Sedative drugs modulate the neuronal activity in the subthalamic nucleus of parkinsonian patients

Abstract

Microelectrode recording (MER) is often used to identify electrode location which is critical for the success of deep brain stimulation (DBS) treatment of Parkinson’s disease. The usage of anesthesia and its’ impact on MER quality and electrode placement is controversial. We recorded neuronal activity at a single depth inside the Subthalamic Nucleus (STN) before, during, and after remifentanil infusion. The root mean square (RMS) of the 250–6000 Hz band-passed signal was used to evaluate the regional spiking activity, the power spectrum to evaluate the oscillatory activity and the coherence to evaluate synchrony between two microelectrodes. We compare those to new frequency domain (spectral) analysis of previously obtained data during propofol sedation. Results showed Remifentanil decreased the normalized RMS by 9% ( P < 0.001), a smaller decrease compared to propofol. Regarding the beta range oscillatory activity, remifentanil depressed oscillations (drop from 25 to 5% of oscillatory electrodes), while propofol did not (increase from 33.3 to 41.7% of oscillatory electrodes). In the cases of simultaneously recorded oscillatory electrodes, propofol did not change the synchronization while remifentanil depressed it. In conclusion, remifentanil interferes with the identification of the dorsolateral oscillatory region, whereas propofol interferes with RMS identification of the STN borders. Thus, both have undesired effect during the MER procedure. Trial registration : NCT00355927 and NCT00588926.

Optimized Propofol Anesthesia Increases Power of Subthalamic Neuronal Activity in Patients with Parkinson’s Disease Undergoing Deep Brain Stimulation

“…Previous studies have shown that the use of remifentanil or propofol inhibits MER signals, which seems to be different from our results [ 16 , 30 , 31 ]. However, it is worth noting that Mciver et al [ 30 ] used a bolus administration (propofol 0.3 mg/kg or remifentanil 0.05 mg/kg) and Benady et al [ 31 ] used continuous constant rate administration (propofol 50 μg/kg/min or remifentanil 0.1 μg/kg/min) without an objective level of consciousness assessment or local scalp anesthesia. In this study, we used an electroencephalogram monitoring-guided propofol-remifentanil TCI (1–2 μg/ml and 2–3 ng/ml, respectively) with the local scalp anesthesia regimen.…”

“…Previous studies have shown that the use of remifentanil or propofol inhibits MER signals, which seems to be different from our results [16,30,31]. However, it is worth noting that Mciver et al [30] used a bolus administration (propofol 0.3 mg/kg or remifentanil 0.05 mg/ kg) and Benady et al [31] used continuous Fig.…”

Impact of Procedural Sedation on the Clinical Outcome of Microelectrode Recording Guided Deep Brain Stimulation in Patients with Parkinson’s Disease

“…Many centers employing MER-based DBS surgery prefer to perform the procedure under awake conditions to obtain reliable neurophysiological mapping and enable intraoperative test stimulation to observe the motor improvement and potential side-effects. In our recent work we have shown that anesthetic agents alter the firing characteristics of the STN, which is consistent with data obtained from previous studies [ 10 , 11 , 12 , 13 , 14 , 15 ]. These findings provide important arguments to avoid the use of anesthetic drugs during DBS surgery.…”

“…Contrary to most sedatives, α 2 agonists do not have a direct gamma-aminobutyric acid (GABA)-ergic effect and so have a less profound effect on MER compared to the GABA-ergic drugs [ 10 , 32 ]. Remifentanil, acting mainly on the mu opioid receptor agonist, has limited effects on STN neuronal activity at low doses, though a recently published report showed a significant reduction in STN neuronal activity with doses above 0.1 µg/kg/min [ 10 , 15 ].…”

“…In the second, more recent study, the effect of continuous infusion of remifentanil (0.1 µg/kg/min) on neuronal activity was investigated. The authors found that remifentanil interferes with the dorsolateral identification of the STN [ 15 ]. Unfortunately, the positioning accuracy of the electrode implantation was not reported, and therefore the clinical relevance of these findings remain unclear.…”