Effective botulinum toxin injection guide for treatment of cervical dystonia

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.

Sihler's staining technique: How to and guidance for botulinum neurotoxin injection in human muscles

The Sihler's stain is a whole-mount nerve staining technique that allows visualization of the nerve distribution and permits mapping of the entire nerve supply patterns of the organs, skeletal muscles, mucosa, skin, and other structures that contain myelinated nerve fibers. Unlike conventional approaches, this technique does not require extensive dissection or slide preparation. To date, the Sihler's stain is the best tool for demonstrating the precise intramuscular branching and distribution patterns of skeletal muscles. The intramuscular neural distribution is used as a guidance tool for the application of botulinum neurotoxin injections. In this review, we have identified and summarized the ideal botulinum neurotoxin injection points for several human tissues.

Distribution of the intramuscular innervation of the triceps brachii: Clinical importance in the treatment of spasticity with botulinum neurotoxin

This study aimed to identify ideal sites for botulinum toxin injection by analyzing the intramuscular nerve patterns of the triceps brachii muscles. A modified Sihler's method was applied to the triceps brachii muscle (15 specimens), with long, medial, and lateral heads. The intramuscular arborization areas of the long, medial, and lateral heads of the triceps brachii muscle were measured as a percentage of the total distance from the midpoint of the olecranon (0%) to the anteroinferior point of the acromion (100%), by dividing the medial and lateral parts based on the line connecting the midpoint of the olecranon and the anteroinferior point of the acromion. Intramuscular arborization patterns were observed at the long head at two medial regions, proximally 30%-50% and distally 60%-70%; medial head of 30%-40%; and lateral head of 30%-60%. These results suggest that the treatment of spasticity of the triceps brachii muscles involves botulinum toxin injections in specific areas. The areas corresponding to the areas of maximum arborization are recommended as the most effective and safe points for botulinum toxin injection.

Novel anatomical guidelines for botulinum neurotoxin injection in the mentalis muscle: a review

The mentalis muscle is a paired muscle originating from the alveolar bone of the mandible. This muscle is the main target muscle for botulinum neurotoxin (BoNT) injection therapy, which aims to treat cobblestone chin caused by mentalis hyperactivity. However, a lack of knowledge on the anatomy of the mentalis muscle and the properties of BoNT can lead to side effects, such as mouth closure insufficiency and smile asymmetry due to ptosis of the lower lip after BoNT injection procedures. Therefore, we have reviewed the anatomical properties associated with BoNT injection into the mentalis muscle. An up-to-date understanding of the localization of the BoNT injection point according to mandibular anatomy leads to better injection localization into the mentalis muscle. Optimal injection sites have been provided for the mentalis muscle and a proper injection technique has been described. We have suggested optimal injection sites based on the external anatomical landmarks of the mandible. The aim of these guidelines is to maximize the effects of BoNT therapy by minimizing the deleterious effects, which can be very useful in clinical settings.

Intramuscular neural distribution of the teres minor muscle using Sihler's stain: application to botulinum neurotoxin injection

The aim of this study was to elucidate the intramuscular arborization of the teres minor muslce for effective botulinum neurotoxin injection. Twelve specimens from 6 adult Korean cadavers (3 males and 3 females, age ranging from 66 to 78 years) were used in the study. The reference line between the 2/3 point of the axillary border of the scapula (0/5), where the muscle originates ant the insertion point of the greater tubercle of the humerus (5/5). The most intramuscular neural distribution was located on 1/5-3/5 of the muscle. The tendinous portion was observed in the 3/5-5/5. The result suggests the botulinum neurotoxin should be delivered in the 1/5-3/5 area of the teres minor muscle.

Anatomical proposal of local anesthesia injection for median nerve block in treating hyperhidrosis with botulinum neurotoxin

INTRODUCTION

Hyperhidrosis, causing excessive sweat, can be treated with Botulinum neurotoxin injection. Botulinum toxin, an effective and safe treatment for hyperhidrosis, unfortunately involves significant pain due to multiple injections. This study aims to propose a more efficient and less painful approach to nerve blocks for relief, by identifying optimal injection points to block the median nerve, thereby enhancing palmar hyperhidrosis treatment.

METHODS

This study, involving 52 Korean cadaver arms (mean age 73.5 years), measured the location of the median nerve relative to the transverse line at the pisiform level to establish better nerve block injection sites.

RESULTS

In between the extensor carpi radialis and palmaris longus, the median nerve was located at an average distance of 47.39 ± 6.43 mm and 29.39 ± 6.43 mm from the transverse line at the pisiform level.

DISCUSSION

To minimize discomfort preceding the botulinum neurotoxin injection, we recommend the optimal injection site for local anesthesia to be located 4 cm distal to the transverse line of the pisiform, within the tendons of the palmaris longus and flexor carpi radialis muscles.

Intramuscular Neural Distribution of the Gastrocnemius for Botulinum Neurotoxin Injection: Application to Cosmetic Calf Shaping

PURPOSE

Anatomical landmarks can provide vital information on the distribution of nerves in the gastrocnemius muscle. We aimed to provide an anatomical perspective on appropriate locations for botulinum neurotoxin (BoNT) injections in the medial and lateral parts of the gastrocnemius for calf shaping.

MATERIALS AND METHODS

A modified Sihler's method was applied to both the medial and lateral parts of the gastrocnemius muscles (16 specimens). Intramuscular neural distributions were revealed by dissecting along a transverse line crossing the fibular head and superior margin of the calcaneal tuberosity.

RESULTS

The intramuscular neural distribution for the medial and lateral parts of the gastrocnemius had the greatest arborized patterns in the 7/10-8/10 section of the medial head and 7.5/10-8.5/10 section of the lateral part of the gastrocnemius.

CONCLUSION

We propose that BoNT injections should be directed to the 7/10-8/10 section of the medial head and the 7.5/10-8.5/10 section of the lateral part of the gastrocnemius. Following our guidelines, clinicians can ensure satisfactory results with the use of minimal doses to limit adverse effects, such as gait disturbance, antibody production, and bruising, due to multiple injections. The results can also be altered and applied to electromyography.

Lessons about Botulinum Toxin A Therapy from Cervical Dystonia Patients Drawing the Course of Disease: A Pilot Study

AIM OF THE STUDY

To compare the course of severity of cervical dystonia (CD) before and after long-term botulinum toxin (BoNT) therapy to detect indicators for a good or poor clinical outcome.

PATIENTS AND METHODS

A total of 74 outpatients with idiopathic CD who were continuously treated with BoNT and who had received at least three injections were consecutively recruited. Patients had to draw the course of severity of CD from the onset of symptoms until the onset of BoNT therapy (CoDB graph), and from the onset of BoNT therapy until the day of recruitment (CoDA graph) when they received their last BoNT injection. Mean duration of treatment was 9.6 years. Three main types of CoDB and four main types of CoDA graphs could be distinguished. The demographic and treatment-related data of the patients were extracted from the patients' charts.

RESULTS

The best outcome was observed in those patients who had experienced a clear, rapid response in the beginning. These patients had been treated with the lowest doses and with a low number of BoNT preparation switches. The worst outcome was observed in those 17 patients who had drawn a good initial improvement, followed by a secondary worsening. These secondary nonresponders had been treated with the highest initial and actual doses and with frequent BoNT preparation switches. A total of 12 patients were primary nonresponders and did not experience any improvement at all. No relation between the CoDB and CoDA graphs could be detected. Primary and secondary nonresponses were observed for all three CoDB types. The use of initial high doses as a relevant risk factor for the later development of a secondary nonresponse was confirmed.

CONCLUSIONS

Patients' drawings of their course of disease severity helps to easily detect "difficult to treat" primary and secondary nonresponders to BoNT on the one hand, but also to detect "golden responders" on the other hand.

Guidance in botulinum neurotoxin injection for lower extremity spasticity: Sihler's staining technique

Spasticity is a motor disease characterized by a velocity-dependent acceleration in muscle tone or tonic stretch reflexes linked to hypertonia. Lower limb spasticity has been successfully treated with botulinum neurotoxin; however, the injection sites have not been generalized. Sihler's stain has been used to visualize intramuscular nerve distribution to guide botulinum neurotoxin injection. Sihler staining is a whole-mount nerve staining technique that allows visualization of nerve distribution and mapping of entire nerve supply patterns in skeletal muscle with hematoxylin-stained myelinated nerve fibers. This study reviewed and summarized previous lower extremity spasticity studies to determine the ideal injection site for botulinum neurotoxin.

Improving the Efficacy of Botulinum Toxin for Cervical Dystonia: A Scoping Review

Cervical dstonia (CD) is a chronic disorder with a significant detrimental impact on quality of life, requiring long-term treatment. Intramuscular injections of botulinum neurotoxin (BoNT) every 12 to 16 weeks have become the first-line option for CD. Despite the remarkable efficacy of BoNT as a treatment for CD, a significantly high proportion of patients report poor outcomes and discontinue the treatment. The reasons that drive sub-optimal response or treatment failure in a proportion of patients include but are not limited to inappropriate muscle targets and/or BoNT dosing, improper method of injections, subjective feeling of inefficacy, and the formation of neutralizing antibodies against the neurotoxin. The current review aims to complement published research focusing on the identification of the factors that might explain the failure of BoNT treatment in CD, highlighting possible solutions to improve its outcomes. Thus, the use of the new phenomenological classification of cervical dystonia known as COL-CAP might improve the identification of the muscle targets, but more sensitive information might come from the use of kinematic or scintigraphic techniques and the use of electromyographic or ultrasound guidance might ensure the accuracy of the injections. Suggestions are made for the development of a patient-centered model for the management of cervical dystonia and to emphasize that unmet needs in the field are to increase awareness about the non-motor spectrum of CD, which might influence the perception of the efficacy from BoNT injections, and the development of dedicated rehabilitation programs for CD that might enhance its effectiveness.

Increasing the Passive Range of Joint Motion in Stroke Patients Using Botulinum Toxin: The Role of Pain Relief

By blocking the release of neurotransmitters, botulinum toxin A (BoNT-A) is an effective treatment for muscle over-activity and pain in stroke patients. BoNT-A has also been reported to increase passive range of motion (p-ROM), the decrease of which is mainly due to muscle shortening (i.e., muscle contracture). Although the mechanism of action of BoNT-A on p-ROM is far from understood, pain relief may be hypothesized to play a role. To test this hypothesis, a retrospective investigation of p-ROM and pain was conducted in post-stroke patients treated with BoNT-A for upper limb hypertonia. Among 70 stroke patients enrolled in the study, muscle tone (Modified Ashworth Scale), pathological postures, p-ROM, and pain during p-ROM assessment (Numeric Rating Scale, NRS) were investigated in elbow flexors (48 patients) and in finger flexors (64 patients), just before and 3-6 weeks after BoNT-A treatment. Before BoNT-A treatment, pathological postures of elbow flexion were found in all patients but one. A decreased elbow p-ROM was found in 18 patients (38%). Patients with decreased p-ROM had higher pain-NRS scores (5.08 ± 1.96, with a pain score ≥8 in 11% of cases) than patients with normal p-ROM (0.57 ± 1.36) (p < 0.001). Similarly, pathological postures of finger flexion were found in all patients but two. A decreased finger p-ROM was found in 14 patients (22%). Pain was more intense in the 14 patients with decreased p-ROM (8.43 ± 1.74, with a pain score ≥ 8 in 86% of cases) than in the 50 patients with normal p-ROM (0.98 ± 1.89) (p < 0.001). After BoNT-A treatment, muscle tone, pathological postures, and pain decreased in both elbow and finger flexors. In contrast, p-ROM increased only in finger flexors. The study discusses that pain plays a pivotal role in the increase in p-ROM observed after BoNT-A treatment.

Botulinum neurotoxin injection in the deltoid muscle: application to cosmetic shoulder contouring

BACKGROUND AND OBJECTIVES

This study describes the intramuscular nerve branching of the deltoid muscle in relation to shoulder surface anatomy, with the aim of providing essential information regarding the most appropriate sites for botulinum neurotoxin injection during shoulder line contouring.

METHODS

The modified Sihler's method was used to stain the deltoid muscles (16 specimens). The intramuscular arborization areas of the specimens were demarcated using the marginal line of the muscle origin and the line connecting the anterior and posterior upper edges of the axillary region.

RESULTS

The intramuscular neural distribution of the deltoid muscle had the greatest arborization patterns in the area between the horizontal 1/3 and 2/3 lines of the anterior and posterior deltoid bellies, and 2/3 to axillary line in middle deltoid bellies. The greatest part of the posterior circumflex artery and axillary nerve ran below the areas with the highest aborizations.

CONCLUSION

We propose that botulinum neurotoxin injections should be administered in the area between the 1/3 and 2/3 lines of the anterior and posterior deltoid bellies, and 2/3 to axillary line on middle deltoid bellies. Accordingly, clinicians will ensure minimal dose injections and fewer adverse effects of the botulinum neurotoxin injection. Deltoid intramuscular injections, such as vaccines and trigger point injections, should ideally be adapted according to our results.

Guidelines for botulinum neurotoxin injection for facial contouring

SUMMARY

The hypertrophied temporalis and masseter muscles give a muscular shaped and bulky contour to the face. Botulinum neurotoxin injection methods are commonly used for facial contouring; however, adverse effects have been reported owing to a lack of delicate anatomical information. The anatomical considerations when injecting botulinum neurotoxin into the temporalis and masseter muscles have been reviewed in the present study. Current knowledge on the localization of the botulinum neurotoxin injection point with more recent anatomical dissection and modified Sihler's staining procedures was assessed. We found that for the muscles, the injection point can be more precisely demarcated. Optimal injection sites are presented for the temporalis and masseter muscles, and the injection technique has been suggested. We propose the optimal injection sites in relation to external anatomical landmarks for the frequently injected muscles of the face to facilitate the efficiency of botulinum neurotoxin injections. In addition, these guidelines would aid in more precise practice without the adverse effects of botulinum neurotoxin.

Guidance to trigger point injection for treating myofascial pain syndrome: Intramuscular neural distribution of the quadratus lumborum

Postural habits and repetitive motion contribute toward the progress of myofascial pain by affecting overload on specific muscles, the quadratus lumborum (QL) muscle being the most frequently involved. The therapy of myofascial pain syndrome includes the release of myofascial pain syndrome using injective agents such as botulinum neurotoxin, lidocaine, steroids, and normal saline. However, an optimal injection point has not been established for the QL muscle. This study aimed to propose an optimal injection point for this muscle by studying its intramuscular neural distribution using the whole mount staining method. A modified Sihler's procedure was completed on 15 QL muscles to visualize the intramuscular arborization areas in terms of the inferior border of the 12th rib, the transverse processes of L1-L4, and the iliac crest. The intramuscular neural distribution of the QL had the densely arborized areas in the three lateral portions of L3-L4 and L4-L5 and the medial portion between L4 and L5.

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 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.

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.

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.

A consensus statement on the use of botulinum toxin in pediatric patients

Botulinum toxin has been used in medicine for the past 30 years. However, there continues to be controversy about the appropriate uses and dosing, especially in the pediatric population. A panel of nine pediatric physiatrists from different regions and previous training programs in the United States were nominated based on institutional reputation and botulinum toxin (BoNT) experience. Based on a review of the current literature, the goal was to provide the rationale for recommendations on the administration of BoNT in the pediatric population. The goal was not only to review safety, dosing, and injection techniques but also to develop a consensus on the appropriate uses in the pediatric population. In addition to upper and lower limb spasticity, the consensus also provides recommendations for congenital muscular torticollis, cervical dystonia, sialorrhea, and brachial plexus palsies.

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

PURPOSE

This study aimed to detect the idyllic locations for botulinum neurotoxin injection by analyzing the intramuscular neural distributions of the sartorius muscles.

METHODS

An 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%).

RESULTS

Intramuscular 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.

CONCLUSIONS

These locations, corresponding to the locations of maximum arborization, are suggested as the most suggestive points for botulinum neurotoxin injection.

Application of Botulinum Neurotoxin Injections in TRAM Flap for Breast Reconstruction: Intramuscular Neural Arborization of the Rectus Abdominis Muscle

Breast reconstruction after mastectomy is commonly performed using transverse rectus abdominis myocutaneous (TRAM) flap. Previous studies have demonstrated that botulinum neurotoxin injections in TRAM flap surgeries lower the risk of necrosis and allow further expansion of arterial cross-sectional diameters. The study was designed to determine the ideal injection points for botulinum neurotoxin injection by exploring the arborization patterns of the intramuscular nerves of the rectus abdominis muscle. A modified Sihler's method was performed on 16 rectus abdominis muscle specimens. Arborization of the intramuscular nerves was determined based on the most prominent point of the xyphoid process to the pubic crest. All 16 rectus abdominis muscle specimens were divided into four muscle bellies by the tendinous portion. The arborized portions of the muscles were located on the 5-15%, 25-35%, 45-55%, and 70-80% sections of the 1st, 2nd, 3rd, and 4th muscle bellies, respectively. The tendinous portion was located at the 15-20%, 35-40%, 55-60%, and 90-100% sections. These results suggest that botulinum neurotoxin injections into the rectus abdominis muscles should be performed in specific sections.

Guidelines for botulinum neurotoxin injections in piriformis syndrome

BACKGROUND

The piriformis muscle is normally involved in piriformis syndrome and can be treated with botulinum neurotoxin using several different injection methods. However, definitive injection guidelines for the muscle have not been reported previously.

AIMS

This study aimed to determine the ideal area for injections based on the intramuscular nerve distribution as obtained using a modified Sihler's staining technique.

MATERIALS AND METHODS

A modified Sihler's method was applied to the piriformis muscle in 15 specimens. The intramuscular arborization areas were identified based on two anatomical landmarks: (a) the lateral border of the sacrum bone and (b) the greater trochanter.

RESULTS

The nerve entry point for both piriformis muscles was found in the area between the lateral border of the sacrum and one-fifth of the distance toward the greater trochanter. The intramuscular nerve distribution for the piriformis muscle had the largest arborization patterns between one-fifth and two-fifths of the distance from the sacrum to the greater trochanter. The piriformis muscle was tendinous from two-fifths of the distance to the greater trochanter.

DISCUSSION

This study has yielded suggested optimal injection locations for the piriformis muscle relative to external anatomical landmarks.

CONCLUSION

Clinicians can use these guidelines to ensure the effectiveness of not only botulinum neurotoxin injections but also other agents such as steroids, anesthetics, and normal saline. These guidelines will also help to avoid adverse outcomes of injection treatments.

Quantifying the effects of electrode placement and montage on measures of cVEMP amplitude and muscle contraction

BACKGROUND

The cervical vestibular evoked myogenic potential (cVEMP) can be affected by the recording parameters used to quantify the response.

OBJECTIVE

We investigated the effects of electrode placement and montage on the variability and symmetry of sternocleidomastoid (SCM) contraction strength and cVEMP amplitude.

METHODS

We used inter-side asymmetries in electrode placement to mimic small clinical errors in twenty normal subjects. cVEMPs were recorded at three active electrode sites and referred to the distal SCM tendon (referential montages: upper, conventional and lower). Additional bipolar montages were constructed offline to measure SCM contraction strength using closely-spaced electrode pairs (bipolar montages: superior, lower and outer).

RESULTS

The conventional montage generally produced the largest cVEMP amplitudes (P < 0.001). SCM contraction strength was larger for referential montages than bipolar ones (P < 0.001). Inter-side electrode position errors produced large variations in cVEMP and SCM contraction strength asymmetries in some subjects, producing erroneous abnormal test results.

CONCLUSION

Recording locations affect cVEMP amplitude and SCM contraction strength. In most cases, small changes in electrode position had only minor effects but, in a minority of subjects, the different montages produced large changes in cVEMP and contraction amplitudes and asymmetry, potentially affecting test outcomes.

Anatomical guide for botulinum neurotoxin injection: Application to cosmetic shoulder contouring, pain syndromes, and cervical dystonia

INTRODUCTION

This study proposes an ideal botulinum toxin injection point of the trapezius muscle for shoulder line contouring, pain management, and functional impairment. This study describes the intramuscular nerve branching in the trapezius muscle, providing essential information for botulinum neurotoxin injection.

METHOD

A modified Sihler's method was performed on the trapezius muscles (16 specimens). The intramuscular arborization areas were elucidated regarding the external occipital protuberance superiorly, spinous process of the 12th thoracic vertebra inferiorly and acromion of the scapula.

RESULT

The intramuscular neural distribution for the superior, middle, and inferior regions of the trapezius muscle had the greatest arborized patterns in the horizontal 1/5-2/5 and vertical 2/10-4/10 sections, the horizontal 1/5-3/5 and vertical 4/10-5/10 sections, and the horizontal 1/5-2/5 and vertical 5/10-7/10 sections, respectively.

DISCUSSION

We propose that BoNT treatments should be directed to the horizontal 1/5-2/5 and vertical 2/10-4/10 sections of the superior trapezius, the horizontal 1/5-3/5 and vertical 4/10-5/10 sections of the middle trapezius and the horizontal 1/5-2/5 and vertical 5/10-7/10 sections of the inferior trapezius. Additionally, injective treatment at the horizontal 2/5-3/5 and vertical 2/10-4/10 nerve entry points should be avoided to prevent nerve trunk damage causing paralysis. According to our guidelines, clinicians can ensure minimal dose injections and fewer adverse effects in botulinum neurotoxin injective treatment.

Effective botulinum neurotoxin injection in treating iliopsoas spasticity

INTRODUCTION

To detect ideal locations for botulinum toxin (BoNT) injection by exploring the intramuscular nerve arborization of the psoas major and iliacus muscles.

METHOD

A modified Sihler's method was performed on the psoas major and iliacus muscles (16 specimens each). Intramuscular nerve arborization was recorded according to the most prominent point of the anterior superior iliac spine (ASIS), the posterior superior iliac spine (PSIS), the lesser trochanter (LT), and the transverse process of the 12th thoracic vertebra.

RESULTS

Intramuscular nerve arborization of the psoas major muscle was the largest from 1/5 to 3/5 the distance from the transverse process of the 12th thoracic vertebra to the PSIS, and the tendinous portion of the muscle occupied from 3/5 to 5/5 this distance. In terms of the plane of the ASIS, the PSIS, and the LT, the arborization of the iliacus muscle was the largest from 1/5 to 3/5 the horizontal distance and 0 to 1/3, the distance longitudinally, and from 1/5 to 2/5, the horizontal distance and 1/3 to 2/3, the longitudinal distance.

DISCUSSION

These results suggest that an injection of BoNT to the psoas major and iliacus muscle should be applied in specific areas. Additionally, the posterior approach is an ideal method for targeting only the psoas major because the injection point is above the PSIS. However, when treating both the psoas major and iliacus muscles, the proximal anterior approach is an ideal method according to the arborization patterns.

Intramuscular Neural Distribution of Rhomboid Muscles: Evaluation for Botulinum Toxin Injection Using Modified Sihler's Method

This study describes the nerve entry point and intramuscular nerve branching of the rhomboid major and minor, providing essential information for improved performance of botulinum toxin injections and electromyography. A modified Sihler method was performed on the rhomboid major and minor muscles (10 specimens each). The nerve entry point and intramuscular arborization areas were identified in terms of the spinous processes and medial and lateral angles of the scapula. The nerve entry point for both the rhomboid major and minor was found in the middle muscular area between levels C7 and T1. The intramuscular neural distribution for the rhomboid minor had the largest arborization patterns in the medial and lateral sections between levels C7 and T1. The rhomboid major muscle had the largest arborization area in the middle section between levels T1 and T5. In conclusion, botulinum neurotoxin injection and electromyography should be administered in the medial and lateral sections of C7-T1 for the rhomboid minor and the middle section of T1-T7 for the rhomboid major. Injections in the middle section of C7-T1 should also be avoided to prevent mechanical injury to the nerve trunk. Clinicians can administer safe and effective treatments with botulinum toxin injections and other types of injections by following the methods in our study.