Stereotactic and Functional Neurosurgery最新文献

Introduction: In 2015, directional leads have been released in Europe for deep brain stimulation (DBS) and have been particularly used for subthalamic nucleus (STN) DBS for Parkinson's disease (PD). In this study we aimed to compare an omnidirectional and directional leads cohort of PD patients when it comes to clinical effectiveness and to assess the correlation with volume of tissue activated - target overlap (VTA-target).

Methods: A total of 60 consecutive patients were retrospectively included. 27 patients with bilateral directional leads were compared to 33 patients with bilateral omnidirectional leads. MDS-UPDRS part III scores, levodopa equivalent daily dose (LEDD), and VTA overlaps using both motor STN region and motor improvement sweetspot volume were compared at 12 months after surgery.

Results: There is a significantly higher LEDD reduction in the directional leads group (51.3 % reduction vs 42.7% reduction, p= 0.042) when compared to the omnidirectional group, with similar MDS-UPDRS III motor scores at 12 months. Omnidirectional leads patients had a significantly superior VTA-motor STN overlap volume than directional leads patients (32.01 mm3 vs 20.38 mm2, p = 0.0226). In directional leads patients, LEDD reduction was correlated to VTA overlap with the overall motor improvement mean map sweetspot (R = 0.36, p = 0.036), which was not the case for omnidirectional leads patients (R = 0.11, p = 0.276). Forty one percent of patients implanted with directional leads had a directional stimulation setting at 12 months, compared to thirty three percent at 3 months follow up. In directional leads patient's subgroup analysis, there was no significant difference in MDS UPDRS III scores, LEDD reduction, VTA overlaps with motor STN or overall motor improvement mean map sweetspot between patients stimulated omnidirectionally and directionally at 12 months.

Conclusion: At 12 months, when compared to omnidirectional leads, directional leads manage with smaller VTA-target overlaps to obtain comparable MDS-UPDRS III scores with greater LEDD reduction in STN DBS for PD patients.

Introduction: Functional thalamic surgery is known for alleviating isolated focal hand dystonia; however, the optimal target site in the thalamus is not determined. This study aimed to identify effective sites for thalamic deep brain stimulation (DBS) in treating this condition.

Methods: Four patients presenting with focal hand dystonia underwent thalamic DBS. Effective stimulation sites were identified through a combination of physiological and radiological mapping.

Results: All patients exhibited significant improvement in their hand dystonia. The most effective stimulation sites were localized in the anterior regions of the ventral intermedius nucleus (Vim), involving both Vim and the ventro-oral nucleus (VO).

Conclusion: Thalamic DBS proves highly effective in managing focal hand dystonia. The identified effective stimulation sites suggest the involvement of both the pallidothalamocortical and cerebellothalamocortical pathways in its pathophysiology.

Objective: There has been rapid advancement in the development of deep brain stimulation (DBS) as a treatment option for adults for neurological and neuropsychiatric conditions. Here, we present a scoping review of completed and ongoing clinical trials focused on DBS in pediatric populations, highlighting key knowledge gaps.

Methods: Three databases (PubMed, OVID, and Embase) and the clinicaltrials.gov registry were queried to identify clinical trials for DBS in pediatric cohorts (age < 18). Prospective and retrospective case series were excluded. No restrictions were placed on the diagnoses or measured clinical outcomes. Individual patient demographics, diagnosis, DBS target, and primary endpoints were extracted and summarized.

Results: A total of 13 clinical trials were included in the final review, consisting of 9 completed trials (357 screened) and 4 ongoing trials (82 screened). Of the completed trials, 6 studied dystonia (both inherited and acquired; participants aged 4-18), and 3 studied drug-resistant epilepsy (participants aged 4-17). Amongst the 6 trials for dystonia, 5 used the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) as the primary endpoint. There were a total of 18 adverse events documented across 63 participants, with 5 of 9 studies reporting adverse events. Ongoing clinical trials are evaluating DBS for dystonia (N=2), epilepsy (N=1), and self-injurious behaviour (N=1).

Conclusions: This scoping review summarizes the landscape of clinical trials for DBS in children and youth. In dystonia, further research is warranted with more relevant pediatric outcome measures and for understudied patient subgroups and targets. There are also significant gaps in our understanding of evaluate the role of DBS in other neurological and neurodevelopmental disorders in pediatric populations.

Introduction: Cerebellar deep brain stimulation (DBS) is gaining traction as a potential treatment for movement disorders and stroke, and there is renewed interest in the cerebellum as a target for neuromodulation. Despite the safety and accuracy of frame-based approaches to the posterior fossa, unconventional stereotactic frame placement may be necessary to allow for low posterior fossa trajectories. Current literature lacks a comprehensive protocol detailing inverted frame placement and targeting.

Methods: Preoperative imaging was acquired prone. An inverted Leksell G frame was applied along with an open-topped CT fiducial box, followed by a prone CT with the scanner set to the "legs first, nose up" configuration. Target coordinates were extracted from navigation software after image fusion. Intraoperatively, the patient was positioned prone, and the stereotactic arc was mounted in the lateral-right orientation, with inverted arc supports. Confirmatory stereotaxy to a scalp staple was performed, and the DBS leads were then inserted.

Conclusion: Our standardized protocol provides a flexible platform for posterior fossa DBS, allowing for low trajectories and multiple electrodes. Unlike conventional upright frame placement, an inverted frame permits an unobstructed view of suboccipital entry sites and incision placement. A conventional frame and regular planning software are sufficient, with no additional mathematical calculations required.

Introduction: Rising NHS waiting lists are a major problem following the COVID-19 pandemic. In our institution, surgical waiting time for elective functional neurosurgical procedures, such as deep brain stimulation (DBS) and radiofrequency ablation (RFA), reached >1.5 years by the end of 2022. During 2023, reduced operating room availability, intraoperative MRI (iMRI) suite closure for refurbishment, and ongoing strikes threatened to increase waiting times further.

Methods: Our previous surgical workflow for DBS and RFA procedures was examined. Several aspects were identified, and changes implemented to increase efficiency. Procedure numbers, waiting times, lead placement accuracy, and complication rates before and after these changes were compared.

Results: Prior to 2023, an average of 0.8 new procedures were performed per surgical list. Introduction of a new workflow in 2023 allowed an average of 1.6 new procedures per surgical list (100% increase in productivity). In 2023, 95 DBS and 31 RFA procedures were performed on 79 surgical lists. This represents a 52% increase over "pre-pandemic" activity in 2019 (74 DBS, 9 RFA) on 102 available surgical lists. Mean (SD) targeting accuracy (0.8 [0.4] mm) was comparable to previous years (0.9[0.3] mm). In 2023, there were no infections requiring hardware removal and only one asymptomatic haemorrhage following an RFA procedure. The surgical waiting time was reduced from >1.5 years to <4 months by the end of 2023.

Conclusion: Changes in surgical workflow, with neurosurgeons working in parallel, maximise surgical efficiency and productivity, significantly increasing the number of DBS and RFA procedures without compromising accuracy and safety.

Introduction: Direct targeting in deep brain stimulation (DBS) has remarkably impacted the patient's experience throughout the surgery and the overall logistics of the procedure. When the individualised plan is co-registered with a 3D image acquired intraoperatively, the electrodes can be safely placed under general anaesthesia. How this applies to a general practice scenery (outside clinical trials and in a moderate caseload centre) has been scarcely reported.

Methods: Prospective single-centre study of patients treated with asleep subthalamic DBS for Parkinson's disease between January 2021 and December 2022. Clinical, motor, medication-dependence, and quality-of-life outcomes were evaluated after optimal programming (6 months). Wilcoxon test was used to compare pre- versus post-repeated measures. Surgical-related parameters were also analysed.

Results: Eighty-nine patients primarily operated for DBS were included in the study. Intraoperative electrode replacement was not necessary. Mean surgical duration was 217 (SD 44) minutes, including the implantation of the generator; and mean length of stay was 3 (SD 1) days. There was one surgical-related complication (delayed infection). Significant and clinically relevant improvement was seen in UPRS III (mean decrease 62%) (p < 0.001) and PDQ-8 (50% increase) (p < 0.001) after 6 months. Daily doses of medication were decreased by a mean of 68%, p < 0.001).

Conclusion: DBS can be safely performed under general anaesthesia in a pragmatic clinical environment, provided a multidisciplinary committee for patient selection and a dedicated surgical and anaesthetic team are available. The effectiveness in ameliorating motor symptoms, the ability to reduce the drug load, and the improvement in quality of life demonstrated in clinical trials could be reproduced under more generalised conditions as in our centre. The need for a team learning curve and the progressive evolution in, and adaptation to, trajectory planning software, anaesthetic management, intraoperative imaging, DBS device upgrades, and programming schemes should be contemplated in the transition process to direct targeting.

Introduction: Magnetic resonance imaging (MRI) is both a crucial clinical and research tool for patients with deep brain stimulation (DBS) devices. However, safety concerns predominantly related to device heating have limited such imaging. Rigorous safety testing has demonstrated that scanning outside of vendor guidelines may be both safe and feasible, unlocking unique opportunities for advanced imaging in this patient population. Currently, however, 3T MRI safety data including advanced MRI sequences in novel directional and sensing DBS devices is lacking.

Methods: An anthropomorphic phantom replicating bilateral DBS system was used to assess the temperature rise at the electrode tips, implantable pulse generator, and cranial loop during acquisition of routine clinical sequences (three dimensional [3D] T1, GRE T2*, T2 FSE) and advanced imaging sequences including functional MRI (fMRI), arterial spin labelling (ASL), and diffusion weighted imaging (DWI). Measures of radiofrequency exposure (specific absorption rate [SAR] and root-mean square value of the MRI effective component of the radiofrequency transmission field [B1+rms]) were also recorded as an indirect measure of heating. Testing involved both a new directional and sensing DBS device (Medtronic: B30015 leads and Percept PC neurostimulator) and a previous-generation DBS device (Medtronic: 3,387 leads and Percept PC neurostimulator) in combination with a state-of-the-art (Siemens MAGNETOM Prisma) and a previous-generation (GE Signa HDxt) 3T MRI scanner.

Results: On the state-of-the-art 3T MRI scanner, the new DBS device produced safe temperature rises with clinically used sequences and fMRI but not with other advanced sequences such as DWI and ASL, which also exceeded B1+rms vendor guidelines (i.e., ≤2 μT). When scanned on the previous MRI scanner, the recent DBS device produced overall lower and slower temperature rises compared to the previous DBS model. Among the sequences performed on this scanner, several (3D T1, DWI, T2 FSE, and ASL) exceeded the approved SAR vendor limit (<1 W/kg), but only ASL resulted in an unacceptable temperature rise during scanning of the previous DBS model.

Conclusion: These phantom safety data show that both clinically used MRI sequences and research sequences such as fMRI can be successfully acquired on 3T MRI scanners with a novel directional and sensing DBS model. As several of these sequences were obtained outside regulatory-approved vendor guidelines, preemptive safety testing should be done. As directional leads become increasingly common, improving MRI safety knowledge is crucial to expand clinical and research possibilities.

Introduction: Postherpetic neuralgia (PHN) is a pain syndrome that develops within few months after the acute herpetic outbreak. The pain may be accompanied by specific cutaneous signs in the distribution of affected dermatomes and feel unbearable reaching up to 9-10/10 on visual analog scale (VAS). Despite the introduction of new medications, drug resistance develops in at least 50% of cases. Neuromodulation techniques such as spinal cord stimulation (SCS) and peripheral nerve stimulation (PNS) are considered as ones of the last resorts for PHN treatment, especially in pharmacoresistant patients. Recently, several studies with limited number of cases have shown high efficiency of neuromodulation (regression of pain syndrome in more than 82% of cases) after SCS in PHN patients, but these findings require further confirmation and have not been supported by large RCTs.

Methods: Initially, 32 patients diagnosed with chronic drug-resistant PHN underwent a trial of SCS. Based on the trial results, a decision was made whether to implant a permanent SCS system. The condition of all patients implanted with SCS system was assessed using the VAS, SF-36, Patient Global Impression of Change (PGIC), and Medicine Quantification Scale, version III (MQS) questionnaires before the surgery and in the long-term follow-up. We also conducted systematic follow-up of patients who did not pass the test stimulation stage, using them as a control group to track the levels of pain. The hypothesis of normal distribution for quantitative values was tested using Shapiro-Wilk tests.

Results: During the trial period, tonic spinal stimulation was effective in 16 out of 32 (50%) patients with drug-resistant PHN. Among 14 patients with implanted stimulators, a significant pain reduction (more than 50% from the baseline) was observed in 10 patients (71.4%). The pain level in patients with a tonic SCS was statistically lower than in patients receiving conservative therapy. For the entire group of patients with implanted SCS, a significant improvement was also observed in results of SF-36, PGIC, and MQS.

Conclusion: Our clinical series demonstrates that tonic SCS was effective in 50% of patients with refractory PHN undergoing SCS trial. Significant improvement in pain control obtained during the long-term follow-up in patients treated with tonic SCS improves the quality of life and reduces the need for analgesic medications.