Object: The authors of this preliminary study investigated the outcome and feasibility of intraoperative microelectrode recording (MER) in patients with Parkinson disease (PD) undergoing deep brain stimulation of the subthalamic nucleus (STN) after anesthetic inhalation. Methods: The authors conducted a retrospective analysis of 10 patients with PD who received a desflurane anesthetic during bilateral STN electrode implantation. The MERs were obtained as an intraoperative guide for final electrode implantation and the data were analyzed offline. The functional target coordinates of the electrodes were compared preoperatively with estimated target coordinates. Results: Outcomes were evaluated using the Unified Parkinson's Disease Rating Scale 6 months after surgery. The mean improvement in total and motor Unified Parkinson's Disease Rating Scale scores was 54.27 ± 17.96% and 48.85 ± 16.97%, respectively. The mean STN neuronal firing rate was 29.7 ± 14.6 Hz. Typical neuronal firing patterns of the STN and substantia pars nigra reticulata were observed in each patient during surgery. Comparing the functional target coordinates, the z axis coordinates were noted to be significantly different between the pre- and postoperative coordinates. Conclusions: The authors found that MER can be adequately performed while the patient receives a desflurane anesthetic, and the results can serve as a guide for STN electrode implantation. This may be a good alternative surgical method in patients with PD who are unable to tolerate deep brain stimulation surgery with local anesthesia.

The neuropsychological effects of chronic subthalamic nucleus (STN)-deep brain stimulation (DBS) as a treatment for Parkinson's disease are variable. Whether these side effects result from the target per se or current diffusion into neighboring structures is uncertain. In this study, the relationship between clinical outcomes and coordinates of active contact are analyzed and compared between patients with and without neuropsychological sequelae. Thirty-eight Parkinsonian patients who underwent bilateral STN-DBS were enrolled in this retrospective cohort study. They were followed for at least 12 months. During the follow-up period, they were divided into two groups for comparison; Group A included patients with neuropsychological side effects and Group B was composed of patients without neuropsychological side effects. The position of the active contact of the electrode was defined with postoperative magnetic resonance imaging scans according to the midcommissural line. Active contact coordinates and clinical outcomes were compared for the two groups. Among the 38 Parkinsonian patients who underwent STN-DBS, eight patients who had neuropsychological side effects were assigned to Group A; the other 30 patients were assigned to Group B. In Groups A and B, the mean follow-up periods were 13.9 and 12.1 months, respectively, the Unified Parkinson's Disease Rating Scale motor score was improved by 53.4 and 45.2% (P = 0.24), respectively, and the levodopa equivalent daily dosage was decreased by 68.4 and 46.4% (P = 0.16), respectively. The mean coordinates of active contact in both Groups A and B were x = 10.1 and 10.5 mm, respectively, y = -2.8 and -3.9 mm, respectively, and z = -6.3 and -6.2 mm, respectively, relative to the midcommissural point. A significant difference was observed on the y axis (P = 0.01). When taking spatial influence into consideration, the neuropsychological effects of chronic STN-DBS were related to a significant anteriorly located active contact within the ventral STN in this preliminary study. This might suggest the existence of topography of STN in patients with Parkinson's disease concerning limbic and associative circuits.

The endoplasmic reticulum (ER) is an intracellular organelle that performs multiple functions, such as lipid biosynthesis, protein folding, and maintaining intracellular calcium homeostasis. Thus, conditions wherein the ER is unable to fold proteins is defined as ER stress, and an inbuilt quality control mechanism, called the unfolded protein response (UPR), is activated during ER stress, which serves as a recovery system that inhibits protein synthesis. Further, based on the severity of ER stress, the response could involve both proapoptotic and antiapoptotic phases. Intracerebral hemorrhage (ICH) is the second most common subtype of cerebral stroke and many lines of evidence have suggested a role for the ER in major neurological disorders. The injury mechanism during ICH includes hematoma formation, which in turn leads to inflammation, elevated intracranial pressure, and edema. A proper understanding of the injury mechanism(s) is required to effectively treat ICH and closing the gap between our current understanding of ER stress mechanisms and ICH injury can lead to valuable advances in the clinical management of ICH.

Background: The efficacy and feasibility of bilateral subthalamic deep brain stimulation (STN-DBS) for Parkinson’s disease (PD) under general anesthesia (GA) has not been evaluated. Objective: We compared the outcome of patients under GA with those who were operated on under local anesthesia (LA). Material and Methods: Thirty-three patients were assigned to the GA group (desflurane) and 19 patients were assigned to the LA group. Microelectrode recording (MER) was performed in both groups. The surgical outcomes of the patients were evaluated using the Unified Parkinson’s Disease Rating Scale (UPDRS) after at least 12 months after surgery. Results: Postoperatively, there was no significant difference on the UPDRS scores in either groups. A significant deterioration in cognitive function in the GA group was observed (p = 0.017). The recorded electrode coordinates, the average tracts for the MER, and STN depth were comparable in both groups. The overall incidence of adverse effects did not show any difference except that the incidence of sialorrhea and dysarthria was significantly higher in the GA group. Conclusion: Desflurane GA was shown to be a good alternative anesthetic method for PD patients undergoing DBS. Although the motor outcomes were comparable, a significant cognitive decline may be seen in the GA group with a higher occurrence of stimulation side effects.

Background/Aims: Bilateral subthalamic nucleus deep brain stimulation (STN-DBS) has been shown to have long-term benefits in Parkinson’s disease (PD). Through analyzing different variables, this study identified prognostic factors for the short- and long-term effects of STN-DBS. Methods: Thirty-six PD patients underwent bilateral STN-DBS. Clinical evaluations were performed 1 month before and 3 months after surgery, with additional follow-up examinations for a mean of 31.3 months. Results: There was a trend for long-term STN-DBS-induced improvements in the Unified Parkinson’s Disease Rating Scale (UPDRS) part II and part III measures to be greater in younger patients. Preoperative levodopa responsiveness only led to consistent UPDRS part III improvement from STN-DBS at 3 months, and this predictive value did not exist in the long term. The preoperative levodopa response of tremor and axial symptoms in motor disability predicted long-term DBS effect only. Preoperative cognitive function positively correlated with postoperative improvement from DBS in UPDRS part III during long-term follow-up only. Conclusions: The prognostic factors for STN-DBS benefit were different for short- and long-term follow-ups. Good prognostic factors for long-term STN-DBS for PD patients were good cognitive function and tremor dominance. Poor prognostic factors were related to older age and non-dopaminergic-responsive axial disability.