Stereotactic and Functional Neurosurgery最新文献

Background: Advances in MRI technology have increased interest in direct targeting for deep brain stimulation (DBS). Various imaging sequences have been shown to provide increased contrast of numerous common DBS targets, such as T1-weighted, Fast Gray Matter Acquisition T1 Inversion Recovery (FGATIR), gray matter nulled, and Edge-Enhancing Gradient Echo (EDGE); however, the continual increase in the number of necessary sequences has led to an increase in imaging time, which is undesirable. Additionally, carefully timed inversion pulses can often lead to less-than-ideal contrast in some subjects, particularly in ultra-high field MRI, where B1+ field inhomogeneity can lead to substantial contrast variation.

Objectives: This study proposes using 3D MP2RAGE-based T1 maps to retrospectively synthesize images of any desired inversion time, including T1-weighted, FGATIR, and EDGE contrasts, to visualize specific DBS targets at both 3T and 7T.

Method: First, a systematic sequence optimization framework was applied to optimize MP2RAGE T1 mapping sequence parameters for the purpose of DBS planning. Next, we show that synthetic inversion-time images can be generated through a mathematical transformation of the T1 maps. The sequence was then applied to patients undergoing preoperative planning for DBS at 3T and 7T to generate synthetic contrasts used in surgical planning.

Results: We show that synthetic image contrasts can be generated across a full range of inversion times at 3T and 7T, including commonly used sequences for DBS targeting, such as T1-weighted, FGATIR, and EDGE. Acquisition through a single sequence shortens scan time compared to acquiring the sequences independently without affecting image quality or contrast.

Conclusions: The generation of synthetic images for DBS targeting allows faster acquisition of many key sequences, as well as the ability to optimize contrast properties post-acquisition to account for the variable B1+ effects present in ultra-high field MRI. The proposed approach has the potential to reduce imaging time and improve the accuracy of DBS targeting at 1.5T, 3T, and 7T.

Introduction: The size of vestibular schwannomas (VS) is a major factor guiding the initial decision of treatment and the definition of tumor control or failure. Accurate measurement and standardized definition are mandatory; yet no standard exist. Various approximation methods using linear measures or segmental volumetry have been reported. We reviewed different methods of volumetry and evaluated their correlation and agreement using our own historical cohort.

Methods: We selected patients treated for sporadic VS by Gammaknife radiosurgery (GKRS) in our department. Using the stereotactic 3D T1 enhancing MRI on the day of GKRS, 4 methods of volumetry using linear measurements (5-axis, 3-axis, 3-axis-averaged, and 1-axis) and segmental volumetry were compared to each other. The degree of correlation was evaluated using an intraclass correlation test (ICC 3,1). The agreement between the different methods was evaluated using Bland-Altman diagrams.

Results: A total of 2,188 patients were included. We observed an excellent ICC between 5-axis volumetry (0.98), 3-axis volumetry (0.96), and 3-axis-averaged volumetry (0.96) and segmental volumetry, respectively, irrespective of the Koos grade or Ohata classification. The ICC for 1-axis volumetry was lower (0.72) and varied depending on the Koos and Ohata subgroups. None of these methods were substitutable.

Conclusion: Although segmental volumetry is deemed the most accurate method, it takes more effort and requires sophisticated computation systems compared to methods of volumetry using linear measurements. 5-axis volumetry affords the best adequacy with segmental volumetry among all methods under assessment, irrespective of the shape of the tumor. 1-axis volumetry should not be used.

Background: Implantable pulse generators (IPGs) store energy and deliver electrical impulses for deep brain stimulation (DBS) to treat neurological and psychiatric disorders. IPGs have evolved over time to meet the demands of expanding clinical indications and more nuanced therapeutic approaches.

Objectives: The aim of this study was to examine the workflow of the first 4-lead IPG for DBS in patients with complex disease.

Method: The engineering capabilities, clinical use cases, and surgical technique are described in a cohort of 12 patients with epilepsy, essential tremor, Parkinson's disease, mixed tremor, and Tourette's syndrome with comorbid obsessive-compulsive disorder between July 2021 and July 2022.

Results: This system is a rechargeable 32-channel, 4-port system with independent current control that can be connected to 8 contact linear or directionally segmented leads. The system is ideal for patients with mixed disease or those with multiple severe symptoms amenable to >2 lead implantations. A multidisciplinary team including neurologists, radiologists, and neurosurgeons is necessary to safely plan the procedure. There were no serious intraoperative or postoperative adverse events. One patient required revision surgery for bowstringing.

Conclusions: This new 4-lead IPG represents an important new tool for DBS surgery with the ability to expand lead implantation paradigms for patients with complex disease.

Magnetic resonance-guided high-intensity focused ultrasound (MRgFUS) is a rapidly developing technique used for tremor relief in tremor-predominant Parkinson's disease (PD) and essential tremor that has demonstrated successful results. Here, we describe the neuropathological findings in a woman who died from a fall 10 days after successful MRgFUS for tremor-predominant PD. Histological analysis demonstrates the characteristic early postoperative MRI findings including 3 distinct zones on T2-weighted imaging: (1) a hypointense core, (2) a hyperintense region with hypointense rim, and (3) a slightly hyperintense, poorly marginated surrounding area. Histopathological analyses also demonstrate the suspected cellular processes composing each of these regions including central hemorrhagic necrosis with surrounding cytotoxic edema and a rim of mostly unaffected vasogenic edema with some reactive and reparative processes. Overall, this case demonstrates the correlation of postoperative imaging findings with the subacute neuropathological findings after MRgFUS for PD.

Introduction: Pediatric deep brain stimulation (pDBS) is commonly used to manage treatment-resistant primary dystonias with favorable results and more frequently used for secondary dystonia to improve quality of life. There has been little systematic empirical neuroethics research to identify ethical challenges and potential solutions to ensure responsible use of DBS in pediatric populations.

Methods: Clinicians (n = 29) who care for minors with treatment-resistant dystonia were interviewed for their perspectives on the most pressing ethical issues in pDBS.

Results: Using thematic content analysis to explore salient themes, clinicians identified four pressing concerns: (1) uncertainty about risks and benefits of pDBS (22/29; 72%) that poses a challenge to informed decision-making; (2) ethically navigating decision-making roles (15/29; 52%), including how best to integrate perspectives from diverse stakeholders (patient, caregiver, clinician) and how to manage surrogate decisions on behalf of pediatric patients with limited capacity to make autonomous decisions; (3) information scarcity effects on informed consent and decision quality (15/29; 52%) in the context of patient and caregivers' expectations for treatment; and (4) narrow regulatory status and access (7/29; 24%) such as the lack of FDA-approved indications that contribute to decision-making uncertainty and liability and potentially limit access to DBS among patients who may benefit from it.

Conclusion: These results suggest that clinicians are primarily concerned about ethical limitations of making difficult decisions in the absence of informational, regulatory, and financial supports. We discuss two solutions already underway, including supported decision-making to address uncertainty and further data sharing to enhance clinical knowledge and discovery.

Introduction: A bilateral anterior capsulotomy effectively treats refractory obsessive-compulsive disorder (OCD). We investigated the geometry of lesions and disruption of white matter pathways within the anterior limb of the internal capsule (ALIC) in patients with different outcomes.

Methods: In this retrospective study, we analyzed data from 18 patients with refractory OCD who underwent capsulotomies. Patients were grouped into "responders" and "nonresponders" based on the percentage of decrease in the Yale-Brown Obsessive-Compulsive Scale (YBOCS) after surgery. We investigated neurobehavioral adverse effects and analyzed the overlap between lesions and the ventromedial prefrontal (vmPFC) and dorsolateral prefrontal (dlPFC) pathways. Probabilistic maps were constructed to investigate the relationship between lesion location and clinical outcomes.

Results: Of the 18 patients who underwent capsulotomies, 12 were responders (>35% improvement in YBOCS), and six were nonresponders. The vmPFC pathway was more involved than the dlPFC pathway in responders (p = 0.01), but no significant difference was observed in nonresponders (p = 0.10). The probabilistic voxel-wise efficacy map showed a relationship between ventral voxels within the ALIC with symptom improvement. Weight gains occurred in 11/18 (61%) patients and could be associated with medial voxels within the ALIC.

Conclusion: The optimal outcome after capsulotomy in refractory OCD is linked to vmPFC disruption in the ALIC. Medial voxels within the ALIC could be associated with weight gains following capsulotomy.

Background: Chronic cluster headache (CCH) is a severe and debilitating sub-type of trigeminal autonomic cephalalgia that can be resistant to medical management and associated with significant impairment in quality of life. Studies of deep brain stimulation (DBS) for CCH have provided promising results but have not been assessed in a comprehensive systematic review/meta-analysis.

Objective: The objective was to perform a systematic literature review and meta-analysis of patients with CCH treated with DBS to provide insight on safety and efficacy.

Methods: A systematic review and meta-analysis were performed according to PRISMA 2020 guidelines. 16 studies were included in final analysis. A random-effects model was used to meta-analyze data.

Results: Sixteen studies reported 108 cases for data extraction and analysis. DBS was feasible in >99% of cases and was performed either awake or asleep. Meta-analysis revealed that the mean difference in headache attack frequency and headache intensity after DBS were statistically significant (p < 0.0001). Utilization of microelectrode recording was associated with statistically significant improvement in headache intensity postoperatively (p = 0.006). The average overall follow-up period was 45.4 months and ranged from 1 to 144 months. Death occurred in <1%. The rate of major complications was 16.67%.

Conclusions: DBS for CCHs is a feasible surgical technique with a reasonable safety profile that can be successfully performed either awake or asleep. In carefully selected patients, approximately 70% of patients achieve excellent control of their headaches.

Introduction: Parkinson's disease (PD) is one of the most common neurodegenerative progressive disorders. Despite the dominance of neurostimulation technology, stereotactic lesioning operations play a significant role in the treatment of PD. The aim of the study was to evaluate the effectiveness and safety of staged bilateral asymmetric radiofrequency (RF) stereotactic lesioning in a highly selected group of PD patients.

Material and methods: A retrospective review of 418 consecutive patients undergoing stereotactic ablation for advanced PD at our institution revealed 28 patients who underwent staged asymmetric bilateral ablation. In this subset, after initial RF thalamotomy, contralateral pallidotomy was performed in 16 (57.1%) patients (group Vim-GPi), and contralateral lesion of the subthalamic nucleus (STN) was performed in 12 (32.9%) patients (group Vim-STN). The mean duration of disease before the first surgery was 9.9 ± 0.8 years. The mean interval between the two operations was 3.5 ± 0.4 years (range, 1-10 years); in the Vim-GPi group, it was 3.1 ± 0.4 years; and in the Vim-STN group, it was 4.3 ± 0.1 years. After the second operation, the long-term follow-up lasted from 1 to 8 years (mean 4.8 ± 0.5 years). All patients were evaluated 1 year after the second operation.

Results: One year after staged bilateral lesioning, the mean tremor score improved from baseline, prior to the first operation, from 19.8 to 3.8 (improvement of 81%), the overall mean rigidity score improved from 11.0 to 3.7 (improvement of 66%), and hypokinesia improved from 14.8 to 8.9 (improvement of 40%). One year after staged bilateral lesioning, the total UPDRS score improved in the Vim-GPi group by 47% in the OFF and 45.9% in the ON states. In the Vim-STN group, the total UPDRS score improved from baseline, prior to the first operation, by 44.8% in the OFF and 51.6% in the ON states. Overall, levodopa dose was reduced by 43.4%. Neurological complications were observed in 4 (14.3%) cases; among them, 1 (3.6%) patient had permanent events related to local ischemia after pallidotomy.

Conclusion: Staged asymmetric bilateral stereotactic RF lesioning can be a safe and effective method in highly selected patients with advanced PD, particularly where deep brain stimulation is not available or desirable. Careful identification and selection of patients for ablative surgery allow achieving optimal results in the treatment of PD with bilateral symptoms.

Introduction: Nucleotractotomy is an efficient surgical technique that provides a high pain relief rate for specific clinical indications. There are two main approaches for performing this operation: an open and percutaneous technique.

Methods: In the Federal Center of Neurosurgery (Novosibirsk, Russia) from 2016 to 2022, 13 trigeminal nucleotractotomies (7 open and 6 percutaneous) were performed in 12 patients (5 women and 7 men). The indications for surgery were deafferentation pain and chronic drug-resistant pain syndrome caused by malignancy in the facial region. A neurological examination was done on each patient 1 day before the surgery, right after the surgery, and at the follow-up (examinations were done after 1, 6, and 12 months, or when the patient independently applied to our hospital). In the early postoperative period, patients underwent brain MRI.

Results: The average pain intensity score before nucleotractotomy on the 11-point (0-10) visual analog scale (VAS) was 9.3. The effectiveness of open interventions was somewhat higher; the average VAS score in the early postoperative period for the open technique was 1.57, in the group of patients who underwent percutaneous nucleotractotomy were 2.66. Complete regression of the pain syndrome was achieved in 6 patients; in 5 patients, the pain in the face decreased by more than 50%. One case had an unsatisfactory outcome. In the open-surgery group in the early postoperative period, according to MRI, the average length of the visualized area of signal change was longer (21.5 mm, the average diameter was 3.75 mm) than in a percutaneous nucleotractotomy group (16 mm, the average diameter was 3.75 mm). During the postoperative period (average follow-up 40 months), the pain recurred in 3 patients (30%): 2 patients after percutaneous nucleotractotomy (3 and 18 months after surgery) and in 1 patient 4 months after the open surgery. The mean VAS score at the last follow-up was 2.6.

Conclusion: Trigeminal nucleotractotomy is an effective approach to the treatment of intractable facial pain. Our experience suggests this technique is highly effective in patients with drug-resistant pain caused by craniofacial tumors and deafferentation conditions after treating trigeminal neuralgia.