Related Experiment Video
Updated: Mar 11, 2026

Intramuscular Injections Along the Motor End Plates: A Minimally Invasive Approach to Shuttle Tracers Directly into Motor Neurons
Published on: July 13, 2015
Functional impact of different muscle localization techniques for Botulinum neurotoxin A injections in clinical
Kirsten E Zeuner1, Arne Knutzen1, Carina Kühl1
1a Department of Neurology , Kiel University , Germany.
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.
Related Concept Videos
Directly Acting Muscle Relaxants: Dantrolene and Botulinum Toxin
The binding of dantrolene to the RYR1...
Skeletal Muscle Relaxants: Therapeutic Uses
Classification of Skeletal Muscle Relaxants
Peripherally acting skeletal muscle relaxants interfere with the neurotransmission at the neuromuscular end plate to induce paralysis during...
Skeletal Muscle Relaxants: Adverse Effects
Unlike...
Peripherally and Centrally Acting Muscle Relaxants: A Comparison
Centrally acting muscle relaxants can be further divided into spasmolytic and antispasmodic drugs. Spasmolytic...
Centrally Acting Muscle Relaxants: Therapeutic Uses
Centrally acting drugs are classified into spasmolytic and antispasmodic drugs. Spasmolytic drugs such as baclofen, diazepam, and tizanidine inhibit spinal motor neurons and decrease muscle tone. Spasmolytic drugs are administered for severe and chronic spasms due to multiple sclerosis, cerebral palsy, stroke, and spinal cord and muscle injuries. However,...

