Stereotactic and Functional Neurosurgery最新文献

Introduction: MR-guided laser interstitial thermal therapy (MRgLITT) is a minimally invasive technique for treating deep-seated brain lesions. However, the dynamics of imaging changes that occur after the ablation are not well characterized. This study aimed to describe the clinical outcomes and volume changes that occur over time after MRgLITT.

Methods: We retrospectively collected clinical and imaging data of all adult patients who underwent MRgLITT of brain tumors (primary and metastatic) between 01/2020 and 06/2024. Volumes and diameters of the lesions were measured on gadolinium-enhanced T1-weighted images using Brainlab Elements. Local control was assessed at the last follow-up.

Results: Twenty-nine patients with 32 treated lesions were available for assessment. Most lesions (n = 21) were metastatic, while 11 lesions were gliomas. The mean follow-up period was 23.4 ± 13.1 months. The average preoperative tumor volume was 2.8 ± 1.8cc. Post-ablation, the lesions' volumes increased on average by 250% (up to 450%) in the first month after surgery compared to the preoperative volumes. The enhancing ring extended distally beyond the tip of the catheter for an average of 4.5 ± 1.8 mm. Glial lesions had a median progression-free survival of 8.5 months. The volume of metastatic lesions decreased below the preoperative volume on average 3 months after surgery. Local control was achieved in 16 of 21 metastatic lesions (76%) and was significantly better for lesions smaller than 4cc in volume and 16 mm in maximal diameter that could be completely covered by the thermal damage estimation. Nodular enhancement at 3 months post-surgery was correlated with local failure.

Conclusion: MRgLITT can achieve good local control in metastatic brain lesions and should be considered early during follow-up after radiosurgery when local failure is suspected. The enhancing lesion extends beyond the tip of the catheter and enlarges during the first month post-ablation before gradually decreasing in size. Failure to decrease in size after 3 months or appearance of a nodular enhancement should raise suspicion of local failure.

Introduction: Intraoperative microelectrode recording (MER) is a widely employed technique for the physiological identification of the subthalamic nucleus (STN) during deep brain stimulation (DBS) surgery targeting the STN. However, failure to detect typical STN activity may raise concerns about diagnostic accuracy and treatment efficacy. Objective of this study were to retrospectively evaluate the clinical characteristics and long-term outcomes of patients with advanced Parkinson's disease (PD) in whom STN neuronal activity was not detected during intraoperative MER and to explore the implications of this finding for differential diagnosis and DBS candidacy.

Methods: Among 624 STN-DBS procedures performed at Juntendo University Hospital between 2012 and 2024, we identified 3 patients (0.5%) in whom intraoperative MER failed to detect typical STN neuronal activity. Clinical records were reviewed retrospectively, including demographic data, levodopa responsiveness, preoperative images, intraoperative MER findings, surgical decision-making processes, and postoperative clinical courses.

Results: All 3 patients were male, in their 60s at the time of surgery, with disease durations ranging from 5 to 7 years. Cognitive function was preserved in all cases. Gait disturbance was a prominent early symptom, and all patients experienced relatively early wearing-off phenomena. None exhibited dyskinesia, yet all showed good responsiveness to levodopa, confirmed by preoperative levodopa challenge tests. Despite multiple MER trajectories, no characteristic STN neuronal firing patterns were observed. DBS electrodes were implanted according to the initial surgical plan in 2 cases; in the other case, implantation was aborted. Following surgery, all patients demonstrated progressive axial motor deterioration. Based on their clinical course and imaging findings, all were ultimately diagnosed with or strongly suspected to have progressive supranuclear palsy-parkinsonism (PSP-P).

Conclusions: The absence of detectable STN activity during intraoperative MER may reflect underlying neurodegenerative pathology distinct from idiopathic PD, such as PSP-P. These findings suggest that MER, beyond its role in anatomical targeting, may serve as a valuable intraoperative biological indicator for diagnostic refinement. Even within a multidisciplinary setting led by movement disorder specialists, distinguishing PD from PSP-P prior to surgery remains a significant challenge. Improved diagnostic accuracy is critical to optimize patient selection for DBS and to prevent ineffective or potentially deleterious interventions.

Introduction: Trigeminal schwannomas (TSs) are rare benign tumors arising from the trigeminal nerve. Gamma Knife radiosurgery (GKS) offers a minimally invasive alternative to surgical resection, but the long-term clinical outcomes, particularly regarding change of trigeminal nerve function, remain under-characterized. This study aimed to evaluate long-term clinical outcomes and identify prognostic factors for neurological sequelae following primary GKS for TS.

Methods: A retrospective analysis was performed on 89 patients who underwent primary GKS for TS between 2002 and 2023. Patients with prior surgery or hypofractionation were excluded. Clinical and imaging data were analyzed for tumor control, symptom relief, and new-onset, or persistent post-GKS morbidities. Symptoms were classified as new-onset transient, new-onset permanent, or persistent preexisting. The Kaplan-Meier analysis, Logistic regression, and Cox regression were used to identify prognostic factors.

Results: Over a median follow-up of 57 months (range, 6.8-184), tumor control was 93.3%. Symptom relief occurred in 46.9% of preexisting deficits, highest for headache (70.6%) and dizziness (100%), but modest for trigeminal pain (33.3%) and paresthesia (36.7%). New-onset morbidities included trigeminal sensory disturbance (33.7%, permanent in 15) and pain (22.5%, permanent in 5). In Cox analysis, higher margin dose reduced the hazard of new paresthesia (HR 0.511, p = 0.036), while older age increased risk (HR 1.041, p = 0.037).

Conclusion: Primary GKS achieves durable tumor control for TS with lower risk than microsurgery. However, a considerable proportion of patients may experience long-term trigeminal dysfunction. Adequate dosing may mitigate sensory morbidity, though pain relief remains modest. Careful selection, counseling, and follow-up are essential.

Introduction: Bilateral electrode implantation is the primary approach for deep brain stimulation (DBS) in Parkinson's disease (PD). However, it may lead to gait deterioration in some patients. This study aimed to investigate the efficacy of unilateral DBS on gait in PD patients as an alternative with fewer side effects and lower costs.

Methods: We systematically searched four major clinical databases to evaluate the effects of unilateral DBS on UPDRS gait score, gait velocity, stride length, cadence, and gait initiation in PD patients. Twenty-three studies were included in the review, selected from an initial pool of 2,415 studies. We also performed a meta-analysis to assess the impact of unilateral DBS on gait velocity and compare its efficacy to bilateral stimulation. The study protocol was registered at PROSPERO with the registration code: CRD42024585359.

Results: The included studies assessed gait measures in patients receiving unilateral DBS targeting the STN, globus pallidus internus, pedunculopontine nucleus, and ventral intermediate nucleus. According to the systematic review of clinical evidence, unilateral DBS can improve the UPDRS gait score, freezing of gait, and gait velocity, although to a lesser extent than bilateral stimulation. The meta-analysis revealed a nonsignificant positive pooled effect on gait velocity in the unilateral DBS condition compared to the control condition and no significant difference when compared to bilateral DBS.

Conclusion: Unilateral DBS shows promise for improving gait in PD, as an alternative with lower costs and side effects, especially in early-stage or asymmetric cases.

Background: Deep brain stimulation (DBS) is a well-established treatment for several neurological and neuropsychiatric conditions, including movement disorders such as Parkinson's disease, essential tremor, and dystonia, as well as Gilles de la Tourette's syndrome, epilepsy, and obsessive-compulsive disorder.

Summary: In recent years, research has expanded to explore the potential of DBS for other indications, including dementia, addiction, disorders of consciousness (e.g., minimally conscious state), and eating disorders. Over the past 3 decades, significant technological advancements have been made in DBS devices, including improvements in electrode design, stimulation parameters, and battery life. However, despite these technological innovations, equitable access to DBS has not progressed at a similar pace. Barriers to access remain a persistent challenge globally, influenced by socioeconomic, geographic, systemic, and policy-related factors.

Key message: This review summarizes the current literature on access to DBS, highlighting disparities, challenges, and potential strategies to improve availability and equity in its application.

Background Radiofrequency lesioning (RL) had been a mainstay in functional neurosurgery for dystonic movement disorders before the widespread adoption of deep brain stimulation (DBS). Outcomes of RL in hemidystonia have varied. This review provides a systematic analysis of RL for hemidystonia and evaluates the spectrum of clinical outcome. Methods A systematic literature review was performed according to PRISMA guidelines in PubMed, Embase, and Web of Science using a customized software (UiPath, NY) to identify all case reports, case series, and cohort studies reporting patients with hemidystonia treated with RF. Manuscripts were automatically searched for the term "hemidystonia". The selected manuscripts were then manually screened. Detailed information from two recent multi-patient studies was added. Clinical improvement was classified as follows: (0) no improvement; (I) mild; (II) moderate; (III) marked improvement. Results Twenty-eight studies with individual patient data were included, totaling 101 cases published between 1962 and 2024. Thalamotomy was performed in 80 cases, pallidotomy in 16, and both in 5. At last follow-up, 18 patients (19.35%) showed marked improvement, 41 (44.09%) moderate, 16 (17.21%) mild, and 18 (19.35%) no benefit. No significant differences in outcomes were found between targets or etiologies, though patients with traumatic brain injury tended to fare worse. A significant negative linear correlation was found between the degree of improvement and age at surgery. Conclusion With advancements in targeting and technology, RL may be reconsidered as a treatment option for hemidystonia. Further studies with standardized outcome assessments are needed to better characterize response variability and identify prognostic factors.

Stereotactic anterior cingulotomy is a neurosurgical technique that can offer significant pain relief in patients with refractory cancer pain, particularly in the palliative setting. Despite being described in the 1960s, its use has recently resurged due to limitations of pharmacologic and neuromodulatory therapies in terminally ill patients. The anterior cingulate cortex plays a crucial role in the affective processing of pain, and its disruption through targeted lesioning may reduce suffering without eliminating nociception. This review summarises the historical background, patient selection criteria, surgical approaches, efficacy data, and safety outcomes associated with bilateral anterior cingulotomy for cancer-related pain. Additionally, the Queen Square approach, incorporating MRI-guided targeting and diffusion imaging, is described. Available data support the procedure's short-term efficacy in the majority of patients, with limited cognitive side effects and minimal morbidity. Future directions include network-based targeting, refinement of lesion techniques, and consideration of non-invasive alternatives such as focused ultrasound. Further research is warranted to optimise selection criteria and understand the neural mechanisms underlying pain relief.

Introduction: Deep brain stimulation (DBS) was approved for essential tremor by the Food and Drug Administration (FDA) in 1997. Since that time, technological advancements in implanted hardware and operative technique have changed the landscape of functional neurosurgery. Interventional MRI-guided DBS lead placement is an emerging technique that can be used to treat ET patients, though the data are limited due to the perceived difficulty of direct targeting the ventral intermediate nucleus (VIM) relative to other structures. Here we review the experience of a single surgeon with interventional MRI-guided DBS targeting of the VIM in ET patients under general anesthesia in a community setting.

Method: We conducted a retrospective chart review of ET patients who underwent DBS under general anesthesia using an MRI-guided ClearPoint surgical technique at Willis-Knighton Health System between 2016 and 2021. Demographics, radial error, procedure details, complications, and clinical outcomes were collected. Clinical outcome measures included postoperative medication reduction, the Quality of Life in Essential Tremor Questionnaire (QUEST), and a reduced 19-item version of the Fahn-Tolosa-Marín (FTM) tremor rating scale (upper-limb items from parts A-C; maximum 76 points).

Results: A total of 113 ET patients (50 females [44.2%]; mean age 68.1 ± 9.4) underwent placement of 175 DBS leads. The 2D radial error was 0.43 ± 0.33 mm with only 2 leads requiring more than one pass. Following DBS placement, 69.2% stopped or reduced medication. On the reduced 19-item FTM (maximum 76 points), scores improved from 34.0 preoperatively to 8.9 postoperatively (-76.4%, p < 0.001). The QUEST Summary Index improved from 47.1 preoperatively to 29.4 postoperatively with an average improvement of 77.8%.

Conclusion: Interventional MRI-guided DBS lead placement under general anesthesia is a feasible and effective technique for ET patients that may expand the reach of DBS therapy to those with significant anxiety regarding traditional, awake surgery.