Morphological characteristics of the posterior neck muscles and anatomical landmarks for botulinum toxin injections

Contouring With Neuromodulators

BACKGROUND AND OBJECTIVE

Botulinum toxins, originally used for facial rejuvenation, have emerged as a promising tool for sculpting and refining contours for both the face and body.

METHODS

The peer-reviewed literature on neuromodulator contouring treatments was analyzed, with a particular emphasis on studies and case reports involving the use of botulinum toxin type A.

RESULTS

Modification of face, neck, shoulder, arm, and calf contour has been reported. Treatment and dosing protocols vary with the strength and depth of the target muscle. Regional effects of neuromodulator treatment begin to appear approximately 2 weeks after injection and are often most prominent at the 70- to 90-day time point. Although treatments are generally well tolerated, short-term muscle weakness and other side effects may occur.

CONCLUSION

The use of neuromodulators to enhance facial and body contours has demonstrated efficacy, but further research is needed to validate their use and explore the full potential of this intervention through larger randomized controlled trials. The application of neuromodulators as a minimally invasive tool to address the rising demand for nonsurgical body sculpting represents a promising frontier in aesthetics.

Retroform Cervical Dystonia: Target Muscle Selection and Efficacy of Botulinum Toxin Injection

Introduction

Retroform cervical dystonia (RCD), which includes retrocaput and retrocollis, is a rare form of cervical dystonia. Few reports have been published on RCD. The present study aimed to characterize the target muscles involved in RCD and the efficacy of botulinum toxin type A (BTX-A) injection.

Methods

Patients with consecutive cervical dystonia with RCD as the most problematic feature were retrospectively analyzed over a 10-year period. Target muscles were screened and confirmed based on clinical evaluation, single-photon emission computed tomography, and electromyography. In addition, efficacy and adverse events following BTX-A injection in patients with RCD were evaluated.

Results

A total of 34 patients with RCD were included, 18 of whom presented with retrocaput and 16 with retrocollis. The most frequently injected muscles in RCD were splenius capitis (SPCa, 97.1%) and semispinalis capitis (SSCa, 97.1%), followed by levator scapulae (LS, 50.0%), rectus capitis posterior major (RCPM, 47.1%), trapezius (TPZ, 41.2%), and sternocleidomastoid muscle (SCM, 41.2%). Besides cervical muscles, the erector spinae was also injected in 17.6% of patients. Most muscles were predominantly bilaterally injected. The injection schemes of retrocaput and retrocollis were similar, possibly because in patients with retrocollis, retrocaput was often combined. BTX-A injection achieved a satisfactory therapeutic effect in RCD, with an average symptom relief rate of 69.0 ± 16.7%. Mild dysphagia (17.6%) and posterior cervical muscle weakness (17.6%) were the most common adverse events.

Conclusion

SPCa, SSCa, LS, RCPM, LS, and SCM were commonly and often bilaterally injected in RCD. Patients with RCD could achieve satisfactory symptom relief after BTX-A injection.