Electromyographic Guidance Research Articles

Botulinum Toxin Injection under Electromyography Guidance for the Treatment of Primary Dysfunction of Cricopharyngeal Muscle

Botulinum Toxin Injection under Electromyography Guidance for the Treatment of Primary Dysfunction of Cricopharyngeal Muscle

Trial of Botulinum Toxin for Isolated or Essential Head Tremor

BackgroundLocal injections of botulinum toxin type A have been used to treat essential head tremor but have not been extensively studied in randomized trials.MethodsIn a multicenter, double-blind, randomized trial, we assigned, in a 1:1 ratio, adult patients with essential or isolated head tremor to receive botulinum toxin type A or placebo. Botulinum toxin or placebo was injected under electromyographic guidance into each splenius capitis muscle on the day of randomization (day 0) and during week 12. The primary outcome was improvement by at least 2 points on the Clinical Global Impression of Change (CGI) scale at week 6 after the second injection (week 18 after randomization). The CGI scale was used to record the patient’s assessment of the degree of improvement or worsening of head tremor since baseline; scores range from 3 (very much improved) to −3 (very much worse). Secondary outcomes included changes in tremor characteristics from baseline to weeks 6, 12, and 24.ResultsA total of 120 patients were enrolled; 3 patients were excluded during screening, and 117 patients were randomly assigned to receive botulinum toxin (62 patients) or placebo (55 patients) and were included in the intention-to-treat analysis. Twelve patients in the botulinum toxin group and 2 patients in the placebo group did not receive injections during week 12. The primary outcome — improvement by at least 2 points on the CGI scale at week 18 — was met by 31% of the patients in the botulinum toxin group as compared with 9% of those in the placebo group (relative risk, 3.37; 95% confidence interval, 1.35 to 8.42; P=0.009). Analyses of secondary outcomes at 6 and 12 weeks but not at 24 weeks were generally supportive of the primary-outcome analysis. Adverse events occurred in approximately half the patients in the botulinum toxin group and included head and neck pain, posterior cervical weakness, and dysphagia.ConclusionsInjection of botulinum toxin into each splenius capitis muscle on day 0 and during week 12 was more effective than placebo in reducing the severity of isolated or essential head tremor at 18 weeks but not at 24 weeks, when the effects of injection might be expected to wane, and was associated with adverse events. (Funded by the French Ministry of Health; Btx-HT ClinicalTrials.gov number, NCT02555982.)

NeuroGrasp: Real-Time EEG Classification of High-Level Motor Imagery Tasks Using a Dual-Stage Deep Learning Framework.

Brain-computer interfaces (BCIs) have been widely employed to identify and estimate a user's intention to trigger a robotic device by decoding motor imagery (MI) from an electroencephalogram (EEG). However, developing a BCI system driven by MI related to natural hand-grasp tasks is challenging due to its high complexity. Although numerous BCI studies have successfully decoded large body parts, such as the movement intention of both hands, arms, or legs, research on MI decoding of high-level behaviors such as hand grasping is essential to further expand the versatility of MI-based BCIs. In this study, we propose NeuroGrasp, a dual-stage deep learning framework that decodes multiple hand grasping from EEG signals under the MI paradigm. The proposed method effectively uses an EEG and electromyography (EMG)-based learning, such that EEG-based inference at test phase becomes possible. The EMG guidance during model training allows BCIs to predict hand grasp types from EEG signals accurately. Consequently, NeuroGrasp improved classification performance offline, and demonstrated a stable classification performance online. Across 12 subjects, we obtained an average offline classification accuracy of 0.68 (±0.09) in four-grasp-type classifications and 0.86 (±0.04) in two-grasp category classifications. In addition, we obtained an average online classification accuracy of 0.65 (±0.09) and 0.79 (±0.09) across six high-performance subjects. Because the proposed method has demonstrated a stable classification performance when evaluated either online or offline, in the future, we expect that the proposed method could contribute to different BCI applications, including robotic hands or neuroprosthetics for handling everyday objects.

Efficacy of Dry Needling Under EMG Guidance for Myofascial Neck and Shoulder Pain: A Randomized Clinical Trial.

PurposeTo determine the difference in maintenance of improvement of pain and disability for dry needling (DN) under needle electromyography (EMG) guidance technique in myofascial neck and shoulder pain patients, compared with DN alone.Patients and MethodsIn this randomized single-blind clinical trial, 30 participants with myofascial pain in the neck and shoulder were randomly allocated to two groups: myofascial trigger points (MTrPs) DN with EMG guided (DN-EMG) group and MTrPs DN without EMG (DN) group. Needling treatment lasted for 2 weeks, twice a week. The primary outcome was pain intensity as assessed by visual analogue scale (VAS) and neck disability index (NDI). A number of mappings referred to pain and spontaneous muscle activity (SEA) were considered secondary outcomes. VAS and NDI were measured before treatment, after 2 weeks of intervention and at 4-, 6- and 12-week follow-up periods after the intervention. Secondary outcomes were assessed before each treatment (T1–T4). Data were analysed using mixed-model analyses of variance (ANOVA) with time as a within-subject variable and groups as between-subject variables followed by Bonferroni’s post-hoc test.ResultsMixed-model ANOVA revealed significant time-by-group interaction effects (F = 3.49, P = 0.01) for VAS. Post-hoc analysis showed a significant decrease in VAS and NDI after 2 weeks of intervention and at all follow-up periods compared with baseline in both groups (p < 0.01). The DN-EMG group exhibited higher improvements in VAS at 6- and 12-week follow-up period than the DN group (p < 0.05). In the SEA of MTrPs, we found positive sharp waves, fibrillation and fascicular potentials. DN-EMG group exhibited lower amplitudes at T2–T4 and frequencies at T2 and T3.ConclusionDN under needle EMG guidance technique exhibited greater improvements in maintenance of improvement of pain and lower SEA value than the DN group due to sufficient MTrPs inactivation.

Botulinum Toxin for Essential Tremor and Hands Tremor in the Neurological Diseases: A Meta-Analysis of Randomized Controlled Trials

Tremor is a common movement disorder. Essential tremor (ET) is the most common etiology of tremor, while hands tremor is the most disabling type of tremor. This study aimed to explore the effects of Botulinum toxin (BoNT) on tremor within 6 weeks of treatment, and the muscular weakness adverse effect within 6 weeks specifically in randomized controlled trials. PubMed, Embase, and Cochrane Library databases were searched. Tremor severity and grip strength after BoNT treatment were investigated. BoNT significantly attenuated hand tremor severity in patients with either essential tremor (ET), Parkinson’s disease or multiple sclerosis (Standardized mean difference [SMD] = −0.59, 95% confidence interval [CI], −0.95 to −0.24, p = 0.001, I2 = 46%). Regarding people with ET, BoNT significantly reduced their tremor severity, including hands tremor and head tremor within 6 weeks of treatment (SMD = −0.58, 95% CI, −0.28 to −0.88, p = 0.002, I2 = 0%). Electromyography (EMG) but not anatomical guidance BoNT injection provided significant benefit on the relief of tremor in both conditions. The principal adverse event was weakness, but it did not worse within 6 weeks of BoNT treatment (SMD = −0.35, 95% CI, −0.83 to 0.12, p = 0.07, I2 = 57%), as assessed by the subjective grip strength. In conclusion, BoNT was an effective treatment for the hand tremor and ET, and EMG guidance injection was preferred. In addition, the muscular weakness adverse effect was not significant.

Functional Popliteal Artery Entrapment Syndrome: An Approach to Diagnosis and Management.

Popliteal Artery Entrapment Syndrome (PAES) is an uncommon syndrome that predominantly affects young athletes. Functional PAES is a subtype of PAES without anatomic entrapment of the popliteal artery. Patients with functional PAES tend to be younger and more active than typical PAES patients. A number of differential diagnoses exist, the most common of which is chronic exertional compartment syndrome. There is no consensus regarding choice of investigation for these patients. However, exercise ankle-brachial indices and magnetic resonance imaging are less invasive alternatives to digital subtraction angiography. Patients with typical symptoms that are severe and repetitive should be considered for intervention. Surgical intervention consists of release of the popliteal artery, either via a posterior or medial approach. The Turnipseed procedure involves a medial approach with a concomitant release of the medial gastrocnemius and soleal fascia, the medial tibial attachments of the soleus and excision of the proximal third of the plantaris muscle. Injection of botulinum A toxin under electromyographic guidance has recently shown promise as a diagnostic and/or therapeutic intervention in small case series. This review provides relevant information for the clinician investigating and managing patients with functional PAES.

In-house tooth-supported guide for the injection of botulinum toxin into the lateral pterygoid muscle using Blue Sky Plan software: A technical note

Hyperactivity of the lateral pterygoid muscle (LPM) is one of the theories postulated to explain anterior disc displacement, which can result in difficulty in jaw opening, jaw protrusion, or jaw-deviation dystonias and interferes with mastication, speech, and swallowing. Injection of botulinum toxin of the LPM is considered a conservative therapeutic modality for this condition.The LPM is a deep facial structure and several techniques have been described that use magnetic resonance imaging, arthroscopic, or electromyographic guidance to perform intramuscular botulinum toxin injection safely this to prevent incorrect injection or complications, such arterial bleeding. This study provided a described step-by-step description of the computer-aided design and manufacturing procedure for the fabrication of an in-house guide to simplify the method of botulinum toxin injection in the LPM and ensure accuracy and safety in medical office.

Botulinum toxin type-A infiltration of the external anal sphincter to treat outlet constipation in motor incomplete spinal cord injury: pilot cohort study

Background Outlet constipation is a major problem in spinal cord injury (SCI) patients. We aimed to study the efficacy of external anal sphincter (EAS) infiltration with type-A botulinum toxin (BTX-A) in motor incomplete SCI patients with outlet constipation. Methods Double blind, randomized, placebo controlled, comparative study in 16 motor incomplete SCI subjects. Patients were randomly assigned toreceive100 UI of BTX-A (n = 9) or physiologic serum infiltration (n = 7) in the EAS under electromyographic guidance. Outcome measures included a questionnaire for clinical bowel function evaluation, colonic transit time and anorectal manometry. All assessments were done at baseline, 1 and 3 months after treatment. Results Fourteen patients completed the study. In the BTX-A group we observed an improvement of subjective perception of bowel function (p = 0.01), constipation (p = 0.02) and neurogenic bowel dysfunction score (p = 0.02). The anorectal manometry revealed are duction of EAS voluntary contraction pressure (p = 0.01). No changes were observed in the placebo group. No significant side effects were observed in none of the groups. Conclusion BTX-A infiltration of the EAS is a safe technique that in motor incomplete SCI, decreases the EAS contraction and the anal canal pressure during straining, and improves outlet constipation symptoms. Future studies in larger populations are needed.

Botulinum neurotoxin in cervical dystonia revisited - recent advances and unanswered questions.

Cervical dystonia (CD) usually presents a complex pattern of head/neck movements accompanied by tremor, myoclonic jerks and a wide spectrum of non-motor disturbances such as pain, depression, anxiety, and sleep problems. This is the most challenging indication for botulinum neurotoxin (BoNT) treatment. It can offer significant improvement, but it can be difficult after the first injection. Thorough examination and identification of the proper CD pattern, the identification of the muscles responsible, and adjusting doses given precisely under ultrasound and/or electromyographic guidance seem to be the key success modifiers. Nevertheless, this is a lifelong treatment and should be planned and conducted carefully to avoid failures and drop outs. The aim of this paper was to examine the current concepts in terms of anatomy, physiology and CD patterns (Col-Cap concept) as well as the proper dosages and any possible obstacles impeding successful treatment.

Comparing soleus injections and gastrocnemius injections of botulinum toxin for treating adult spastic foot drop: a monocentric observational study.

ObjectiveOutcome differences between selective abobotulinumtoxin type A (aboBoNT/A) injections into the soleus (SOL) and gastrocnemius (GAS) muscles were investigated in post-stroke patients with spastic foot drop.MethodsA monocentric observational study was conducted at a university hospital botulinum toxin clinic including 24 free-walking adult, botulinum toxin-naive patients with post-stroke hemiplegia. AboBoNT/A (800 MU in 4 mL saline) was injected into the SOL or GAS muscle under electromyographic guidance. After 30 days post-injection, the effect of aboBoNT/A injection was assessed by patients. The treating physician scored spasticity and measured angles at the knee and ankle joint and gait speed.ResultsAfter 30 days, significant improvements of subjective and objective outcome measures were observed. No significant difference was observed in the modified Ashworth scale, gait speed, ankle and knee angles, or their angle combinations between the SOL and GAS groups. Tendencies toward greater active range of motion (RoM) improvement in the SOL group and passive RoM improvement in the GAS group were observed. The difference between active and passive ankle extensions plus knee flexions was significantly larger in the SOL group.ConclusionsSelective 800 MU aboBoNT/A injections into the SOL or GAS muscle were effective but without relevant clinical difference.

Efficacy and Safety of Electromyography‐Guided Injection of Botulinum Toxin to Treat Retrograde Cricopharyngeus Dysfunction

ObjectiveTo report the efficacy and safety of electromyography-guided percutaneous botulinum toxin injection into the cricopharyngeus muscle in an office setting for treatment of the inability to belch and associated symptoms caused by retrograde cricopharyngeus dysfunction (R-CPD).Study DesignRetrospective case series of treated patients.SettingTertiary care laryngology clinic.MethodsA retrospective review was performed on 18 consecutive patients who were diagnosed syndromically with R-CPD. The combined diagnostic test and treatment—specifically, botulinum toxin injection into the cricopharyngeus muscle—was accomplished in an office setting by a single surgeon using electromyography guidance. Items assessed are efficacy, safety, complications, and duration of benefit.ResultsAll 18 patients (100%) treated in the in-office setting gained the ability to burp with improvement in the associated symptoms of R-CPD at initial follow-up. Of those who had the in-office procedure performed initially, 80% maintained the ability to burp at 6 months with relief of all the associated symptoms of R-CPD. No patients experienced permanent complications from the injection, but 7 patients experienced varying degrees of noisy breathing within 1 week after the procedure, which was managed with breathing techniques and resolved.ConclusionIn a case series of 18 patients with R-CPD, all patients gained the ability to burp with improvement in the majority of their symptoms of R-CPD at the time of their initial follow-up at 1 week. None experienced severe complications, and 7 experienced transient noisy breathing, which resolved.

Botulinum Toxin Injection with Conjunctival Microincision for the Treatment of Acute Acquired Comitant Esotropia and Its Effectiveness.

Purpose To report on an improved botulinum toxin injection with conjunctival microincision for beginners, and to determine the effectiveness of botulinum toxin A (BTXA) in the treatment of patients with acute acquired comitant esotropia (AACE). Methods Medical records of 29 AACE patients were retrospectively analyzed. BTXA was injected into the unilateral or bilateral medial rectus muscle with conjunctival microincision without electromyographic guidance. Success was defined as total horizontal deviation ≤10 prism diopters (PD) and evidence of binocular vision. Results Twenty-nine patients were included, of whom 22 were male and 7 were female. The mean age at onset was 14.2 ± 7.4 (range, 4–34) years. The mean time from onset of AACE to injection was 18.4 ± 20.3 (range, 1–96) weeks. All patients completed at least 6 months of follow-up, and the mean follow-up after BTXA injection was 12.3 ± 4.8 months (range, 7–24 months). Neurological evaluation and brain magnetic resonance imaging (MRI) were unremarkable in all patients. The mean spherical equivalent refraction was −1.22 ± 2.85D and −0.97 ± 2.80D in the right and left eyes, respectively. Mean preinjective esotropia was 38.4 ± 18.9 PD (range, +10–+80 PD) at near and 40.2 ± 17.7 PD (range, +20–+80 PD) at far distance. The mean angle of deviation at 6 months after injection was 0.6 ± 4.1 PD (range, −3–+15 PD) at near and 3.0 ± 5.9 PD (range, 0–+20 PD) at far distance. There was significant difference in the angle of deviation at near and far fixation between pre-BTXA and post-BTXA 6 months (p < 0.001, p < 0.001, resp.). There was no significant difference in the angle of deviation at near and far fixation between post-BTXA 6 months and post-BTXA at final follow-up (p = 0.259 and 0.326, resp.). Mean stereoacuity improved from 338 to 88 arc seconds. During the follow-up period, 5 of 29 patients had recurrent esotropia. Two patients refused all further treatment, and the other 3 patients required incisional strabismus surgery. The success rates were 86.2% (25/29) at 6 months and 82.8% (24/29) at final follow-up. Conclusion Conjunctival microincision injection of botulinum toxin is a practical and safe method for beginners to locate an extraocular muscle, which is as effective as the traditional methods. Botulinum toxin injection can be preferred as the first-line treatment for AACE patients with potential binocular vision.

Botulinum toxin injection without electromyographic guidance in consecutive esotropia.

To investigate the efficacy of botulinum toxin injection without electromyographic guidance for the treatment of consecutive esotropia. A retrospective study was performed on 49 subjects with consecutive esotropia who received botulinum toxin injection in the medial rectus muscles without the use of electromyographic guidance. Treatment was considered successful if the final ocular alignment was orthotropic or esodeviation was ≤10 prism diopters (PD) during distant fixation. The mean age was 15.2 ± 8.3 years. The mean esodeviation before injection was 21.8 ± 9.1 PD at distance and 21.3 ± 8.3 PD at near. The mean number of injections per patient was 1.3 ± 0.7, and 46 patients (93.9%) received two or fewer injections. At 6 months after the final injection, the mean angle of esodeviation was 7.3 ± 6.0 PD at distance and 7.5 ± 6.6 PD at near (all p<0.001), and 69.4% showed successful alignment. By multivariate analysis, an initial postoperative esodeviation of ≤18 PD at one month after exotropia surgery was considered to be a predictive factor for successful botulinum toxin injection (P = 0.007). Vertical deviation and/or ptosis occurred in 4 patients (8.2%) at two weeks after injection, which all resolved within three months. There was no recurrence of exotropia up to the final follow-up examination. Botulinum toxin injection without electromyographic guidance is safe and effective in the treatment of consecutive esotropia without causing recurrent exotropia. Successful botulinum toxin injection is likely in patients with an initial postoperative esodeviation of 18PD or less at one month after exotropia surgery.

Efficacy of a Combined Treatment of Botulinum Toxin and Intensive Physiotherapy in Hereditary Spastic Paraplegia.

IntroductionThe Hereditary Spastic Paraplegia (HSP) is a heterogeneous group of neurodegenerative disorders characterized by progressive spasticity and lower limbs (LL) weakness. There is no treatment to cure or halt the disease, except for symptomatic therapy. The use of botulinum toxin type A (BoNT-A) is one of the primary treatment for focal spasticity. Physiotherapy (PT) can help in maintaining residual functioning. We performed a retrospective study to evaluate the effect of the combined BoNT-A and intensive PT in patients with HSP.MethodsEighteen adult patients (50% females) with clinical diagnosis of HSP were recruited. Eleven patients had a genetic diagnosis of SPG4, 5, 7, 8, 11, 72. Patients were all autonomously deambulant or needed support. BoNT-A was injected in 36 LL in different spastic muscles under electromyographic guidance and followed by intensive PT sessions. Outcome measures included disease severity, motor functional measures, perceived pain self-report and quality of life. Assessments occurred at baseline, 1 and 3 months after BoNT-A injection.ResultsMost inoculated muscles were hamstrings, rectus femoris and gastrocnemius. We observed an improvement in muscle tone, in the gait velocity and distance length. Spastic Paraplegia Rating Scale was significantly reduced after treatment, in addition to improving pain and quality of life. These results were riconfirmed in 3 months time.ConclusionOur study indicates that combined treatment of BoNT-A and PT can lead to improvement of spasticity and quality of life in patients with HSP.

Injection into the Longus Colli Muscle via the Thyroid Gland

<strong>Background:</strong> Anterior forms of cervical dystonia are considered to be the most difficult to treat because of the deep cervical muscles that can be involved. <strong>Case Report:</strong> We report the case of a woman with cervical dystonia who presented with anterior sagittal shift, which required injections through the longus colli muscle to obtain a satisfactory outcome. The approach via the thyroid gland was chosen. <strong>Discussion:</strong> The longus colli muscle can be injected under electromyography (EMG), computed tomography (CT), ultrasonography (US), or endoscopy guidance. We recommend using both ultrasonography and electromyography guidance as excellent complementary techniques for injection at the C5-C6 level.

Extraoral Versus Intraoral Botulinum Toxin Type A Injection for Management of Temporomandibular Joint Disc Displacement With Reduction.

: The present study was conducted to compare between extraoral and intraoral approach for botulinum toxin type A (BTX-A) injection into the lateral pterygoid muscle (LPM) in patients suffering from anterior disc displacement with reduction (ADDWR).Fourteen patients suffering from ADDWR were included in this prospective cohort study. Patients were enrolled randomly into 2 groups according to injection approach; where extraoral used in group I, while intraoral approach used in group II. The LPM was injected with 20 IU BTX-A under electromyography (EMG) guidance. Postoperative evaluation of the patients included: mouth opening assessment, LPM tenderness, temporomandibular joint TMJ (clicking), and tenderness. The LPM insertional EMG activity was assessed. Also, magnetic resonance imaging (MRI) was performed to evaluate disc position. Descriptive and inferential analysis was conducted to compare between groups.There was significant patient's convenience during injection and significant injection time reduction in group II. A slight decrease in mouth opening immediate post-injection followed by significant improvement from 8th weeks post-injection was reported in both approaches. There was a significant improvement in TMJ clicking from 1st-week post-injection with no group difference. The EMG assessment documented LPM hyperactivity pre-injection followed by significantly decreased muscle activity at 8 and 16 weeks post-injection without statistical difference. The MRI showed no change in disc position after injection. CONCLUSION:: The BTX-A injection into LPM is a simple technique that can be used with high success and low complication rate for treatment of ADDWR. The intraoral approach was superior to the extraoral concerning patient convenience and injection duration with no statistical difference regarding other clinical outcomes.

Intraoperative Intercostal Nerve Cryoanalgesia Improves Pain Control After Descending and Thoracoabdominal Aortic Aneurysm Repairs

We reviewed the efficacy of intraoperative intercostal nerve cryoanalgesia for pain control in patients undergoing descending and thoracoabdominal aortic aneurysm repairs. During 2013 and 2017, 241 patients underwent descending and thoracoabdominal aortic aneurysm repair. Of those, 38 patients were treated with intraoperative cryoanalgesia to the intercostal nerves at the level of 4th to 10th under electromyography guidance and were compared with patients who did not receive cryoanalgesia. Both groups received multilevel paravertebral block and local infiltration with liposomal bupivacaine. Numerical pain scale scores and amount of opioid usage in morphine milligram equivalences on the first to fourth and eighth postoperative days were collected. We excluded patients from the study who were extubated after the third postoperative day or who were reintubated. One hundred twenty-six patients met the inclusion criteria: 28 in the cryoanalgesia group and 98 in the control group. Preoperative patient demographics were similar in both groups, except for more frequent chronic dissection in patients with cryoanalgesia (93% vs 65%, P= .004). Postoperative major complications, length of stay, and discharge to home were not significantly different in either group. However, median ventilation hours were significantly shorter in the cryoanalgesia group (5 vs 12 hours, P < .001). Opioid use was significantly less in the cryoanalgesia group after postoperative day 4. Indexed morphine milligram equivalences, adjusted with body surface area, and numerical pain scale scores were significantly lower in the cryoanalgesia group throughout the postoperative course. Intercostal nerve cryoanalgesia under electromyography guidance provided improved pain control and reduced narcotic use after descending and thoracoabdominal aortic aneurysm repairs compared with those who only received paravertebral block.

Botulinum toxin for chronic pelvic pain in women with endometriosis: a cohort study of a pain-focused treatment

Background and objectivesMany women with endometriosis continue to have pelvic pain despite optimal surgical and hormonal treatment; some also have palpable pelvic floor muscle spasm. We describe changes in pain,...

Botulinum neurotoxin a therapy efficacy and safety for oromandibular dystonia: a meta-analysis.

Oromandibular dystonia (OMD) is a focal dystonia involving the mouth, jaw, and tongue. Botulinum neurotoxin (BoNT) therapy might be one form of treatment in OMD. Systematic pooling of BoNT studies in OMD remains wanting, as the derived data could provide useful information in regard to efficacy and safety issues. This meta-analysis determined the effects of botulinum neurotoxin type A (BoNT/A) on the reduction of dystonic movement and its safety among patients with OMD. A systematic search of the literature that met the following eligibility criteria were done: (1) patients treated with BoNT/A for OMD, (2) studies of high methodological quality and (3) outcome criteria specified as regard to efficacy. Risk of unresolved dystonia was computed before and after BoNT/A intervention. Random effect size (p < 0.05ɑ) and test of heterogeneity (< I2 50%) were computed as meta-analysis tool using REVMAN ver 5.3 program. Safety data, where available, were systematically reviewed. Nine studies involved 387 cases in total of OMD. The pooled risk ratio is 0.607 with a confidence interval of 0.371-0.783, a zvalue of 3.85, and a pvalue of 0.0001. Results indicate that risk of dystonic movements is lower by 39.30% in the treatment group than in the control group. A total of 105/387 patients (27.1%) experienced adverse events most commonly dysphagia. Whilst cited literatures have inherent weaknesses, results show that BoNT/A is efficacious in reducing dystonic movements of patients with OMD. Majority of studies employed electromyography (EMG) guidance in muscle targeting. Given the potential adverse event of dysphagia, one may take a cautious stand while delivering injections to target muscles. These findings are congruent with what has been published in regard to efficacy of BoNT/A in focal dystonia.

Common practices in botulinum toxin injection for spasmodic dysphonia treatment: A national survey.

Although no clear guidelines exist, protocols in the treatment of spasmodic dysphonia (SD) vary among physicians. Previously published work comes from relatively few centers. A descriptive survey among experts (laryngologists who practice Botulinum toxin injections for SD). An online 58-item survey was sent to all otolaryngologists who self-identify as laryngologists on the American Academy of Otolaryngology-Head and Neck Surgery website. Items surveyed included botulinum toxin injection technique, laterality, and dosage. An 80% response rate was achieved (70 completed the survey). Participants collectively reported treating >4,000 SD patients in the past year (mean, 71 ± 68 patients/laryngologist). Eighty-seven percent perform injections exclusively in the office; the remainder both in the office and operating room. For adductor SD injections, 88% use electromyographic (EMG) guidance alone via cricothyroid approach. The remainder use anatomical landmarks alone (9%) or EMG with endoscopic guidance (3%). Sitting is the preferred patient position (70%; supine, 30%). A substantial majority (87%) begin with bilateral injections (starting dosage mode, 1.25 units/side). For abductor SD injections, 67% use EMG guidance alone and 31% use endoscopic guidance with or without EMG. Sitting is the preferred patient position (84%; supine, 16%). The preferred approach is anterior-translaryngeal (51%), followed by lateral-retrolaryngeal with rotation (34%). A considerable majority (79%) begin with unilateral injections (starting dosage mode, 5 units). When deciding on initial dosage, the most influential factor was balancing patients' desire/needs, followed by patients' frailty and risk of aspiration. The typical planned interval between injections is 3 to 4 months. Laryngologists follow fairly uniform protocols in the treatment of SD with some important and previously unpublished differences. This study documents areas of agreement and discordance among laryngologists in the United States for the treatment of SD. 4 Laryngoscope, 129:1650-1656, 2019.