Stereotactic and Functional Neurosurgery最新文献

Objective Bilateral temporal lobe epilepsy represents a subset of patients with medically intractable epilepsy that is particularly difficult to treat. This systematic review and meta-analysis aimed to evaluate the safety and efficacy of three neuromodulation techniques-Vagus Nerve Stimulation (VNS), Responsive Neurostimulation (RNS), and Deep Brain Stimulation (DBS)-in refractory BTLE. Methods In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a thorough electronic literature search using Ovid MEDLINE, Ovid Embase, and PubMed databases. Data from the selected studies were extracted, analyzed, and a quality assessment was performed. Meta-analysis was performed comparing mean seizure reduction rates in VNS, RNS, and DBS. Results Twenty studies (4 VNS, 7 RNS, 9 DBS) involving 142 BTLE patients were included in the systematic review. Meta-analysis of 12 studies (2 VNS, 5 RNS, 5 DBS) revealed comparable efficacy between VNS (61.69%), RNS (67.51%), and DBS (66.68%), with no statistically significant difference (p = 0.932) between the modalities. All three techniques demonstrated efficacy in seizure reduction. Additionally, complication rates did not significantly differ between VNS, RNS, and DBS. (p = 0.85). Conclusion This study provides a comprehensive assessment of existing data regarding the use of neuromodulation in refractory BTLE. VNS, RNS, and DBS demonstrated comparable efficacy, supporting their consideration in treatment planning. Clinical decision-making should weigh factors such as surgical candidacy, patient preferences, comorbidities, and side effect profiles. Further research, including standardized reporting and head-to-head trials, is vital for optimizing treatment protocols and expanding our understanding of neuromodulation's impact on seizure reduction, quality of life, and cognitive outcomes in patients with BTLE.

Introduction Tremor-predominant Parkinson's disease (TPPD) generally responds favorably to Deep Brain Stimulation (DBS) targeting the subthalamic nucleus (STN). However, traditional stereotactic targeting of the STN does not universally yield the anticipated intraoperative improvement, prompting exploration of additional targets to achieve optimal results prior to permanent implantation of electrodes. The posterior subthalamic area (PSA), including the caudal zona incerta (cZI), have been associated with tremor suppression and can be easily compared to the neighboring STN intraoperatively. Methods We retrospectively compared intraoperative and clinical outcomes in tremor-dominant PD patients who prospectively underwent dual trajectory microelectrode monitor (MER) targeting the STN and PSA/cZI. We compared the neurophysiology and tremor response of both the central (STN) and posterior (PSA) trajectories in 22 patients and analyzed outcomes in those who ultimately received traditional STN (16) or PSA/cZI lead implantation (12). Results While both groups achieved substantial overall motor improvement under chronic stimulation, intraoperative test stimulation through the posterior path produced more consistent tremor arrest compared with STN. These findings suggest that positioning the DBS lead further posteriorly to engage the PSA can augment tremor suppression in select cases of TPPD without compromising other parkinsonian symptom relief. Conclusion Our results emphasize the value of intraoperative physiological feedback in trajectory selection in tremor-predominant patients and are consistent with emerging literature that PSA/cZI DBS is an effective and potentially superior target for management of tremor in PD.

Background and objectives: High-Intensity Focused Ultrasound (HIFU) has evolved significantly since its introduction to neurosurgery over 15 years ago. In the past decade, its clinical use has expanded to treat a broader range of surgical domains and indications. However, the pace and pattern of this evolution remain poorly characterized within the literature. This systematic review aims to synthesize global research on HIFU in neurosurgery over the past ten years, identifying trends across indications and regions.

Methods: Following PRISMA guidelines, we identified clinical studies involving HIFU in neurosurgical practice from January 1, 2014, to November 1, 2024. Studies were categorized by application and country of origin, and a quantitative analysis was performed to assess distribution and trends in these factors.

Results: A total of 498 studies were included. Research output increased over the period, from 13 studies in 2014 to 92 in 2024. While the scope of clinical applications expanded from 6 to 13 domains over this period, a disparity in research volume persisted, with movement disorders-particularly essential tremor (62.0%) and Parkinson's disease (29.9%)- accounting for the majority of publications. Nonetheless, growth was observed in previously underrepresented domains such as neurooncology, psychiatry, epilepsy, chronic pain, and neurovascular disorders. Geographically, the United States accounted for the largest share of publications (38.4%), followed by Switzerland (11.6%) and the United Kingdom (8.2%). Over this period, study quality improved with a shift from case reports and pilot studies toward an increasing number of cohort studies and randomized controlled trials.

Conclusion: This review outlines the accelerating, yet uneven, exploration of HIFU in neurosurgical practice over the past decade. While movement disorders remain the central focus of this technology, expanding interest in underexplored indications indicates a shifting landscape. At the same time, the maturation of study designs reflects a strengthening evidence base. As the field advances, increased global collaboration and greater attention to budding applications are necessary.

Background: Asleep deep brain stimulation (DBS) is limited by its reliance on interventional/intraoperative MRI in many cases. A frameless stereotaxy system can be used in combination with optical navigation for initial coarse alignment, followed by a navigational iCT scan to enable asleep DBS in standard operating rooms, aiming to improve accessibility and precision. Methods This retrospective study analyzed 32 patients (33 procedures) undergoing DBS electrode placement using the SmartFrame OR™ system (ClearPoint Neuro Inc., San Diego, CA). Radial targeting error and operative duration were assessed. Surgical workflows combined O-arm imaging (Medtronic Inc, Minneapolis, MN) and StealthStationTM S8 neuronavigation (Medtronic Inc, Minneapolis, MN) Targets included the ventral intermediate nucleus (VIM), subthalamic nucleus (STN), globus pallidus internus (GPi), hippocampus, and thalamic nuclei. Results Median radial targeting error was 0.40 mm (range: 0-1.6 mm), with bilateral procedures showing marginally lower errors (0.35 mm vs. 0.50 mm unilateral). The VIM exhibited the highest precision (0.35 mm), while STN targeting had slightly higher error (0.53 mm). Median operative time was 189 minutes (140-275 minutes), with bilateral procedures requiring longer durations (190 vs. 155 minutes, p = 0.001). No major complications occurred, and no revisions were needed. Conclusion The ClearPoint SmartFrame OR™ system achieved submillimeter accuracy and operational efficiency comparable to MRI-guided platforms while eliminating MRI dependency. Its integration with O-arm and Stealth Navigation enhances accessibility, reduces costs, and maintains safety, positioning it as a scalable solution for asleep DBS in standard neurosurgical settings.

Introduction Skull density ratio (SDR) is an important criterion for predicting efficacy of high-intensity focused ultrasound (HIFU) thalamotomy for essential tremor (ET) and tremor-dependent Parkinson's disease (TDPD). Bisphosphonates are known to increase bone density and are postulated to raise SDR and improve HIFU energy transmission efficiency. However, the impact of bisphosphonate pre-treatment on HIFU outcomes has not been investigated. Methods A retrospective analysis was conducted on the sonication parameters of patients with SDR<0.45 who were pre-treated off-label with bisphosphonates prior to HIFU. For comparison, the sonication parameters were also collected for patients with SDR<0.45 not pre-treated with bisphosphonates, patients with mid-range SDR (0.45-0.49), and patients with high-SDR (0.5-0.55). All patients underwent HIFU thalamotomy between March 2022 and December 2024. Results The bisphosphonate pre-treatment group (28 patients) and the low-SDR untreated group (29 patients) both had mean SDRs of 0.41. Respectively, the bisphosphonate-treated and low-SDR untreated group had mean final sonication energy of 23 kJ versus 26 kJ, final sonication duration of 27.1 versus 28.6 seconds, mean maximum temperature of 52.8°C versus 53.2°C, and average of 5.6 versus 4.9 sonications per treatment (p>0.05 for each comparison). No significant differences between the two low-SDR groups were found for the thermal efficiency of sonication. Compared to the bisphosphonate-treated low-SDR group, the mid- and high-SDR groups exhibited significantly decreased sonication energy (p<0.0001), final sonication duration (p<0.0001), and higher final sonication max temperature (p<0.01). Across all patients, a negative correlation was observed between SDR and final sonication energy (p<0.0001, r=-0.48) and a positive correlation was observed between SDR and last sonication temperature (p<0.005, r=0.27), although in the low-SDR cohort, a correlation was not observed. No clinically significant differences were found in demographics, self-reported tremor improvement, or incidence of side effects. Conclusion No significant differences were found in sonication response parameters between the bisphosphonate-treated and untreated low-SDR groups, whereas mid- and high-SDR groups had significantly reduced sonication energy and time to produce greater heat. These findings show that while bisphosphonates are an established way of raising bone density in osteoporosis, pre-treatment with bisphosphonates does not shift the sonication response from that of a low-SDR to a mid-range SDR. Additionally, other factors besides just skull density likely determine the thermal response to sonication.

Introduction Deep brain stimulation (DBS) is an established treatment for Parkinson's disease (PD). The traditional method for accurate implantation is awake microelectrode recordings (MER) to map out the borders of the target nucleus. However, a significant portion of patients are unable to tolerate awake surgical procedures. Asleep MER techniques under different general anesthesia regimens have been described with variable effects on recording quality and required a lower inhaled sevoflurane level to obtain single unit recordings. Hence, a reliable method for asleep MER mapping is needed without compromising patient safety and comfort. We aimed to assess the feasibility and quality of basal ganglia MER under general anesthesia using inhalational agents including adding nitrous oxide as an adjunct to sevoflurane(N2O-GA). Methods This study retrospectively examined PD patients undergoing DBS implantation targeting either the subthalamic nucleus (STN) or the globus pallidus internus (GPi) at a single center. Anesthetic data on end-tidal (ET) sevoflurane and nitrous oxide, with the derived minimum alveolar concentration (MAC) were captured during the time of MER mapping. We evaluated the feasibility of identifying target nuclei borders, the quality of neuronal unit isolation, and the physiological dimensions of the targeted nuclei. We calculated the concordance between the nuclei sizes based on MER mapping and imaging. We also reported the firing characteristics of isolated units. Results We identified 18 patients (34 nuclei) who underwent STN (n=11) and GPi (n=7) DBS implantation. Background activity changes were reliable in all patients for border identification. The length of the tract identified by MER was highly concordant with the anatomical tract length identified by postoperative imaging (concordance correlation coefficient: 0.84, p <0.001). Firing in both nuclei showed higher bursting rates. Pallidal cells showed typical firing patterns with "pauser" cells in the GPe and continuous firing in the GPi. No complications were observed during follow-up.16 patients had MER data available for offline analysis. We identified 516 units (single/multi) across MER 28 tracts (STN=284, GP=232). In the 14 patients received the N2O-GA, anesthetic depth was maintained at 0.97 ± 0.06 MAC, compared to 0.525 ± 0.04 MAC in the sevoflurane-only cases. Conclusion MER under N2O-GA is feasible for DBS target nuclei identification for both STN and GPi and offers a safe and accurate surgical approach for PD patients unable to tolerate awake mapping.

Background: Gamma Knife radiosurgery (GKRS) is an established treatment for refractory trigeminal neuralgia, however, predictors of pain relief following treatment remain unclear. We aimed to identify the factors associated with pain relief after the index GKRS session.

Methods: We retrospectively analyzed 204 patients with trigeminal neuralgia treated with GKRS between 1998 and 2023 (mean age 65.2 years, 68.5% female). Patient variables (pretreatment Roswell Park and Barrow Neurological Institute pain scores, symptom duration, prior therapies, multiple sclerosis status), MRI metrics (neurovascular contact and trigeminal nerve dimensions), and radiosurgery parameters (isocenter location and radiation dose, including biologically effective dose [BED]) were assessed. Responders were defined as BNI

Results: At last follow-up (median 20 months, range 6 months to 26 years), 57.3% of patients achieved pain relief. At ≥3-year follow-up, 74.1% of patients maintained adequate pain relief. Multiple sclerosis and prior interventions were associated with lower response rates: MS patients had 27.7% response vs 57.7% without MS (p=0.008), and prior microvascular decompression (MVD) had 34.4% vs 62.7% without prior MVD (p=0.005). GKRS as first-line therapy yielded better outcomes than when used after other treatments (63.9% vs 38.9%, p=0.045). Responders had a smaller trigeminal nerve (mean diameter 3.04 vs 3.42 mm, p=0.007) and a greater isocenter to brainstem orthogonal distance (4.2 vs 3.5 mm, p=0.02). A BED ≥ 2000 Gy was associated with higher response rate (75.8% vs 48.8%, p=0.006). In multivariate analysis, absence of MS, no prior MVD, smaller nerve diameter, and BED ≥ 2000 Gy independently predicted pain relief.

Conclusions: Non-modifiable factors that affected response included absence of MS and smaller trigeminal nerve size. Modifiable factors that were associated with higher response rates included no prior MVD, placing the isocenter farther from the brainstem surface, and BED≥ 2000 Gy. These findings support individualized treatment sequencing and GKRS planning to optimize GKRS outcomes in trigeminal neuralgia.

Introduction: Stereoelectroencephalography (sEEG) is a commonly used invasive method of mapping the epileptogenic zone (EZ) in patients with drug-resistant epilepsy. Generating radiofrequency thermocoagulation (RF-TC) lesions during sEEG coverage, by connecting a radiofrequency generator to a single electrode, has recently emerged as an adjunct to resective surgery. However, single-electrode RF-TC has not been effective in maintaining long-term seizure control, largely due to the small heat lesion size it can produce, and, therefore, has limited use. The "cross-bonding" technique has recently been reported, where bipolar lesioning is performed between two different and separated electrodes, in an attempt to ablate larger areas of the EZ. The purpose of this study was to analyse cross-bonding lesion characteristics using the DIXI medical electrodes and DIXI interface system and determine optimal RF-TC parameters for safe and effective clinical practice.

Methodology: A chicken albumin in vitro model was created with DIXI sEEG electrodes, DIXI interface system, and a Cosman radiofrequency generator. RF power and interelectrode distance was altered and lesion size, time and confluence were recorded and analysed.

Results: Confluent lesions were reliably produced at interelectrode distances of up to 7 mm. The largest lesions were produced at a RF power of 4-5 W, where increases in power greater than this paradoxically produced smaller lesions. Maximal lesion dimensions for height, width, and depth of lesions were identified. Lesion expansion routinely continued beyond 180 s of current delivery, with averages close to 400 s for the largest lesions generated.

Conclusion: Our in vitro modelling of the cross-bonding technique supports the use of the DIXI sEEG electrodes for generating thermal lesions in a safe, effective, and reproducible manner.