Utilization of shear wave elastography to quantify and predict response to upper extremity botulinum toxin injections in patients with cerebral palsy: A pilot study.

OBJECTIVE: Shear wave elastography (SWE) was used to quantify change in upper extremity muscle stiffness in patients with unilateral spastic cerebral palsy (USCP) following botulinum toxin A (BTX-A) therapy. We hypothesized that SWE measures would decrease following ultrasound-guided BTX-A injection, and correlate with functional improvement. METHODS: SWE measures of BTX-A treated muscles were recorded immediately pre-injection, and at 1-, 3- and 6-months post-injection. At the same timepoints, functional assessment was performed using the Modified Ashworth Scale (MAS), and passive and active range of motion (PROM and AROM) measures. Correlation of SWE with MAS, PROM and AROM, as well as the relationship between change in SWE and change in MAS, PROM and AROM was determined using Spearman's rank correlation coefficient and generalized estimating equation modeling. RESULTS: 16 muscles were injected and longitudinally assessed. SWE and MAS scores decreased following BTX-A injection (p = 0.030 and 0.004, respectively), reflecting decreased quantitative and qualitative muscle stiffness. Decreased SWE reached statistical significance at 1- and 3-months, and 1-, 3- and 6-months for MAS. When comparing relative change in SWE to relative change in AROM, larger change in SWE strongly correlated with positive change in AROM (p-value range:<0.001-0.057). BTX-A responders also demonstrated lower baseline SWE (1.4 m/s) vs. non-responders (1.9 m/s), p = 0.035. CONCLUSION: Ultrasound-guided BTX-A injections in patients with USCP resulted in decreased quantitative and qualitative muscle stiffness. Strong correlation between change in SWE and AROM, as well as the significant difference in baseline SWE for BTX-A responders and non-responders, suggests SWE may provide a useful tool to predict and monitor BTX-A response.

Ultrasound imaging of nerves in the neck: Correlation with MRI, EMG, and clinical findings.

OBJECTIVE: We evaluated the performance of ultrasound in the detection of neuropathy of the suprascapular nerve (SSN), long thoracic nerve (LTN), spinal accessory nerve (SAN), and phrenic nerve and compared this performance with MRI. METHODS: A retrospective review of 56 patients who had undergone ultrasound imaging of the SSN, LTN, SAN, and phrenic nerve was performed. Diagnoses made by ultrasound, MRI, EMG reports, and clinical and operative notes were recorded. RESULTS: Ultrasound was successful in visualizing nerves in the neck in the overwhelming majority of cases. Sonographic findings were typically in agreement with MRI and clinical findings. CONCLUSION: Ultrasound is effective in the visualization and diagnostic evaluation of the SSN, LTN, SAN, and phrenic nerve. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that ultrasound can effectively visualize and diagnose neuropathy of the SSN, LTN, SAN, and phrenic nerve in the neck.

Ultrasound imaging of brachial plexus trauma in gunshot injury.

INTRODUCTION: Brachial plexus trauma related to gunshot (GS) injury requires early examination and characterization to ensure appropriate treatment. Magnetic resonance imaging (MRI) may be contraindicated when there are metal fragments in a patient's body. Ultrasound (US) may present an alternative to imaging GS-related brachial plexus injury. METHODS: Three patients with GS-related brachial plexus injury who underwent US imaging evaluation at our institution were identified. A retrospective review of the patients' medical records was performed. RESULTS: US characterization of nerve abnormalities after GS injury to the brachial plexus was in agreement with electrodiagnostic and intraoperative findings. DISCUSSION: Information from the US reports was useful in preparation for brachial plexus reconstruction surgery. As such, US has unique utility when MRI cannot be performed. US imaging can provide useful characterization of the brachial plexus after GS injury when performed by an experienced operator. Muscle Nerve 59:707-711, 2019.