Functional neuronal activity and connectivity within the subthalamic nucleus in Parkinson’s disease (original) (raw)
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Mapping of subthalamic nucleus using microelectrode recordings during deep brain stimulation
Scientific reports, 2020
Alongside stereotactic magnetic resonance imaging, microelectrode recording (MER) is frequently used during the deep brain stimulation (DBS) surgery for optimal target localization. The aim of this study is to optimize subthalamic nucleus (STN) mapping using MER analytical patterns. 16 patients underwent bilateral STN-DBS. MER was performed simultaneously for 5 microelectrodes in a setting of Ben's-gun pattern in awake patients. Using spikes and background activity several different parameters and their spectral estimates in various frequency bands including low frequency (2-7 Hz), Alpha (8-12 Hz), Beta (sub-divided as Low_Beta (13-20 Hz) and High_Beta (21-30 Hz)) and Gamma (31 to 49 Hz) were computed. The optimal STN lead placement with the most optimal clinical effect/ side-effect ratio accorded to the maximum spike rate in 85% of the implantation. Mean amplitude of background activity in the low beta frequency range was corresponding to right depth in 85% and right location in 94% of the implantation respectively. MER can be used for STN mapping and intraoperative decisions for the implantation of DBS electrode leads with a high accuracy. Spiking and background activity in the beta range are the most promising independent parameters for the delimitation of the proper anatomical site. Deep brain stimulation of the subthalamic nucleus (STN-DBS), now established as a standard therapeutic option, is an effective therapy for patients with Parkinson's disease (PD) 1. The principle effects of the stimulation are for the improvement of major clinical motor symptoms like tremor, rigidity, and bradykinesia 2. Parkinson's disease and the effect of DBS for optimal clinical response have been shown to be a network level effect 3,4. However, both clinical and computational observations have shown that the success of STN-DBS depends fundamentally in placing the DBS electrodes with high precision into the sensorimotor region of the STN corresponding to the dorsolateral posterior part of the nucleus 5-9. The somatotopic arrangement of sensorimotor region in subthalamic nucleus and its relation to movement and tremor in PD patients has been well established 10,11. To accomplish a high precision implantation in this region, preoperative MRI images-based navigation systems and intraoperative microelectrode recordings (MER) are widely used. The visualization technique for locating the STN by using preoperative MRI is prone to giving inaccurate results due to brain shift induced parenchymal alterations or cerebrospinal fluid loss 12. Hence, the intraoperative MER allows improving the target localiza-tion during stereotactic surgery by recording the electrical activity of the individual neurons from targeted structure. The main principle of this procedure for the STN-DBS is based on the fact that spike patterns for neurons in the subthalamic nucleus (STN) are characteristic and differ from neuronal spike patterns of the surrounding structures 13. Several previous studies have shown the association of dorsolateral posterior STN field potentials and firing rate to effective clinical outcome 13-15 , quantification of motor subtypes 16 , severity of rigidity and bradykinesia in PD 17 , optimal DBS implantation trajectory 18 and simulation parameters 19 among others. Recent studies have further used various recordings using MER for localizing dorsal-ventral border of STN 20 and predicting therapeutic volume of tissue activation 21. Despite extensive research in the pathophysiological role and clinical correlation of these electrophysiological activity patterns in PD and target localization, studies focusing on the differential use of them for improving the accurate implantation of the electrodes in sensorimo-tor region of STN is still insufficient. Moreover, specific use of all MER parameters either to accurately target the OPEN
Neurophysiological identification of the subthalamic nucleus in surgery for Parkinson's disease
Annals of Neurology, 1998
Microelectrode recording methods for stereotactic localization of the subthalamic nucleus (STN) and surrounding structures are described. These methods accurately define targets for chronic deep brain stimulation in the treatment of Parkinson's disease. Mean firing rates and a burst index were determined for all recorded neurons, and responses to active and passive limb and orofacial movements were tested. STN neurons had a mean firing rate of 37 ± 17 Hz (n = 248) and an irregular firing pattern (median burst index, 3.3). Movement-related activity and tremor cells were identified in the STN. Ventral to the STN, substantia nigra pars reticulata neurons had a mean rate of 71 ± 23 Hz (n = 56) and a more regular firing pattern (median burst index, 1.7). Short trains (1–2 seconds) of electrical microstimulation of STN could produce tremor arrest but were and found to be useful for localization. Compared with data from normal monkeys our findings suggest that STN neuronal activity is elevated in Parkinson's disease.
Neuromodulation : journal of the International Neuromodulation Society, 2018
Target localization for deep brain stimulation (DBS) is a challenging step that determines not only the correct placement of stimulation electrodes, but also influences the success of the DBS procedure as reflected in the desired clinical outcome of a patient. We report on the feasibility of DBS target localization in the subthalamic nucleus (STN) by long-latency somatosensory evoked potentials (LL-SSEPs) (>40 msec) in Parkinson's disease (PD) patients. Micro-macroelectrode recordings were performed intraoperatively on seven PD patients (eight STN hemispheres) who underwent DBS treatment. LL-SSEPs were elicited by ipsi- and contralateral median nerve stimulation to the wrist. Four distinctive LL-SSEP components were elicited ("LL-complex" consisting of P80, N100, P140, and N200). The P80 appeared as the most visible and reliable intraoperative component. Localization of the "LL-complex" within the target was approved with typical microelectrode firing acti...
Multiple Microelectrode Recordings in STN-DBS Surgery for Parkinson's Disease: A Randomized Study
Movement disorders clinical practice
Subthalamic nucleus deep brain stimulation improves motor symptoms and fluctuations in advanced Parkinson's disease, but the degree of clinical improvement depends on accurate anatomical electrode placement. Methods used to localize the sensory-motor part of the nucleus vary substantially. Using microelectrode recordings, at least three inserted microelectrodes are needed to obtain a three-dimensional map. Therefore, multiple simultaneously inserted microelectrodes should provide better guidance than single sequential microelectrodes. We aimed to compare the use of multiple simultaneous versus single sequential microelectrode recordings on efficacy and safety of subthalamic nucleus stimulation. Sixty patients were included in this double-blind, randomized study, 30 in each group. Primary outcome measures were the difference from baseline to 12 months in the MDS-UPDRS motor score (part III) in the off-medication state and quality of life using the Parkinson's Disease Question...
Iranian journal of neurology, 2016
Subthalamic nucleus (STN) stimulation is the treatment of choice for carefully chosen patients with idiopathic Parkinson's disease (PD) and refractory motor fluctuations. We evaluated the value of intraoperative electrophysiology during STN deep brain stimulation (DBS) procedures in refining the anatomically-defined target. We determined the spatial distance between the anatomical and physiological targets along x, y and z axes in 50 patients with PD who underwent bilateral subthalamic nucleus DBS surgery. The mean spatial distance between anatomical and functional targets was 1.84 ± 0.88 mm and the least distances in different methods were 0.66 mm [standard error (SE): 0.07], 1.07 mm (SE: 0.08) and 1.01 mm (SE: 0.08) on x, y and z axes, respectively, for the combined method. The most physiologically-accurate anatomical targeting was achieved via a combination of multiple independent methods. There was a statistically significant difference between the anatomical and functional ...
Experimental Neurology, 2008
Parkinson's disease is treated pharmacologically with dopamine replacement medication and, more recently, by stimulating basal-ganglia nuclei such as the subthalamic nucleus (STN). Depth recordings after this procedure have revealed excessive activity at frequencies between 8 and 35 Hz that are reduced by dopamine therapy in tandem with improvements in bradykinesia/rigidity, but not tremor . It has also been shown that improvements in motor symptoms after dopamine correlate with single unit activity in the beta range ( , . We recorded local field potentials (LFPs) from the subthalamic nucleus of patients with Parkinson's disease (PD) after surgery to implant deep brain stimulating electrodes while they were on and off dopaminergic medication. As well as replicating Kuhn et al., using the same patients we were able to extend Weinberger et al. to show that LFP beta oscillatory activity correlated with the degree of improvement in bradykinesia/ rigidity, but not tremor, after dopamine medication. We also found that the power of beta oscillatory activity uniquely predicted improvements in bradykinesia/rigidity, but again not tremor, after stimulation of the STN in a regression analysis. However improvements after STN stimulation related inversely to beta power, possibly reflecting the accuracy of the electrode placement and/or the limits of STN stimulation in patients with the greatest levels of beta oscillatory activity.
Operative Neurosurgery, 2005
The success of subthalamic nucleus (STN) surgery for Parkinson's disease depends on accuracy in target determination. The objective of this study was to determine which of the following techniques was most accurate and precise in identifying the location for stimulation in STN deep brain stimulation surgery that is most clinically effective: direct targeting, indirect targeting using the positions of the anterior and posterior commissures, or a technique using the red nucleus (RN) as an internal fiducial marker. METHODS: We reviewed 14 patients with Parkinson's disease treated with bilateral STN deep brain stimulation (28 STN targets). Electrode implantation was based on direct and indirect targeting using two-dimensional magnetic resonance imaging with refinement using microelectrode recording. Optimal settings, including the contacts used, were determined during the clinical follow-up. The position of the best contact was defined with postoperative magnetic resonance imaging. This location was compared with the modified direct, indirect, and RN-based targets. The mean distances between the targets and the final position of the optimal contact were calculated. The accuracy and variance of each target were analyzed. RESULTS: The mean position of the best contact was x ϭ 12.12 (standard deviation [SD], 1.45 mm), y ϭ Ϫ2.41 (SD, 1.63 mm), and z ϭ Ϫ2.39 (SD, 1.49 mm) relative to the midcommissural point. The mean distance between the optimal contact position and the planned target was 3.19 mm (SD, 1.19 mm) using the RN-based method, 3.42 mm (SD, 1.34 mm) using indirect targeting, and 4.66 mm (SD, 1.33 mm) using a modified direct target. The mean distance between the optimal contact and the RN-based target was significantly smaller than the mean distance between the optimal contact and the direct target (post hoc with Tamhane's correction, P Ͻ 0.001) but not between the optimal contact and the indirect target. The RN-based target had the smallest variance (F test, P Ͻ 0.001), indicating greater precision. CONCLUSION: The use of the RN as an internal fiducial marker for targeting the optimal region of STN stimulation was reliable and closely approximates the position of the electrode contact that provides the optimal clinical results.