Chronic Spinal Cord Stimulation in the Treatment of Cerebral and Spinal Spasticity

Abstract

Objectives: The aim of this investigation is to assess the effectiveness of spinal cord stimulation (SCS) in different groups of patients with spasticity of different origin. Materials and Methods: A retrospective study of the use of the method of SCS in 71 patients. The patient population was divided into two groups: 52 cerebral palsy (CP) cases and 19 patients diagnosed with spasticity caused by spinal injury. The mean age was 7.14 ± 4.06 and 35.68 ± 12.42 years, respectively. The CP group included 41 cases of paraparesis and 11 cases tetraparesis. One quadripolar electrode was implanted into the posterior epidural space at Th10-Th12 level and an implantable pulse generator (Itrel3, Medtronic) was placed in a standard fashion. We performed 3-5 stimulation sessions per day; each lasted 30 min. The stimulation parameters were as follows: rate 100-130 Hz, pulse width 120-300 ms, amplitude 1.5-4 V. The follow-up ranged from 2 to 9 years. Results: Decrease in muscle tone was observed in all cases in the group of patients with spinal spasticity: from 3.71 ± 0.61 on the Ashworth scale before the operation to 2.26 ± 0.56 after the operation (p < 0.001). In the group of cerebral spasticity a significant decrease in muscle tone was observed only in patients with spastic lower paraparesis: from 3.36 ± 0.41 before the operation to 1.97 ± 0.91 after the operation (p < 0.005). In patients with spastic tetraparesis we did not observe any significant change in muscle tone. In 8 cases we discontinued the therapy several years after the procedure due to improvement in spasticity: in the CP group in 7 cases and in 1 spinal spasticity case, where SCS systems were explanted. Conclusion: Chronic SCS may be a method of choice for patients with moderate spinal and cerebral spasticity with predominant spastic lower paraparesis. In patients with spastic tetraparesis SCS therapy did not prove to be effective. We encountered improvement of the spasticity and no need for further SCS therapy in a small group of patients (11%). This phenomenon requires further investigation.