Surface anatomy and levator scapulae muscle injection: A cadaveric investigation.

Accurate detection of the levator scapulae muscle is critical for effective diagnostic and therapeutic interventions. The commonly used surface anatomy approach has not been validated and is less accurate than ultrasound-guided techniques. Therefore, we determined the needle insertion point for the levator scapulae using a new technique based on the anatomy of the scapula. This investigation used 15 fresh-frozen cadavers to explore the relationship between the acromial angle and medial tip of the scapular spine (O) of the scapular spine. Based on the x-axis (the distance [L] from Point O to point acromial angle) and the y-axis perpendicular to the x-axis passing through Point O, the barycentric coordinates were determined through the intersections of each axis and the superior angle of the scapula with the levator scapulae. Various ratios involving the established distance L) were ascertained, we compared the measurements and ratios between the male and female groups, and the accuracy of the new technique was compared with the conventional technique. The optimal site of the new technique was within 6 to 7% of distance L on the x-axis and 42 to 44% of distance L on the y-axis. This technique was significantly more accurate than the conventional technique (P = .006). Although ultrasound allows for accurate injections via real-time visualization, its unavailability in some cases highlights the importance of understanding surface anatomy landmarks. Our new technique, based on the anatomy of the scapula and relative measurements, is more accurate than the conventional technique. This should enable more precise detection of the levator scapulae for accurate and efficient diagnostic and therapeutic procedures.

Increasing precision during neuromodulator injections for frontal rhytids-Using ultrasound imaging to identify the line of convergence.

BACKGROUND: Recent research introduced the concept of the "line of convergence" as a guide for injectors to enhance precision and avoid complications when treating the frontalis muscle with toxins. However, currently, no pre-injection ultrasound scanning is employed to increase precision and reduce adverse events when searching for the line of convergence. OBJECTIVE: To explore the feasibility and practicality of implementing pre-injection ultrasound scanning into aesthetic neuromodulator treatments of the forehead. METHODS: The sample of this study consisted of n = 55 volunteers (42 females and 13 males), with a mean age of 42.24 (10.3) years and a mean BMI of 25.07 (4.0) kg/m2. High-frequency ultrasound imaging was utilized to measure the thickness, length, and contractility of the frontal soft tissue and to determine the precise location of the line of convergence during maximal frontalis muscle contraction. RESULTS: The results revealed that the line of convergence was located at 58.43% (8.7) of the total forehead height above the superior border of the eyebrow cilia without a statistically significant difference between sex, age, or BMI. With frontalis muscle contraction, the forehead shortens in males by 25.90% (6.5), whereas in females it shortens only by 21.74% (5.1), with p < 0.001 for sex differences. CONCLUSION: This study demonstrated the feasibility and practicality of pre-injection ultrasound scanning for facial aesthetic neuromodulator treatments. Knowing the location of the line of convergence, injectors can determine precisely and on an individual basis where to administer the neuromodulator deep or superficial or when the injection location is at risk to cause eyebrow ptosis.

Ultrasound Evaluation and Guided Injection of the Subscapularis and Serratus Anterior Muscles Between the Scapula and the Thoracic Cage: A Technical Note.

Most subscapularis and serratus anterior muscles lie between the scapula and the thoracic cage. Evaluation of this area in patients with scapulothoracic dyskinesis, snapping scapular syndrome, or interscapular pain can provide valuable information to clinicians. However, ultrasound scanning of pathologies in this area is hindered by anatomical limitations. In this study, we described a simple patient setup position and scanning method for ultrasound evaluation and guided intervention of the subscapularis and serratus anterior muscles between the scapula and thoracic cage.

Intramuscular nerve distribution of the sternocleidomastoid muscle for the botulinum toxin injection.

PURPOSE: The aim of this study is to define the intramuscular nerve distribution of the sternocleidomastoid muscle (SCM) and the innervation zones (IZ) to describe the optimal botulinum toxin injection sites. METHODS: The cricoid cartilage (CC), laryngeal prominence (LP) and hyoid bone (HB) and angle of mandible (AM) were determined as landmarks. The length of the muscles were measured between the sternoclavicular joint and tip of the mastoid process. SCM was evaluated in two parts as anterior and posterior divided by the line where the length of the muscle was measured. Measurements were made to define the relationships of the SCM with common carotid artery, internal and external jugular veins. IZ were described according to these vessels. Afterwards, Modified Sihler's staining technique was applied to expose the intramuscular nerve distribution. RESULTS: The average length of SCM was 160,1 mm. Motor entry point of the accessory nerve fibers were between the AM-HB lines, in the range of 30-40% of the muscle length, and in the posterior part of the muscles. IZ were between the HB-CC lines in the anterior and posterior part. When this interval was examined according to the vessels, the optimal injection sites were between the LP-CC lines. CONCLUSIONS: This study shows the position of the intramuscular nerve fibers endings of the SCM according to the chosen landmarks and the relationship of the IZ with the vessels to prevent complications. These results can be used as a guide for safe and effective botulinum toxin injections with optimal quantities.

Comparison of local versus intramuscular steroid injection in patients with carpal tunnel syndrome: A prospective open label randomized clinical trial.

AIM: This study compared the efficacy and safety of local corticosteroid injection (LCI) vs intramuscular (IM) corticosteroid injection in mild to moderate carpal tunnel syndrome (CTS). METHODS: This is an open labeled, randomized controlled trial conducted during December 2021 to August 2023. Eighty-six patients with CTS were randomized in 1:1 ratio to receive either single 40 mg methylprednisolone (MP) injection at the wrist (LCI arm), or single 40 mg MP intramuscular injection (IM arm) in the deltoid. Primary outcome was absolute Symptom Severity Scale (SSS) at 3 months. Secondary outcomes were SSS score at 1-month, Functional Status Scale (FSS) score at 1 and 3 months, and recurrence at 3 months and injection site pain assessed on visual analog (VAS) scale. RESULTS: Median age was 45 (range 22 - 80) years, and 86 % were females. Baseline characteristics were comparable between groups. Mean SSS score at 3 months was similar in two arms (1.72 ± 0.71 vs 2.0 ± 0.93) with mean difference (MD) -0.03 (-0.31 to 0.25, p = 0.83) after adjusting for baseline SSS scores. LCI, however, resulted in significantly better SSS (1.48 ± 0.51 vs 1.88 ± 0.69, adjusted p = 0.04), and FSS scores (1.57 ± 0.44 vs 1.80 ± 0.66, adjusted p = 0.03) at 1 month compared to IM arm. Response rate (67.4 % vs 55.8 %; p = 0.30) and recurrence rate (17.1 % vs 22.6 %, p = 0.74) at 3 months were similar. Injection site pain was severe in LCI arm[median 5 (range 3 - 8) vs median 3 (range 2 - 6)]. CONCLUSIONS: In patients with mild to moderate CTS, LCI resulted in better improvement in the BCTQ scores at 1 month compared to IM steroid. However, 3-month's outcome was similar. Intramuscular steroid injection was better tolerated.

Does the guidance method affect the doses of botulinum toxin in writer's cramp?

PURPOSE: Botulinum neurotoxin (BoNT) injections are the main medical treatment of writer's cramp. When the outcome is favourable, patients usually receive injections several times per year in the long-term. However, we know little about the course of BoNT doses and nothing about the impact of the guidance method on the clinical outcome or injection strategy. METHODS: We studied, in the long-term, the doses of BoNT and the target muscles in a group of patients with writer's cramp, according to the guidance method (electrical stimulation or ultrasound). Patients received at least three injection cycles guided by electrical stimulation, followed by at least three injection cycles guided by ultrasound. RESULTS: Twenty-four patients were included. More target muscles were injected after switching to ultrasound guidance, especially the flexor carpi ulnaris and the flexor carpi radialis. The mean dose by muscle was lower when ultrasound guidance was used. When using electrical stimulation guidance, the dose in the flexors of the fingers decreased in the long-term, but increased in the flexors of the wrist. The course of the BoNT doses and of the number of target muscles per cycle were not the same during the first period (electrical stimulation) and the second period (ultrasound). CONCLUSIONS: Switching to ultrasound guidance, the BoNT dose decreased, mainly in the flexors of the wrist. Based on the results of our study, we suggest a starting dose in several muscles (flexor carpi ulnaris, flexor carpi radialis, flexor digitorum profundus and flexor pollicis longus).

Musculoskeletal injections for palliative treatment of neuromuscular hip dysplasia patients: how I do it.

This review describes our institution's standardized technique as well as potential pitfalls for therapeutic steroid injections in children with symptomatic neuromuscular hip dysplasia. Symptomatic, painful neuromuscular hip dysplasia can dramatically affect quality of life. Steroid injections are used to identify the source of perceived pain, temporarily treat pain while awaiting surgical intervention, or for therapeutic management for nonoperative hip joints.

Trial of Botulinum Toxin for Isolated or Essential Head Tremor.

BACKGROUND: Local injections of botulinum toxin type A have been used to treat essential head tremor but have not been extensively studied in randomized trials. METHODS: In 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. RESULTS: A 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. CONCLUSIONS: Injection 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.).

Intramuscular injection: exploring the evidence on effective administration.

Administering medicines by intramuscular (IM) injection is a familiar, though not necessarily common, nursing procedure. To ensure effective administration of IM injections it is important that nurses are up to date with the evidence on factors such as selection of injection site, use of appropriate equipment and injection technique. This article explores the evidence on effective administration of IM injections with the aim of enhancing nurses' decision-making and technique when undertaking this procedure.

A Bayesian Network Meta-Analysis and Systematic Review of Guidance Techniques in Botulinum Toxin Injections and Their Hierarchy in the Treatment of Limb Spasticity.

Accurate targeting of overactive muscles is fundamental for successful botulinum neurotoxin (BoNT) injections in the treatment of spasticity. The necessity of instrumented guidance and the superiority of one or more guidance techniques are ambiguous. Here, we sought to investigate if guided BoNT injections lead to a better clinical outcome in adults with limb spasticity compared to non-guided injections. We also aimed to elucidate the hierarchy of common guidance techniques including electromyography, electrostimulation, manual needle placement and ultrasound. To this end, we conducted a Bayesian network meta-analysis and systematic review with 245 patients using the MetaInsight software, R and the Cochrane Review Manager. Our study provided, for the first time, quantitative evidence supporting the superiority of guided BoNT injections over the non-guided ones. The hierarchy comprised ultrasound on the first level, electrostimulation on the second, electromyography on the third and manual needle placement on the last level. The difference between ultrasound and electrostimulation was minor and, thus, appropriate contextualization is essential for decision making. Taken together, guided BoNT injections based on ultrasound and electrostimulation performed by experienced practitioners lead to a better clinical outcome within the first month post-injection in adults with limb spasticity. In the present study, ultrasound performed slightly better, but large-scale trials should shed more light on which modality is superior.

Análise das gestações ectópicas íntegras tratadas com o protocolo de dose única de metotrexato / Analysis of unruptured ectopic pregnancies treated with single-dose methotrexate protocol

Objetivo: Avaliar o índice de sucesso do tratamento da gravidez ectópica com o protocolo de dose única do metotrexato e verificar sua correlação com variáveis clínicas e dados dos exames complementares. Métodos: É um estudo epidemiológico observacional, analítico, retrospectivo, de delineamento transversal. Foi realizado de janeiro de 2014 a agosto de 2020 em um hospital público, de ensino, em nível terciário, do Sul do Brasil. Em 73 casos com diagnóstico de gestação ectópica íntegra, foi utilizado o protocolo de dose única de metotrexato intramuscular, com a dose de 50 mg/m2 de superfície corporal. As variáveis do estudo foram relacionadas ao sucesso do tratamento e abordaram as características clínicas na admissão, dos exames complementares e do tratamento realizado. As variáveis foram comparadas por análise de regressão de Poisson. O nível de significância estabelecido foi de p < 0,05. Resultados: O índice de sucesso foi de 83,6%, e em nove casos foi necessária uma segunda dose da medicação. Nível de ß-hCG inicial superior a 5.000 mUI/mL foi relacionado a menor chance de sucesso (odds ratio ajustado de 0,20 [0,05-0,95]). Tamanho da imagem anexial, presença de líquido livre na cavidade abdominal e demais variáveis estudadas não afetaram a chance de sucesso do tratamento. Conclusão: O protocolo de dose única de metotrexato mostrou-se uma opção válida para o tratamento da gestação ectópica íntegra, notadamente quando o nível de ß-hCG inicial é inferior 5.000 mUI/mL.

Objective: The purpose of the present study is to evaluate the success rate of treatment of ectopic pregnancy with the single-dose methotrexate protocol and to verify its correlation with clinical variables and complementary exam data. Methods: This is a retrospective epidemiological observational analytical cross-sectional study. It was carried out from January 2014 to August 2020 in a tertiary level teaching hospital in southern Brazil. In 73 cases with a diagnosis of intact ectopic pregnancy, the intramuscular methotrexate single-dose protocol was applied with a dose of 50 mg/m2 of body surface. The study variables were related to the success of the treatment and addressed the clinical characteristics on admission, the complementary exams and the treatment performed. The variables were compared by Poisson regression analysis. The level of significance was set at p < 0.05. Results: The success rate was 83.6%, and in nine cases a second dose of the medication was necessary. An initial ß-hCG level greater than 5,000 mIU/mL was related to a lower chance of success (adjusted odds ratio of 0.20 [0.05- 0.95]). The size of the adnexal image, the presence of free fluid in the abdominal cavity and other variables studied did not affect the chance of a successful treatment. Conclusion: The methotrexate single-dose protocol proved to be a valid option for the treatment of intact ectopic pregnancy, notably when the initial ß-hCG level is below 5,000 mIU/mL.

Comparison of pain levels developed during intramuscular injections to laterofemoral and ventrogluteal regions in children: a randomized controlled study.

OBJECTIVE: The aim of this study was to compare the levels of pain developed during intramuscular injections to the laterofemoral and ventrogluteal regions in children. METHODS: The study population consisted of all children aged between 7 and 12 years who presented to the pediatric emergency clinic of a hospital. The sample consisted of 62 children who met the inclusion criteria and agreed to participate in the study, and the children were randomly assigned to each group (laterofemoral n=31, ventrogluteal n=31). "Buzzy" and "deep breathing" were applied to children in both groups to relieve pain during the procedure. The data were obtained using an Information Form, a visual analog scale, and the Facial Pain Scale-Revised. RESULTS: It was determined that the children in the ventrogluteal group during the intramuscular injections had lower visual analog scale and faces pain scale-revised scores immediately after the procedure compared with the vastus lateralis group, that is, they experienced less pain, and the difference between the two groups was significant (p<0.001). CONCLUSION: In children, it is recommended to choose the less painful ventrogluteal region for intramuscular injection and to inform health professionals about it.

What variables should inform needle length choice for deltoid intramuscular injection? A systematic review.

OBJECTIVES: (1) Assess the distribution of skin-to-deltoid-muscle distance (SDMD) at the deltoid intramuscular (IM) injection site; (2) its relationship with demographic and anthropometric variables and (3) Consider the findings in relation to clinical guidance on IM injection, such as COVID-19 vaccines. DESIGN: Systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. DATA SOURCES: MEDLINE, EMBASE, ClinicalTrials.gov, Cochrane Library, CINAHL and SCOPUS between June and July 2021 with no publication date limit. ELIGIBILITY CRITERIA: Studies reporting measurements of the SDMD in living adults aged 16 years and older, at the deltoid IM injection site, published in English were considered. DATA EXTRACTION AND SYNTHESIS: Two independent reviewers performed each stage of screening, data extraction and quality assessments using the Joanna Briggs Institute Critical Appraisal Checklist for analytical cross sectional studies. RESULTS: 16 105 papers were identified, of which 11 studies were suitable for review, representing 1414 participants. Heterogeneity in the definition of the deltoid IM injection site, locations measured and methods of measurement precluded meta-analysis. Evidence from ultrasound SDMD measurements demonstrated some patients in all but 'underweight' body mass index (BMI) categories, may require needles longer than 25 mm for successful IM injection. Calliper measurements overestimated SDMD compared with ultrasound. Female sex, higher BMI categories and greater weight in women were associated with greater SDMD. CONCLUSIONS: The reviewed evidence was insufficient to inform definitive needle length 'cut points' for IM injection based on demographic or anthropomorphic variables. Contemporary clinical guidance currently based on this evidence, including the site of injection and choice of needle length, may result in subcutaneous administration in a small proportion of recipients, particularly if obese or of female sex. PROSPERO REGISTRATION NUMBER: CRD42021264625.

Investigation of the Necessity of Aspiration During the Intramuscular Injection Administered in the Ventrogluteal Site and Its Effect on Pain: A Randomized Controlled Trial.

This experimental study, which was conducted to examine the necessity of aspiration procedure and its effect on pain in intramuscular (IM) injections made into the ventrogluteal site (VGS), is randomized controlled and double-blind. The patients in the study group (n = 834) were assigned to the IM group with the aspiration period of 5 to 10 seconds (Implementation Group A-IGA), the aspiration period of 1 to 2 seconds (Control Group-CG), and no aspiration (Implementation Group B-IGB) according to stratified block randomization list. Patients' pain levels were evaluated with the Visual Analog Scale (VAS). No bleeding was observed when aspiration periods of 1 to 2 and 5 to 10 seconds were followed during the injections administered to the VGS. The difference between the pain medians of patients in IGB and the CG were not significant (p = .521). It can be said that there is no need to apply aspiration in IM applied into the VGS if the correct site is determined.

Pharmacokinetic and pharmacodynamic comparison of epinephrine, administered intranasally and intramuscularly: An integrated analysis.

BACKGROUND: Manual intramuscular epinephrine injection is the standard of care for treating severe allergic reactions and anaphylaxis. Epinephrine autoinjectors were approved on the basis of the assumption that their pharmacokinetic and pharmacodynamic profiles are equivalent to manual intramuscular injection; however, although there is emerging evidence for product-related differences in pharmacokinetic profiles, very little is known about the comparative pharmacodynamic profiles. OBJECTIVE: To compare pharmacokinetic and pharmacodynamic profiles of epinephrine delivered through manual intramuscular injection, autoinjectors, and intranasal spray. METHODS: This integrated analysis was based on data from 4 randomized cross-over phase 1 trials that compared the pharmacokinetics and pharmacodynamics of epinephrine using manual intramuscular epinephrine 0.3 mg injection, epinephrine 0.3 mg autoinjectors (Symjepi and EpiPen), and epinephrine 1 mg intranasal spray (neffy). RESULTS: Data from 175 participants showed that although neffy (1.0 mg intranasal spray) resulted in a maximum concentration (258 pg/mL) that was lower than or comparable with manual epinephrine intramuscular injection (254 pg/mL), Symjepi (438 pg/mL) and EpiPen (503 pg/mL), it led to comparable increases in systolic blood pressure (maximum effect [Emax], 16.9, 10.9, 14.9, and 18.1 mm Hg, respectively). The effect of neffy on diastolic blood pressure was also markedly more pronounced than that of other products (Emax, 9.32, 5.51, 5.78, and 5.93 mm Hg, respectively). CONCLUSION: Intranasal delivery of epinephrine using neffy increases systolic blood pressure more efficiently than do manual intramuscular injection and epinephrine autoinjectors, despite lower maximum plasma concentrations.

Intramuscular Neural Distribution of the Serratus Anterior Muscle: Regarding Botulinum Neurotoxin Injection for Treating Myofascial Pain Syndrome.

The serratus anterior muscle is commonly involved in myofascial pain syndrome and is treated with many different injective methods. Currently, there is no definite injection point for the muscle. This study provides a suggestion for injection points for the serratus anterior muscle considering the intramuscular neural distribution using the whole-mount staining method. A modified Sihler method was applied to the serratus anterior muscles (15 specimens). The intramuscular arborization areas were identified in terms of the anterior (100%), middle (50%), and posterior axillary line (0%), and from the first to the ninth ribs. The intramuscular neural distribution for the serratus anterior muscle had the largest arborization patterns in the fifth to the ninth rib portion of between 50% and 70%, and the first to the fourth rib portion had between 20% and 40%. These intramuscular neural distribution-based injection sites are in relation to the external anatomical line for the frequently injected muscles to facilitate the efficiency of botulinum neurotoxin injections. Lastly, the intramuscular neural distribution of serratus anterior muscle should be considered in order to practice more accurately without the harmful side effects of trigger-point injections and botulinum neurotoxin injections.

A Novel Piriformis Injection Technique Utilizing Combined Fluoroscopy and Ultrasound - A Pilot Study.

BACKGROUND: Piriformis syndrome is a constellation of symptoms associated with low back, gluteal, and sciatic pain. One treatment for piriformis syndrome is the injection of local anesthetic, steroid, or botulinum toxin into the piriformis muscle. Various approaches for needle navigation into the piriformis muscle have been described using fluoroscopy or ultrasound. This study introduces a new method of image guidance combining fluoroscopy and ultrasound. OBJECTIVES: The primary aim of this study was examining whether the imaging modality used for needle guidance was associated with significant differences in pre- and post-piriformis injection pain scores. Secondary objectives were assessing differences in adverse events and procedure time. STUDY DESIGN: This study is a retrospective cohort study. SETTINGS: This study was conducted at Oregon Health and Science University's Comprehensive Pain Center, Portland, OR, USA. METHODS: Institutional chart review was performed from 09/21/2014 to 01/21/2020 to identify patients that underwent piriformis steroid injections which generated a list of 95 patients and totaled 154 procedures. Inclusion criteria were met for 78 patients and 109 procedures. Pain scores were modeled longitudinally using robust variance estimates. The nonparametric Kruskal-Wallis test was used for procedure duration, while adverse events were too rare to evaluate statistically. RESULTS: Piriformis steroid injections using the combined ultrasound and fluoroscopy technique had the lowest mean post-procedure pain score of 1.3 (SD 1.7) and the largest change in pain with a score difference of -3.9 (SD 2.1). Procedure durations were 8 (quartiles 5 to 10), 10 (quartiles 7 to 13), and 11 minutes (quartiles 9 to 13) for fluoroscopy alone, ultrasound alone, and combined techniques, respectively. All 3 modalities had duration ranges of minimum time of 3-5 minutes and a maximum time of 25-28 minutes. Adverse events across all imaging strategies were noted in 5 patients at the time of procedure and in 7 patients during follow-up appointments, the most common symptom being transient leg weakness or numbness. LIMITATIONS: The major limitation is the retrospective collection of data. Another limitation is that 6 different providers performed the injections, which may influence procedural consistency. Additionally, the inclusion of subjects with low pre-procedure pain scores could create a floor effect that minimized the occurrence of clinically significant shifts in pain scores. Adverse events were too few across all groups to assess. CONCLUSION: Piriformis injections using combined fluoroscopic and ultrasound guidance provides comparable efficiency to standard techniques and may result in improved accuracy into the target and thus improved efficacy. Larger prospective trials are required to comprehensively examine the efficacy of this novel technique.

Botulinum Toxin Type A Injection in the Treatment of Postparetic Facial Synkinesis: An Integrative Review.

ABSTRACT: This study aimed to review the recent literature about botulinum toxin type A treatment patterns, including muscle targets, doses, duration of effect, adverse effects, and clinical outcomes in patients with postparetic synkinesis. A bibliographic research of studies published in the last 10 yrs was carried out on PubMed database, using the medical subject heading terms: botulinum toxin and synkinesis. English-language cohort studies or randomized controlled trials about botulinum toxin type A treatment on patients with postparetic synkinesis were eligible for inclusion. Ten studies met the inclusion criteria, seven prospective studies, two retrospective studies, and one randomized controlled trial, involving 23-99 patients. The target facial muscles included frontalis, corrugator supercilli, orbicularis oculi, levator labii superioris, zygomaticus major, orbicularis oris, risorius, buccinator, depressor anguli oris, depressor labii inferioris, mentalis, and platysma. The dose of onabotulinumtoxinA administered per injection site ranged between 0.5 and 10 U. Adverse effects were rare and temporary. The mean duration of onabotulinumtoxinA effect ranges from 66 days to 4 mos. There was a statistically significant improvement in posttreatment evaluation, both in objective and subjective assessments. There is scientific evidence of the benefit of botulinum toxin type A treatment for postparetic synkinesis, but there is lack of standardized treatment protocols.

Pharmacokinetics of tranexamic acid after intravenous, intramuscular, and oral routes: a prospective, randomised, crossover trial in healthy volunteers.

BACKGROUND: In response to the World Health Organization call for research on alternative routes for tranexamic acid (TXA) administration in women with postpartum haemorrhage, we examined the pharmacokinetics of TXA after i.v., i.m., or oral administration. METHODS: We conducted a randomised, open-label, crossover trial in 15 healthy volunteers who received i.v. TXA 1 g, i.m. TXA 1 g, or oral TXA solution 2 g. Blood samples were drawn up to 24 h after administration. Tranexamic acid concentration was measured with liquid chromatography-mass spectrometry, and the parameters of the pharmacokinetic models were estimated using population pharmacokinetics. RESULTS: The median time to reach a concentration of 10 mg L-1 was 3.5 min for the i.m. route and 66 min for the oral route, although with the oral route the target concentration was reached in only 11 patients. Median peak concentrations were 57.5, 34.4, and 12.8 mg L-1 for i.v., i.m., and oral routes, respectively. A two-compartment open model with body weight as the main covariate best fitted the data. For a 70 kg volunteer, the population estimates were 10.1 L h-1 for elimination clearance, 15.6 L h-1 for intercompartmental clearance, 7.7 L for the volume of central compartment, and 10.8 L for the volume of the peripheral compartment. Intramuscular and oral bioavailabilities were 1.0 and 0.47, respectively, showing that i.m. absorption is fast and complete. Adverse events were mild and transient, mainly local reactions and low-intensity pain. CONCLUSIONS: The i.m. (but not oral) route appears to be an efficient alternative to i.v. tranexamic acid. Studies in pregnant women are needed to examine the impact of pregnancy on the pharmacokinetics. CLINICAL TRIAL REGISTRATION: EudraCT 2019-000285-38; NCT03777488.

The botulinum neurotoxin for pain control after breast reconstruction: neural distribution of the pectoralis major muscle.

INTRODUCTION: The use of the botulinum neurotoxin injection is a growing area of research and clinical activity, with a focus on its role in facilitating postoperative pain management after reconstructive breast surgery. The study aimed to find out the standard injection points for botulinum neurotoxin injection by revealing the intramuscular nerve arborization of the pectoralis major. METHODS: Sihler's technique was conducted on the pectoralis major muscles (16 cadaveric specimens). The intramuscular nerve arborization was documented relative to the inferior border of the clavicle bone and lateral border of the sternum. RESULTS: After the staining, the pectoralis major was divided into fifths transversely from the inferior border of the clavicle and vertically into fifths from the lateral border of the sternum. Intramuscular nerve arborization of the pectoralis major muscle was the largest in the middle sections of the muscle belly. DISCUSSION: The results indicate that botulinum neurotoxin should be applied to the pectoralis major in certain regions. The regions of major arborization are optimal as the most effective and most reliable points for injecting botulinum neurotoxin.