title: Instrumented assessment of the effect of Botulinum Toxin-A in the medial hamstrings in children with cerebral palsy.
abstract: This study examined the sensitivity of an instrumented spasticity assessment of the medial hamstrings (MEH) in children with cerebral palsy (CP). Nineteen children received Botulinum Toxin type A (BTX-A) injections in the MEH. Biomechanical (position and torque) and electrophysiological (surface electromyography, EMG) signals were integrated during manually-performed passive stretches of the MEH at low, medium and high velocity. Signals were examined at each velocity and between stretch velocities, and compared pre and post BTX-A (43 ± 16 days). Average change between pre and post BTX-A was interpreted in view of the minimal detectable change (MDC) calculated from previously published reliability results. Improvements greater than the MDC were found for nearly all EMG-parameters and for torque parameters at high velocity and at high versus low velocity (p<0.03), however large inter-subject variability was noted. Moderate correlations were found between the improvement in EMG and in torque (r=0.52, p<0.05). Biomechanical and electrophysiological parameters proved to be adequately sensitive to assess the response to treatment with BTX-A. Furthermore, studying both parameters at different velocities improves our understanding of spasticity and of the physiological effect of selective tone-reduction. This not only provides a clinical validation of the instrumented assessment, but also opens new avenues for further spasticity research.
authors.affiliation: Clinical Motion Analysis Laboratory, University Hospital, Leuven, Pellenberg, Belgium; Department of Rehabilitation Sciences, KU Leuven, Leuven, Belgium. Electronic address: lynn.1.bar-on@uzleuven.be.
authors.forename: L
authors.initials: L
authors.lastname: Bar-On
authors.forename: E
authors.initials: E
authors.lastname: Aertbeliën
authors.forename: G
authors.initials: G
authors.lastname: Molenaers
authors.forename: A
authors.initials: A
authors.lastname: Van Campenhout
authors.forename: B
authors.initials: B
authors.lastname: Vandendoorent
authors.forename: A
authors.initials: A
authors.lastname: Nieuwenhuys
authors.forename: E
authors.initials: E
authors.lastname: Jaspers
authors.forename: C
authors.initials: C
authors.lastname: Hunaerts
authors.forename: K
authors.initials: K
authors.lastname: Desloovere
mesh_terms: D000293:Adolescent; D001696:Biomechanical Phenomena; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage*; D002547:Cerebral Palsy / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy*; D002648:Child; D002675:Child, Preschool; D004305:Dose-Response Relationship, Drug; D004576:Electromyography / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007273:Injections, Intramuscular; D007866:Leg; D008297:Male; D009128:Muscle Spasticity / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology; D018482:Muscle, Skeletal / Q000503:physiopathology*; D009465:Neuromuscular Agents / Q000008:administration & dosage; D015203:Reproducibility of Results; D013997:Time Factors; D019415:Torque; D016896:Treatment Outcome
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A
keywords: Biomechanics; Botulinum Toxin-A; Cerebral palsy; Electromyography; Spasticity