Search

Background: Parkinson's disease (PD) is a common neurodegenerative disease affecting the quality of life in the elderly. We speculated that PD patients might have abnormal pharmacodynamics due to the degenerative neural system, and the present study was performed to investigate the pharmacodynamics of remifentanil in PD patients., Materials and Methods: Two arms of patients were recruited, including 31 PD patients undergoing pulse generator placement after deep brain stimulator implantation and 31 pair-controlled patients undergoing intracranial surgery without PD (NPD). Patients were anesthetized with target-controlled infusion of propofol and remifentanil. The effective concentration of remifentanil to inhibit responses to intubation and skin incision in 50% and 95% patients (EC50 and EC95) was determined by the up and down method., Results: Demographic data, bispectral index, and hemodynamic values were similar between the PD and the NPD groups. The average remifentanil concentration used in the PD group for tracheal intubation is significantly lower than in the NPD group (P<0.001). The EC50 for inhibiting the response to tracheal intubation were 1.86 ng/mL (95% confidential interval [CI], 1.77-1.96 ng/mL) in the PD group and 3.20 ng/mL (95% CI, 3.13-3.27 ng/mL) in the NPD group. The average remifentanil concentration used in the PD group for skin incision is significantly lower than in the NPD group (P<0.001). EC50 for inhibiting the response to skin incision were 2.17 ng/mL (95% CI, 2.09-2.25 ng/mL) in the PD group and 3.09 ng/mL (95% CI, 3.02-3.17 ng/mL) in the NPD group., Conclusions: The remifentanil concentrations required for inhibiting responses to tracheal intubation and skin incision are reduced markedly in PD patients undergoing pulse generator placement (NCT01992692).

Deep brain stimulation (DBS) is an effective technique for treating Parkinson's disease (PD) in the middle and advanced stages. The subthalamic nucleus (STN) is the most common target for clinical treatment using DBS. While STN-DBS can significantly improve motor symptoms in PD patients, adverse cognitive effects have also been reported. The specific effects of STN-DBS on cognitive function and the related mechanisms remain unclear. Thus, it is imperative to identify the influence of STN-DBS on cognition and investigate the potential mechanisms to provide a clearer view of the various cognitive sequelae in PD patients. For this review, a literature search was performed using the following inclusion criteria: (1) at least 10 patients followed for a mean of at least 6 months after surgery since the year 2006; (2) pre- and postoperative cognitive data using at least one standardized neuropsychological scale; and (3) adequate reporting of study results using means and standard deviations. Of ∼170 clinical studies identified, 25 cohort studies (including 15 self-controlled studies, nine intergroup controlled studies, and one multi-center, randomized control experiment) and one meta-analysis were eligible for inclusion. The results suggest that the precise mechanism of the changes in cognitive function after STN-DBS remains obscure, but STN-DBS certainly has effects on cognition. In particular, a progressive decrease in verbal fluency after STN-DBS is consistently reported and although executive function is unchanged in the intermediate stage postoperatively, it tends to decline in the early and later stages. However, these changes do not affect the improvements in quality of life. STN-DBS seems to be safe with respect to cognitive effects in carefully-selected patients during a follow-up period from 6 months to 9 years.

Objective: To investigate the influence of high frequency stimulation of the subthalamic nucleus on the levels of amino acids neurotransmitters in striatum of hemi-parkinsonian monkeys., Methods: Two rhesus monkeys were successfully prepared for the subsequent microdialysis sessions. Collecting the dialysate before turning on the pulse generator, and collecting at 1 week, 1, 8 and 12 months after high frequency stimulation of the subthalamic nucleus. The level of Glu, GABA and Tau were determined by high performance liquid chromatography and fluorometric detection (HPLC-FD)., Results: After high frequency stimulation (HFS), PD symptoms of monkeys significantly improved. The levels of Glu in putamen and caudate nucleus of electrodes side at 1 week, 1, 8 and 12 months were increased significantly. The levels of GABA in putamen and caudate nucleus of electrodes side at 1 week, 1 month increased significantly compared with before turning on the pulse generator while decreased at 8, 12 months. The level of Tau in putamen and caudate nucleus increased significantly., Conclusion: Long-term STN HFS can increase the level of glutamate and taurine, while decrease the level of GABA in putamen and caudate nucleus of electrodes side. It improves symptoms of hemi-parkinsonian rhesus monkey significantly.