High-Frequency Ultrasound Guidance for Neurotoxin Injections

Comparison of Ultrasound and Electrical Stimulation Guidance for Onabotulinum Toxin-A Injections: A Randomized Crossover Study

Background

Botulinum neurotoxin (BoNT) injection is an established therapy for limb spasticity and focal limb dystonia. Comparative benefits of injection guidance procedures have not been rigorously studied.

Objectives

We compared 2 targeting techniques for onabotulinumtoxin-A (onabotA) injection for the treatment of focal hand dystonia and upper limb spasticity: electrophysiologic guidance using electrical stimulation (E-stim) and ultrasound (US).

Methods

This was a 2-center, randomized, crossover, assessor-blinded trial. Participants with focal hand dystonia or upper limb spasticity, on stable onabotA therapy for at least 2 previous injection cycles, were randomly assigned to either E-stim or US with crossover at 3 months. The primary outcome was improvement in dystonia or spasticity severity on a visual analog scale (VAS; 0-100) measured 1 month after each injection. The secondary outcome was participant discomfort assessed on a VAS. Repeated-measures analysis of covariance was used with linear mixed-model covariate selection.

Results

A total of 19 participants (13 men) completed the study, 10 with upper limb spasticity and 9 with dystonia. Benefit was equivalent between the 2 techniques (VAS least-square mean [LSmean] 51.5 mm with US and 53.1 with E-stim). E-stim was perceived as more uncomfortable by participants (VAS LSmean 34.5 vs. 19.9 for E-stim and US, respectively). Procedure duration was similar with the 2 procedures. There were no serious adverse events related to either approach.

Conclusions

US and E-Stim localization guidance techniques provide equivalent efficacy in onabotA injections for spasticity and dystonia. US guidance injections are more comfortable for participants. Both techniques are effective guidance methods, with US potentially preferable based on participant comfort.

Improving Botulinum Toxin Efficiency in Treating Post-Stroke Spasticity Using 3D Innervation Zone Imaging

Spasticity is a common post-stroke syndrome that imposes significant adverse impacts on patients and caregivers. This study aims to improve the efficiency of botulinum toxin (BoNT) in managing spasticity, by utilizing a three-dimensional innervation zone imaging (3DIZI) technique based on high-density surface electromyography (HD-sEMG) recordings. Stroke subjects were randomly assigned to two groups: the control group ([Formula: see text]) which received standard ultrasound-guided injections, and the experimental group ([Formula: see text]) which received 3DIZI-guided injections. The amount of BoNT given was consistent for all subjects. The Modified Ashworth Scale (MAS), compound muscle action potential (CMAP) and muscle activation volume (MAV) from bilateral biceps brachii muscles were obtained at the baseline, 3 weeks, and 3 months after injection. Intra-group and inter-group comparisons of MAS, CMAP amplitude and MAV were performed. An overall improvement in MAS of spastic elbow flexors was observed during the 3-week visit ([Formula: see text]), yet no statistically significant difference found with intra-group or inter-group analysis. Compared to the baseline, a significant reduction of CMAP amplitude and MAV were observed in the spastic biceps muscles of both groups at 3-week post-injection, and returned to approximate baseline value at 12-week post injection. A significantly higher reduction was found in CMAP amplitude ([Formula: see text]% versus [Formula: see text]%, [Formula: see text]) and MAV ([Formula: see text]% versus [Formula: see text]%, [Formula: see text]) in the experimental group compared to the control group. The study has demonstrated preliminary evidence that precisely directing BoNT to the innervation zones (IZs) localized by 3DIZI leads to a significantly higher treatment efficiency improvement in spasticity management. Results have also shown the feasibility of developing a personalized BoNT injection technique for the optimization of clinical treatment for post-stroke spasticity using proposed 3DIZI technique.

Ultrasound Guidance for Botulinum Neurotoxin Chemodenervation Procedures

Injections of botulinum neurotoxins (BoNTs) are prescribed by clinicians for a variety of disorders that cause over-activity of muscles; glands; pain and other structures. Accurately targeting the structure for injection is one of the principle goals when performing BoNTs procedures. Traditionally; injections have been guided by anatomic landmarks; palpation; range of motion; electromyography or electrical stimulation. Ultrasound (US) based imaging based guidance overcomes some of the limitations of traditional techniques. US and/or US combined with traditional guidance techniques is utilized and or recommended by many expert clinicians; authors and in practice guidelines by professional academies. This article reviews the advantages and disadvantages of available guidance techniques including US as well as technical aspects of US guidance and a focused literature review related to US guidance for chemodenervation procedures including BoNTs injection.

Histological and immunohistochemical findings of the action of botulinum toxin in salivary gland: systematic review

The treatment of sialorrhea is necessary for the constant risks posed by hypersalivation. A new therapeutic option comes up with the application of botulinum toxin in salivary glands. However, little is known about its mechanism of action in glandular tissue. Based on the above, this work had the objective to systematically review the literature about the action of botulinum toxin on submandibular and parotid salivary glands tissues. Electronic search was performed in databases of great relevance for this study (PubMed, SciELO, HighWire, Crossref, Scopus, Science Direct, MEDLINE, OLDMEDLINE, Serials Database, NLM Catalog, LILACS and IBECS). Inclusion and exclusion criteria for articles were established, and a total number of 14 articles were selected and used. There are few publications that clarify how the salivary gland acini behave with application of botulinum toxin. Although, the immunohistochemical findings were consistent among authors, showing weak immunoreactivity in glands treated with botulinum toxin. Histometric data are divergent, requiring more detailed studies to answer the questions about the efficacy and safety of botulinum toxin in salivary glands.

Effect of Radial Shock Wave Therapy on Spasticity of the Upper Limb in Patients With Chronic Stroke: A Prospective, Randomized, Single Blind, Controlled Trial

Recently, studies have reported that extracorporeal shock wave therapy (ESWT) is a safe, noninvasive, alternative treatment for spasticity. However, the effect of ESWT on spasticity cannot be determined, because most studies to date have enrolled small patient numbers and have lacked placebo-controlled groups and/or long-term follow-up. In addition, whether varying the number of ESWT sessions would affect the duration of the therapeutic effect has not been investigated in a single study. Hence, we performed a prospective, randomized, single blind, placebo-controlled study to investigate the long-term effect of radial ESWT (rESWT) in patients with poststroke spasticity and surveyed the outcome of functional activity.Sixty patients were randomized into 3 groups. Group A patients received 1 session of rESWT per week for 3 consecutive weeks; group B patients received a single session of rESWT; group C patients received one session of sham rESWT per week for 3 consecutive weeks. The primary outcome was Modified Ashworth Scale of hand and wrist, whereas the secondary outcomes were Fugl-Meyer Assessment of hand function and wrist control. Evaluations were performed before the first rESWT treatment and immediately 1, 4, 8, 12, and 16 weeks after the last session of rESWT.Compared to the control group, the significant reduction in spasticity of hand and wrist lasted at least 16 and 8 weeks in group A and B, respectively. Three sessions of rESWT had a longer-lasting effect than one session. Furthermore, the reduction in spasticity after 3 sessions of rESWT may be beneficial for hand function and wrist control and the effect was maintained for 16 and 12 weeks, respectively.rESWT may be valuable in decreasing spasticity of the hand and wrist with accompanying enhancement of wrist control and hand function in chronic stroke patients.

Impact of Injection-Guiding Techniques on the Effectiveness of Botulinum Toxin for the Treatment of Focal Spasticity and Dystonia: A Systematic Review

OBJECTIVE

To conduct a systematic review of the impact of different injection-guiding techniques on the effectiveness of botulinum toxin type A (BoNT-A) for the treatment of focal spasticity and dystonia.

DATA SOURCES

MEDLINE via PubMed, Academic Search Premier, PASCAL, The Cochrane Library, Scopus, SpringerLink, Web of Science, EM Premium, and PsycINFO.

STUDY SELECTION

Two reviewers independently selected studies based on predetermined inclusion criteria.

DATA EXTRACTION

Data relating to the aim were extracted. Methodological quality was graded independently by 2 reviewers using the Physiotherapy Evidence Database assessment scale for randomized controlled trials (RCTs) and the Downs and Black evaluation tool for non-RCTs. Level of evidence was determined using the modified Sackett scale.

DATA SYNTHESIS

Ten studies were included. Seven were randomized. There was strong evidence (level 1) that instrumented guiding (ultrasonography [US], electrical stimulation [ES], electromyogram [EMG]) was more effective than manual needle placement for the treatment of spasmodic torticollis, upper limb spasticity, and spastic equinus in patients with stroke, and spastic equinus in children with cerebral palsy. Three studies provided strong evidence (level 1) of similar effectiveness of US and ES for upper and lower limb spasticity in patients with stroke, and spastic equinus in children with cerebral palsy, but there was poor evidence or no available evidence for EMG or other instrumented techniques.

CONCLUSIONS

These results strongly recommend instrumented guidance of BoNT-A injection for the treatment of spasticity in adults and children (ES or US), and of focal dystonia such as spasmodic torticollis (EMG). No specific recommendations can be made regarding the choice of instrumented guiding technique, except that US appears to be more effective than ES for spastic equinus in adults with stroke.

The utility of musculoskeletal ultrasound in rehabilitation settings

Aside from its prompt use in musculoskeletal injuries (sports lesions, degenerative/inflammatory joint disorders, and peripheral nerve pathologies), ultrasonographic imaging can be used quite conveniently in various types of rehabilitation conditions as well. If used in a rehabilitation setting, ultrasound can significantly contribute to the diagnostic/therapeutic algorithm of rehabilitation patients. Accordingly, in this article, the authors focus on the diagnostic/interventional utility of ultrasound particularly for shoulder problems, overuse injuries of wheelchair users, heterotopic ossification, amputee follow-up, peripheral nerve and botulinum toxin injections, and diaphragm imaging/electromyography.

Accurate targeting of botulinum toxin injections: how to and why

Botulinum toxin (BTX), the exotoxin of the obligate anaerobe, Clostridium botulinum, is used to ameliorate pain and treat conditions associated with glandular, smooth and skeletal muscle overactivity. The benefits derived from the injection of BTX may be negated by unintended weakness of uninjected muscles. Performance of BTX injections may be facile, requiring only surface marking or clinical-localisation techniques but may be more technically demanding, necessitating the use of equipment, such as electromyography (EMG) or ultrasonography (U/S). Less often, endoscopic, fluoroscopic or computed tomographic (CT) guidance may be required. Despite evidence to support the efficacy of BTX injections in treating many conditions, there is no evidence to support the superiority of any one injection technique over needle localisation using surface anatomy. This is possibly due to the lack of well-designed controlled studies, that is, current studies are hampered by small patient numbers, lack of consistency of injection technique and the application of different rating scales. Intuitively, certain injection techniques are more suited to injection of specific muscles or conditions, for example, U/S or passive-monitoring EMG should be used to treat cervical dystonia, active-monitoring EMG applied for strabismus injections, whereas either active-monitoring EMG or endoscopy is indicated when giving BTX for spasmodic dysphonia. Finally, electrical-stimulation EMG or U/S (or a combination of both) would be most suitable when injecting the forearm muscles for spasticity or writer's cramps.