Bas J.H. van Lith, Jasper den Boer, Bart P.C. van de Warrenburg, Vivian Weerdesteyn, Alexander C. Geurts
Rehabilitation, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, 6541GX Nijmegen, The Netherlands. E-mail: Bas.vanLith@radboudumc.nl
DOI: 10.2340/16501977-2556

Objective: To investigate the functional effects of bilateral botulinum toxin A treatment and subsequent stretching of spastic hip adductors on gait and reactive lateral stepping responses in patients with pure hereditary spastic paraplegia.
Design: Explorative pre-post intervention study.
Patients: Twenty-five patients with pure hereditary spastic paraplegia.
Methods: Patients were treated with bilateral botulinum toxin A injections in the hip adductors and performed daily self-administered stretching exercises for 16 weeks. Before the intervention (T0), and 6 (T1) and 16 (T2) weeks thereafter, gait width, gait speed, and leg angles at first stepping-foot contact after lateral balance perturbations were assessed, as well as the corresponding success rates of reactive lateral steps.
Results: Compared with baseline, gait width increased by 12. 6% and 9. 7% and comfortable gait speed by 8. 3% and 11. 5% at T1 and T2, respectively. In known perturbation directions, leg angles increased by 5. 9% at T1 and 8. 0% at T2, while success rates increased from 70% at baseline to 90% at T1 and T2. No effects were found for maximal gait speed or lateral stepping responses in unknown perturbation directions.
Conclusion: Bilateral botulinum toxin A treatment and subsequent stretching of the hip adductors may improve gait and reactive lateral stepping in patients with pure hereditary spastic paraplegia.

Patients with pure hereditary spastic paraplegia often have hip adductor spasticity, causing reduced gait width and a narrow base of support. In addition, they experience difficulties stepping sideways to recover from sideward balance perturbations. A small base of support and the presumed side-stepping difficulties probably increase their risk of falling. Botulinum toxin type A injections are commonly used to reduce spasticity in patients with hereditary spastic paraplegia, but no studies have systematically investigated the effects of botulinum toxin type A in (with subsequent stretching of) the hip adductors on gait and balance. The results of this study indicate that, after botulinum toxin type A administration, there is an increase in comfortable gait speed and gait width. Furthermore, patients show improved reactive stepping responses when the perturbation direction is known. It is concluded that botulinum toxin type A treatment and subsequent stretching of the hip adductors may improve gait and reactive lateral stepping in patients with pure hereditary spastic paraplegia.