Table 1.
Data from single-center studies on directional DBS
| Author and year | Sample size | Lead configuration | Clinical setting | Efficacy measures | FUP | Main results |
|---|---|---|---|---|---|---|
| Pollo et al. 2014 [8] |
11 PD (STN) 2 ET (Vim) |
2 distal segmented contacts (3 segments each) 2 proximal ring contacts |
Intraoperative double-blinded evaluation | Full effect on rigidity or good effect on tremor | NA | TW 41.3% wider and TCS 43% lower with directional vs. omnidirectional stimulation |
| Contarino et al. 2014 [9] | 8 PD (STN) | 32 oval disc-shaped contacts | Intraoperative double-blinded evaluation | Full effect on rigidity | NA | TW wider (0.5–1.5 mA) with directional vs. omnidirectional stimulation |
| Steigerwald et al. 2016 [10] | 7 PD (STN) |
2 central segmented contacts (3 segments each) 1 proximal and 1 distal ring contacts |
Retrospective unblinded analysis of permanently implanted patients | Full effect on rigidity | 3–6 months |
TW variations from − 100% to + 440% with directional vs. omnidirectional stimulation Best TW improvement with the best directional contact at the less effective level At 3–6 months, all patients remained in directional stimulation |
| Dembek et al. 2017 [11] | 10 PD (STN) |
2 central segmented contacts (3 segments each) 1 proximal and 1 distal ring contacts |
Prospective double-blinded | Improvement of at least 1.5 points in the UPDRS-III composite scores of upper limb rigidity, finger tapping, and hand rotation | 3–6 months |
TW wider with directional vs. omnidirectional stimulation (median 2 mA vs 1 mA) SET higher with directional vs. omnidirectional stimulation (median 4 mA vs 3 mA) At 3–6 months, 14 leads remained in directional stimulation |
| Rebelo et al. 2018 [12] |
3 PD (Vim) 3 DT (Vim) 2 ET (Vim) |
2 central segmented contacts (3 segments each) 1 proximal and 1 distal ring contacts |
Retrospective unblinded analysis of permanently implanted patients | Full effect on tremor | 6 months |
TW wider (1.86 mA vs. 0.97 mA) and TCS lower (1.51 mA vs. 2.19 mA) with directional vs. omnidirectional stimulation TEED 6–18% lower with directional vs. omnidirectional stimulation At 6 months, 9 leads remained in directional stimulation |
DT dystonic tremor, ET essential tremor, FUP follow-up, PD Parkinson disease, NA not applicable, SET side effects threshold, STN subthalamic nucleus, TCS therapeutic current strength, TEED total electrical energy delivered, TW therapeutic window, UPDRS Unified PD Rating Scale, Vim ventral intermediate nucleus