Alessandro Picelli, Elisa Battistuzzi, Mirko Filippetti, Angela Modenese, Marialuisa Gandolfi, Daniele Munari, Nicola Smania
Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, IT-37134 Verona, Italy. E-mail: alessandro.picelli@univr.it
DOI: 10.2340/16501977-2693

Objective: To evaluate the role of diagnostic nerve block in predicting the outcome of subsequent botulinum toxin type A treatment for spastic equinovarus foot due to chronic stroke.
Design: Retrospective observational study.
Patients: Fifty chronic stroke patients with spastic equinovarus foot.
Methods: Each patient was given diagnostic tibial nerve block (lidocaine 2% perineural injection) assessment followed by botulinum toxin type A inoculation into the same muscles as had been targeted by the nerve block. All patients were evaluated before diagnostic nerve block, after the nerve block, and 4 weeks after botulinum toxin injection. Outcomes were ankle dorsiflexion passive range of motion of the affected side, and calf muscle spasticity, measured with the modified Ashworth scale and the Tardieu Scale.
Results: Significant improvements were measured after diagnostic nerve block and botulinum toxin injection compared with the baseline condition. Diagnostic nerve block led to significantly greater improvements in all outcomes than botulinum toxin injection.
Conclusion: This study confirmed diagnostic nerve block as a valuable screening tool in deciding whether to treat spastic equinovarus with botulinum toxin. However, the results support the evidence that diagnostic nerve block results in a greater reduction in muscle overactivity than does botulinum toxin type A in patients with spastic equinovarus due to stroke.

This study reviewed data from 50 chronic stroke patients with spastic equinovarus foot in order to compare the outcome of tibial nerve (main trunk and motor branches) diagnostic block (which temporarily relieves focal muscle overactivity, allowing assessment of the contribution of different muscles) with that of subsequent botulinum toxin injected into the same muscles as were targeted by the nerve block. Outcome measures were passive motility of the affected ankle and overactivity of the calf muscles. All patients were evaluated before and after the nerve block, and 4 weeks after the botulinum toxin injection. Significant improvements were found both after the nerve block and after botulinum toxin injection in comparison with the baseline condition; however, the improvements observed after nerve block were significantly greater. These results confirm that diagnostic nerve block is a useful screening tool for use before botulinum toxin treat-ment, although less improvement occurred after botulinum toxin injection compared with after nerve block.