Utility of laryngeal electromyography for establishing prognosis and individualized treatment after laryngeal neuropathies.

Laryngeal electromyography (LEMG) is a technique used to characterize neuropathic injuries to the recurrent laryngeal nerve (RLN) and superior laryngeal nerve (SLN). The RLN and SLN innervate the laryngeal muscles to produce vocal fold (VF) motion and elongation, respectively. VF motion deficiencies can affect voice, swallowing, and breathing, which can greatly affect a patient's quality of life. Neuropathy-related VF motion deficiencies most often result from surgical interventions to the skull base, neck, or chest likely due to the circuitous route of the RLN. LEMG is ideally conducted by an electromyographer and an otolaryngologist using a team-approach. LEMG is a powerful diagnostic tool to better characterize the extent of neuropathic injury and thus clarify the prognosis for VF motion recovery. This updated review discusses current techniques to improve the positive and negative predictive values of LEMG using laryngeal synkinesis and quantitative LEMG. Synkinesis can be diagnosed by comparing motor unit potential amplitude during vocalization and sniff maneuvers when recording within adductor muscles. Quantitative turns analysis can measure motor unit recruitment to avoid subjective descriptions of reduced depolarization during vocalization, and normal values are >400 turns/s. By integrating qualitative, quantitative, and synkinetic data, a robust prognosis can help clinicians determine if VF weakness will recover. Based on LEMG interpretation, patient-centered treatment can be developed to include watchful waiting, temporary VF augmentation, or definitive medialization procedures and laryngeal reinnervation.

Assessing muscle architecture with ultrasound: implications for spasticity.

Botulinum Neurotoxin Type A (BoNT-A) injections using Ultrasound (US) guidance have led to research evaluating changes in muscle architecture. Controversy remains as to what constitutes increased Echo-Intensity (EI) in spastic muscles and whether this may affect outcomes. We aim to provide a narrative review of US muscle architecture changes following Central Nervous System (CNS) lesions and explore their relationship to spasticity. Medline, CINAHL, and Embase databases were searched with keywords: ultrasonography, hypertonia, spasticity, fibrosis, and Heckmatt. Three physicians reviewed the results of the search to select relevant papers. Reviews identified in the search were used as a resource to identify additional studies. A total of 68 papers were included. Four themes were identified, including histopathological changes in spastic muscle, effects of BoNT-A on the muscle structure, available US modalities to assess the muscle, and utility of US assessment in clinical spasticity. Histopathological studies revealed atrophic and fibro-fatty changes after CNS lesions. Several papers described BoNT-A injections contributing to those modifications. These changes translated to increased EI. The exact significance of increased muscle EI remains unclear. The Modified Heckmatt Scale (MHS) is a validated tool for grading muscle EI in spasticity. The use of the US may be an important tool to assess muscle architecture changes in spasticity and improve spasticity management. Treatment algorithms may be developed based on the degree of EI. Further research is needed to determine the incidence and impact of these EI changes in spastic muscles.

Electromyography findings in radiation-induced unilateral tongue immobility.

BACKGROUND: We used electromyography to characterize hypoglossal nerve function among radiation-treated head and neck cancer survivors with later onset unilateral tongue immobility. METHODS: Patients with unilateral tongue immobility without evidence of recurrent cancer were seen at a tertiary academic institution between February and September 2021. All patients were at least 2 years post-treatment with radiation therapy for head and neck squamous cell carcinoma. Participants were under annual surveillance and displayed no evidence of operative injury to the hypoglossal nerve. RESULTS: The median symptom-free interval for the 10 patients included in this study was 13.2 years (range 2-25 years). Myokymia alone was present in 3 of 10 patients, fibrillation potentials alone were present in 3 of 10 patients, and 1 subject displayed both fibrillation and myokymia. Three out of 10 patients had normal hypoglossal nerve function. DISCUSSION: These findings highlight how disparate mechanisms may underlie similar clinical presentations of radiation-induced neuromuscular dysfunction.

Technical Challenges for Laryngeal Electromyography.

BACKGROUND/OBJECTIVE: Laryngeal electromyography (LEMG) is a useful diagnostic test in the evaluation of vocal fold paralysis (VFP). This study investigates factors that can make LEMG challenging to perform. METHODS: Patients with subacute unilateral VFP presented for LEMG were prospectively enrolled. Demographic data including BMI, previous neck surgery, and anatomic factors were collected. Patient-reported pain related to the procedure was recorded on a visual analogue scale (VAS). Electromyographer and otolaryngologist recorded a consensus rating of the perceived difficulty in performing the test and confidence in using the results for clinical decision-making. RESULTS: A total of 111 patients (56.8% female) were enrolled between August 2015 and August 2018. The mean age was 55 ± 14 years, and the average body mass index (BMI) was 28.5 ± 6.4. The mean patient-reported VAS score for pain was 35 ± 24. Notably, 31.2% of the tests were considered "very easy," 32.1% were considered "mildly challenging" and 23.9% and 12.8% were considered "moderately challenging" and "extremely challenging," respectively, by the clinicians. Common factors affecting LEMG difficulty included poorly palpable surface anatomy (50.5%) and patient intolerance (15.6%). Clinicians felt confident in 76.1% of the test findings. Bivariate analyses showed that prior neck surgery is associated with elevated VAS (p = 0.02), but clinician-perceived difficulty of performing the test is not associated with elevated VAS scores (p = 0.55). CONCLUSIONS: Majority of LEMG tests are well tolerated by patients. Physicians reported more confidence using LEMG for clinical decision-making when the test was easier to perform. Difficult surface anatomy and patient intolerance affects clinician confidence in integrating the test results with clinical care. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:831-834, 2024.

Improvement in Quality-of-Life-Related Outcomes Following Treatment with IncobotulinumtoxinA in Adults with Limb Spasticity: A Pooled Analysis.

A strong correlation has been reported between patient-reported quality of life (QoL) and the investigator-rated Disability Assessment Scale (DAS) in patients with spasticity. The current analysis evaluates the effect of incobotulinumtoxinA on QoL-related outcomes (limb position abnormality, as well as dressing- and hygiene-related disability, measured with the DAS) in adults with upper limb spasticity, using pooled data from six studies. Separate analyses for each DAS domain were performed using data from patients with disabilities for that domain (DAS score ≥1). Results showed that a significantly greater proportion of incobotulinumtoxinA-treated compared with placebo-treated patients achieved a ≥1-point reduction from baseline in each of the DAS domains (improvement) 4 weeks after the first injection. The benefits of incobotulinumtoxinA were observed regardless of the baseline severity of DAS impairment and of the time elapsed since stroke. The effects of incobotulinumtoxinA 4 weeks after injection were maintained or enhanced over multiple injection cycles for all three DAS domains, supporting the use of repeated injection cycles to provide sustained QoL benefit. IncobotulinumtoxinA represents an important treatment option to achieve better QoL-related outcomes for patients with upper limb spasticity, irrespective of the duration of their condition.

Vocal fold injection material does not preclude interpretation of laryngeal electromyography.

INTRODUCTION/AIMS: Temporary vocal fold injection (VFI) is a common treatment for acute and subacute vocal fold paralysis (VFP). Laryngeal electromyography (LEMG) is useful for diagnosing neurogenic causes of VFP. This study evaluated whether the presence of VFI material prevents interpretation of LEMG in patients with acute and subacute VFP. METHODS: Patients with acute and subacute unilateral VFP (onset ≤6 mo) who underwent temporary VFI within 3 mo preceding LEMG were evaluated. A matched control group that did not undergo VFI was also studied. The LEMG team (laryngologist and electromyographer) performed and interpreted LEMG using a pre-specified protocol, including qualitative and quantitative motor unit analysis. RESULTS: Eighteen patients with VFI underwent LEMG successfully with interpretation of spontaneous activity and motor unit recruitment. Fourteen patients were seen in follow-up to determine accuracy of established LEMG prognosis. Seven of seven subjects with poor LEMG prognosis did not recover vocal fold motion. Five of seven subjects with fair LEMG prognosis recovered vocal fold motion. Findings were similar for the control group. DISCUSSION: VFI augmentation material did not prevent interpretation of meaningful LEMG data in patients with acute and subacute VFP, and accurate prognoses of vocal fold motion recovery were established.

Ergonomic Recommendations in Ultrasound-Guided Botulinum Neurotoxin Chemodenervation for Spasticity: An International Expert Group Opinion.

Ultrasound (US)-guided botulinum neurotoxin (BoNT) injections are becoming a mainstay in the treatment of muscle spasticity in upper motor neuron syndromes. As a result, there has been a commensurate increase in US-guided BoNT injection for spasticity training courses. However, many of these courses do not emphasize the importance of ergonomics. This paper aims to highlight the importance of ultrasound ergonomics and presents ergonomic recommendations to optimize US-guided BoNT injection techniques in spasticity management. Expert consensus opinion of 11 physicians (4 different continents; representing 8 countries, with an average of 12.6 years of practice using US guidance for BoNT chemodenervation (range 3 to 22 years)). A search using PubMed, College of Physicians and Surgeons of British Columbia database, EMbase was conducted and found no publications relating the importance of ergonomics in US-guided chemodenervation. Therefore, recommendations and consensus discussions were generated from the distribution of a 20-question survey to a panel of 11 ultrasound experts. All 11 surveyed physicians considered ergonomics to be important in reducing physician injury. There was complete agreement that physician positioning was important; 91% agreement that patient positioning was important; and 82% that ultrasound machine positioning was important. Factors that did not reach our 80% threshold for consensus were further discussed. Four categories were identified as being important when implementing ultrasound ergonomics for BoNT chemodenervation for spasticity; workstation, physician, patient and visual ergonomics. Optimizing ergonomics is paramount when performing US-guided BoNT chemodenervation for spasticity management. This includes proper preparation of the workspace and allowing for sufficient pre-injection time to optimally position both the patient and the physician. Lack of awareness of ergonomics for US-guided BoNT chemodenervation for spasticity may lead to suboptimal patient outcomes, increase work-related injuries, and patient discomfort. We propose key elements for optimal positioning of physicians and patients, as well as the optimal setup of the workspace and provide clinical pearls in visual identification of spastic muscles for chemodenervation.

Abnormal Laryngeal Electromyography Findings in Asymptomatic Adults Across the Age Spectrum.

OBJECTIVES/HYPOTHESIS: Laryngeal electromyography (LEMG) is a diagnostic tool for patients with suspected neurogenic abnormalities of the larynx. LEMG is often used with the assumption that any abnormality is symptom-/disease-related. We sought to determine the prevalence of abnormal LEMG findings in a group of healthy asymptomatic adults across a large age spectrum. STUDY DESIGN: Open, prospective study, gender-match and age balanced by decade. METHODS: Forty-six healthy participants (age 20-78) underwent LEMG, including 178 muscles. Participants had no history of voice problems, normal VHI-10, and normal flexible laryngoscopy. Qualitative and quantitative LEMG (bilateral) were performed involving the thyroarytenoid-lateral cricoarytenoid muscle complex (TA-LCA) and cricothyroid (CT) muscles. LEMG parameters included evaluation for fibrillation potentials, sharp waves, reduced recruitment, polyphasic potentials, electrical synkinesis, and measurement of turns per second. RESULTS: Of participants, 4% had at least one abnormal qualitative finding (slightly reduced recruitment or two to three discrete polyphasic potentials). There were no findings of fibrillation potentials or sharp waves. There were no abnormal qualitative findings in the CT muscles tested. Of participants, 16% had at least one abnormal synkinesis finding. LEMG qualitative abnormalities and quantitative abnormalities do not appear to correlate with gender or age. CONCLUSION: Abnormal qualitative and quantitative LEMG findings were uncommon and minor in severity in our group of asymptomatic healthy adults. The likelihood of abnormal LEMG results in asymptomatic adults was 2.2% for qualitative findings, 9.3% for synkinesis, and 5.4% for turns/s. LEVEL OF EVIDENCE: 3 Laryngoscope, 131:2065-2069, 2021.

Sustained efficacy of incobotulinumtoxina repeated injections for upper-limb post-stroke spasticity: A post hoc analysis.

OBJECTIVE: This post hoc analysis assessed the impact of repeated incobotulinumtoxinA injections on muscle tone, disability, and caregiver burden in adults with upper-limb post-stroke spasticity. DESIGN: Data from the double-blind, placebo-controlled main period and three open-label extension cycles of two Phase 3, randomized, multicentre trials were pooled. METHODS: Subjects received incobotulinumtoxinA 400 Units at 12-week intervals (±3 days) (study 3001, NCT01392300) or ≤ 400 Units at ≥12-week intervals based on clinical need (study 0410, NCT00432666). Ashworth Scale (AS) arm sumscore (sum of elbow, wrist, finger and thumb flexor, and forearm pronator AS scores), Disability Assessment Scale (DAS), and Carer Burden Scale (CBS) scores were assessed. RESULTS: Among 465 subjects, from study baseline to 4 weeks post-injection, mean (standard deviation) AS arm sumscore improved continuously: main period, -3.23 (2.55) (placebo, -1.49 (2.09)); extension cycles 1, 2, and 3, -4.38 (2.85), -4.87 (3.05), and -5.03 (3.02), respectively. DAS principal target domain responder rate increased from 47.4% in the main period (placebo 27.2%) to 66.6% in extension cycle 3. Significant improvements in CBS scores 4 weeks post-injection accompanied improved functional disability in all cycles. CONCLUSION: IncobotulinumtoxinA conferred sustained improvements in muscle tone, disability, and caregiver burden in subjects with upper-limb post-stroke spasticity.

Long-Term Observational Results from the ASPIRE Study: OnabotulinumtoxinA Treatment for Adult Lower Limb Spasticity.

INTRODUCTION: OnabotulinumtoxinA treatment for spasticity varies according to numerous factors and is individualized to meet treatment goals. OBJECTIVE: To explore real-world onabotulinumtoxinA utilization and effectiveness in patients with lower limb spasticity from the Adult Spasticity International Registry (ASPIRE) study. DESIGN: Two-year, multicenter, prospective, observational registry (NCT01930786). SETTING: Fifty-four international clinical sites. PATIENTS: Adults (naïve or non-naïve to botulinum toxin[s] treatment for spasticity, across multiple etiologies) with lower limb spasticity related to upper motor neuron syndrome. INTERVENTIONS: OnabotulinumtoxinA administered at the clinician's discretion. MAIN OUTCOME MEASURES: OnabotulinumtoxinA treatment utilization, clinician- and patient-reported satisfaction. RESULTS: In ASPIRE, 530 patients received ≥1 onabotulinumtoxinA treatment for lower limb spasticity (mean age, 52 years; stroke, 49.4%; multiple sclerosis, 20.4%). Equinovarus foot was treated most often (80.9% of patients), followed by flexed knee (26.0%), stiff extended knee (22.5%), and flexed toes (22.3%). OnabotulinumtoxinA doses ranged between 10 and 1100 U across all presentations. Electromyography (EMG) was most commonly used for injection localization (≥41.1% of treatment sessions). Despite low patient response on the satisfaction questionnaire, clinicians (94.6% of treatment sessions) and patients (84.5%) reported satisfaction/extreme satisfaction that treatment helped manage spasticity, and clinicians (98.3%) and patients (91.6%) would probably/definitely continue onabotulinumtoxinA treatment. These data should be interpreted with care. Twenty-one adverse events (AEs) in 18 patients (3.4%) were considered treatment-related. Sixty-seven patients (12.6%) reported 138 serious AEs; 3 serious AEs in two patients (0.4%) were considered treatment-related. No new safety signals were identified. CONCLUSIONS: ASPIRE provides long-term observational data on the treatment of lower limb spasticity with onabotulinumtoxinA. Real-world data from this primary analysis can help to guide the clinical use of onabotulinumtoxinA to improve spasticity management.

The effect of wrist posture on extrinsic finger muscle activity during single joint movements.

Wrist posture impacts the muscle lengths and moment arms of the extrinsic finger muscles that cross the wrist. As a result, the electromyographic (EMG) activity associated with digit movement at different wrist postures must also change. We sought to quantify the posture-dependence of extrinsic finger muscle activity using bipolar fine-wire electrodes inserted into the extrinsic finger muscles of able-bodied subjects during unrestricted wrist and finger movements across the entire range of motion. EMG activity of all the recorded finger muscles were significantly different (p < 0.05, ANOVA) when performing the same digit movement in five different wrist postures. Depending on the wrist posture, EMG activity changed by up to 70% in individual finger muscles for the same movement, with the highest levels of activity observed in finger extensors when the wrist was extended. Similarly, finger flexors were most active when the wrist was flexed. For the finger flexors, EMG variations with wrist posture were most prominent for index finger muscles, while the EMG activity of all finger extensor muscles were modulated in a similar way across all digits. In addition to comprehensively quantifying the effect of wrist posture on extrinsic finger EMG activity in able-bodied subjects, these results may contribute to designing control algorithms for myoelectric prosthetic hands in the future.

Individualized OnabotulinumtoxinA Treatment for Upper Limb Spasticity Resulted in High Clinician- and Patient-Reported Satisfaction: Long-Term Observational Results from the ASPIRE Study.

INTRODUCTION: OnabotulinumtoxinA treatment for spasticity is dependent on numerous factors and varies according to selected treatment goals. OBJECTIVE: To examine real-world onabotulinumtoxinA treatment utilization and effectiveness in patients with upper limb spasticity over 2 years from the Adult Spasticity International Registry (ASPIRE) study. DESIGN: Multicenter, prospective, observational registry (NCT01930786). SETTING: Fifty-four international clinical sites in North America, Europe, and Asia. PATIENTS: Adults (naïve or non-naïve to botulinum toxins for spasticity) with upper limb focal spasticity related to upper motor neuron syndrome across multiple etiologies. INTERVENTIONS: OnabotulinumtoxinA administered at clinician's discretion. MAIN OUTCOME MEASURES: OnabotulinumtoxinA utilization, clinician and patient satisfaction. RESULTS: Four hundred eighty-four patients received ≥1 treatment of onabotulinumtoxinA for upper limb spasticity. Patients were on average 55.1 years old, 50.8% male, predominantly Caucasian (72.3%), and 38.6% were naïve to botulinum toxins. Stroke was the most frequently reported underlying etiology (74.0%). Most patients (81.2%) had moderate to severe spasticity at baseline. The most commonly treated upper limb clinical presentation was clenched fist (79.1% of patients). Across all presentations, onabotulinumtoxinA doses ranged between 5-600U. Electromyography (EMG) was most often utilized to localize muscles (≥57.0% of treatment sessions). Clinicians (92.9% of treatment sessions) and patients (85.7%) reported being extremely satisfied/satisfied that treatment helped manage spasticity, and clinicians (98.6%) and patients (92.2%) would definitely/probably continue onabotulinumtoxinA treatment. One hundred seventy-nine patients (37.0%) reported 563 adverse events (AEs); 15 AEs in 14 patients (2.9%) were considered treatment related. Sixty-nine patients (14.3%) reported 137 serious AEs; 3 serious AEs in 2 patients (0.4%) were considered treatment related. No new safety signals were identified. CONCLUSIONS: ASPIRE captured the real-world individualized nature of onabotulinumtoxinA utilization for upper limb spasticity over 2 years, with consistently high clinician- and patient-reported satisfaction. Data in this primary analysis will guide clinical use of onabotulinumtoxinA, as well as provide insights to improve educational programs on spasticity management.

IncobotulinumtoxinA Treatment in Upper-Limb Poststroke Spasticity in the Open-Label Extension Period of PURE: Efficacy in Passive Function, Caregiver Burden, and Quality of Life.

BACKGROUND: Poststroke spasticity affects motor function and the ability to perform activities of daily living, with the potential to affect quality of life (QoL) and increase caregiver burden. OBJECTIVE: To investigate the effect of repeated incobotulinumtoxinA treatment on spasticity-associated functional disability, caregiver burden, and QoL in the 36-week open-label extension of the phase 3 PURE study (NCT01392300). DESIGN: Open-label extension period of a prospective, double-blind, placebo-controlled, randomized, multicenter study. SETTING: Forty-six investigation sites in seven countries (Czech Republic, Germany, Hungary, India, Poland, Russia, United States). PARTICIPANTS: Adults, aged 18-80 years, ≥12 months since last botulinum neurotoxin injection or entirely toxin naïve, with median poststroke upper-limb spasticity of >2 years' duration. METHODS: Participants who completed the 12-week, double-blind main period could enter the open-label extension and receive up to three additional incobotulinumtoxinA treatments (fixed total dose 400 U at 12-week intervals) into the affected muscles of one upper limb. MAIN OUTCOME MEASURES: Functional disability (Disability Assessment Scale; DAS), caregiver burden (Carer Burden Scale), and quality of life (QoL; EuroQol [EQ] 5-dimensions three-level [EQ-5D-3L]). RESULTS: The open-label extension included 296 treated patients. Mean DAS score for the principal target domain improved significantly from the main period baseline to the end-of-study visit (P < .0001). Carer Burden Scale scores also significantly improved from the main period baseline to the end-of-study visit (P < .05 for all caregiving activities except "applying a splint"). At the end-of-study visit, versus the main period baseline, 19.7%-33.3% of patients experienced improvements for each parameter on the EQ-5D-3L, except "mobility," with significant improvement in EQ-5D visual analog scale scores (P < .001). CONCLUSIONS: Repeated incobotulinumtoxinA treatments at 12-week intervals in participants with chronic poststroke upper-limb spasticity resulted in significant improvements in QoL, as well as significant reductions in upper-limb functional disability and caregiver burden.

Reliability and Validity of the Modified Heckmatt Scale in Evaluating Muscle Changes With Ultrasound in Spasticity.

OBJECTIVES: To determine the reliability and validity of the Modified Heckmatt scale in assessing muscle echotexture in spasticity. DESIGN: Prospective, observational, 2-center study. Two residents and 2 ultrasound experienced staff physicians each rated 100 ultrasound images that were also analyzed using quantitative gray-scale. SETTING: Academic ambulatory spasticity clinic. PARTICIPANTS: Participants (N=50) included 45 patients with upper or lower extremity spasticity and 5 healthy references. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Modified Heckmatt scale ratings and quantitative gray-scale scores. RESULTS: Inter- and intra-rater intraclass correlation coefficients were 0.76 and 0.81, respectively (P<.001), indicating good to excellent reliability. A significant relationship was found between Modified Heckmatt scores and quantitative gray-scale scores (r=0.829; P<.001). CONCLUSIONS: The Modified Heckmatt scale demonstrated good reliability and validity to assess the pathologic muscle changes that occur in patients with spasticity.

IncobotulinumtoxinA Efficacy and Safety in Adults with Upper-Limb Spasticity Following Stroke: Results from the Open-Label Extension Period of a Phase 3 Study.

INTRODUCTION: The objective of the study was to investigate the efficacy and safety of repeated incobotulinumtoxinA injections for the treatment of upper-limb post-stroke spasticity in adults. METHODS: Adults 18-80 years of age with post-stroke upper-limb spasticity who completed the 12-week randomized, double-blind, placebo-controlled main period (MP) of a phase 3 trial (NCT01392300) were eligible to enrol in the 36-week open-label extension period (OLEX). The OLEX included three treatment cycles at fixed 12-week injection intervals; subjects were injected with 400 U incobotulinumtoxinA into the affected upper limb. Efficacy assessments included evaluation of muscle tone using the Ashworth Scale (AS) and the Global Impression of Change Scale (GICS) assessed by the investigator, subject, and caregiver. The incidence of adverse events (AEs) was monitored throughout the OLEX. RESULTS: A total of 296 of 299 subjects (99.0%) who completed the MP received incobotulinumtoxinA in the OLEX, and 248 subjects completed the 36-week OLEX. The proportion of subjects with at least a 1-point improvement in AS score from each incobotulinumtoxinA treatment to the respective 4-week post-injection visit ranged by cycle from 52.3% to 59.2% for wrist flexors, 49.1% to 52.3% for elbow flexors, 59.8% to 64.5% for finger flexors, 35.5% to 41.2% for thumb flexors, and 37.4% to 39.9% for forearm pronators (P < 0.0001 for all). Over 90% of subjects were assessed by the investigator to be at least minimally improved (4 weeks post-injection) on the GICS during each injection cycle; 61.0% in the 1st cycle, 58.2% in the 2nd cycle, and 57.4% in the 3rd cycle were considered much improved or very much improved on the GICS. Three percent of subjects (9/296) reported treatment-related AEs; the most frequently reported were pain in the extremity (n = 2, 0.7%) and constipation (n = 2, 0.7%). Serious AEs were reported by 22 subjects (7.4%); however, none were considered treatment-related. CONCLUSIONS: Repeated injections of incobotulinumtoxinA for the treatment of post-stroke upper-limb spasticity led to significant improvements in muscle tone and investigator's global impression of change. Treatment was well tolerated, with no serious treatment-related AEs. FUNDING: Merz Pharmaceuticals GmbH.

Innervation status in chronic vocal fold paralysis and implications for laryngeal reinnervation.

OBJECTIVE: Treatment options for symptomatic unilateral vocal fold paralysis (VFP) include vocal fold augmentation, laryngeal framework surgery, and laryngeal reinnervation. Laryngeal reinnervation (LR) has been suggested to provide "tone" to the paralyzed VF. This implies a loss of tone as a result of denervation without reinnervation. We performed laryngeal electromyography (LEMG) in patients with chronic VFP to understand the innervation status associated with a chronically paralyzed vocal fold. STUDY DESIGN: Retrospective review of LEMG data in adult patients with chronic VFP from January 2009 to December 2014. METHODS: LEMG was performed at least 6 months after-onset of VFP. Qualitative LEMG, quantitative LEMG, and adductory synkinesis testing were performed, and the parameters were collected. RESULTS: Twenty-seven vocal folds were studied (23 unilateral VFP and 2 bilateral VFP). Average age was 59 ± 17 years. The median duration from recurrent laryngeal nerve injury to LEMG was 8.5 months (range 6-90 months). The majority of patients, 24 of 27 (89%), had motor unit potentials during phonation tasks on LEMG, and only 3 of 27 (11%) patients were electrically silent. Quantitative LEMG showed 287.8 mean turns per second (normal ≥ 400). Motor unit configuration was normal in 12 of 27 (44%), polyphasic in 12 of 27 (44%), and absent in the electrically silent patients. Adductory synkinesis was found in 6 of 20 (30%) patients. CONCLUSION: Chronic vocal fold paralysis is infrequently associated with absent motor-unit recruitment, indicating some degree of preserved innervation and/or reinnervation in these patients. LEMG should be part of the routine workup for chronic VFP prior to consideration of LR. LEVEL OF EVIDENCE: 4. Laryngoscope, 128:1628-1633, 2018.

Comparing Electrical Stimulation With and Without Ultrasound Guidance for Phenol Neurolysis to the Musculocutaneous Nerve.

BACKGROUND: Ultrasound guidance is increasingly being used for neurolytic procedures that have traditionally been done with electrical stimulation (e-stim) guidance alone. Ultrasound visualization with e-stim-guided neurolysis can potentially allow adjustments in injection protocols that will reduce the volume of neurolytic agent needed to achieve clinical improvement. OBJECTIVE: This study compared e-stim only to e-stim with ultrasound guidance in phenol neurolysis of the musculocutaneous nerve (MCN) for elbow flexor spasticity. We also evaluated the ultrasound appearance of the MCN in this population. DESIGN: Retrospective review. SETTING: University hospital outpatient clinic. PARTICIPANTS: Adults (N = 167) receiving phenol neurolysis to the MCN for treatment of elbow flexor spasticity between 1997 and 2014 and adult control subjects. METHODS: For each phenol injection of the MCN, the method of guidance, volume of phenol injected, technical success, improved range of motion at the elbow postinjection, adverse effects, reason for termination of injections, and details of concomitant botulinum toxin injection were recorded. The ultrasound appearance of the MCN, including nerve cross-sectional area and shape, were recorded and compared between groups. MAIN OUTCOME MEASURES: The volume of phenol injected and MCN cross-sectional area and shape as demonstrated by ultrasound. RESULTS: The addition of ultrasound to e-stim-guided phenol neurolysis was associated with lower doses of phenol when compared to e-stim guidance alone (2.31 mL versus 3.69 mL, P < .001). With subsequent injections, the dose of phenol increased with e-stim guidance (P < .001), but not with e-stim and ultrasound guidance (P = .95). Both methods of guidance had high technical success, improved ROM at elbow postinjection, and low rates of adverse events. In comparing the ultrasound appearance of the MCN in patients with spasticity to that of normal controls, there was no difference in the cross-sectional area of the nerve, but there was more variability in shape. CONCLUSIONS: Combined e-stim and ultrasound guidance during phenol neurolysis to the MCN allows a smaller volume of phenol to be used for equal effect, both at initial and repeat injection. The MCN shape was more variable in individuals with spasticity; this should be recognized so as to successfully locate the nerve to perform neurolysis. LEVEL OF EVIDENCE: IV.

Effect of intralaryngeal muscle synkinesis on perception of voice handicap in patients with unilateral vocal fold paralysis.

OBJECTIVES/HYPOTHESIS: Intralaryngeal muscle synkinesis associated with unilateral vocal fold paralysis (UVFP) is thought to preserve thyroarytenoid-lateral cricoarytenoid muscle complex tone, resulting in a better voice despite the presence of vocal fold paralysis (VFP). This study compares voice handicap in patients with unilateral VFP (UVFP) with and without evidence of adductory synkinesis on laryngeal electromyography (LEMG). STUDY DESIGN: Retrospective review of LEMG data and Voice Handicap Index-10 (VHI-10) scores of patients diagnosed with permanent UVFP. METHODS: LEMG was performed within 1 to 6 months post onset of UVFP. Patients were stratified into two groups: 1) recurrent laryngeal nerve (RLN) neuropathy with synkinesis and 2) RLN neuropathy without synkinesis. Synkinesis was diagnosed when the sniff to phonation maximum amplitude ratio was ≥0.65. VHI-10 scores at 6-month follow-up were recorded. RESULTS: Four hundred forty-nine patients with UVFP and who had an LEMG were reviewed. Eighty-three patients met the inclusion criteria, with 16 in group 1 and 67 in group 2. There was no significant difference between the groups with regard to age, timing of LEMG from onset of VFP, number of patients undergoing temporary vocal fold injection or use of off-label nimodipine. Average VHI-10 scores at 6 months post onset of VFP were 14.4 ± 10.6 for patients with LEMG-identified synkinesis (group 1) and 21.0 ± 10.1 for patients with no LEMG evidence of synkinesis (group 2). This was statistically significant (P = .02). CONCLUSIONS: Patients with unilateral vocal fold paralysis and LEMG evidence of laryngeal synkinesis are more likely to have less perceived voice handicap than those without synkinesis. LEVEL OF EVIDENCE: 4. Laryngoscope, 127:1628-1632, 2017.

Diagnosis of Ulnar Nerve Entrapment at the Arcade of Struthers with Electromyography and Ultrasound.

Ulnar neuropathy is caused by compression of the ulnar nerve in the upper extremity, frequently occurring at the level of the elbow or wrist. Rarely, ulnar nerve entrapment may be seen proximal to the elbow. This report details a case of ulnar neuropathy diagnosed and localized to the arcade of Struthers with electromyography (EMG) and ultrasound (US) imaging and confirmed at time of operative release. US imaging and EMG findings were used to preoperatively localize the level of compression in a patient presenting with left ulnar neuropathy. In this case, ulnar entrapment 8 cm proximal to the medial epicondyle was diagnosed. Surgical release was performed and verified the level of entrapment at the arcade of Struthers in the upper arm. Alleviation of symptoms was noted at 8-week follow-up; no complications occurred. US imaging can be used in complement with EMG studies to properly diagnose and localize the level of ulnar nerve entrapment. This facilitates full release of the nerve and may prevent the need for revision surgery.