Ultrasound Guidance for Botulinum Neurotoxin Chemodenervation Procedures

Abstract

Injections of botulinum neurotoxins (BoNTs) are prescribed by clinicians for a variety of disorders that cause over-activity of muscles; glands; pain and other structures. Accurately targeting the structure for injection is one of the principle goals when performing BoNTs procedures. Traditionally; injections have been guided by anatomic landmarks; palpation; range of motion; electromyography or electrical stimulation. Ultrasound (US) based imaging based guidance overcomes some of the limitations of traditional techniques. US and/or US combined with traditional guidance techniques is utilized and or recommended by many expert clinicians; authors and in practice guidelines by professional academies. This article reviews the advantages and disadvantages of available guidance techniques including US as well as technical aspects of US guidance and a focused literature review related to US guidance for chemodenervation procedures including BoNTs injection.

Abobotulinum Toxin A in the Treatment of Chronic Low Back Pain

“…It is conceivable that the cause of chronic low back pain may have some influence on the magnitude of pain response to botulinum toxin treatment. Better localization of the injected muscles with newer techniques such as ultrasound (as sole technique or in addition to EMG) may help improve the results of botulinum toxin [40,42]. A comparison of studies that use different outcome measures is not possible even when they use identical techniques due to potential problems with toxin dose equivalence and heterogeneity in the patient cohorts.…”

Utility of neuromuscular ultrasound for electromyographic needle localization within diseased muscle

“…Ultrasound‐guided needle placement has been described previously for optimal muscle selection in needle‐directed muscle biopsy, and is increasingly being used for muscle targeting in botulinum toxin therapy . We stress that the EMG findings in this case were not necessary to arrive at the diagnosis of FSHD.…”

Safe Needle Insertion Locations for Motor Point Injection of the Triceps Brachii Muscle: A Pilot Cadaveric and Ultrasonography Study

“…Also, although intramuscular endings are identified through cadaveric dissection, special staining techniques were not employed in our study. However, the midpoints between the most proximal and distal nerve endings, as used in this study, are an accurate estimation of the end points and have been consis- www.e-arm.org tently used to define the MoEP for spasticity treatment in many muscles [9][10][11]. Some limiting factors in this study need to be considered.…”

“…The area where the intramuscular endings are most dense was defined as the www.e-arm.org MoEP, the midpoint between the PLP and DLP, as mentioned in previous studies. Accurate administration of botulinum toxin with respect to the MoEPs is crucial for the best efficacy in the treatment of spasticity [8][9][10][11].…”

“…It is important to inject botulinum toxin at exact motor end plates to maximize its chemodenervation effect [7]. The efficacy of botulinum toxin injections to control spasticity was maximized by injection at a motor point, specifically where the zones of the intramuscular endings are reported to be most dense, known as the motor endplate zones (MoEPs) [8][9][10][11]. Triceps brachii muscles are especially associated with elbow extensor spasticity more than the anconeus muscle [12].…”