evaluates the consistency, effect size and incidence of persistent side effects of lesional neurosurgical interventions in the treatment of tremor due to Parkinson's disease (PD), essential tremor (ET), multiple sclerosis (MS) and midbrain lesions.

METHODS

Systematic review and meta-analysis according to PRISMA-P guidelines. Random effects meta-analysis of standardised mean difference based on a peer-reviewed protocol (PROSPERO no. CRD42016048049).

RESULTS

From 1249 abstracts screened, 86 peer-reviewed studies reporting 102 cohorts homogeneous for tremor aetiology, surgical target and technique were included.Effect on PD tremor was better when targeted at the ventral intermediate nucleus (V.im.) by radiofrequency ablation (RF) (Hedge's g: -4.15;) over V.im. by Gamma Knife (GK) (-2.2), subthalamic nucleus (STN) by RF (-1.12) and globus pallidus internus (GPi) by RF (-0.89). For ET MRI-guided focused ultrasound (MRIgFUS) ablation of the cerebellothalamic tract (CTT) (-2.35) and V.im. (-2.08) showed similar mean tremor reductions to V.im. ablation by RF (-2.42) or GK (-2.13). In MS V.im. ablation by GK (-1.96) and RF (-1.63) were similarly effective.Mean rates of persistent side effects after unilateral lesions in PD were 12.8% (RF V.im.), 13.6% (RF STN), 9.2% (RF GPi), 0.7% (GK V.im.) and 7.0% (MRIgFUS V.im.). For ET, rates were 9.3% (RF V.im.), 1.8% (GK V.im.), 18.7% (MRIgFUS V.im.) and 0.0% (MRIgFUS CTT), for MS 37.7% (RF V.im.) and for rubral tremor 30.3% (RF V.im.).

CONCLUSION

This meta-analysis quantifies safety, consistency and efficacy of lesional neurosurgical interventions for tremor by target, technique and aetiology.

Magnetic Resonance-Guided Focused Ultrasound Neurosurgery for Essential Tremor: A Health Technology Assessment

BACKGROUND

The standard treatment option for medication-refractory essential tremor is invasive neurosurgery. A new, noninvasive alternative is magnetic resonance-guided focused ultrasound (MRgFUS) neurosurgery. We aimed to determine the effectiveness, safety, and cost-effectiveness of MRgFUS neurosurgery for the treatment of moderate to severe, medication-refractory essential tremor in Ontario. We also spoke with people with essential tremor to gain an understanding of their experiences and thoughts regarding treatment options, including MRgFUS neurosurgery.

METHODS

We performed a systematic review of the clinical literature published up to April 11, 2017, that examined MRgFUS neurosurgery alone or compared with other interventions for the treatment of moderate to severe, medication-refractory essential tremor. We assessed the risk of bias of each study and the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We performed a systematic review of the economic literature and created Markov cohort models to assess the cost-effectiveness of MRgFUS neurosurgery compared with other treatment options, including no surgery. We also estimated the budget impact of publicly funding MRgFUS neurosurgery in Ontario for the next 5 years. To contextualize the potential value of MRgFUS neurosurgery as a treatment option for essential tremor, we spoke with people with essential tremor and their families.

RESULTS

Nine studies met our inclusion criteria for the clinical evidence review. In noncomparative studies, MRgFUS neurosurgery was found to significantly improve tremor severity and quality of life and to significantly reduce functional disability (GRADE: very low). It was also found to be significantly more effective than a sham procedure (GRADE: high). We found no significant difference in improvements in tremor severity, functional disability, or quality of life between MRgFUS neurosurgery and deep brain stimulation (GRADE: very low). We found no significant difference in improvement in tremor severity compared with radiofrequency thalamotomy (GRADE: low). MRgFUS neurosurgery has a favourable safety profile.We estimated that MRgFUS neurosurgery has a mean cost of $23,507 and a mean quality-adjusted survival of 3.69 quality-adjusted life-years (QALYs). We also estimated that the mean costs and QALYs of radiofrequency thalamotomy and deep brain stimulation are $14,978 and 3.61 QALYs, and $57,535 and 3.94 QALYs, respectively. For people ineligible for invasive neurosurgery, we estimated the incremental cost-effectiveness ratio (ICER) of MRgFUS neurosurgery compared with no surgery as $43,075 per QALY gained. In people eligible for invasive neurosurgery, the ICER of MRgFUS neurosurgery compared with radiofrequency thalamotomy is $109,795 per QALY gained; when deep brain stimulation is compared with MRgFUS neurosurgery, the ICER is $134,259 per QALY gained. Of note however, radiofrequency thalamotomy is performed very infrequently in Ontario. We also estimated that the budget impact of publicly funding MRgFUS neurosurgery in Ontario at the current case load (i.e., 48 cases/year) would be about $1 million per year for the next 5 years.People with essential tremor who had undergone MRgFUS neurosurgery reported positive experiences with the procedure. The tremor reduction they experienced improved their ability to perform activities of daily living and improved their quality of life.

CONCLUSIONS

MRgFUS neurosurgery is an effective and generally safe treatment option for moderate to severe, medication-refractory essential tremor. It provides a treatment option for people ineligible for invasive neurosurgery and offers a noninvasive option for all people considering neurosurgery.For people ineligible for invasive neurosurgery, MRgFUS neurosurgery is cost-effective compared with no surgery. In people eligible for invasive neurosurgery, MRgFUS neurosurgery may be one of several reasonable options. Publicly funding MRgFUS neurosurgery for the treatment of moderate to severe, medication-refractory essential tremor in Ontario at the current case load would have a net budget impact of about $1 million per year for the next 5 years.People with essential tremor who had undergone MRgFUS neurosurgery reported positive experiences. They liked that it was a noninvasive procedure and reported a substantial reduction in tremor that resulted in an improvement in their quality of life.

Pretherapeutic Functional Imaging Allows Prediction of Head Tremor Arrest After Thalamotomy for Essential Tremor: The Role of Altered Interconnectivity Between Thalamolimbic and Supplementary Motor Circuits

OBJECTIVE

To correlate pretherapeutic resting-state functional magnetic resonance imaging (rs-fMRI) measures with pretherapeutic head tremor presence and/or further improvement 1 year after stereotactic radiosurgical thalamotomy (SRS-T) for essential tremor (ET).

METHODS

We prospectively collected head tremor scores (range, 0-3) and rs-fMRI data for a cohort of 17 consecutive ET patients in pretherapeutic and 1 year after SRS-T states. We additionally acquired rs-fMRI data for a healthy control (HC) group (n = 12). Group-level independent component analysis (n = 17 for pretherapeutic rs-fMRI) was applied to decompose neuroimaging data into 20 large-scale brain networks using a standard approach. Through spatial regression, we projected 1 year after SRS-T and HC rs-fMRI time points, on the same 20 brain networks.

RESULTS

Pretherapeutic interconnectivity (IC) strength between the network including bilateral thalamus and limbic system with left supplementary motor area predicted head tremor improvement at 1 year after SRS-T (family-wise corrected P < 0.001, cluster size K_c = 146). For the statistically significant cluster, IC strength was strongest in HCs (mean, 4.6; median, 3.8) compared with pre- (mean, 0.1; median, 0.2) or posttherapeutic (mean, -0.2; median, 0.09) states.

CONCLUSIONS

Baseline measures of IC between bilateral thalamus and limbic system with left supplementary motor area may predict head tremor arrest after thalamotomy. However, procedures such as SRS-T, for this particular clinical feature, do not align patients to HCs in terms of functional brain connectivity. We postulate that supplementary motor area is modulating head tremor appearance, by abnormal connectivity with the thalamolimbic system.

Vocal tract characteristics in Parkinson's disease

PURPOSE OF REVIEW

Voice tremor is strongly linked to the Parkinson's disease speech-voice symptom complex. Little is known about the underlying anatomic source(s) of voice tremor when it occurs. We review recent literature addressing this issue. Additionally we report findings from a study we conducted employing rating of vocal tract structures viewed using nasolaryngoscopy during vocal and nonspeech tasks.

RECENT FINDINGS

In Parkinson's disease, using laryngeal electromyography, tremor has not been identified in muscles in the vocal folds even when perceived auditorily. Preliminary findings using nasolaryngoscopy suggest that Parkinson's disease voice tremor is not associated with the vocal folds and may involve the palate, the global larynx, and the arytenoids. Tremor in the vertical larynx on /a/, and tremor in the arytenoid cartilages on /s/ differentiated patients with Parkinson's disease from neurologically healthy controls. Visual reliable detection of tremor when it is absent or borderline present, is challenging.

SUMMARY

Parkinson's disease voice tremor is likely to be related to oscillatory movement in structures across the vocal tract rather than just the vocal folds. To progress clinical practice, more refined tools for the visual rating of tremor would be beneficial. How far voice tremor represents a functionally significant factor for speakers would also add to the literature.

Tremor

Tremor is a phenomenon observed in a broad spectrum of diseases with different pathophysiologies. While patients with tremor may not complain in the clinic of symptoms of imbalance, gait difficulties, or falls, laboratory research studies using quantitative analysis of gait and posture and neurophysiologic techniques have demonstrated impaired gait and balance across a variety of tremor etiologies. These findings have been supported by careful epidemiologic studies assessing symptoms of imbalance. Imaging and neurophysiologic studies have identified cerebellar networks as important mediators of tremor, and therefore a likely common site of dysfunction to explain the phenomenologic overlap between impaired postural and gait control with tremor. Further understanding of these mechanisms and networks is of crucial importance in the development of new treatments, particularly surgical or minimally invasive lesional therapies.

Botulinum Toxin Type A Injections as Monotherapy for Upper Limb Essential Tremor Using Kinematics

Background:There is a significant need for a targeted therapy for essential tremor (ET), as medications have not been developed specifically for ET, and the ones prescribed are often not well-tolerated, so that many patients remain untreated. Recent work has shown that, unlike previous experience, kinematically guided individualized botulinum toxin type A (BoNT-A) injections provide benefit along with minimal weakness. Ours is the first long-term (96-week) safety and efficacy study of BoNT-A as monotherapy for ET using kinematically driven injection parameters.Methods:Ten ET patients were administered six serial BoNT-A treatments every 16 weeks and were assessed at 6 weeks following treatment. During each study visit, the Fahn–Tolosa–Marin (FTM) scale, the Unified Parkinson’s Disease Rating Scale, and the Quality of Life for Essential Tremor Questionnaire (QUEST) were administered along with kinematic assessment of the treated limb. Participants performed scripted tasks with motion sensors placed over each arm joint. Dosing patterns were determined using the movement disorder neurologist’s interpretation of muscles contributing to the kinematically analyzed upper limb tremor biomechanics.Results:There was a 33.8% (p<0.05) functional improvement (FTM part C) and a 39.8% (p<0.0005) improvement in QUEST score at week 96 compared to pretreatment scores at week 0. Although there was a 44.6% (p<0.0005) non-dose-dependent reduction in maximal grip strength, only 2 participants complained of mild weakness. Following the fourth serial treatment, mean action tremor score was reduced by 62.9% (p=0.001) in the treated and by 44.4% (p=0.03) in the untreated arm at week 96 compared to week 48.Conclusions:Individualized BoNT-A dosing patterns to each individual’s tremor biomechanics provided an effective monotherapy for ET as function improved without functionally limiting muscle weakness.

Symptomatic treatment of neurologic symptoms in Wilson disease

Wilson disease (WD) is a potentially treatable neurodegenerative disorder. In the majority of cases, treatment with drugs that induce a negative copper balance (usually chelators or zinc salts) leads to improvements in liver function and neurologic signs. However, some patients show severe neurologic symptoms at diagnosis, such as tremor, dystonia, parkinsonism, and chorea. In this patient group, some neurologic deficits may persist despite adequate treatment, and further neurologic deterioration may be observed after treatment initiation. Such patients may require additional treatment to alleviate neurologic symptoms. Apart from general recommendations for WD anticopper treatment, there are currently no guidelines for managing neurologic symptoms in WD. The aim of this chapter is to summarize possible treatments of neurologic symptoms in WD based on the presently available medical literature.

Movement disorders in multiple sclerosis and their treatment

Hyperkinetic movement disorders such as tremors are not uncommon in patients with multiple sclerosis (MS). The classical feature is intention tremor, whereas rest tremors appear not to occur. Treatment is mainly invasive, with options of Gamma Knife surgery, thalamotomy or deep brain stimulation depending on individual circumstances. Deep brain stimulation is the only option for patients who require a bilateral intervention. All treatment recommendations have only low evidence. Tremors can also be cured spontaneously by a subsequent strategic MS lesion. Paroxysmal dyskinesias are rarer than tremors. The rarest MS movement disorder is symptomatic paroxysmal choreoathetosis, tonic spasms or ‘brain stem fits’; attacks are short but frequent, up to 200 per day and generally respond well to carbamazepine.

Approach to a tremor patient

Tremors are commonly encountered in clinical practice and are the most common movement disorders seen. It is defined as a rhythmic, involuntary oscillatory movement of a body part around one or more joints. In the majority of the population, tremor tends to be mild. They have varying etiology; hence, classifying them appropriately helps in identifying the underlying cause. Clinically, tremor is classified as occurring at rest or action. They can also be classified based on their frequency, amplitude, and body part involved. Parkinsonian tremor is the most common cause of rest tremor. Essential tremor (ET) and enhanced physiological tremor are the most common causes of action tremor. Isolated head tremor is more likely to be dystonic rather than ET. Isolated voice tremor could be considered to be a spectrum of ET. Psychogenic tremor is not a diagnosis of exclusion; rather, demonstration of various clinical signs is needed to establish the diagnosis. Severity of tremor and response to treatment can be assessed using clinical rating scales as well as using electrophysiological measurements. The treatment of tremor is symptomatic. Medications are effective in half the cases of essential hand tremor and in refractory patients; deep brain stimulation is an alternative therapy. Midline tremors benefit from botulinum toxin injections. It is also the treatment of choice in dystonic tremor and primary writing tremor.

Non-invasive Central and Peripheral Stimulation: New Hope for Essential Tremor?

Essential tremor (ET) is among the most frequent movement disorders. It usually manifests as a postural and kinematic tremor of the arms, but may also involve the head, voice, lower limbs, and trunk. An oscillatory network has been proposed as a neural correlate of ET, and is mainly composed of the olivocerebellar system, thalamus, and motor cortex. Since pharmacological agents have limited benefits, surgical interventions like deep brain stimulation are the last-line treatment options for the most severe cases. Non-invasive brain stimulation techniques, particularly transcranial magnetic or direct current stimulation, are used to ameliorate ET. Their non-invasiveness, along with their side effects profile, makes them an appealing treatment option. In addition, peripheral stimulation has been applied in the same perspective. Hence, the aim of the present review is to shed light on the emergent use of non-invasive central and peripheral stimulation techniques in this interesting context.

Cannabinoids and Tremor Induced by Motor-related Disorders: Friend or Foe?

Tremor arises from an involuntary, rhythmic muscle contraction/relaxation cycle and is a common disabling symptom of many motor-related diseases such as Parkinson disease, multiple sclerosis, Huntington disease, and forms of ataxia. In the wake of anecdotal, largely uncontrolled, observations claiming the amelioration of some symptoms among cannabis smokers, and the high density of cannabinoid receptors in the areas responsible for motor function, including basal ganglia and cerebellum, many researchers have pursued the question of whether cannabinoid-based compounds could be used therapeutically to alleviate tremor associated with central nervous system diseases. In this review, we focus on possible effects of cannabinoid-based medicines, in particular on Parkinsonian and multiple sclerosis-related tremors and the common probable molecular mechanisms. While, at present, inconclusive results have been obtained, future investigations should extend preclinical studies with different cannabinoids to controlled clinical trials to determine potential benefits in tremor.

Permanent reversal of essential tremor following a frontal lobe stroke

Following a right prerolandic stroke, a 76 year old woman with bilateral upper extremity essential tremor (ET) recovered permanently from the latter contralaterally to the affected hemisphere. The ischemic stroke likely interrupted the cortical component of the ET network. Given the magnitude of neuronal loss, post-stroke cortical reorganization was unable to restore this important component of the ET network, accounting for the permanent nature of ET suppression.

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.