Methods for Surgical Targeting of the STN in Early-Stage Parkinson’s Disease

Abstract

Patients with Parkinson's disease (PD) experience progressive neurological decline, and future interventional therapies are thought to show most promise in early stages of the disease. There is much interest in therapies that target the subthalamic nucleus (STN) with surgical access. While locating STN in advanced disease patients (Hoehn-Yahr Stage III or IV) is well understood and routinely performed at many centers in the context of deep brain stimulation surgery, the ability to identify this nucleus in early-stage patients has not previously been explored in a sizeable cohort. We report surgical methods used to target the STN in 15 patients with early PD (Hoehn-Yahr Stage II), using a combination of image guided surgery, microelectrode recordings, and clinical responses to macrostimulation of the region surrounding the STN. Measures of electrophysiology (firing rates and root mean squared activity) have previously been found to be lower than in later-stage patients, however, the patterns of electrophysiology seen and dopamimetic macrostimulation effects are qualitatively similar to those seen in advanced stages. Our experience with surgical implantation of Parkinson's patients with minimal motor symptoms suggest that it remains possible to accurately target the STN in early-stage PD using traditional methods.

Subthalamic nucleus deep brain stimulation in early stage Parkinson's disease

“…This study also suggests that it is likely possible to accurately target and implant bilateral STN deep brain stimulating electrodes in patients with early stage PD and very mild symptomatology [12, 14]. In addition to intraoperative microelectrode recordings and post-operative imaging verification of lead placement, all implanted subjects underwent lead interrogation of all four contacts on each side of the brain in the off medication state and all subjects had at least one efficacious contact.…”

“…Complete descriptions of the trial design, methods, recruitment of subjects, study procedures, consent process, surgical technique, targeting procedure, intraoperative microelectrode recording procedure, and baseline subject characteristics have been previously reported and are briefly reviewed as follows [10–14]. …”

Network fingerprint of stimulation-induced speech impairment in essential tremor

“…However, the theoretical concept of VTA modelling constitutes a simplification that neglects factors like fiber orientation (Anderson et al, 2019). Regarding the concept of predicting effects of deep brain stimulation in relation to the anatomical target area there have been several approaches in the past, such as investigating lead positions (Delcour et al, 2011;Camalier et al, 2014;Barbe et al, 2018;Dafsari et al, 2018), the creation of probabilistic sweet spots (Eisenstein et al, 2014;Dembek et al, 2017;Dembek et al, 2019b;Reich et al, 2019), and the estimation of beneficial Running head: Networks in DBS-induced dysarthria connectivity profiles (Horn et al, 2017;Al-Fatly et al, 2019). In this study, we focused on providing an atlas structure that is easy to implement in planning and programming software and therefore decided to base our predictive model on an approach introduced by Baldermann et al (Baldermann et al, 2019).…”

Advances in functional neurosurgery for Parkinson's disease

“…The researchers concluded that DBS is well tolerated in very early PD. In a separate publication, they reported that traditional surgical methods, including image‐guided targeting, microelectrode recording (MER), and macrostimulation, enable accurate identification and targeting of the STN in PD patients with minimal motor impairment . Together, these studies form the basis for an upcoming, recently FDA‐approved, double‐blind, placebo‐controlled, phase III clinical trial of STN DBS in patients with early‐stage PD.…”