Effects of Relative Low-Frequency Bilateral Globus Pallidus Internus Stimulation for Treatment of Cervical Dystonia

Abstract

Objective: To assess the effect of relative lower amplitude and frequency for globus pallidus internus (GPi) deep brain stimulation (DBS) of cervical dystonia (CD). Materials and Methods: Between February 2005 and October 2008, 14 patients diagnosed with CD underwent bilateral GPi DBS and all the patients received low-frequency stimulation and were followed for more than 2 years. We activated the implantable pulse generator 3–4 days postoperatively and initial amplitude, pulse width, and frequency were set at 1.5 V, 120 µs, and 70 Hz. The Toronto Western Spasmodic Torticolis Rating Scale (TWSTRS) was applied preoperatively and at 1, 6, 12 and 24 months postoperatively. Results: The overall TWSTRS scores improved 71.2% 2 years postoperatively (p = 0.001). The mean improvement was 78.4% in severity subscores, 68.4% in disability, and 66.8% in pain scores for the 2-year follow-up period. The TWSTRS scores were significantly reduced (p < 0.05), suggesting that the most significant improvement of the TWSTRS scores occurred within 1 month. The final amplitude was 2.9/2.7 V with the pulse width of 147.9/147.9 µs and the frequency of 101.1/100 Hz. Conclusion: According to our results, the initial settings of low amplitude and especially relatively low frequency are safe and effective for treatment of CD.

Bilateral Pallidal Stimulation for “Sticking-Out Tongue” Feature in Patients With Primary Focal Tongue Protrusion Dystonia

“…In recently published study, low‐amplitude stimulation is appropriate to attain a sustained clinical and functional control of segmental dystonia . Our previous report also suggested that the initial setting as lower parameter after DBS surgery is most important to maintain other benefits in cervical dystonia . Patient who started with higher setting sometimes experienced stimulation‐induced side effects, or early depletion of implanted pulse generator (IPG).…”

Non-motor effects of deep brain stimulation in dystonia: A systematic review

“…After 6 months of non-blinded stimulation the mean pain reduction was 52% (p < 0.001), which was higher than the reduction in dystonia symptom severity (28%). In addition, nine case series (n = 6-14) showed a mean pain improvement from 48% to 73% which remained stable at follow-up ranging between 12 and 64 months [12,[18][19][20][21][22]. No correlations between motor and pain outcome were reported, but six case series highlighted a dissociation between motor and pain response in timing and/or the extent [11,12,19,21,23,24].…”

Functional Neural Changes after Low-Frequency Bilateral Globus Pallidus Internus Deep Brain Stimulation for Post-Hypoxic Cortical Myoclonus: Voxel-Based Subtraction Analysis of Serial Positron Emission

“…Low-frequency stimulation reduced the clinical myoclonus, which is also not consistent with the results of previous studies. While the mechanism underlying the improvement of myoclonus with low-frequency stimulation remains unclear, some studies proposed that low-frequency stimulation of the Gpi might also be effective for the treatment of dystonia [ 31 , 32 , 33 , 34 , 35 ]. Although a mean firing rate of the Gpi during an operation does not represent an optimal frequency of stimulation, Starr et al demonstrated a mean firing rate of the Gpi of 50 Hz in intraoperative MER of Gpi neurons in patients undergoing pallidal surgery for dystonia [ 36 ], and Alterman et al suggested that low-frequency stimulation may approximate the intraoperative firing rate of the target neurons [ 33 ].…”