The effect of dexmedetomidine on the firing properties of STN neurons in Parkinson's disease |
| |
Authors: | Vibhor Krishna Gavin Elias Francesco Sammartino Diellor Basha Nicolas K K King Alfonso Fasano Renato Munhoz Suneil K Kalia Mojgan Hodaie Lashmi Venkatraghavan Andres M Lozano William D Hutchison |
| |
Institution: | 1. Division of Neurosurgery, Toronto Western Hospital, University of Toronto, Toronto, ON M5T2S8, Canada;2. Department of Physiology, Toronto Western Hospital, University of Toronto, Toronto, ON, Canada;3. Morton and Gloria Shulman Movement Disorders Centre and the Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital, Toronto, ON, Canada;4. Department of Anesthesiology, Toronto Western Hospital, University of Toronto, Toronto, ON, Canada |
| |
Abstract: | Dexmedetomidine (an alpha‐2 adrenergic agonist) sedation is commonly used during subthalamic nucleus (STN) deep‐brain stimulation (DBS). Its effects on the electrophysiological characteristics of human STN neurons are largely unknown. We hypothesised that dexmedetomidine modulates the firing rates and bursting of human STN neurons. We analysed microelectrode recording (MER) data from patients with Parkinson's disease who underwent STN DBS. A ‘Dex bolus’ group (dexmedetomidine bolus prior to MER; 27 cells from seven patients) was compared with a ‘no sedation’ group (29 cells from 11 patients). We also performed within‐patient comparisons with varying dexmedetomidine states. Cells were classified as dorsal half or ventral half based on their relative location in the STN. Neuronal burst and oscillation characteristics were analysed using the Kaneoke–Vitek methodology and local field potential (LFP) oscillatory activity was also investigated. Dexmedetomidine was associated with a slight increase in firing rate (41.1 ± 9.9 vs. 34.5 ± 10.6 Hz, P = 0.02) but a significant decrease in burstiness (number of bursts, P = 0.02; burst index, P < 0.001; percentage of spikes in burst, P = 0.002) of dorsal but not ventral STN neurons. This was not associated with modulation of beta oscillations in the spike‐oscillations analysis(beta peak, P = 0.4; signal‐to‐noise ratio in the beta range for spikes and bursts, P = 0.3 and P = 0.5, respectively) and LFP analysis (Beta power, P = 0.17). As bursting pattern is often used to identify STN and guide electrode placement, we recommend that high‐dose dexmedetomidine should be avoided during DBS surgery. |
| |
Keywords: | alpha‐2 adrenergic agonist beta oscillations burst pattern deep brain stimulation intra‐operative sedation microelectrode recording |
|
|