Long-Term Results of a Simultaneous Trial of Deep Brain and Motor Cortex Stimulation in Refractory Neuropathic Pain

Abstract

Objective: Although deep brain stimulation (DBS) and motor cortex stimulation (MCS) have been reported to be effective in selected patients with refractory neuropathic pain, their application is still empirical and there is no consensus on which one is better. Methods: To enhance the success rate of test stimulation of invasive brain neuromodulation techniques and identify more proper stimulation targets in an individual patient, we performed a simultaneous trial of thalamic ventralis caudalis (Vc) DBS and MCS in 11 patients with chronic neuropathic pain and investigated the results of the stimulation trial and long-term pain relief (Table 1, Fig. 1). Results: Of the 11 patients initially implanted with both DBS and MCS electrodes, nine (81.8%) had successful trials. Seven of these nine patients (77.8%) responded to MCS and two (18.2%) responded to Vc DBS. With long-term follow-up (56±27.5 months), the mean numerical rating scale (NRS) decreased significantly (p<0.05). Percentage pain relief values in the chronic MCS (n=7) and chronic DBS (n=2) groups were 34.1±18.2% and 37.5%, respectively, and there was no difference (p=0.807). Five out of the seven MCS patients (71%) and both patients with DBS were assessed successful with long-term success defined as more than 30% pain relief compared with baseline. (Table 2) Conclusions: With the simultaneous trial of DBS and MCS, we could enhance the initial success rate of invasive trials. Considering the initial success rate and the less invasive nature of epidural MCS over DBS, we think MCS may be a more reasonable, initial means of trial in chronic intractable neuropathic pain. Further investigation including other subcortical targetassociated medial pain pathway may be warranted. (Figure Presented).