Hemiparetic gait and changes in functional performance due to OnabotulinumtoxinA injection to lower limb muscles Alberto Esquenazi * , Daniel Moon, Amanda Wikoff, Patricio Sale MossRehab Gait & Motion Analysis Laboratory and Department of PM&R MossRehab, Elkins Park, PA, USA article info Article history: Received 14 July 2015 Received in revised form 28 July 2015 Accepted 4 August 2015 Available online xxx Keywords: Gait analysis Hemiparesis OnabotulinumtoxinA Spasticity abstract Objective: To review gait alterations and evaluate the effects of OnabotulinumtoxinA on spatiotemporal walking parameters of patients with hemiparetic gait. Design: Retrospective pre- and post-intervention analysis. Setting: Gait analysis laboratory in a tertiary level rehabilitation hospital. Participants: 42 patients with hemiparesis. 19 males and 23 females, age 18e78 years were included. Intervention: Spatiotemporal parameters collected before and within 4e10 weeks after OnabotA injec- tion to the ankle muscles. Data was recorded at self-selected velocity on a 12 m instrumented walkway. The most common muscles injected were medial and lateral gastrocnemius, soleus and tibialis posterior. Average total OnabotulinumtoxinA dose was 320 ± 107 units. Main outcome: Spatiotemporal parameters of walking assessed before (T 0 ) and within 4e10 weeks post injection (T 1 ). Paired t-test was used to compare pre- and post-intervention data. A sequential Holm eBonferroni procedure was used to adjust for multiple comparisons and minimize the risk of type I error. Statistical significance was set at p < 0.05. Results: Statistically significant increases were seen for walking velocity (20%) (T 0 ¼ 0.40 ± 0.26 m/s and T 1 ¼ 0.48 ± 0.29 m/s; p ¼ 0.006), and increased cadence (T 0 ¼ 63.48 ± 23.93 steps/min, and T 1 ¼ 70.88 ± 23.65 steps/min; p ¼ 0.006) following OnabotulinumtoxinA injections. Conclusion: This study demonstrates that injection of OnabotulinumtoxinA 320 units to ankle muscles selected with the aid of dynamic electromyography can significantly increase gait velocity and enhance functional ambulation in adults with hemiparesis due to upper motor neuron syndrome. © 2015 Elsevier Ltd. All rights reserved. 1. Introduction Many persons with upper motor neuron (UMN) syndrome are able to ambulate, but often with inefficient movement strategies, limb instability, and pain (Mayer et al., 2001). The objective of this paper is to review and discuss the alterations of hemiparetic gait and evaluate the effects of OnabotulinumtoxinA (OnabotA) on temporal spatial walking parameters of patients with hemiparetic gait dysfunction. Supraspinal structures are involved in the control of ambulation, including the brainstem reticular formation, basal ganglia, motor, premotor, and supplementary motor area of the motor cortex, as well as the cerebellum (Dietz, 1997; Duysens and Van De Crommert, 1998). Peripheral nerves located in tendons, muscles, ligaments, and joints relay information regarding limb position and kinesthesia. Proprioceptive information transmitted to the cortex assists with controlling volitional movements planned by the mo- tor cortex. Proprioceptive information transferred to the cere- bellum assists with involuntary modulation of motor control (Schneider et al., 1977). Load information sensed by mechanical receptors in the sole of the feet and from proprioceptive inputs in the extensor muscles of the foot (Dietz and Duysens, 2000), as well as afferents that signal hip-joint position (Pang and Yang, 2000), play a role in muscle activation patterns and stanceeswing phase transitions during ambulation. Ambulation is the end result of a well-choreographed pattern of phasic muscle activation and deactivation that is modulated by complex interactions within and between the central and periph- eral nervous system and the gravitational forces. Given the multiple and complex neural pathways involved in producing ambulation, it is not surprising that disorders of the neurologic system result in gait disturbances. The various hemiparetic gait patterns are the * Corresponding author. E-mail address: aesquena@einstein.edu (A. Esquenazi). Contents lists available at ScienceDirect Toxicon journal homepage: www.elsevier.com/locate/toxicon http://dx.doi.org/10.1016/j.toxicon.2015.08.004 0041-0101/© 2015 Elsevier Ltd. All rights reserved. Toxicon xxx (2015) 1e5 Please cite this article in press as: Esquenazi, A., et al., Hemiparetic gait and changes in functional performance due to OnabotulinumtoxinA injection to lower limb muscles, Toxicon (2015), http://dx.doi.org/10.1016/j.toxicon.2015.08.004