Effect of Anesthesia on Microelectrode Recordings during Deep Brain Stimulation Surgery in Tourette Syndrome Patients

Background: Deep brain stimulation (DBS) is an accepted treatment for patients with medication-resistant Tourette syndrome (TS). Sedation is commonly required during electrode implantation to attenuate anxiety, pain, and severe tics. Anesthetic agents potentially impair the quality of microelectrode recordings (MER). Little is known about the effect of these anesthetics on MER in patients with TS. We describe our experience with different sedative regimens on MER and tic severity in patients with TS. Methods: The clinical records of all TS patients who underwent DBS surgery between 2010 and 2018 were reviewed. Demographic data, stimulation targets, anesthetic agents, perioperative complications, and MER from each hemisphere were collected and analyzed. Single-unit activity was identified by filtering spiking activity from broadband MER data and principal component analysis with K-means clustering. Vocal and motor tics which caused artifacts in the MER data were manually selected using visual and auditory inspection. Results: Six patients underwent bilateral DBS electrode implantation. In all patients, the target was the anterior internal globus pallidus. Patient comfort and hemodynamic and respiratory stability were maintained with conscious sedation with one or more of the following anesthetic drugs: propofol, midazolam, remifentanil, clonidine, and dexmedetomidine. Good quality MER and clinical testing were obtained in 9 hemispheres of 6 patients. In 3 patients, MER quality was poor on one side. Conclusion: Cautiously applied sedative drugs can provide patient comfort, hemodynamic and respiratory stability, and suppress severe tics, with minimal interference with MER. (C) 2019 The Author(s) Published by S. Karger AG, Base

Influence of Anesthesia and Clinical Variables on the Firing Rate, Coefficient of Variation and Multi-Unit Activity of the Subthalamic Nucleus in Patients with Parkinson's Disease

BACKGROUND: Microelectrode recordings (MER) are used to optimize lead placement during subthalamic nucleus deep brain stimulation (STN-DBS). To obtain reliable MER, surgery is usually performed while patients are awake. Procedural sedation and analgesia (PSA) is often desirable to improve patient comfort, anxiolysis and pain relief. The effect of these agents on MER are largely unknown. The objective of this study was to determine the effects of commonly used PSA agents, dexmedetomidine, clonidine and remifentanil and patient characteristics on MER during DBS surgery. METHODS: Data from 78 patients with Parkinson's disease (PD) who underwent STN-DBS surgery were retrospectively reviewed. The procedures were performed under local anesthesia or under PSA with dexmedetomidine, clonidine or remifentanil. In total, 4082 sites with multi-unit activity (MUA) and 588 with single units were acquired. Single unit firing rates and coefficient of variation (CV), and MUA total power were compared between patient groups. RESULTS: We observed a significant reduction in MUA, an increase of the CV and a trend for reduced firing rate by dexmedetomidine. The effect of dexmedetomidine was dose-dependent for all measures. Remifentanil had no effect on the firing rate but was associated with a significant increase in CV and a decrease in MUA. Clonidine showed no significant effect on firing rate, CV or MUA. In addition to anesthetic effects, MUA and CV were also influenced by patient-dependent variables. CONCLUSION: Our results showed that PSA influenced neuronal properties in the STN and the dexmedetomidine (DEX) effect was dose-dependent. In addition, patient-dependent characteristics also influenced MER

Influence of Anesthesia and Clinical Variables on the Firing Rate, Coefficient of Variation and Multi-Unit Activity of the Subthalamic Nucleus in Patients with Parkinson's Disease

Background: Microelectrode recordings (MER) are used to optimize lead placement during subthalamic nucleus deep brain stimulation (STN-DBS). To obtain reliable MER, surgery is usually performed while patients are awake. Procedural sedation and analgesia (PSA) is often desirable to improve patient comfort, anxiolysis and pain relief. The effect of these agents on MER are largely unknown. The objective of this study was to determine the effects of commonly used PSA agents, dexmedetomidine, clonidine and remifentanil and patient characteristics on MER during DBS surgery. Methods: Data from 78 patients with Parkinson's disease (PD) who underwent STN-DBS surgery were retrospectively reviewed. The procedures were performed under local anesthesia or under PSA with dexmedetomidine, clonidine or remifentanil. In total, 4082 sites with multi-unit activity (MUA) and 588 with single units were acquired. Single unit firing rates and coefficient of variation (CV), and MUA total power were compared between patient groups. Results: We observed a significant reduction in MUA, an increase of the CV and a trend for reduced firing rate by dexmedetomidine. The effect of dexmedetomidine was dose-dependent for all measures. Remifentanil had no effect on the firing rate but was associated with a significant increase in CV and a decrease in MUA. Clonidine showed no significant effect on firing rate, CV or MUA. In addition to anesthetic effects, MUA and CV were also influenced by patient-dependent variables. Conclusion: Our results showed that PSA influenced neuronal properties in the STN and the dexmedetomidine (DEX) effect was dose-dependent. In addition, patient-dependent characteristics also influenced MER