Journal of Rehabilitation Medicine 51-6 | Page 40

J Rehabil Med 2019; 51: 434–441 ORIGINAL REPORT FUNCTIONAL EFFECTS OF BOTULINUM TOXIN TYPE A IN THE HIP ADDUCTORS AND SUBSEQUENT STRETCHING IN PATIENTS WITH HEREDITARY SPASTIC PARAPLEGIA Bas J. H. VAN LITH, MSc 1 , Jasper DEN BOER, PT, PhD 1 , Bart P. C. VAN DE WARRENBURG, MD, PhD 2 , Vivian WEERDESTEYN, PT, PhD 1 and Alexander C. GEURTS, MD, PhD 1 From the 1 Department of Rehabilitation and 2 Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands Objective: To investigate the functional effects of bi- lateral botulinum toxin A treatment and subsequent stretching of spastic hip adductors on gait and reac- tive 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 bo- tulinum toxin A injections in the hip adductors and performed daily self-administered stretching exerci- ses 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 reac- tive lateral steps. Results: Compared with baseline, gait width in- creased by 12.6% and 9.7% and comfortable gait speed by 8.3% and 11.5% at T1 and T2, respecti- vely. In known perturbation directions, leg angles increased by 5.9% at T1 and 8.0% at T2, while suc- cess 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 per- turbation 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. Key words: hereditary spastic paraplegia; botulinum toxin; balance control; gait. Accepted Mar 29, 2019; Epub ahead of print Apr 10, 2019 J Rehabil Med 2019; 51: 434–441 Correspondence address: Bas van Lith, Department of Rehabilitation, Donders Institute for Brain, Cognition and Behaviour, Radboud Uni- versity Medical Center, PO Box 9101, 6500 HB Nijmegen, The Nether- lands. E-mail: [email protected] P atients with pure hereditary spastic paraplegia (HSP) show a slow, retrograde axonal degeneration of the corticospinal tract, which leads to bilateral pro- gressive lower extremity spasticity. Although muscle strength and somatosensation are often also affected, the degree of paresis and sensory loss is usually milder than in other conditions with spastic paraparesis (e.g. LAY ABSTRACT Patients with pure hereditary spastic paraplegia often have hip adductor spasticity, causing reduced gait width and a narrow base of support. In addition, they expe- rience difficulties stepping sideways to recover from si- deward balance perturbations. A small base of support and the presumed side-stepping difficulties probably in- crease their risk of falling. Botulinum toxin type A injec- tions 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 administra- tion, there is an increase in comfortable gait speed and gait width. Furthermore, patients show improved reac- tive stepping responses when the perturbation direction is known. It is concluded that botulinum toxin type A treatment and subsequent stretching of the hip adduc- tors may improve gait and reactive lateral stepping in patients with pure hereditary spastic paraplegia. spinal cord injury or multiple sclerosis) (1, 2). Hip adductor spasticity is often prominently present in patients with pure HSP. Besides loss of gait propulsion and deterioration of balance in the plane of progression (1, 3), patients are usually also affected by frontal-plane imbalance, to which hip adductor spasticity is sug- gested to be an important contributing factor (4). This may be explained by spasticity of the hip adductors leading to forced, spontaneous narrowing of the base of support while standing and walking (“scissoring”). In addition, patients with HSP may experience difficul- ties stepping sideways to recover from lateral balance perturbations, as the hip abductors have to overcome the involuntary activity of the spastic hip adductors. The small base of support in combination with the pre- sumed difficulties in side-stepping probably increase the risk of falling in patients with HSP. Botulinum toxin type A (BTX-A) injections are commonly used for reducing spasticity in patients with HSP (2, 5–8), although BTX-A is still on off-label prescription in HSP for all commercially available toxins. BTX-A treatment of the hip adductors, calf muscles and hamstrings has been suggested to lead to functional improvements in balance and gait capacities This is an open access article under the CC BY-NC license. www.medicaljournals.se/jrm doi: 10.2340/16501977-2526 Journal Compilation © 2019 Foundation of Rehabilitation Information. ISSN 1650-1977