Injection Of Neurotoxin Research Articles

Botulinum toxin injections in jaw-opening dystonia. The lateral pterygoid – maxillary artery problem

It has been suggested that the variations in the trajectory of the maxillary artery (MA) near the lateral pterygoid muscle (LPM) play a critical role in Botulinum neurotoxin (BoNT) injections in patients with jaw-opening/deviation dystonia (JOD). In the case of a lateral course to the LPM, an extraoral injection entails risks of MA injury, pain, and hematoma. Previous reports suggest geographical differences in variations of the MA-LPM relationship. We aimed to determine these variations in Turkish individuals and highlight the need to establish a consensus on approach to LPM injections. In 284 individuals, contrast-enhanced magnetic resonance angiography (MRA) images were evaluated by two radiologists on both sides for the variations in the course of the MA in the infratemporal fossa. Images of 44 were excluded due to trauma, arteriovenous malformation, mass, surgery, and imaging artifacts. Of the included, 62.1% were female. In 480 evaluations of 240 individuals, the MA passed lateral to the LPM in 65.6% (n = 315). No sex difference was noted. In 51 individuals (21.3%), the MA course differed on the right and left sides (medial–lateral asymmetry). These results confirm that the lateral course of the MA is more frequent. In patients with JOD, the trajectory of the MA should be determined with imaging prior to extraoral BoNT injections. In the case of a lateral course, an intraoral approach seems to be safer to avoid a potential MA injury.

Novel Anatomical Guidelines on Botulinum Neurotoxin Injection for Wrinkles in the Nose Region.

Botulinum neurotoxin injection surrounding the nose area is frequently used in aesthetic settings. However, there is a shortage of thorough anatomical understanding that makes it difficult to treat wrinkles in the nose area. In this study, the anatomical aspects concerning the injection of botulinum neurotoxin into the nasalis, procerus, and levator labii superioris alaeque muscles are assessed. In addition, the present knowledge on localizing the botulinum neurotoxin injection point from a newer anatomy study is assessed. It was observed that, for the line-associated muscles in the nose region, the injection point may be more precisely defined. The optimal injection sites are the nasalis, procerus, and levator labii superioris alaeque muscles, and the injection technique is advised. We advise the best possible injection sites in association with anatomical standards for commonly injected muscles to increase efficiency in the nose region by removing the wrinkles. Similarly, these suggestions support a more precise procedure.

Intramuscular Innervation of the Supraspinatus Muscle Assessed Using Sihler's Staining: Potential Application in Myofascial Pain Syndrome.

Despite the positive effects of botulinum neurotoxin (BoNT) injection into the neural arborized area, there is no anatomical evidence in the literature regarding the neural arborization of the supraspinatus muscle. The present study aimed to define the intramuscular neural arborized pattern of the supraspinatus muscle using the modified Sihler’s staining method to facilitate the establishment of safe and effective injection sites in patients with myofascial pain in the supraspinatus muscle. Seventeen supraspinatus muscles from 15 embalmed cadavers were dissected. Precise suprascapular nerve entry locations were also observed. Intramuscular neural arborization was visualized by Sihler’s staining. The supraspinatus muscle was divided into four portions named A, B, C, and D. The nerve entry points were observed in 88.2% (15 of 17 cases) of section B and 76.5% (13 of 17 cases) of section C of the supraspinatus muscle, respectively. The concentration of intramuscular neural arborization was highest in section B of the supraspinatus muscle, which was the center of the supraspinatus muscle. When the clinician performs a trigger point and a BoNT injection into the supraspinatus muscle, injection within the medial 25–75% of the supraspinatus muscle will lead to optimal results when using small amounts of BoNT and prevent undesirable paralysis.

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.

Anatomical Proposal for Botulinum Neurotoxin Injection for Glabellar Frown Lines.

Botulinum neurotoxin injection for treating glabellar frown lines is a commonly used method; however, side effects, such as ptosis and samurai eyebrow, have been reported due to a lack of comprehensive anatomical knowledge. The anatomical factors important for the injection of the botulinum neurotoxin into the corrugator supercilii muscle has been reviewed in this study. Current understanding on the localization of the botulinum neurotoxin injection point from newer anatomy examination was evaluated. We observed that for the glabellar-frown-line-related muscles, the injection point could be more accurately demarcated. We propose the injection method and the best possible injection sites for the corrugator supercilii muscle. We propose the optimal injection sites using external anatomical landmarks for the frequently injected muscles of the face to accelerate effective glabellar frown line removal. Moreover, these instructions would support a more accurate procedure without adverse events.

Response to botulinum neurotoxin injections in large-angle infantile esotropia: a post hoc analysis

To determine the anticipated reduction of baseline angle of esotropia and identify predictors of change following botulinum neurotoxin (BNT) injections in large-angle infantile esotropia. This was a prospective, longitudinal study of children <10 years of age diagnosed with infantile esotropia of >30Δ and given either 1, 2, or 3 BNT injections. Post-injection change from baseline deviation was recorded, and predictors of reduction were analyzed. For this study, children were further divided into subgroups based on initial deviation of ≤60Δ (group 1) and >60Δ (group 2). The outcomes of subsequent surgeries in failed cases were analyzed. A total of 117 children were included, 55 in group 1 and 62 in group 2. Mean age was 30.3 ± 18.8 months. Mean baseline deviation was 62.5Δ ± 13.1Δ: 51.4Δ ± 8.4Δ in group 1 and 73Δ± 7.5Δ in group 2. The mean number of injections was 2.2 ± 0.7. Success was achieved in 25.6% of patients (33.4% in group 1; 16.2% in group 2). The mean percentage reduction of deviation after BNT injection was 55.2% ± 26%, larger in group 1 than in group 2 (61.3% vs 51.1% [P = 0.001]). Five children reverted to baseline deviation. In multivariate analysis, adjusting for number of injections, younger age and larger baseline deviation were significant independent predictors of a larger absolute amount of reduction (P = 0.02, and 0.002, resp.). Thirty-two children had subsequent surgery; 22 were followed for a minimum of 6 months, and 20 were aligned within 10Δ of orthotropia. In large-angle esotropia there was a reduction of approximately 50% of baseline deviation, with greater relative reduction for smaller baseline deviations; the absolute change in angle was greater in younger children. Alignment after subsequent surgery appeared to remain stable and surgery required less recession than would have been needed for the original angle of esotropia.

A Retrospective and Anatomical Study Describing the Injection of Botulinum Neurotoxins in the Depressor Anguli Oris.

The depressor anguli oris acts to lower the lateral corners of the mouth and can cause an individual to appear sad or angry and contribute to the development of the labiomental folds. Many patients can benefit from the injection of small amounts of botulinum neurotoxin into the depressor anguli oris to enable the lip elevators to reposition the corners of the mouth. Although effective, the procedure is off-label, and the proximity of the depressor anguli oris to the depressor labii inferioris, particularly inferiorly, can lead to inadvertent treatment of the latter, resulting in lip asymmetry. The authors have taken a threefold approach to establish a depressor anguli oris injection technique that provides optimal aesthetic outcomes with a low incidence of adverse events. This involved, first, reviewing the limited existing literature for studies discussing depressor anguli oris anatomy and botulinum neurotoxin treatment technique; second, supplementing information from the published literature with information from cadaver dissections to demonstrate the relationship between the depressor anguli oris and surrounding anatomical structures; and third, performing a retrospective chart review of 275 patients treated with the authors' three-point injection technique. Combining data from published studies, cadaver dissections, and clinical experience, the authors demonstrate that a three-point technique performed in the upper half of the depressor anguli oris is associated with good clinical outcome and avoids common side effects related to injection or spread of neurotoxin to adjacent muscles. Therapeutic, IV.

Intramuscular Neural Arborization of the Latissimus Dorsi Muscle: Application of Botulinum Neurotoxin Injection in Flap Reconstruction.

Postoperative pain after breast reconstruction surgery with the latissimus dorsi flap is a common occurrence. Botulinum neurotoxin (BoNT) injection during surgery is effective in reducing postoperative pain. This study aimed to determine the most appropriate locations for BoNT injection. A modified Sihler’s method was performed on the latissimus dorsi muscles in 16 specimens. Intramuscular nerve arborization was noted under the landmark of the medial side surgical neck of the humerus to the line crossing the spinous process of T5 and the middle of the iliac crest. The latissimus dorsi muscles were divided into medial, middle, and lateral segments with 10 transverse divisions to give 10 sections (each 10%). Intramuscular nerve arborization of the latissimus dorsi muscle was the largest from the medial and lateral part of the muscle ranging from 40 to 60%, middle part from 30 to 60% and medial, middle and lateral part from 70 to 90%. The nerve entry points were at the medial and lateral part with 20–40% regarding the medial side of surgical neck of the humerus to the line crossing spinous process of T5 to the middle of iliac crest. These outcomes propose that an injection of BoNT into the latissimus dorsi muscles should be administered into specific zones.

Botulinum Neurotoxin Injection as a Therapeutic Option in Thoracic Outlet Syndrome Caused by a Supernumerary Scalenus Muscle: A Case Report

Thoracic Outlet Syndrome (TOS) is a neurovascular syndrome and may occur as a result of compression of brachial plexus elements and/or subclavian vessels as they traverse the cervicoaxillary canal. One of the causes of TOS is the existence of a supernumerary scalene muscle, usually denominated as scalenus minimus. Botulinum Toxin Type A (BoNT-A) acts by binding presynaptically to high-affinity recognition sites on the cholinergic nerve terminals and decreases the release of acetylcholine, suppressing muscle overactivity. BoNT-A reduces contraction in injected muscles, causing focal chemodenervation and has been described as a non surgical effective treatment in selected cases of TOS. Here, is the case of a 44-year-old woman diagnosed with refractory TOS, who presented with paresthesia in the fourth and fifth fingers of her right hand, associated with a feeling of lack of coordination in the same hand. On Magnetic Resonance Imaging (MRI), a supernumerary scalene muscle was identified as a probable cause of TOS. She was treated with chemodenervation of the scalenus anterior muscle (30 Units) and scalenus medius muscle (30 Units), using incobotulinumtoxin A. The patient had a very significant clinical improvement after Anterior Scalene (AS) and Middle Scalene (MS) muscle BoNT-A injections. Incobotulinumtoxin A neurotoxin injection is a therapeutic option in TOS.

The Effect of Different Doses of Botulinum Toxin on Masseter Muscle in Patients with Bruxism.

Background and Objectives: Botulinum toxin type A is produced by clostridium botulinum. It acts by inhibiting the release of acetylcholine from cholinergic neurons. Botulinum toxin has been used for management of bruxism, which is a parafunctional disorder and characterized by clenching or grinding of the teeth or both. This study aimed to find out the effect of two different doses of injecting botulinum neurotoxin in masseter muscle in a patient with bruxism. Materials and Methods: A prospective clinical open trial study was conducted from November 2018 to November 2019. Thirty patients, aged 20‐45 years, with bruxism were subjected to injection of two different doses of botulinum toxin in masseter muscle. Patients were divided into two equal groups. The first group included 15 patients treated by 18 units of botulinum toxin, 9 units for each side and the second group included 15 patients treated by 24 units of botulinum toxin 12 unit for each side. Parameters, as visual analogue scale (VAS), Bite force, patient’s evaluation of lower facial slimming were recorded for each patient before and after the injections of botulinum neurotoxin at 2 weeks, 4 weeks and 3 months. Results: The study showed a significant reduction in VAS, bite force and patient's evaluation of facial slimming for both groups after 2 weeks, 4 weeks and 3 months of follow up (P &lt; 0.05) with no significant differences in both group doses. Conclusion: Both doses of botulinum toxin (18 and 24) units have significantly improved pain score, and bite force and have the same efficacy in treating patients with bruxism., therefore dose of 18 units of the drug is preferable over 24 units in treating bruxism.

Novel approaches to the treatment of cervical dystonia. The concept of dual navigation control

Сervical dystonia (CD) is the most common type of focal dystonia (up to 50% of all dystonia cases). Botulinum neurotoxin (BoNT) injections is the treatment choice for CD. However, the effectiveness and tolerability of botulinum therapy in CD depends on the correct choice of target muscles and the accuracy of the BoNT injection. The publication presents literature data and our own clinical experience regarding the use of navigation in BoNT injections in CD.According to the majority of authors, the use of navigation equipment, such as ultrasound (US) and electromyography (EMG), definitely increases the effectiveness of CD treatment and reduces the likelihood of adverse events. For the first time, an algorithm for the diagnosis and treatment of CD is proposed, based on the use of the method of «double- (EMG and US) guided navigation», a variant for determining the comparative activity of muscles by the intensity of the EMG signal and the design of an individual «passport» of the CD. The possibilities of analyzing the US of muscles, drawing up an accurate treatment regimen, targeted administration of BoNT, and using a non-injectable EMG electrode are shown. We present 4 clinical cases demonstrating the advantages of the double- (EMG+US) guided navigation method over the EMG-guided navigation for injection. The proposed algorithm for the diagnosis and treatment of CD makes it possible to increase the effectiveness of treatment, optimize the costs of BoNT and diagnostic equipment (injection EMG needle).

Does ultrasound-guidance improve the outcome of botulinum toxin injections in cervical dystonia?

PurposeUltrasound-guided injections of botulinum neurotoxin in cervical dystonia have a number of theoretical advantages. However, their action has never been compared to that of non-guided injections. The objectives of the study were to compare the outcome of botulinum neurotoxin type A treatment in patients with idiopathic, focal cervical dystonia, according to two methods: inspection and palpation of anatomical landmarks (non-guided group) or ultrasound guidance (ultrasound-guided group). MethodsWe included consecutive patients in this single-center, prospective, real-life, non-randomized study. The outcomes were evaluated one month after the injections: Cervical Dystonia Impact Profile 58 (main outcome), Toronto Western Spasmodic Torticollis Rating Scale-2 (pain and disability subscores), Toronto Western Spasmodic Torticollis Rating Scale-PSYCH, patient-rated Clinical Global Impression - Improvement and adverse events. We used propensity score methods for statistical analysis; ten predefined confounding factors were used to build the propensity score. ResultsSixty-three patients were included in the non-guided group, and 60 other patients in the ultrasound-guided group. We found no difference in main and secondary outcomes between the two study groups. ConclusionThis is the first direct comparison between ultrasound-guided and non-guided botulinum neurotoxin type A injections in patients with cervical dystonia. We hypothesize that ultrasound guidance made it possible to obtain the same results in the most severe (or the most demanding) patients as in the best responders. Further studies are still needed to assess the impact of botulinum neurotoxin injections into deep cervical muscles.

Direct Inhibition of Microglia Activation by Pretreatment With Botulinum Neurotoxin A for the Prevention of Neuropathic Pain.

Peripheral injection of botulinum neurotoxin A (BoNT/A) has been demonstrated to have a long-term analgesic effect in treating neuropathic pain. Around peripheral nerves, BoNT/A is taken up by primary afferent neurons and inhibits neuropeptide release. Moreover, BoNT/A could also be retrogradely transported to the spinal cord. Recent studies have suggested that BoNT/A could attenuates neuropathic pain by inhibiting the activation of spinal glial cells. However, it remains unclear whether BoNT/A directly interacts with these glial cells or via their interaction with neurons. Our aim here is to determine the direct effect of BoNT/A on primary microglia and astrocytes. We show that BoNT/A pretreatment significantly inhibits lipopolysaccharide (LPS) -induced activation and pro-inflammatory cytokine release in primary microglia (1 U/mL BoNT/A in medium), while it has no effect on the activation of astrocytes (2 U/mL BoNT/A in medium). Moreover, a single intrathecal pre-administration of a low dose of BoNT/A (1 U/kg) significantly prohibited the partial sciatic nerve ligation (PSNL)- induced upregulation of pro-inflammatory cytokines in both the spinal cord dorsal horn and dorsal root ganglions (DRGs), which in turn prevented the PSNL-induced mechanical allodynia and thermal hyperalgesia. In conclusion, our results indicate that BoNT/A pretreatment prevents PSNL-induced neuropathic pain by direct inhibition of spinal microglia activation.

Botulinum Neurotoxin Type A in the Treatment of Facial Seborrhea and Acne: Evidence and a Proposed Mechanism.

Intradermal injection of botulinum neurotoxin is a frequently performed procedure in aesthetic dermatology to improve facial skin tone, texture, fine wrinkles, and enlarged pores. In practice, botulinum neurotoxin type A is also used to reduce skin oiliness of the face. There is increasing evidence that acetylcholine plays specific roles in sebum production, suggesting that botulinum neurotoxin type A may reduce sebum production by interfering with cholinergic transmission between sebaceous glands and autonomic nerve terminals. Botulinum neurotoxins can also inhibit several pathogenetic components of acne development, suggesting that botulinum neurotoxins can be used as a safe and effective treatment modality for acne and other skin disorders related to overactivity of sebaceous glands. This review aims to explore the current evidence behind the treatment of facial seborrhea and acne with botulinum neurotoxin type A.

Tear osmolarity, dry eye syndrome, blepharospasm and botulinum neurotoxin

To assess the severity of dry eye disease in patients with blepharospasm (BEB) before (control) and after injection of botulinum neurotoxin A (BoNT/A). Cross-sectional study. Patients with clinically diagnosed BEB and no known history of dry eye syndrome prior to the onset of the disease, before (controls) or after injection with one of the three available types of BoNT/A: onabotulinumtoxinA (Botox®; Allergan, Irvine, CA, USA), abobotulinumtoxinA (Dysport®; Beaufour Ipsen Pharma SAS, Paris, France) or incobotulinumtoxinA (Xeomin®; Merz Pharma GmbH, Frankfurt, Germany) every 3 months. Tear osmolarity and Schirmer's I-test were measured at the first visit for non-treated BEB patients as controls and 3 months after BoNT/A injection. The study consisted of 101 BEB patients (86 females, 15 males) with a mean age of 67 years (range 30-86 years). Seventeen patients were untreated, 26 treated with onabotulinumtoxinA, 23 treated with abobotulinumtoxinA and 35 treated with incobotulinumtoxinA. Post-injection mean tear osmolarity was not significantly higher among patients treated with onabotulinumtoxinA, abobotulinumtoxinA, or incobotulinumtoxinA (P=0.65, P=0.92, and P=0.15, respectively), compared to controls, remaining less than 308 mosm/mL. Mean Schirmer's I-test results remained under 5mm and did not vary between the four groups. The results clearly demonstrate that reduced tear secretion appears to be present in BEB patients even prior to treatment. This decreased lacrimal secretion was not correlated with hyperosmolarity. Clinicians should proactively treat dry eye syndrome in conjunction with management of the blepharospasm.

Botulinum neurotoxin injection guidelines regarding flap surgeries in breast reconstruction

Breast cancer is one of the most diagnosed cancers, accounting for over 30% of all cancers in women. The incidence of breast cancer continues to increase annually, but mortality has declined to 15% because of early diagnosis and improved medical treatments. Following the surgical procedures, reconstruction with breast implants enables the fulfillment of the patient's esthetic aspirations. Each year, the number of mastectomy patients who decide to undergo post-mastectomy breast reconstruction continues to increase1.

Intramuscular tetanus neurotoxin reverses muscle atrophy: a randomized controlled trial in dogs with spinal cord injury.

BackgroundMotor symptoms of spinal cord injury (SCI) considerably impair quality of life and are associated with a high risk of secondary diseases. So far, no pharmacological treatment is available for these symptoms. Therefore, we conducted a randomized, double‐blinded, placebo‐controlled study in dogs with spontaneous SCI due to disc herniation to test whether a reduction of spinal inhibitory activity by intramuscular injections of tetanus neurotoxin (TeNT) alleviates motor symptoms such as muscle atrophy or gait function.MethodsTo this end, 25 dogs were treated with injections of either TeNT or placebo into their paretic hindlimb muscles. Effects of TeNT on muscle thickness were assessed by ultrasound, while effects on gait function were measured using the modified functional scoring system in dogs.ResultsFour weeks after the TeNT injections, muscle thickness of the gluteus medius muscle (before median 1.56 cm [inter‐quartile range {IQR} 1.34–1.71 cm] and after median 1.56 cm [IQR 1.37–1.85 cm], P‐value 0.0133) as well as of the rectus femoris muscle (before median 0.76 cm [IQR 0.60–0.98 cm] and after median 0.93 cm [IQR 0.65–1.05 cm], P‐value 0.0033) significantly increased in the TeNT group. However, there was no difference in gait function between the TeNT and placebo groups. The treatment was well tolerated by all dogs without any signs of generalized tetanus symptoms or any spreading of effects beyond the lumbar level of the injected hindlimbs.ConclusionsWith regard to the beneficial effects on muscle thickness, intramuscular injections of TeNT represent the first pharmacological approach that focally reverses muscle atrophy in SCI. Moreover, the study data support the safety of this treatment when TeNT is used at low dose.

Current practice trends for lacrimal gland neurotoxin in the management of epiphora-a BOPSS survey.

Injection of botulinum neurotoxin A (BoNTA) to the lacrimal gland (LG) offers a simple and effective treatment in the management of epiphora. However, there is little data on current practice trends or uptake as an alternative to surgery. This study assesses current practice trends of such treatment amongst BOPSS (British Oculoplastic Surgery Society) members. All consultant BOPSS members were invited to participate in a web-based survey which consisted of 5 questions, with a reminder invitation to participate. The role, dose, potential side effects, use as an alternative to surgical intervention, and impact on service delivery were assessed. Fifty-one BOPSS consultants (43% uptake) completed the survey. Ninety percent of respondents were regularly using LG BoNTA in their management of epiphora. The main indicators for considering BoNTA use were medical comorbidities and elderly patients. The mean first treatment dose of Botox® was 3.6 units (SD 1.5). Diplopia and ptosis complications were always discussed in the consent for treatment in addition to dry eye. Twenty-five percent of surgeons reported doing less conjunctivo-dacryocystorhinostomies (cDCR) due to the availability of LG BoNTA. No respondents felt that the requirement for repeated BoNTA treatments was impacting on their service delivery. Uptake of LG BoNTA in the management of epiphora is at a similar rate to all other available treatments. As a result, respondents are performing less surgical procedures, particularly cDCR in patients at higher surgical morbidity.

Surgical Versus Nonsurgical Lower Face Contouring: Layperson Perceptions of Attractiveness and Personality Traits.

Traditional approaches to lower face contouring involve ostectomy of the mandibular angle or body. More recently, nonsurgical techniques have gained popularity, including neurotoxin injection to the masseter muscle. This study aims to evaluate layperson perceptions of patient attractiveness and personality traits following lower face contouring using either surgical or nonsurgical treatment. In this survey study distributed via Amazon's Mechanical Turk, respondents viewed a series of 14 patient images obtained in clinic before and after surgical or nonsurgical jawline slimming, or without any facial aesthetic procedure. Respondents rated changes in attractiveness and personality trait scores between the before and after image (score: -50 to 50, with 50 representing the greatest posttreatment increase and 0 representing no change). We used descriptive statistics and multivariable regression to determine differences in respondent ratings between patient images. A total of 415 respondents (mean age 38 years, 50.6% female) successfully completed the survey. Compared to patients who underwent nonsurgical treatment, those who received surgery had significantly greater increases in perceived attractiveness (P < 0.001), femininity (P < 0.001), friendliness (P < 0.001), intelligence (P < 0.001), trustworthiness (P < 0.001), financial wealthiness (P < 0.001), dominance (P < 0.01), and self-esteem (P < 0.001). Gonial angles increased and jaw widths decreased following both surgical and nonsurgical intervention, with no statistically significant difference between treatment groups. From the layperson perspective, surgical compared to nonsurgical jawline contouring offers greater improvements in perceptions of attractiveness and favorable personality traits.

Anatomical locations of the motor endplates of sartorius muscle for botulinum toxin injections in treatment of muscle spasticity.

PurposeThis study aimed to detect the idyllic locations for botulinum neurotoxin injection by analyzing the intramuscular neural distributions of the sartorius muscles.MethodsAn altered Sihler’s staining was conducted on sartorius muscles (15 specimens). The nerve entry points and intramuscular arborization areas were measured as a percentage of the total distance from the most prominent point of the anterior superior iliac spine (0%) to the medial femoral epicondyle (100%).ResultsIntramuscular neural distribution were densely detected at 20–40% and 60–80% for the sartorius muscles. The result suggests that the treatment of sartorius muscle spasticity requires botulinum neurotoxin injections in particular locations.ConclusionsThese locations, corresponding to the locations of maximum arborization, are suggested as the most suggestive points for botulinum neurotoxin injection.