BOTULINUM TOXIN TYPE A THERAPY FOR CERVICAL DYSTONIA IN SEVERE CEREBRAL PALSY

Objectives: We studied clinical effectiveness of botulinum toxin type A (BTX-A) for cervical dystonia in severe cerebral palsies.

Methods: We performed BTX-A injection in 9 patients with severe cerebral palsy (CP) aged from 9 to 49 years (M=36.1, SD=12.4). Six are spastic, 2 are mixed type and 1 is atethotic tetraplegia. Seven out of 9 have profound mental retardation. All have dysphagia, and 4 receive parenteral nutrition. Seven have respiratory dysfunction, and one was tracheostomized and 2 used mechanical ventilators. Injected muscles were selected from the neck and paraspinal muscles by electromyogram. Injections were repeated every 3 months. Initial dose of BTX-A was 60 mouse units µ in adults and 2 mu per kg of body weight in children, then it was increased up to 300 mu in adults and 6 mu per kg in children. Cervical dystonia was evaluated with Tsui score just before the day of each BTX-A injection. Respiratory function was evaluated by observing the signs of narrowing or obstruction of the respiratory way. Blood oxygen saturation of the capillary (SpO2) was measured if necessary. Change of swallowing was also observed. Follow up period was from 8 to 25 months (mean 10 months).

Results: All patients got significant decrease of not only cervical dystonia but also general muscle tone. Mean Tsui score decreased from 21(13–26) to 13.3(5–20) (p<0.001). Respiratory function improved in 3 patients, and one could stop assist ventilation. Dysphagia became more serious in 5, and value of SpO2 dropped during the mealtime in 3, but all of them recovered by reducing muscle reluxants and cooking changes.

Conclusion: BTX-A injection is a very effective therapy for cervical dystonia in the patients of severe cerebral palsy.