The predictive nature of diagnostic nerve blocks for lower extremity spasticity management with botulinum toxin and neurotomy: A systematic review
Katherine Archibold, Jeremy Slayter, Emily M. Krauss, Alexander WhelanAbstract
Introduction/Objective
Diagnostic nerve blocks (DNBs) involve the injection of anesthetic around peripheral nerves to temporarily reduce motor tone. Although they are used clinically to inform spasticity treatment with neurotomy and chemodenervation, there is little research exploring the predictive nature of DNBs.
Methods
A systematic review was conducted to identify and analyze studies that compared clinical outcomes between DNBs and neurotomies or chemodenervation with botulinum toxin.
Results
In total, nine eligible articles were analyzed, with five studies involving neurotomies and four studies involving chemodenervation. These studies focused exclusively on lower limb spasticity. There were different DNB protocols used across the eligible articles. DNBs resulted in similar clinical outcomes after neurotomy on gait and spasticity measurements. DNBs resulted in reduced agonist muscle strength as compared to neurotomy outcomes, particularly those collected a year or longer after surgery. DNBs were less predictive of clinical response to chemodenervation and to range of motion assessments.
Conclusion
This review has identified a gap in research regarding the predictability of DNBs, with heterogeneity in study design. As DNBs resulted in more similar spasticity and gait outcomes when compared to neurotomy rather than chemodenervation procedures, this may suggest that DNBs have a larger role to play in surgical decision‐making. Given the current research, future studies on DNBs should explore upper extremity spasticity management as well as outcomes that relate to patient reported goals and experiences.