Asleep subthalamic deep brain stimulation for Parkinson’s disease
Deep brain stimulation (DBS) implantation under general anesthesia (GA) is of great importance for patients with disabling off-medication symptoms or medical comorbidities. However, the relative advantages/disadvantages of routine local anesthesia (LA) surgery versus GA regarding clinical outcomes are controversial, and the safety of DBS implantation under GA is debatable.
Liu et al. systematically reviewed the literature to compare the efficacy and safety of awake and asleep deep brain stimulation surgery. They identified cohort studies from the Cochrane library, MEDLINE, and EMBASE (January 1970 to August 2019) by using Review Manager 5.3 software to conduct a meta-analysis following the PRISMA guidelines. Fourteen cohort studies involving 1,523 patients were included. The meta-analysis results showed that there were no significant differences between the GA and LA groups in UPDRSIII score improvement (standard mean difference [SMD] 0.06; 95% CI -0.16 to 0.28; p = 0.60), postoperative LEDD requirement (SMD -0.17; 95% CI -0.44 to 0.12; p = 0.23), or operation time (SMD 0.18; 95% CI -0.31 to 0.67; p = 0.47). Additionally, there was no significant difference in the incidence of adverse events (OR 0.98; 95% CI 0.53-1.80; p = 0.94), including postoperative speech disturbance and intracranial hemorrhage. However, the volume of intracranial air was significantly lower in the GA group than that in the LA group. In a subgroup analysis, there was no significant difference in clinical efficacy between the microelectrode recording (MER) and non-MER groups. We demonstrated equivalent clinical outcomes of DBS surgery between GA and LA in terms of improvement of symptoms and the incidence of adverse events. Key Messages: MER might not be necessary for DBS implantation. For patients who cannot tolerate DBS surgery while being awake, GA should be an appropriate alternative 1).
The objective of a study of Senemmar et al. was to investigate whether asleep deep brain stimulation surgery of the subthalamic nucleus (STN) improves therapeutic window (TW) for both directional (dDBS) and omnidirectional (oDBS) stimulation in a large single-center population.
A total of 104 consecutive patients with Parkinson’s disease (PD) undergoing STN-DBS surgery (80 asleep and 24 awake) were compared regarding TW, therapeutic threshold, side effect threshold, improvement of Unified PD Rating Scale motor score (UPDRS-III) and degree of levodopa equivalent daily dose (LEDD) reduction.
Asleep DBS surgery led to significantly wider TW compared to awake surgery for both dDBS and oDBS. However, dDBS further increased TW compared to oDBS in the asleep group only and not in the awake group. Clinical efficacy in terms of UPDRS-III improvement and LEDD reduction did not differ between groups.
The study provides first evidence for improvement of therapeutic window by asleep surgery compared to awake surgery, which can be strengthened further by dDBS. These results support the notion of preferring asleep over awake surgery but needs to be confirmed by prospective trials 2).
Clinical outcome studies have shown that “asleep” DBS lead placement, performed using intraoperative imaging with stereotactic accuracy as the surgical endpoint, has motor outcomes comparable to traditional “awake” DBS using microelectrode recording (MER), but with shorter case times and improved speech fluency 3).
Ninety-six patients were retrospectively matched pairwise (48 asleep and 48 awake) and compared regarding improvement of Unified PD Rating Scale Motor Score (UPDRS-III), cognitive function, Levodopa-equivalent-daily-dose (LEDD), stimulation amplitudes, side effects, surgery duration, and complication rates. Routine testing took place at three months and one year postoperatively.
Results: Chronic DBS effects (UPDRS-III without medication and with stimulation on [OFF/ON]) significantly improved UPDRS-III only after awake surgery at three months and in both groups one year postoperatively. Acute effects (percentage UPDRS-III reduction after activation of stimulation) were also significantly better after awake surgery at three months but not at one year compared to asleep surgery. UPDRS-III subitems “freezing” and “speech” were significantly worse after asleep surgery at three months and one year, respectively. LEDD was significantly lower after awake surgery only one week postoperatively. The other measures did not differ between groups.
Overall motor function improved faster in the awake surgery group, but the difference ceased after one year. However, axial subitems were worse in the asleep surgery group suggesting that worsening of axial symptoms was risked improving overall motor function. Awake surgery still seems advantageous for STN-DBS in PD, although asleep surgery may be considered with lower threshold in patients not suitable for awake surgery 4).