Parkinson’s disease outcomes after intraoperative CT-guided “asleep” deep brain stimulation in the globus pallidus internus

Abstract

O ver the past 30 years, deep brain stimulation (DBS) has evolved into a mainstream therapy for patients with Parkinson's disease (PD) that is supported by Level 1 evidence. 5,6,25,31,32 The clinical efficacy of DBS depends on appropriate lead placement within the targeted structure. 3,7,20,22 obJective Recent studies show that deep brain stimulation can be performed safely and accurately without microelectrode recording or test stimulation but with the patient under general anesthesia. The procedure couples techniques for direct anatomical targeting on MRI with intraoperative imaging to verify stereotactic accuracy. However, few authors have examined the clinical outcomes of Parkinson's disease (PD) patients after this procedure. The purpose of this study was to evaluate PD outcomes following "asleep" deep brain stimulation in the globus pallidus internus (GPi). methods The authors prospectively examined all consecutive patients with advanced PD who underwent bilateral GPi electrode placement while under general anesthesia. Intraoperative CT was used to assess lead placement accuracy. The primary outcome measure was the change in the off-medication Unified Parkinson's Disease Rating Scale motor score 6 months after surgery. Secondary outcomes included effects on the 39-Item Parkinson's Disease Questionnaire (PDQ-39) scores, on-medication motor scores, and levodopa equivalent daily dose. Lead locations, active contact sites, stimulation parameters, and adverse events were documented. results Thirty-five patients (24 males, 11 females) had a mean age of 61 years at lead implantation. The mean radial error off plan was 0.8 mm. Mean coordinates for the active contact were 21.4 mm lateral, 4.7 mm anterior, and 0.4 mm superior to the midcommissural point. The mean off-medication motor score improved from 48.4 at baseline to 28.9 (40.3% improvement) at 6 months (p < 0.001). The PDQ-39 scores improved (50.3 vs 42.0; p = 0.03), and the levodopa equivalent daily dose was reduced (1207 vs 1035 mg; p = 0.004). There were no significant adverse events. coNclusioNs Globus pallidus internus leads placed with the patient under general anesthesia by using direct anatomical targeting resulted in significantly improved outcomes as measured by the improvement in the off-medication motor score at 6 months after surgery.Clinical trial registration no.: NCT01997398 (clinicaltrials.gov)

Factors Affecting Stereotactic Accuracy in Image-Guided Deep Brain Stimulator Electrode Placement

“…Evaluation of clinical outcomes using image-based techniques alone has been favorable in the treatment of Parkinson disease and essential tremor [13,14]. As these techniques see increasing application, analysis of factors affecting stereotactic accuracy becomes increasingly important.…”

Deep Brain Stimulation: Awake and Asleep Options

“…14,15,40 While advocates of MER may argue that this low deviation supports precision and not necessarily accuracy, current experience has also shown that the site of best MER activity does not necessarily correlate with best clinical response during intraoperative testing or long-term outcome. 41,42 Furthermore, in the setting of improved perioperative imaging, there exists no evidence that MER help prevent suboptimal electrode placement.…”

“…[23][24][25] The outcomes in patients undergoing "asleep" DBS has certainly been comparable, with patients experiencing a 40-66% improvement in UPDRS-III motor scores after 6 months. 15,26,27 Similarly, 41 patients who underwent "asleep" STN DBS continued to demonstrate significant reduction of motor fluctuations, dyskinesias, and demands in dopaminergic medications at 5 years after implantation; however axial symptoms and bradykinesia continued to worsen as part of disease progression. 28 A direct comparison between the two approaches was performed by Saleh et al, who performed a retrospective review in which they compared 14 patients who underwent DBS placement under general anesthesia to 23 patients who underwent DBS placement while awake with MER.…”

“…The main premise of this approach is that MRI technology is now capable of clearly identifying the anatomy of the deep brain target; and that intraoperative imaging can be used to verify the location of the DBS lead in this target. As such, both MRI [11][12][13] and CT [14][15][16][17] placement of a stereotactic (Leksell) frame under local anesthesia. After a reference CT is acquired with the frame on the patient, this image is merged with the MRI containing the stereotactic plan.…”

Use of the Putamen as a Surrogate Anatomical Marker for the Internal Segment of the Globus Pallidus in Deep Brain Stimulation Surgery

“…Deep brain stimulation (DBS) of the internal segment of the globus pallidus (GPi) has shown remarkable therapeutic benefit for patients with dystonia [1,2,3,4,5,6,7,8,9,10] and Parkinson disease [11,12,13,14,15,16,17,18]. Accurate localization of the GPi motor territory is critical for proper placement of DBS electrodes, which in turn determines the efficacy of DBS surgery [3,4,19].…”