Systematic test of neurotoxin dose and volume on muscle function in a rat model

Hulst, Jonah B.; Minamoto, Viviane Balisardo; Lim, Michael; Bremner, Shannon N.; Ward, Samuel R.; Lieber, Richard L.

doi:10.1002/mus.23983

Cited by 10 publications

(20 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As with our previous studies, there was a highly significant relationship between muscle fiber cross‐sectional area and joint torque in all muscles studied (data not shown). Linear regression between muscle fiber CSA and joint torque revealed a highly significant result ( P < 0.0001) with the relationship described by the equation:

T o r q u e true(N m true) = 2.6 * 1 0^{- 5} A r e a true(μ m^{2} true) - 0.0 3 true(n = 30, r^{2} = 0. 71 true)

…”

Section: Discussionsupporting

confidence: 90%

“…This is nearly the identical regression relationship reported previously . The significance of this finding is that muscle fiber area appears to be the primary factor producing joint torque at both the 3‐ and 6‐month postinjection time points.…”

Section: Discussionsupporting

confidence: 88%

“…This appears to be due to the fact that the muscle had not recovered by the 3‐month period, even though this is the period suggested from clinical experience. We suspect and have previously reported, that a relatively low level of muscle force production can still result in enough function to produce a functional effect that would result in the need for treatment. Thus, even after 3 months, when muscle function is approximately half of normal, spastic activity of this muscle may still create joint deformity requiring treatment.…”

Section: Discussionmentioning

confidence: 84%

“…We do not believe that the increased intramuscular lipid accumulation is caused by a direct effect of BoNT; rather, it appears to be an indirect result of NMJ paralysis. This theory is based on previous studies that have demonstrated accumulation of intramuscular lipid after denervation, and that small BoNT doses do not result in lipid accumulation …”

Section: Discussionmentioning

confidence: 99%

See 3 more Smart Citations

Dramatic changes in muscle contractile and structural properties after 2 botulinum toxin injections

et al. 2015

Self Cite

View full text Add to dashboard Cite

Introduction Botulinum toxin is frequently administered serially to maintain therapeutic muscle paralysis, but repeated dose effects on muscle function are largely unknown. This study characterized the muscle response to 2 onabotulinum toxin (BoNT) injections separated by 3 months. Methods Animal subjects received a single toxin injection (n=8), 2 BoNT injections separated by 3 months (n= 14), or 1 BoNT and 1 saline injection separated by 3 months (n=8). Results The functional effect of 2 serial injections was exponentially greater than the effect of a single injection. While both groups treated with a single BoNT injection had decreased torque in the injected leg by about 50% relative to contralateral legs, the double BoNT injected group had decreased torque by over 95% relative to the pre-injection level. Both single and double BoNT injections produced clear signs of fiber-type grouping. Discussion These experiments demonstrate a disproportionately increased effect of a second BoNT injection.

show abstract

T o r q u e true(N m true) = 2.6 * 1 0^{- 5} A r e a true(μ m^{2} true) - 0.0 3 true(n = 30, r^{2} = 0. 71 true)

…”

Section: Discussionsupporting

confidence: 90%

Section: Discussionsupporting

confidence: 88%

Section: Discussionmentioning

confidence: 84%

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Dramatic changes in muscle contractile and structural properties after 2 botulinum toxin injections

et al. 2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…Sections were stained with wheat germ agglutinin to label the sarcolemma, and the muscle fiber cross-sectional area was measured using ImageJ opensource software (n = 5 per muscle per group) (National Institutes of Health). 24 …”

Section: Methodsmentioning

confidence: 99%

Chronic Degeneration Leads to Poor Healing of Repaired Massive Rotator Cuff Tears in Rats

et al. 2015

Self Cite

View full text Add to dashboard Cite

Background Chronic rotator cuff tears present a clinical challenge, often with poor outcomes after surgical repair. Degenerative changes to the muscle, tendon, and bone are thought to hinder healing after surgical repair; additionally, the ability to overcome degenerative changes after surgical repair remains unclear. Purpose/Hypothesis The purpose of this study was to evaluate healing outcomes of muscle, tendon, and bone after tendon repair in a model of chronic rotator cuff disease and to compare these outcomes to those of acute rotator cuff injuries and repair. The hypothesis was that degenerative rotator cuff changes associated with chronic multitendon tears and muscle unloading would lead to poor structural and mechanical outcomes after repair compared with acute injuries and repair. Study Design Controlled laboratory study. Methods Chronic rotator cuff injuries, induced via detachment of the supraspinatus (SS) and infraspinatus (IS) tendons and injection of botulinum toxin A into the SS and IS muscle bellies, were created in the shoulders of rats. After 8 weeks of injury, tendons were surgically reattached to the humeral head, and an acute, dual-tendon injury and repair was performed on the contralateral side. After 8 weeks of healing, muscles were examined histologically, and tendon-to-bone samples were examined microscopically, histologically, and biomechanically and via micro–computed tomography. Results All repairs were intact at the time of dissection, with no evidence of gapping or ruptures. Tendon-to-bone healing after repair in our chronic injury model led to reduced bone quality and morphological disorganization at the repair site compared with acute injuries and repair. SS and IS muscles were atrophic at 8 weeks after repair of chronic injuries, indicating incomplete recovery after repair, whereas SS and IS muscles exhibited less atrophy and degeneration in the acute injury group at 8 weeks after repair. After chronic injuries and repair, humeral heads had decreased total mineral density and an altered trabecular structure, and the repair had decreased strength, stiffness, and toughness, compared with the acute injury and repair group. Conclusion Chronic degenerative changes in rotator cuff muscles, tendons, and bone led to inferior healing characteristics after repair compared with acute injuries and repair. The changes were not reversible after repair in the time course studied, consistent with clinical impressions. Clinical Relevance High retear rates after rotator cuff repair are associated with tear size and chronicity. Understanding the mechanisms behind this association may allow for targeted tissue therapy for tissue degeneration that occurs in the setting of chronic tears.

show abstract

Recovery of rat muscle size but not function more than 1 year after a single botulinum toxin injection

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

Systematic test of neurotoxin dose and volume on muscle function in a rat model

Cited by 10 publications

References 36 publications

Dramatic changes in muscle contractile and structural properties after 2 botulinum toxin injections

Dramatic changes in muscle contractile and structural properties after 2 botulinum toxin injections

Chronic Degeneration Leads to Poor Healing of Repaired Massive Rotator Cuff Tears in Rats

Recovery of rat muscle size but not function more than 1 year after a single botulinum toxin injection

Contact Info

Product

Resources

About