Quantification of surface EMG signals to monitor the effect of a Botox treatment in six healthy ponies and two horses with stringhalt: Preliminary study

• Published in: Equine veterinary journal 2009-03, Vol.41 (3), p.313-318
• Main Authors: Wijnberg, I. D., Schrama, S. E. A., Elgersma, A. E., Maree, J. T. M., De Cocq, P., Back, W.
• Format: Article
• Language: English
• Subjects: adductor spasticity; Animals; australian stringhalt; Biomechanical Phenomena; botulinum toxin type A; Botulinum Toxins, Type A - therapeutic use; botulinum-toxin; clinical-diagnosis; double-blind; dysport(r); electromyography; Electromyography - veterinary; horse; Horse Diseases - drug therapy; Horses; hypermetria; injections; Lameness, Animal - drug therapy; Male; muscle activity; muscle paralysis; Neuromuscular Agents - therapeutic use; quantitative electromyography; toxin type-a
• ISSN: 0425-1644; 2042-3306
• DOI: 10.2746/042516409X397361

Summary Reasons for performing the study: Therapeutic options for stringhalt in horses are limited, whereas medical experiences with botulinum toxin type A (Botox) have been positive. To evaluate its effectiveness in horses, surface electromyography (sEMG) signals before and after injection need to be quantified. Hypothesis: Treatment of healthy ponies and cases with Botox should reduce muscle activity in injected muscles and reduce spastic movements without adverse side effects. Methods: Unilaterally, the extensor digitorum longus, extensor digitorum lateralis and lateral vastus muscles of 6 healthy mature Shetland ponies and 2 talented Dutch Warmblood dressage horses with stringhalt were injected (maximum of 400 iu per pony and 700 iu per case; 100 iu in 5 ml NaCl divided into 5 injections) with Botox under needle EMG guidance. Surface EMG data were evaluated using customised software, and in the individuals gait was analysed using Proreflex. Statistical analysis was performed using mixed models and independent sample t test (P