N. Doan1, L.-W. Chou2, M.-Y. Kuo3
1Quang Nam Northern Mountainous Region General Hospital, Quang Nam, Vietnam/ China Medical University, Department of Physical Therapy., Taichung, Taiwan, 2China Medical University, Taichung, Taiwan/ China Medical University Hospital/Asia University Hospital, Department of Physical Medicine and Rehabilitation, Taichung, Taiwan, 3China Medical University, Department of Physical Therapy, Taichung, Taiwan

Background: Muscle spasticity following upper motor neuron damages impedes patients' rehabilitation progress. Botulinum toxin A (BoNT-A) has been employed to manage muscle spasticity associated with various neurological conditions. Contradictory evidence has been reported by several randomized control trials (RCTs) using BoNT-A as the management of adult lower extremity spasticity (ALES) following stroke and non-progressive brain lesions; furthermore, an optimum dose of BoNT-A for improving ALES has not yet been established.

Purpose: To identify the treatment efficacy and the optimal dose of BoNT-A on ALES.

Methods: We systematically reviewed PubMed, EMBASE, Cochrane libraries to retrieve potential RCTs taking BoNT-A for ALES up to 10th March 2020. Two independent assessors investigated risk of bias assessed by the PEDro scale.  "Meta" and "Metafor" packages in R 3.6.2 version were used to analyze the data. Hedges‘ g statistic was used to calculate effect sizes. The statistical significance was defined as p<0.05. 

Results: In a total of 640 studies, 13 relevant RCTs were included for ALES due to stroke or non-progressive brain lesions. Modified Ashworth scale score significantly decreased without heterogeneity at week 4 ((standardized mean difference (SMD)= -0.38; 95% CI: [-0.49; -0.27]; p < 0.0001; I2 = 0%) and week 12 (SMD= -0.31; 95% CI: [-0.45; -0.17]; p < 0.0001; I2 = 0%). At week 8, Mean difference (MD)= -0.66; 95% CI: [-1.22; -0.09]; p =0.02; I2 = 82.7%, p= 0.016, the considerable heterogeneity was caused by differences in duration of spasticity and concomitant rehabilitation program among studies in which a massive improvement in hypertonia and functional outcomes were observed in the study applying BoNT-A as early intervention in combination with a comprehensive rehabilitation program. Almost all in the seven comparative dose studies argued that the improvement with optimum dose was a medium dose of BoNT-A (approximately 1000U Dysport or 300U Botox).

Conclusion(s): BoNT-A has proven efficacious in attenuating ALES and should be regarded as part of a comprehensive rehabilitation program. The medium dosages of BoNT-A (approximately 1000U Dysport or 300U Botox) are the most preferable and safe but should be personalized based on muscles involved in chronic stage. A lower dose of BoNT-A could be applied to manage spasticity in ALES patients <3 months following stroke or non-progressive brain lesions.

Implications: BoNT-A could be regarded as part of a rehabilitation program for adult patients with lower extremity spasticity. Further study should be performed to confirm the efficacy of BoNT-A combined with a comprehensive rehabilitation program in improving functional outcomes in the early stage of stroke.

Funding, acknowledgements: No funding.

Keywords: Lower extremity spasticity, Botulinum toxin, Optimal dose

Topic: Disability & rehabilitation

Did this work require ethics approval? No
Institution: No
Committee: No
Reason: This is A Systematic Review and meta-analysis.

All authors, affiliations and abstracts have been published as submitted.

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