Ultrasound-Guided BoNT-A (Botulinum Toxin A) Injection Into the Subscapularis for Hemiplegic Shoulder Pain: A Randomized, Double-Blind, Placebo-Controlled Trial

Abstract

Background and Purpose: This study aimed to assess the efficacy of an ultrasound-guided lateral approach for BoNT-A (botulinum toxin A) injections into the subscapularis in patients with hemiplegic shoulder pain. Methods: This single-center trial used a randomized, double-blind, placebo-controlled design. The key inclusion criteria were a visual analog scale score of ≥4 cm and a modified Ashworth scale score of ≥1+. The patients were randomized to receive either BoNT-A injections or a placebo. The outcomes included the visual analog scale score, modified Ashworth scale score, pain-free passive range of motion of the hemiplegic shoulder, Fugl-Meyer assessment score for the upper extremities, and Stroke-Specific Quality-of-Life score. Results: A total of 49 hemiplegic shoulder pain patients were screened, and 36 were included. The participants receiving the BoNT-A injection reported a significant decrease in pain (visual analog scale, −1.39 [95% CI, −2.41 to −0.36]; P =0.002) and spasticity (modified Ashworth scale score for shoulder internal rotation, −0.72 [95% CI, −1.10 to −0.35]; P =0.001; modified Ashworth scale score for shoulder abduction, −0.44 [95% CI, −0.90 to −0.01]; P =0.026) and improved pain-free passive shoulder internal rotation range of motion (14.56 [95% CI, 6.70–21.41]; P <0.001) and quality of life (Stroke-Specific Quality-of-Life upper extremity subscale, P =0.025) compared with those receiving the placebo at the end point. The shoulder abduction range of motion did not significantly improve after the BoNT-A injection at the end point ( P =0.127). In addition, the patients in the BoNT-A group showed significant improvements in the visual analog scale score and shoulder external rotation range of motion at the 12-week follow-up. No injection-related adverse events were observed during or after the interventions in either group. Conclusions: The ultrasound-guided lateral approach for BoNT-A injections into the subscapularis is a precise and reliable method for reducing pain and spasticity and improving quality of life in stroke survivors with hemiplegic shoulder pain. Registration: URL: https://www.chictr.org.cn ; Unique identifier: ChiCTR1900023513.

A practical guide to botulinum neurotoxin treatment of shoulder spasticity 2: Injection techniques, outcome measurement scales, and case studies

“…To aid the injection of BoNT-A, patient positioning is important. Although unassisted injection of superficial shoulder muscles can be done in practice using anatomical landmarks, guided techniques are particularly recommended for this muscle group due to the difficulty of accurate injection, particularly in deeper muscles ( 31 ) and in trunk muscles for risk of penetration into deeper structures like the pleura.…”

Canadian Physicians’ Use of Intramuscular Botulinum Toxin Injections for Shoulder Spasticity: A National Cross-Sectional Survey

“…For example, our participants injected subscapularis and latissimus dorsi in similar frequencies, while Nalysnk et al found that the subscapularis was injected 1.9 times more than latissimus dorsi. Emerging RCTs have shown that BoNT-A injections into the subscapularis have shown improvements in spasticity, range of motion and pain of the shoulder [ 13 ]. The reason for this variability is potentially related to the on-label indications of the individual BoNT-A product monographs where the shoulder girdle muscles are not indicated.…”

“…Canadian Stroke Best Practice Guidelines state that the use of BoNT-A for upper limb spasticity to increase range of motion and decrease pain is supported by Level B evidence in less than 6 months post-stroke and Level A evidence more than 6 months post-stroke [ 10 ]. Multiple randomized controlled trials have studied the use of BoNT-A in the shoulder girdle muscles for post-stroke spasticity [ 11 , 12 , 13 , 14 ] and there is conflicting evidence on its efficacy, likely related to variability in muscles, doses, and dilutions injected. There are currently no publications that describe how Canadian physicians currently use BoNT-A to treat spasticity of the shoulder muscles.…”

The Effectiveness of Ultrasound-Guided Subacromial-Subdeltoid Bursa Combined With Long Head of the Biceps Tendon Sheath Corticosteroid Injection for Hemiplegic Shoulder Pain: A Randomized Controlled Trial

“…A previous study has shown that patients require a 1.4-cm reduction in the VAS pain score to achieve a minimal clinically important difference ( 42 ). In addition, the treatment was considered to have yielded good results when the patient's VAS score was <3.33 cm (i.e., mild pain) or when the score was less than half of the initial score ( 43 ). The secondary endpoints were disability and ADL, measured by the pain-free passive range of motion (PROM) of the shoulder, the upper extremity Fugl-Meyer Assessment (FMA,) and Modified Barthel Index (MBI).…”