Functional impact of different muscle localization techniques for Botulinum neurotoxin A injections in clinical routine management of post-stroke spasticity

ABSTRACT

Background: Treatment options for spasticity include intramuscular botulinum neurotoxin A (BoNT-A) injections. Both ultrasound (US) or electromyographic (EMG) guided BoNT-A injections are employed to isolate muscles. To date, most studies have included patients naïve to BoNT-A or following a prolonged wash out phase.

Objective: To determine the impact of US/EMG guided BoNT-A injections on function in outpatients with spasticity receiving an established re-injection regime.

Methods: Thirty patients post-stroke were investigated in a single-blinded, randomized controlled trial using a cross-over design for the EMG and US and a parallel design for the control group. The Modified Ashworth (MAS), Disability Assessment (DAS), Quality of Life (EQ-5D), self-rating scale and Barthel Index were assessed pre- and post-BoNT-A injections of upper limb muscles by a to the injection technique blinded person.

Results: MAS improved in arm, finger and upper limb 4 weeks after BoNT-A treatment. The improvement showed no significant differences between the three injection techniques. Barthel Index, DAS and EQ-5D remained unchanged in all groups.

Conclusions: This pilot study questions the impact of the instrumental guided injection techniques on everyday functionality in a routine clinical setting with established re-injection intervals. Larger trials are warranted with patients who are under long-term treatment on a regular basis.

KEYWORDS:

• Botulinum neurotoxin
• arm spasticity
• stroke
• electromyography
• ultrasound

Acknowledgements

We are indebted to the patients for participating in this study. Our special thanks to Fiona M. Molloy, MD, Department of Clinical Neurophysiology, Beaumont Hospital, Dublin, Ireland, for editing the manuscript.

Declaration of interest

This study has been supported with ultrasound equipment that was independently provided by Allergan. Kirsten E. Zeuner has received lecture fees from Allergan and Merz Pharmaceuticals. Her research has been supported by the German Research Foundation, by the University of Schleswig Holstein, the Benign Essential Blepharospasmus Foundation, by Allergan and with an unrestricted grant from Ipsen. Arne Knutzen, Carina Kühl and Helge Hellriegel have nothing to disclose. Bettina Möller has received lecture fees from Medtronic. Nils G. Margraf reports lecture fees from Merz Pharmaceuticals. Günther Deuschl has received lecture fees from Medtronic, Sapiens, Britannica, Boston Scientific Lundbeck, TEVA, Orion and Pfizer and has been serving as a consultant for TEVA, Medtronic and Novartis. He received royalties from Thieme publishers. He is a government employee and he receives, through his institution, funding for his research from the German Research Council, the German Ministry of Education and Health and Medtronic. Henning Stolze has received lecture fees from Ipsen, Merz Pharmaceuticals and Allergan.