AUTOMATIC EMG-GUIDED BOTULINUM TOXIN TREATMENT OF SPASTICITY

Conventional electromyographic (EMG) guidance in botulinum toxin thera py can localize a muscle, but the amount of electrical activity is ass essed only subjectively. We wanted to introduce a quantitative EMG cri terion, according to which the decision for/against toxin application could be made. Turn/amplitude analysis (TAA) was applied to nine patie nts with severe paraspasticity (n = 5), right upper or lower limb spas ticity (n = 3), or tetraspasticity (n = 1) before and after toxin admi nistration. Muscles were selected for toxin application if both mean t urns/second and mean amplitude/turn exceeded the level of 150. A mean Dysport dose of 116 mouse units (mu) (range 40-240 mu) was administere d to each of the 26 muscles that met the EMG criterion. Thirty days af ter the injection, activities of daily living, pain, and TAA count imp roved in 89%, tone in 78%, and range of motion in 56% of the patients by at least 1 point on corresponding 5-point rating scales. TAA provid es a useful EMG criterion for/against botulinum toxin application. Mus cle selection according to this criterion leads to a significant subje ctive and objective toxin effect. TAA is a valuable tool to determine the benefit of single and subsequent botulinum toxin injections in the treatment of spasticity.