Learning curve in anatomo-electrophysiological correlations in subthalamic nucleus stimulation

Abstract

Parkinson's disease and other movement disorders, but not limited to them (4,13). The anatomical target definition based on neuroradiological investigation can be supported by intraoperative microrecording using simultaneously or sequentially implanted intracerebral microelectrodes and intraoperative MATERIAL and METHODS:The trajectories of right (first implanted) and left electrodes were compared in the first 50 patients operated on (Group 1) and the next 50 patients (Group 2). RESULTS:In Group 1, 52% of central trajectories were on the right and 38% on the left; in Group 2, the percentage of central trajectories was 76% on the right and 78% on the left; the difference was statistically significant (p=0.021 and 0.001). The difference in the percentage of posterior trajectories reflecting brain shift between the right and left sides was statistically insignificant in Groups 1 (26% and 28%, p=0.999) and 2 (18% and 12%, p=0.549). The percentage of bilateral central electrodes was 14% and 62% in Groups 1 and 2, respectively. CONCLUSION:The correlation between anatomically planned trajectory and final electrode placement markedly improves with the number of patients. However the significant percentage of patients with final electrode trajectory differing from anatomically planned target supports the use of intraoperative monitoring.

How accurately are subthalamic nucleus electrodes implanted relative to the ideal stimulation location for Parkinson’s disease?

“…Thus, there was no evidence that greater surgical experience would have made a difference. Although our dataset included the commencement of a new DBS service, both members of the surgical team had substantial prior experience in DBS and were operating a high-volume service, factors which may improve surgical outcomes [29][30][31]. We also found no difference in location error between electrodes that were placed with (21.2%) or without a preceding microelectrode trajectory change.…”

“…For example, previous studies of mixed DBS targets have suggested that the first hemisphere implanted may have a smaller error, suggesting that clinicians should implant the most clinically important side first [26,27]. Surgical experience is considered an important determinant of DBS outcomes and clinicians are encouraged to accrue an adequate caseload under supervision before embarking on their own DBS practice [28][29][30][31]. The exact surgical method to implant STN DBS is also controversial.…”

Intraoperative electrophysiological monitoring determines the final electrode position for pallidal stimulation in dystonia patients

“…The results confirmed a higher percentage of central electrodes on the first side implanted in patients 1-50 (right 52%, left 38%). The percentages of central electrodes in patients 51-100 substantially increased on the right (76%) and left sides (78%), thereby confirming the learning curve effect (32). However, this learning curve effect in GPi patients has not been confirmed.…”

Electric Field Comparison between Microelectrode Recording and Deep Brain Stimulation Systems—A Simulation Study

“…Clinical experience [ 5 , 6 , 7 ] shows that the position of the DBS contact finally activated for chronic stimulation to induce the best clinical outcome often differs from the intraoperatively chosen position. Possible reasons may include brain shift or the subjective interpretation of stimulation test results.…”