Visualization of Ultrasound-Guided Intramuscular Injections in Muscles Relevant for Cervical Dystonia

Our updated review does not support use of image guidance for injections in the shoulder. Moderate-certainty evidence indicates that ultrasound-guided injection in the treatment of shoulder pain probably provides little or no benefit over injection without imaging in terms of pain or function and low-certainty evidence indicates there may be no difference in quality of life. We are uncertain if ultrasound-guided injection improves participant-rated treatment success, due to very low-certainty evidence. Low-certainty evidence also suggests ultrasound-guided injection may not reduce the risk of adverse events compared with non-image-guided injection. No serious adverse events were reported in any trial. The lack of significant benefit of image guidance over injection without image guidance to improve patient-relevant outcomes or reduce harms, suggests that any added cost of image guidance appears unjustified.

ObjectiveTo compare the accuracy of ultrasound-guided and non-guided botulinum toxin injections into the neck muscles involved in cervical dystonia.MethodsTwo physicians examined six muscles (sternocleidomastoid, upper trapezius, levator scapulae, splenius capitis, scalenus anterior, and scalenus medius) from six fresh cadavers. Each physician injected ultrasound-guided and non-guided injections to each side of the cadaver’s neck muscles, respectively. Each physician then dissected the other physician’s injected muscle to identify the injection results. For each injection technique, different colored dyes were used. Dissection was performed to identify the results of the injections. The muscles were divided into two groups based on the difficulty of access: sternocleidomastoid and upper trapezius muscles (group A) and the levator scapulae, splenius capitis, scalenus anterior, and scalenus medius muscles (group B).ResultsThe ultrasound-guided and non-guided injection accuracies of the group B muscles were 95.8% and 54.2%, respectively (p<0.001), while the ultrasound-guided and non-guided injection accuracies of the group A muscles were 100% and 79.2%, respectively (p<0.05).ConclusionUltrasound-guided botulinum toxin injections into inaccessible neck muscles provide a higher degree of accuracy than non-guided injections. It may also be desirable to consider performing ultrasound-guided injections into accessible neck muscles.

Introduction: Botulinum neurotoxin (BoNT) injection is the gold standard treatment for cervical dystonia (CD). Treatment failures often result from anatomical variations, inadequate technique, incorrect muscle targeting, or suboptimal dosing. Ultrasound guidance has been proposed as a means to address these issues by increasing precision, although its clinical superiority remains debated due to limited robust evidence. Objective: To assess the clinical impact and potential advantages of ultrasound-guided BoNT injections for CD compared to standard anatomical landmark-based methods. Methodology: A narrative review was performed by searching PubMed for studies evaluating ultrasound-guided BoNT injections in patients with CD. Results: Ultrasound guidance significantly enhances injection accuracy, especially for deep cervical muscles such as the obliquus capitis inferior, and semispinalis capitis, reducing variability both within and between operators. It enables better targeting of deep anatomical structures, consequently minimizing adverse effects like dysphagia and unintended muscle weakness. Clinical response rates with ultrasound guidance range from 82–97%, compared to 48–62% using traditional landmark methods. However, improvements in clinical outcomes are not always directly proportional to improved accuracy, suggesting the greatest benefit occurs in refractory cases or anatomically challenging patients. Conclusions: Ultrasound-guided BoNT injections demonstrate significant advantages in precision, safety, and clinical outcomes. The favorable risk-benefit ratio supports broader adoption, especially for injections targeting deeper or thinner muscles, structures near critical anatomical landmarks, patients with obesity, or complex and refractory CD cases.

To describe the detailed anatomy of the equine thoracoabdominal region and to compare the accuracy of ultrasound-guided versus blind intercostal nerve injection techniques, targeting the thoracic intercostal nerves (T12-T18) in equine cadavers. Randomized, blinded, cadaveric study. Eight fresh adult equine cadavers. Eight horse cadavers were used: one in phase I (436 kg; 4 years old) for anatomic landmarks identification and seven in phase II [420 (317-560 kg); 16 (3-22 years old) [median (minimum-maximum)] for comparative study. In phase I, dissections were performed to map muscular landmarks and intercostal nerve courses. In phase II, intercostal nerve injections were performed bilaterally using 3 mL of 0.05% methylene blue per site, with one hemithorax randomized to ultrasound-guided injection (49 repetitions) and the contralateral side to blind technique (49 repetitions). Gross dissections assessed nerve staining, pleural punctures and incorrect intramuscular injections. Statistical analyses included Shapiro-Wilk test for normality and McNemar test. Success in nerve staining was higher with ultrasound-guided (41/49, 83.7%) than blind injections (25/49, 51.0%; p = 0.001). Pleural puncture was identified in ultrasound-guided (3/49, 6.1%) and blind approaches (7/49, 14.3%). Intramuscular dye deposition occurred in 8/49 (16.3%) of ultrasound-guided and 14/49 (28.6%) of blind injections. The costoabdominalis nerve (T18) exhibited the greatest disparity between techniques, with no nerve staining occurring with the blind approach and in 3/7 (42.6%) injections under ultrasound guidance. Gross dissection confirmed anatomical deviation of the T18 nerve, traveling approximately 2.4 ± 1.2 cm ventrocaudally, differing from cranial intercostal nerves. Ultrasound guidance significantly improved the accuracy of intercostal nerve injections in horse cadavers. Detailed anatomical knowledge of the thoracoabdominal region, particularly of T18, is critical for optimizing regional anesthesia techniques in horses.

Prevalence of Bleeding Complications Following Ultrasound-Guided Botulinum Toxin Injections in Patients on Anticoagulation or Antiplatelet Therapy

To compare the use of methylene blue and blue tissue marker in achieving sciatic nerve staining in cadaveric rats after perineural or intramuscular injection. Experimental, randomized, blinded, crossover cadaveric study. A group of 16 fresh-frozen adult Wistar rat cadavers. Phase I: ultrasound-guided sciatic nerve injections were performed using either methylene blue (Group Methb, n = 8) or a blue tissue marker (Group Tmarker, n = 8). ultrasound-guided biceps femoris intramuscular injections were performed with the same dyes (Group Methb IM, n = 8; Group Tmarker IM, n = 8). Volume of each injection was 0.1 mL, followed by a 5 minute interval before anatomical dissection. Positive staining was measured along the sciatic nerve in millimeters. Data analysis included t tests for parametric data and Wilcoxon and Fisher's exact tests for nonparametric data, with significance set at p < 0.05. Phase I: both solutions consistently stained the sciatic nerve in all pelvic limbs. However, the length of staining was significantly greater in Group Methb (18 ± 1.9 mm) than in Group Tmarker (4.7 ± 1.3 mm) (p < 0.001). sciatic nerve staining was observed in the Group Methb IM (7/7, 100%), with a median spread of 12 mm (interquartile range 11-12 mm), whereas no staining was detected in the Group Tmarker IM (0/8) (p = 0.015). and clinical relevance Methylene blue achieved greater staining along the sciatic nerve than blue tissue marker. Furthermore, methylene blue diffused through the biceps femoris, effectively staining the sciatic nerve and surrounding tissues. This difference highlights the potential for overestimation in studies that use methylene blue and underscores the importance of selecting appropriate dye solutions.

BACKGROUNDCervical pregnancy is increasing in morbidity, and a definite diagnosis in early stages is challenging due to its specific onset site. Surgery is the mainstay of treatment for cervical pregnancy, but it may result in the loss of natural fertility. Therefore, it is a great challenge to pursue a safe and effective treatment for cervical pregnancy.CASE SUMMARYWe report the case of a cervical pregnancy successfully treated by ultrasound-guided cervical-intramuscular lauromacrogol injection combined with hysteroscopy. A 23-year-old woman with minor irregular vaginal bleeding was admitted to our department with suspected ectopic pregnancy. Transvaginal ultrasound revealed a gestational sac (approximately 22 mm x 13 mm) situated in the cervical canal with a yolk sac and blood flow signals. No cardiac activity was detected. Serum beta progesterone was 17.06 ng/mL, and serum beta human chorionic gonadotropin (β-HCG) was 5077.0 IU/L. The patient was diagnosed with cervical pregnancy. She was treated by ultrasound-guided cervical-intramuscular injections of lauromacrogol (3 mL) in combination with aborting under hysteroscopic visualization. A gradual decrease in β-HCG levels and normal ultrasound findings were observed. Postoperative pathologic examination showed the presence of villi and changes in the endometrium in the secretory phase. The patient was discharged on day 6, and her β-HCG level was 0.67 mIU/mL after 1 wk. There was no statistical difference between baseline and 1-week postoperative data in terms of serum indices including liver function, renal function, and routine blood analysis after treatment. The patient subsequently became pregnant 2 mo later and no abnormalities were detected on routine screening during pregnancy. CONCLUSIONUltrasound-guided cervical-intramuscular lauromacrogol injection combined with hysteroscopy may be effective and safe in the treatment of cervical pregnancy.

Local Methotrexate Injection as the First-line Treatment for Cesarean Scar Pregnancy: Review of the Literature.

Background: Skeletal muscle injuries represent a major concern in sports medicine. Cell therapy has emerged as a promising therapeutic strategy for muscle injuries, although the preclinical data are still inconclusive and the potential clinical use of cell therapy has not yet been established. Purpose: To evaluate the effects of muscle precursor cells (MPCs) on muscle healing in a small animal model. Study Design: Controlled laboratory study. Methods: A total of 27 rats were used in the study. MPCs were isolated from rat (n = 3) medial gastrocnemius muscles and expanded in primary culture. Skeletal muscle injury was induced in 24 rats, and the animals were assigned to 3 groups. At 36 hours after injury, animals received treatment based on a single ultrasound-guided MPC (105 cells) injection (Cells group) or MPC injection in combination with 2 weeks of daily exercise training (Cells+Exercise group). Animals receiving intramuscular vehicle injection were used as controls (Vehicle group). Muscle force was determined 2 weeks after muscle injury, and muscles were collected for histological and immunofluorescence evaluation. Results: Red fluorescence–labeled MPCs were successfully transplanted in the site of the injury by ultrasound-guided injection and were localized in the injured area after 2 weeks. Transplanted MPCs participated in the formation of regenerating muscle fibers as corroborated by the co-localization of red fluorescence with developmental myosin heavy chain (dMHC)–positive myofibers by immunofluorescence analysis. A strong beneficial effect on muscle force recovery was detected in the Cells and Cells+Exercise groups (102.6% ± 4.0% and 101.5% ± 8.5% of maximum tetanus force of the injured vs healthy contralateral muscle, respectively) compared with the Vehicle group (78.2% ± 5.1%). Both Cells and Cells+Exercise treatments stimulated the growth of newly formed regenerating muscles fibers, as determined by the increase in myofiber cross-sectional area (612.3 ± 21.4 µm2 and 686.0 ± 11.6 µm2, respectively) compared with the Vehicle group (247.5 ± 10.7 µm2), which was accompanied by a significant reduction of intramuscular fibrosis in Cells and Cells+Exercise treated animals (24.2% ± 1.3% and 26.0% ± 1.9% of collagen type I deposition, respectively) with respect to control animals (40.9% ± 4.1% in the Vehicle group). MPC treatment induced a robust acceleration of the muscle healing process as demonstrated by the decreased number of dMHC-positive regenerating myofibers (enhanced replacement of developmental myosin isoform by mature myosin isoforms) (4.3% ± 2.6% and 4.1% ± 1.5% in the Cells and Cells+Exercise groups, respectively) compared with the Vehicle group (14.8% ± 13.9%). Conclusion: Single intramuscular administration of MPCs improved histological outcome and force recovery of the injured skeletal muscle in a rat injury model that imitates sports-related muscle injuries. Cell therapy showed a synergistic effect when combined with an early active rehabilitation protocol in rats, which suggests that a combination of treatments can generate novel therapeutic strategies for the treatment of human skeletal muscle injuries. Clinical Relevance: Our study demonstrates the strong beneficial effect of MPC transplant and the synergistic effect when the cell therapy is combined with an early active rehabilitation protocol for muscle recovery in rats; this finding opens new avenues for the development of effective therapeutic strategies for muscle healing and clinical trials in athletes undergoing MPC transplant and rehabilitation protocols.

Background. Piriformis syndrome is a common cause of low back pain sometimes underdiagnosed due to a lack of distinguishing symptoms and patterns. Two methods of ultrasound-guided intramuscular injection (using a local anesthetic agent and combined with corticosteroids) have become the treatments of choice. However, some studies suggest these methods may result in recurrence even though data regarding the prevalence of recurrence and triggering factors are still lacking. Objective. To identify the prevalence of and factors triggering the recurrence of piriformis syndrome treated with steroid and local anesthetic injections. Methods. This is a prospective cohort following patients diagnosed with piriformis syndrome and treated with either a local anesthetic or a combination with the addition of corticosteroids. Demographic, risk factors, and the onset of pain recurrence data were taken and analyzed. Results. From the 66 patients included in this study, 68.2% (n:45) reported recurrence of pain, with the majority occurring within the first three months post-injection. Subjects treated with combination therapy had a pain-free interval 13.45 weeks longer than subjects treated with a local anesthetic injection. There were no significant differences in risk factors between both groups. Conclusion. Recurrence of piriformis syndrome was most commonly found within the first and third months of treatment. Both methods did not differ significantly, even though combination therapy tends to give longer pain-relief intervals.

Ultrasound-Guided Injection of the Sternocleidomastoid Muscle: A Cadaveric Study with Implications for Chemodenervation.

The objective of this systematic review was to determine the needle length required to reach the dorsogluteal muscle based on body mass index and sex. Our aim was to provide evidence-based recommendations to current intramuscular injection guidelines from the result(s) of this review. Studies worldwide are documenting reduced medication effectiveness due to improperly placed dorsogluteal intramuscular injections because of incorrect needle length, wrong site selection and/or obesity. Current intramuscular injection guidelines lack specific instructions according to weight or sex. While there are similar concerns with other injectable sites, this review focuses solely on adult dorsogluteal intramuscular injections. A systematic review of relevant literature of dorsogluteal intramuscular injections based on body mass index and sex. This systematic review was reported using the PRISMA checklist 2020. The review protocol was registered with Center for Open Science (OSF). We analysed 1,412 articles from nine databases. We compared twelve studies that utilised computerised tomography or ultrasonography using The Johns Hopkins Evidence-Based Practice Model and Guidelines. A significant number of dorsogluteal intramuscular injections are administered into subcutaneous tissue rather than muscle because needles are too short for populations with body mass indexes over 25, especially women. Poor landmarking often results in improperly placed injections. To prevent administering a dorsogluteal intramuscular injection into subcutaneous tissue, women with a BMI of 25 and over require needles longer than 38mm (1.5 inches). Men have less subcutaneous tissue in the dorsogluteal area and only require longer needles if BMI is 35 and over. If skin-to-muscle depth is questionable in either sex, an ultrasound-guided intramuscular injection is warranted for accurate dorsogluteal placement. Landmarking and needle length are key to appropriately placed IM injections. Dorsogluteal injections are often injected into subcutaneous tissue rather than muscle because needles are not long enough to reach muscle, especially in women. Critical elements that determine placement of intramuscular injections into muscle versus subcutaneous tissue are sex, BMI, needle length and landmarking. Medications delivered into subcutaneous tissue may have reduced bioavailability.

Razaq, Sarah MD; Kaymak, Bayram MD; Kara, Murat MD; Özkan, Serhat MD; Özçakar, Levent MD Author Information

Introduction Thoracic outlet syndrome (TOS) is a rare, often perplexing disorder caused by compression of neurovascular structures, leading to cervicogenic–brachial pain and other symptoms in neck and upper limb. Thoracic outlet syndrome is a group of disorders, not a single disorder, and patients may present with a wide variety of signs and symptoms. The wide range of symptoms and signs in TOS may confound clinicians unfamiliar with this condition (Sanders et al ., 2008; Ferrante, 2012; Foley et al ., 2012). Again, because TOS is a group of disorders, there is no “gold standard” to establish the diagnosis. This may lead to misdiagnosis or overdiagnosis of TOS in patients who present with symptoms suggesting TOS but who have other causes for their symptoms. It is, therefore, imperative that physicians be familiar with the range of symptoms and signs of TOS and testing that either supports or refutes this diagnosis. It is also critical that the diagnosis be correctly established before proceeding to invasive interventions for a presumed diagnosis of TOS, including botulinum neurotoxin (BoNT) injections. One of the many emerging applications for BoNT therapy is for the treatment of musculoskeletal pain disorders, including TOS. While the efficacy of BoNT on decreasing pain associated with cervical dystonia and chronic migraine is established, the antinocioceptive mechanism of action of BoNT is not fully understood (Mense, 2004; Aoki, 2005). Reports of reduced pain with BoNT have been reported in various musculoskeletal pain disorders, including joint pain, myofascial pain and cerebral palsy (Barwood et al ., 2000; Gobel et al ., 2006; Singh et al ., 2009). Although there are numerous reports in the literature citing the efficacy of BoNT for pain and other symptoms associated with TOS, additional research is needed to establish the role of BoNT in TOS and other pain disorders (Jordan et al ., 2007; Danielson and Odderson, 2008; Torriani et al ., 2010; Foley et al ., 2012). The proposed mechanism of action includes reduced muscle spasm leading to decreased compression of neurovascular structures (Jordan et al ., 2007; Tsao, 2007; Danielson and Odderson, 2008). Injection of BoNT into muscles also leads to denervation atrophy, which may reduce compression and neurogenic or vasogenic symptoms. It has also been reported that BoNT reduces the release of nocioceptive neurotransmitters, which could also be a contributing factor in reduced pain in TOS.

The mission of the American Journal of Physical Medicine & Rehabilitation is to promote excellence in education, scientific research and evidence-based clinical practice. ​ American Journal of Physical Medicine & Rehabilitation focuses on the practice, research and educational aspects of physical medicine and rehabilitation. Monthly issues keep physiatrists up-to-date on the optimal functional restoration of patients with disabilities, physical treatment of neuromuscular impairments, the development of new rehabilitative technologies, and the use of electrodiagnostic studies. The Journal publishes cutting-edge basic and clinical research, clinical case reports and in-depth topical reviews of interest to rehabilitation professionals. Topics include prevention, diagnosis, treatment, and rehabilitation of musculoskeletal conditions, brain injury, spinal cord injury, cardiopulmonary disease, trauma, acute and chronic pain, amputation, prosthetics and orthotics, mobility, gait, and pediatrics as well as areas related to education and administration. Other important areas of interest include cancer rehabilitation, aging, and exercise. The Journal has recently published a series of articles on the topic of outcomes research. This well-established journal is the official scholarly publication of the Association of Academic Physiatrists (AAP).