Search

Mouse units used to quantify the activity of botulinum A toxin preparations are not equivalent and issues concerning efficacy and safety remain with regard to their respective potencies and diffusion qualities in human tissue. We compared the effects of Botox(R) (BOT) and Dysport(R) (DYS) in different doses and dilutions in a human skin model. Eighteen (8 women, 10 men) healthy volunteers, aged 28.4 years +/- 5.7 years were injected intradermally with pure saline, BOT and DYS at 16 points in the abdomen in random order and in a double-blind condition, using two conversion ratios (1:3 and 1:4) and three different dilution schemes. For an objective outcome, the Ninhydrin sweat test was used to compare the anhidrotic areas. Both preparations showed a linear dose and dilution relationship with similar variances of responses for anhidrosis and hypohidrosis, indicating the same reliability of response. The dose equivalence conversion ratios (BOT: DYS) were 1:1.3 for anhidrosis and 1:1.6 for hypohidrosis (1:1.1-1.5 and 1:1.4-1.8 95% confidence intervals). The diffusion characteristics of both products were similar. A dose equivalence factor of more than 1:2 (BOT:DYS) is not supported by these objective and reproducible data. (c) 2008 Movement Disorder Society. [ABSTRACT FROM AUTHOR]

Examines on the efficacy of botulinum toxin type A (BTX-A) injections on hyperhidrosis. Impact of albumin on BTX-A; Effect of the BTX-A on the anhidrosis of the palm; Factors affecting BTX-A injections.

Examines on the efficacy of botulinum toxin type A (BTX-A) injections on hyperhidrosis. Impact of albumin on BTX-A; Effect of the BTX-A on the anhidrosis of the palm; Factors affecting BTX-A injections.

Abstract Background Previous studies showed that anodal transcranial DC stimulation (tDCS) applied to the primary motor cortex of the affected hemisphere (M1affected hemisphere) after subcortical stroke transiently improves performance of complex tasks that mimic activities of daily living (ADL). It is not known if relatively simpler motor tasks are similarly affected. Here we tested the effects of tDCS on pinch force (PF) and simple reaction time (RT) tasks in patients with chronic stroke in a double-blind cross-over Sham-controlled experimental design. Results Anodal tDCS shortened reaction times and improved pinch force in the paretic hand relative to Sham stimulation, an effect present in patients with higher impairment. Conclusion tDCS of M1affected hemisphere can modulate performance of motor tasks simpler than those previously studied, a finding that could potentially benefit patients with relatively higher impairment levels.

Background and Objectives: Ethanol has been reported to improve tremor severity in approximately two thirds of patients with essential tremor (ET), but the accuracy of that proportion is not certain and the mechanism of action is unknown. The goal of this study was to investigate alcohol response on tremor by applying an a priori objective response definition and subsequently to describe the responder rate to a standardized ethanol dose in a cohort of 85 ET patients. A secondary analysis evaluated other tremor and nontremor features, including demographics, tremor intensity, breath alcohol concentration, nontremor effects of alcohol, self-reported responder status to ethanol, and prior ethanol exposure., Methods: This was a prospective, open-label, single-dose challenge of oral ethanol during which motor and nonmotor measurements were obtained starting immediately prior to ethanol administration and subsequently every 20 min for 120 min. We defined tremor reduction as a 35% decline in power in the patient's tremor frequency recorded during spiral drawing 60 min after ethanol administration., Results: In total, 80% of patients were considered alcohol responsive using our objective definition. Responder status and change in the objective tremor metrics were significantly correlated with the change in breath alcohol concentration levels after ethanol administration, but no other relationships to nontremor metrics were found., Discussion: A high percentage of patients actually respond to acute ethanol. However, their self-reported response does not correlate well with their objective response. Objective response correlates with breath alcohol level but not with sedation, indicating a specific effect of ethanol on tremor., (Published 2023. This article is a U.S. Government work and is in the public domain in the USA. Annals of Clinical and Translational Neurology published by Wiley Periodicals LLC on behalf of American Neurological Association.)

Introduction: In Essential Tremor (ET), tremor characteristics and the impairment caused by tremor may vary from task to task. A variability of tremor frequency between postural and kinetic tasks has been proposed in ET, suggesting either multiple central oscillating networks, or peripheral or proprioceptive feedback-mechanisms. This electrophysiological study aimed to assess tremor frequencies and amplitudes in tasks involving postural and kinetic tremor, and compare findings within and across tasks, to delineate physiological differences underlying individually affected manual tasks in ET., Methods: 40 ET patients were included in the study. Tremor was characterized clinically, as well as electrophysiologically using accelerometry and digitizing tablet tasks. Tremor amplitude measures and frequencies were extracted for tasks involving kinetic (digital spiral drawing, handwriting), as well as postural tremor. Tremor was compared between and within tasks., Results: Digital spiral tremor frequencies were significantly higher compared to postural tremor frequencies, as measured by accelerometry, with a mean difference of >2 Hz (p < 0.001). Within-task variability of repeated digital spirals revealed a significant amplitude reduction over time in both hands (p < 0.001), with an up to 32% reduction compared to the first spiral., Conclusion: ET exhibited a frequency variability, which was dependent on activation condition, suggesting neurophysiologically distinct pathways between postural and kinetic tremor. The reduction of tremor amplitudes observed in repeated digital spiral drawing may be explained by a learning effect or adaptation, and should be considered as non-random factor of variability when using spirals in ET to assess effects of interventions., (Published by Elsevier Ltd.)

Background: Recently, 1-octanol has been shown to have efficacy in treating patients with essential tremor (ET). The primary metabolite of 1-octanol is octanoic acid (OA), which is now thought to be the active substance that mediates tremor suppression. Our aim was to describe the maximum tolerated dose (MTD) of oral OA in patients with ET and assess the pharmacokinetics (PK) and pharmacodynamics (PD) profile of OA., Methods: The MTD was studied using an open-label, single-ascending 3 + 3 dose-escalation design. Predefined single doses ranged from 8 to 128 mg/kg, with grade 2 adverse events (AEs) defined as dose-limiting toxicity. Tremor was assessed using accelerometry, digital spiral analysis, and a standard clinical rating scale at baseline and up to 600 minutes after intake. Safety assessments and PK sampling were also performed., Results: Dose-limiting toxicity was not reached. The most frequent AE was mild abdominal discomfort. Exposure (AUC) increased linearly with the dose. Secondary efficacy measures suggested a dose-dependent reduction of tremor. Accordingly, a single unified PK/PD model with an effect compartment and sigmoid maximum effect (Emax) response could be built that accounted well for the time profiles of plasma concentrations as well as effects on tremor severity across the 5 dose levels., Conclusion: Although our trial did not reach an MTD, a dose-dependent effect was demonstrated in the PK/PD model as well as in secondary efficacy outcomes. Future studies are needed to explore the safety in higher dose ranges and to confirm dose-dependent efficacy in a placebo-controlled design., Trial Registration: Clinicaltrials.gov NCT01468948FUNDING. NINDS Intramural Research Program; TG Therapeutics Inc.

Background: The ability of the Essential Tremor (ET) Rating Assessment Scale (TETRAS) to detect changes in tremor severity is unknown., Methods: Fifteen adult ET patients received a single oral ethanol dose calculated to reach 0.05 g/dL breath alcohol content (brAC). Effects were investigated independently with accelerometry and TETRAS., Results: Accelerometry data were log-transformed and a cumulative score logACC(R+L) was calculated. Correlation between logACC(R+L) and TETRAS was significant. TETRAS and accelerometry showed a significant effect of time point using repeated-measures analysis of variance. The difference between baseline and each of the following six time points as well as the correlation of TETRAS with brAC were significant. The calculated minimum detectable change of TETRAS was 8.9% and the effect size was d = 4.75 (95% confidence interval: 3.60-5.90)., Conclusion: We demonstrated sensitivity to change of the TETRAS performance scale after a therapeutic intervention, which further establishes its potential for use in both clinical and research settings., (© 2013 International Parkinson and Movement Disorder Society.)

Aim: To review current literature on long-chain alcohols and their derivatives as novel pharmacotherapy for the treatment of essential tremor (ET)., Background: Currently available and recommended pharmacotherapies for ET are often limited by suboptimal treatment effects, frequent adverse effects, and drug interactions. While ethanol is reported to profoundly decrease tremor severity in the majority of patients with ET, preclinical experience suggests that long-chain alcohols such as 1-octanol might lead to a comparable tremor reduction without ethanol's typical side effects of sedation and intoxication. Here, we review the literature on the first clinical trials on 1-octanol and its metabolite octanoic acid (OA) for the treatment of ET., Methods: The literature on preclinical and clinical trials on long-chain alcohols as well as OA was reviewed and summarized, and an outlook given on next phases of development., Discussion: 1-octanol was demonstrated to be safe and effective in a double-blind, placebo-controlled low-dose trial, and open-label data showed excellent tolerability and dose-dependent efficacy up to 128 mg/kg. Despite 1-octanol's efficacy, its future viability as an effective therapy is limited by its pharmacological properties that require large volumes to be orally administered. Pharmacokinetic data indicate that OA is the active metabolite of 1-octanol. Preclinical efficacy data for OA are positive, and human pilot data demonstrated excellent safety as well as efficacy in secondary outcome measures of tremor amplitudes. OA also has more favorable pharmacological properties for drug delivery; hence, OA may be worth developing as a pharmaceutical.

We examined whether unilateral exercise creates perception bias in the non-exercised limb and ascertained whether rTMS applied to the primary motor cortex (M1) interferes with this perception. All participants completed 4 interventions: 1) 15-min learning period of intermittent isometric contractions at 35% MVC with the trained hand (EX), 2) 15-min learning period of intermittent isometric contractions at 35% MVC with the trained hand whilst receiving rTMS over the contralateral M1 (rTMS+EX); 3) 15-min of rTMS over the 'trained' M1 (rTMS) and 4) 15-min rest (Rest). Pre and post-interventions, the error of force output production, the perception of effort (RPE), motor evoked potentials (MEPs) and compound muscle action potentials (CMAPs) were measured in both hands. EX did not alter the error of force output production in the trained hand (Δ3%; P>0.05); however, the error of force output production was reduced in the untrained hand (Δ12%; P<0.05). rTMS+EX and rTMS alone did not show an attenuation in the error of force output production in either hand. EX increased RPE in the trained hand (9.1±0.5 vs. 11.3±0.7; P<0.01) but not the untrained hand (8.8±0.6 vs. 9.2±0.6; P>0.05). RPE was significantly higher after rTMS+EX in the trained hand (9.2±0.5 vs. 10.7±0.7; P<0.01) but ratings were unchanged in the untrained hand (8.5±0.6 vs. 9.2±0.5; P>0.05). The novel finding was that exercise alone reduced the error in force output production by over a third in the untrained hand. Further, when exercise was combined with rTMS the transfer of force perception was attenuated. These data suggest that the contralateral M1 of the trained hand might, in part, play an essential role for the transfer of force perception to the untrained hand.

PRES is a clinicoradiologic entity, combining seizures, blindness, and coma with MR imaging findings of predominantly vasogenic and occasional cytotoxic edema. In this clinical report, we determined the type of edema by using DWI and FLAIR sequences on MR imaging as well as ADC maps in 28 patients with PRES. The neuradiologic findings were correlated with levels of serum albumin, which is a main contributor to colloid osmotic pressure and vascular integrity. The presence of vasogenic edema was significantly associated with decreased serum albumin levels, which may be a particular risk factor for the development of PRES.

In the motor system, one specific movement is generated, and, simultaneously, other possible movements are suppressed; a process called surround inhibition. Focal hand dystonia (FHD) is a movement disorder characterized by a loss of surround inhibition. In order to explain the deficit in surround inhibition induced by volitional movement in FHD patients, we examined the inhibitory circuit activated by afferent stimulation at "long latency". We studied 14 patients (age 48.9+/-13.2 years, 3 females, 11 males) with idiopathic task-related FHD. To measure long-latency afferent inhibition (LAI), transcranial magnetic stimulation (TMS) was applied to the affected hemisphere for FHD patients and to the dominant hemisphere for 17 healthy volunteers. Motor evoked potentials (MEPs) were recorded over abductor digiti minimi (ADM) and first dorsal interosseous (FDI) during rest and during voluntary phasic flexion of the second digit. Subjects were given electrical stimulation to either their fifth digit (homotopic to ADM, heterotopic to FDI) or their second digit (heterotopic to FDI, homotopic to ADM) at twice sensory perceptual threshold 180 ms prior to TMS application. Additionally, F-waves were recorded from ADM. At rest, we found a significant decrease in ADM MEP amplitudes with both homotopic and heterotopic stimulation compared to the corresponding non-stimulated trials. There was a trend toward less LAI in FHD patients. During movement, LAI was significantly decreased in both patients and controls. There was no significant group effect. The results for LAI in FDI were similar to those from ADM. F-wave area in ADM was greater during movement for both homo- and heterotopic stimulation. We found no difference in F-wave area between patients and healthy volunteers. Our results indicate that LAI is unlikely to be an underlying mechanism that contributes to the generation of normal surround inhibition in healthy volunteers or in the disruption of surround inhibition in FHD.

Background: Previous studies showed that anodal transcranial DC stimulation (tDCS) applied to the primary motor cortex of the affected hemisphere (M1affected hemisphere) after subcortical stroke transiently improves performance of complex tasks that mimic activities of daily living (ADL). It is not known if relatively simpler motor tasks are similarly affected. Here we tested the effects of tDCS on pinch force (PF) and simple reaction time (RT) tasks in patients with chronic stroke in a double-blind cross-over Sham-controlled experimental design., Results: Anodal tDCS shortened reaction times and improved pinch force in the paretic hand relative to Sham stimulation, an effect present in patients with higher impairment., Conclusion: tDCS of M1affected hemisphere can modulate performance of motor tasks simpler than those previously studied, a finding that could potentially benefit patients with relatively higher impairment levels.

Background: Pain sensation associated with injections of botulinum neurotoxin (BoNT) is commonly reported. To date differences in pain sensation between the commercially available products containing BoNT have not been quantified., Objectives: The pain sensations during injection of Dysport, Botox, Neurobloc, and pure saline (control) were compared. In addition, the nociceptive effect of different volumes used for the dilution of the same BoNT dose was investigated., Methods: In a prospective, double-blind, controlled trial, 10 healthy subjects were injected intradermally with Dysport (12 U), Botox (3 and 4 U), Neurobloc (150 and 300 U) reconstituted in 0.9% saline, and pure saline. Pain sensation was quantified during injections., Results: Neurobloc injections caused significantly more injection pain than Botox, Dysport, and saline. No significant differences between Dysport, Botox, and saline were found, although there was a trend toward less pain with pure saline injections. Higher pain levels with higher volumes could not be demonstrated significantly., Conclusion: Our data demonstrate that BoNT type B injections are associated with substantial pain. There is a considerable difference between the commercially available BoNT type B compared to the two BoNT type A preparations. Therefore, considering mitigation of injection pain seems necessary when using BoNT type B.

During individual finger movement, two opposite phenomena occur at the level of the central nervous system that could affect other intrinsic hand muscle representations, unintentional co-activation, and surround inhibition (SI). At rest, excitability in the motor cortex (M1) is inhibited at about 20 ms after electric stimulation of a peripheral nerve [short-latency afferent inhibition (SAI)]. We sought to determine whether SAI changes during selective index finger movement. Effects were measured by the response to transcranial magnetic stimulation in two functionally distinct target muscles of the hand [abductor digiti minimi muscle (ADM), first dorsal interosseus muscle (FDI)]. An increase in SAI in the ADM during index finger movement compared to at rest could help explain the genesis of SI. Electrical stimulation was applied to either the little finger (homotopic for ADM, heterotopic for FDI) or the index finger (heterotopic for ADM, homotopic for FDI). During index finger movement, homotopic SAI was present only in the ADM, and the effect of peripheral stimulation was greater when there was less co-activation. Heterotopic SAI found at rest disappeared with movement. We conclude that during movement, homotopic SAI on the muscle in the surround of the intended movement may contribute to SI.

Stimulation of a peripheral nerve of a hand at rest modulates excitability in the motor cortex and, in particular, leads to inhibition when applied at an interval of approximately 200 ms (long-latency afferent inhibition; LAI). Surround inhibition (SI) is the process that inhibits neighboring muscles not involved in a particular task. The neuronal mechanisms of SI are not known, and it is possible that LAI might contribute to it. Using transcranial magnetic stimulation (TMS) with and without movement of the index finger, the motor-evoked potentials (MEPs) were measured of two functionally distinct target muscles of the hand (abductor digiti minimi muscle = ADM, 1st dorsal interosseus muscle = FDI). Electrical stimulation was applied 180 ms before TMS to either the fifth finger or the index finger. Both homotopic and heterotopic finger stimulation resulted in LAI without movement. With index finger movement, motor output further decreased with homo- and heterotopic stimulation in the ADM. In the moving FDI, however, there was no change with either homo- or heterotopic stimulation. Additionally, in the unstimulated movement trials, LAI increased with the amount of unintentional co-activation that occurred despite attempts to maintain the ADM at rest. However, with finger stimulation added, there were almost no increased MEPs despite co-activation. These findings suggest that LAI increases during movement and can enhance SI.

Objective: Standard coils used in research and the clinic for noninvasive magnetic stimulation of the human brain are not capable of stimulating deep brain regions directly. As the fields induced by these coils decrease rapidly as a function of depth, only very high intensities would allow functional stimulation of deep brain regions and such intensities would lead to undesirable side effects. We have designed a coil based on numerical simulations and phantom brain measurements that allows stimulation of deeper brain regions, termed the Hesed coil (H-coil). In the present study we tested the efficacy and some safety aspects of the H-coil on healthy volunteers., Methods: The H-coil was compared to a regular figure-8 coil in 6 healthy volunteers by measuring thresholds for activation of the abductor pollicis brevis (APB) representation in the motor cortex as a function of distance from each of the coils., Results: The rate of decrease in the coil intensity as a function of distance is markedly slower for the H-coil. The motor cortex could be activated by the H-coil at a distance of 5.5 cm compared to 2 cm with the figure-8 coil., Conclusions: The present study indicate that the H-coil is likely to have the ability of deep brain stimulation and without the need of increasing the intensity to extreme levels that would cause a much greater stimulation in cortical regions., Significance: The ability of non-invasive deep brain stimulation potentially opens a wide range of both research and therapeutic applications.

Approximately 5% of patients with cervical dystonia receiving repeated botulinum neurotoxin A (BoNT/A) injections develop secondary loss of treatment benefit. Currently available tests to directly detect neutralizing BoNT/A antibodies (BoNT/A-AB) are either expensive or time consuming. To establish a simple, clinically useful test for antibody detection, we adapted the ninhydrin sweat test (NST). Eighteen dystonic patients with secondary nonresponse and clinically suspected BoNT/A-AB formation were tested for BoNT/A-AB in the mouse diaphragm test (MDT). In addition, the size of the anhidrotic area was determined by the NST 21 days after an intradermal dose of 10 U Dysport into the hypothenar region of the left palm. In nine patients, positive BoNT-AB titers were found in the MDT. There was a significant correlation between the BoNT/A-AB titers and the anhidrotic area (Spearman's rho = -0.9, P < 0.0001). Both tests provided comparably good results with respect to qualitative antibody detection. In the clinical situation of secondary nonresponse to BoNT/A therapy, the economical NST may be a helpful tool to detect neutralizing BoNT/A-AB., (Copyright 2004 Movement Disorder Society)

Spastic drop foot can be managed by physical measures, local pharmacological agents, oral anti-spastic drugs and surgical procedures. Recent studies have documented the clear effect of botulinum toxin type A (BTX-A) in the treatment of the spastic drop foot, particularly by reducing the resistance against passive movement and increasing the range of motion. Functional benefit and pain reduction have also been observed. The use of BTX-A is safe and free of serious side effects. Individual realistic treatment goals must be defined by the rehabilitation team before the treatment. Possible purposes of the treatment are the achievement of a straight foot to allow weight bearing or application of an orthosis and to reduce the premature activation of the calf muscles during gait. Other treatment goals are the facilitation of nursing care, as well as physical and occupational therapy. BTX-A injections can reduce pain, and prevent pressure ulcers or surgical interventions. Early physiotherapy or occupational therapy may increase the treatment effect of BTX-A. Close cooperation between the neurologist, physiotherapist, occupational therapist, nursing staff and other multidisciplinary rehabilitation team members is essential to maximize the benefit for the patients.

Introduction: Botulinum A toxin (BTX-A) acts primarily at peripheral cholinergic synapses, inhibiting the release of acetylcholine. Initially it has been used to block the neuromuscular junction in focal dystonic and spastic syndromes. Recently there has been suggestions for potential clinical indications in non-muscular diseases where cholinergic terminals play a role., Gustatory Sweating: In 1995 physicians reported a long-lasting anhidrotic effect of intracutaneous BTX-A injections in patients suffering from gustatory sweating (Frey's syndrome). Consequently, a number of clinical studies demonstrated good efficacy of intradermal injections of botulinumtoxin in patients with focal hyperhidrosis., Focal Hyperhidrosis of the Palms and Axillae: Focal hyperhidrosis is usually confined to the palms and axillae. Excessive sweating may be a social handicap and an occupational hazard. The management of focal hyperhidrosis remains controversial. Topical antiperspirants are only effective in very mild cases. Iontophoresis with tap water or anticholinergic drugs is messy and time consuming with only short-lived effect. Sympathectomy, the cornerstone of surgical management, is usually effective in palmar hyperhidrosis. Complications of this technique include surgical risks, postoperative and cosmetic problems and compensatory hyperhidrosis., Axillary Hyperhidrosis: Several studies confirmed that intracutaneous injections of botulinum toxin are useful in the majority of patients with axillary hyperhidrosis resistant to conventional treatment. In axillary hyperhidrosis total doses are ranging from 200-400 mU Dysport or from 80 to 130 mU Botox to reach a good clinical response. Injections are usually well tolerated and no serious side-effects have been observed. The mean duration of anhidrotic effect ranges between 3 and 9 weeks., Palmar Hyperhidrosis: The use of botulinumtoxin in patients with palmar hyperhidrosis is rather difficult. The therapeutic window is smaller because injections are complicated by transient weakness of the small hand-muscles. Furthermore the injections at the palms are painful which can be overcomed by application of local anaesthetics or the blockade of the ulnar and median nerves. The duration of anhidrotic effect ranges from 20 to 50 weeks., Conclusion: Intracutaneous injections of botulinum-toxin should be offered to patients with focal hyperhidrosis of the palms and axillae causing serious social, psychologic and occupational problems, resistant to other conventional treatment options.

The Barthel Index (BI) is the most commonly used scale for assessing impairment of activities of daily living (ADL). For a global view of patients' abilities and the care needed in everyday neurorehabilitation practice, additional information about basic psychological and cognitive functions is essential. We therefore designed a new disability scale comprised of assessments of consciousness, approachability, orientation, memory, behaviour, emotions, communication, problem solving, perception, and behaviour at night. The scale shows exactly the same inner structure as the BI, with ten items and a score of up to 20 in steps from 0-100% (or 0-20 points). By a careful weighing of the items, the final score of the neuromental index (NMI) should create a clearer picture of both the disabilities and the needed resources. A second aim was to cover a broad range of patients including those in coma and coma remission states and those with only slight neuropsychological or behavioural symptoms. The NMI was examined with a group of 179 neurorehabilitation inpatients and proved to be highly valid, reliable, and practicable. It was designed to enable a global assessment of disability as well as the care resources needed, even in patients with different disability levels in ADL and psychological and cognitive functions.