Explore the vast range of titles available.

Background Precise insertion of pedicle screws is important to avoid injury to closely adjacent neurovascular structures. The standard method for the insertion of pedicle screws is based on anatomical landmarks (free-hand technique). Head-mounted augmented reality (AR) devices can be used to guide instrumentation and implant placement in spinal surgery. This study evaluates the feasibility and precision of AR technology to improve precision of pedicle screw insertion compared to the current standard technique. Methods Two board-certified orthopedic surgeons specialized in spine surgery and two novice surgeons were each instructed to drill pilot holes for 40 pedicle screws in eighty lumbar vertebra sawbones models in an agar-based gel. One hundred and sixty pedicles were randomized into two groups: the standard free-hand technique (FH) and augmented reality technique (AR). A 3D model of the vertebral body was superimposed over the AR headset. Half of the pedicles were drilled using the FH method, and the other half using the AR method. Results The average minimal distance of the drill axis to the pedicle wall (MAPW) was similar in both groups for expert surgeons (FH 4.8 ± 1.0 mm vs. AR 5.0 ± 1.4 mm, p = 0.389) but for novice surgeons (FH 3.4 mm ± 1.8 mm, AR 4.2 ± 1.8 mm, p = 0.044). Expert surgeons showed 0 primary drill pedicle perforations (PDPP) in both the FH and AR groups. Novices showed 3 (7.5%) PDPP in the FH group and one perforation (2.5%) in the AR group, respectively ( p > 0.005). Experts showed no statistically significant difference in average secondary screw pedicle perforations (SSPP) between the AR and the FH set 6-, 7-, and 8-mm screws ( p > 0.05). Novices showed significant differences of SSPP between most groups: 6-mm screws, 18 (45%) vs. 7 (17.5%), p = 0.006; 7-mm screws, 20 (50%) vs. 10 (25%), p = 0.013; and 8-mm screws, 22 (55%) vs. 15 (37.5%), p = 0.053, in the FH and AR group, respectively. In novices, the average optimal medio-lateral convergent angle (oMLCA) was 3.23° (STD 4.90) and 0.62° (STD 4.56) for the FH and AR set screws ( p = 0.017), respectively. Novices drilled with a higher precision with respect to the cranio-caudal inclination angle (CCIA) category ( p = 0.04) with AR. Conclusion In this study, the additional anatomical information provided by the AR headset superimposed to real-world anatomy improved the precision of drilling pilot holes for pedicle screws in a laboratory setting and decreases the effect of surgeon’s experience. Further technical development and validations studies are currently being performed to investigate potential clinical benefits of the herein described AR-based navigation approach.

Ablative neurosurgery has been used to treat Parkinson's disease for many decades. MRI-guided focused ultrasound allows focal lesions to be made in deep brain structures without skull incision. We investigated the safety and preliminary efficacy of unilateral subthalamotomy by focused ultrasound in Parkinson's disease. This prospective, open-label pilot study was done at CINAC (Centro Integral de Neurociencias), University Hospital HM Puerta del Sur in Madrid, Spain. Eligible participants had Parkinson's disease with markedly asymmetric parkinsonism. Patients with severe dyskinesia, history of stereotactic surgery or brain haemorrhage, a diagnosis of an unstable cardiac or psychiatric disease, or a skull density ratio of 0·3 or less were excluded. Enrolled patients underwent focused ultrasound unilateral subthalamotomy. The subthalamic nucleus was targeted by means of brain images acquired with a 3-Tesla MRI apparatus. Several sonications above the definitive ablation temperature of 55°C were delivered and adjusted according to clinical response. The primary outcomes were safety and a change in the motor status of the treated hemibody as assessed with part III of the Movement Disorders Society–Unified Parkinson's Disease Rating Scale (MDS–UPDRS III) in both off-medication and on-medication states at 6 months. Adverse events were monitored up to 48 h after treatment and at scheduled clinic visits at 1, 3, and 6 months after treatment. The study is registered with ClinicalTrials.gov, number NCT02912871. Between April 26 and June 14, 2016, ten patients with markedly asymmetric parkinsonism that was poorly controlled pharmacologically were enrolled for focused ultrasound unilateral subthalamotomy. By 6 months follow-up, 38 incidents of adverse events had been recorded, none of which were serious or severe. Seven adverse events were present at 6 months. Three of these adverse events were directly related to subthalamotomy: off-medication dyskinesia in the treated arm (one patient, almost resolved by 6 months); on-medication dyskinesia in the treated arm (one patient, resolved after levodopa dose reduction); and subjective speech disturbance (one patient). Four of the adverse events present at 6 months were related to medical management (anxiety and fatigue [one patient each] and weight gain [two patients]). The most frequent adverse events were transient gait ataxia (related to subthalamotomy, six patients), transient pin-site head pain (related to the head frame, six patients), and transient high blood pressure (during the procedure, five patients). Transient facial asymmetry (one patient) and moderate impulsivity (two patients) were also recorded. The mean MDS–UPDRS III score in the treated hemibody improved by 53% from baseline to 6 months in the off-medication state (16·6 [SD 2·9] vs 7·5 [3·9]) and by 47% in the on-medication state (11·9 [3·1] vs 5·8 [3·5]). MRI-guided focused ultrasound unilateral subthalamotomy was well tolerated and seemed to improve motor features of Parkinson's disease in patients with noticeably asymmetric parkinsonism. Large randomised controlled trials are necessary to corroborate these preliminary findings and to assess the potential of such an approach to treat Parkinson's disease. Fundación de investigación HM Hospitales and Insightec.

High-frequency (HF) transcranial magnetic stimulation (rTMS) of the left dorsolateral prefrontal cortex (DLPFC) is widely used in Major Depressive Episode (MDE). Optimization of its efficacy with a neuro-navigation system has been proposed based on a small randomized controlled trial (RCT) supporting a large effect. This evaluator- and patient-blind, multicenter RCT assessed the superiority in terms of efficacy of 10 HF rTMS sessions of the left DLPFC targeted with MRI based neuro-navigation versus similar sessions targeted by the standard 5 cm technique. The study was conducted between January 2013 and April 2017, at 4 hospitals centers in France where both in- and out- patients with MDE were included. Randomization was computer-generated (1:1), with allocation concealment implemented within the e-CRF. The main outcome measure was the percentage of responders 44 days (D44) after the rTMS session. Secondary outcomes were percentage of remitters, Beck Depression Inventory and psychomotor retardation assessed with Salpêtrière retardation rating scale (SRRS) for depression at D14 and D44. The results are presented along with their 95% confidence intervals. 105 patients were randomized and 92 were evaluable with respectively 45 patients in the neuronavigation group and 47 in the standard group. A treatment response was observed for 14 (31.8%) of 44 patients analyzed in the intervention group, and for 16 (35.6%) of 45 patients analyzed in the control group with no statistical difference (relative risk 0.89; 95% confidence interval, [0.50;1.61]). No difference was evidenced for secondary outcomes at D44 whether it concerns remission at D44 (relative risk, 0.82; 95% CI, 0.36 to 1.88), or BDI results (difference in means, 0,01; 95% CI, -3.06 to 3.26), or SRRS results (difference in means, 0.11; 95% CI, -2.42 to 5.02). Similar results were observed at D14. Rates of adverse events were similar in both groups with 23 (47.9%) and 1 (2.1%) of adverse events and serious adverse events in the neuro-navigation group versus 20 (40.8%) and 0 (0%) in the standard group. This study failed to reproduce previous findings supporting the use of neuro-navigation system to optimize rTMS efficacy. Limitations of this study includes a small sample size and a number of rTMS sessions that may appear substandard in 2025. NCT01677078.

Even though robotic technology holds great potential for performing spinal surgery and advancing neurosurgical techniques, it is of utmost importance to establish its practicality and to demonstrate better clinical outcomes compared with traditional techniques, especially in the current cost-effective era. Several systems have proved to be safe and reliable in the execution of tasks on a routine basis, are commercially available, and are used for specific indications in spine surgery. However, workflow, usability, interdisciplinary setups, efficacy, and cost-effectiveness have to be proven prospectively. This article includes a short description of robotic structures and workflow, followed by preliminary results of a randomized prospective study comparing conventional free-hand techniques with routine spine navigation and robotic-assisted procedures. Additionally, we present cases performed with a spinal robotic device, assessing not only the accuracy of the robotic-assisted procedure but also other factors (eg, minimal invasiveness, radiation dosage, and learning curves). Currently, the use of robotics in spinal surgery greatly enhances the application of minimally invasive procedures by increasing accuracy and reducing radiation exposure for patients and surgeons compared with standard procedures. Second-generation hardware and software upgrades of existing devices will enhance workflow and intraoperative setup. As more studies are published in this field, robot-assisted therapies will gain wider acceptance in the near future.

Background Despite the widespread use of external ventricular drainage, revision rates, and associated complications are reported between 10 and 40%. Current available image-guided techniques using stereotaxy, endoscopy, or ultrasound for catheter placements remain time-consuming techniques. Recently, a smartphone-assisted guide with high precision has been described. The development of an easy-to-use, portable, image-guided system could reduce the need for multiple passes and improve the rate of accurate catheter placement. This study aims to prospectively compare in a randomized controlled manner the accuracy of the freehand pass technique versus an easy-to-use, portable, adjustable guiding device for ventriculostomy catheter placement. Methods/Design This is a single center, prospective, randomized trial with a blinded endpoint (ventricular catheter tip location) assessment. Adult patients with the indication for ventriculostomy, as proven by computed tomography (CT), will be randomly assigned to the treatment group or the control group. For patients in the treatment group, ventriculostomy will be performed using an adjustable guiding device and DICOM (Digital Imaging and Communications in Medicine) image-reading software assistance (for example, using a mini-tablet) based on preoperative CT imaging. Patients in the control group will receive standard freehand ventriculostomy using anatomical landmarks. The catheter may be placed for external drainage or internal (ventriculoperitoneal) shunting in both groups. The primary outcome measure is the rate of correct placements of the ventricular catheter, defined as a score of 1 to 3 on grading system for catheter tip location on a postoperative CT scan. Participants will be followed for the duration of hospital stay, an expected average of two weeks. The primary outcome will be determined by one of the authors blinded to the treatment allocation. We aim to include 236 patients in three years. Secondary outcome measures include: frequency of placements required, frequency of completed placements within the ventricle of the perforated part of the catheter tip, frequency of very early and early shunt failures (revision of the ventricular drainage within 24 hours and within the hospital stay), frequency and percentage of complications (procedure-related and nonsurgical) at discharge. Discussion This is the study design of a single center, prospective, randomized controlled trial to investigate whether guided ventriculostomy is superior to the standard freehand technique. One strength of this study is the prospective, randomized, interventional type of study testing a new easy-to-handle guided versus freehand ventricular catheter placement. A second strength of this study is that the power calculation is based on catheter accuracy using an available grading system for catheter tip location, and is calculated with the use of recent study results of our own population, supported by data from prominent studies. Trial registration Clinicaltrials.gov identifier: NCT02048553 (registered on 28 January 2014).

Transcranial magnetic stimulation (TMS) guided by magnetic resonance imaging (MRI) has significantly advanced the treatment of mood disorders by enabling precise targeting of brain circuits implicated in their pathophysiology. The integration of neuronavigation systems, which utilize real‐time MRI‐based coil positioning, has improved spatial targeting accuracy, individualization, and therapeutic outcomes. Despite these advancements, achieving optimal stimulation efficacy requires careful consideration of MRI techniques, including anatomical imaging, functional MRI (fMRI), and connectivity‐based methods. Anatomical MRI provides a reliable structural foundation for neuronavigation but lacks specificity regarding functional neural networks implicated in mood disorders. In contrast, fMRI, through task‐based and resting‐state paradigms, enhances target selection precision by identifying patient‐specific neural activity and functional connectivity patterns, although this approach is vulnerable to variability and imaging artifacts. Connectivity‐based MRI neuronavigation represents a promising advancement by explicitly targeting disrupted neural networks. This review critically examines recent technological and methodological progress in MRI‐guided neuronavigation for TMS, addressing current challenges such as image acquisition quality, co‐registration accuracy, artifact mitigation, and practical constraints in clinical settings. Finally, it discusses emerging opportunities and innovations poised to enhance neuronavigation precision, foster wider clinical adoption, and ultimately improve therapeutic outcomes in interventional psychiatry for mood disorders. Key Points MRI‐guided neuronavigation significantly improves TMS targeting accuracy and therapeutic outcomes in mood disorders by precisely mapping patient‐specific brain circuits. Optimal neuronavigation requires careful integration and management of anatomical, functional, and connectivity‐based MRI techniques, each with distinct strengths and challenges. Future improvements in MRI‐guided TMS depend on technological innovation, addressing current methodological limitations, and enhancing clinical usability for broader adoption. Neuronavigation‐based MRI‐guided TMS leverages high‐resolution anatomical and functional imaging to enhance targeting precision and therapeutic response in mood disorders. We review recent technical advances and practical considerations essential for optimizing image acquisition and coil placement, paving the way for broader clinical adoption of personalized TMS interventions.

ObjectIn the past, the accuracy of surface matching has been shown to be disappointing. We aimed to determine whether this had improved over the years by assessing application accuracy of current navigation systems, using either surface matching or point-pair matching.MethodsEleven patients, scheduled for intracranial surgery, were included in this study after a power analysis had shown this small number to be sufficient. Prior to surgery, one additional fiducial marker was placed on the scalp, the “target marker,” where the entry point of surgery was to be expected. Using one of three different navigation systems, two patient-to-image registration procedures were performed: one based on surface matching and one based on point-pair matching. Each registration procedure was followed by the digitization of the target marker’s location, allowing calculation of the target registration error. If the system offered surface matching improvement, this was always used; and for the two systems that routinely offer an estimate of neuronavigation accuracy, this was also recorded.ResultsThe error in localizing the target marker using point-pair matching or surface matching was respectively 2.49 mm and 5.35 mm, on average (p < 0.001). In those four cases where an attempt was made to improve the surface matching, the error increased to 6.35 mm, on average. For the seven cases where the system estimated accuracy, this estimate did not correlate with target registration error (R2 = 0.04, p = 0.67).ConclusionThe accuracy of navigation systems has not improved over the last decade, with surface matching consistently yielding errors that are twice as large as when point-pair matching with adhesive markers is used. These errors are not reliably reflected by the systems own prediction, when offered. These results are important to make an informed choice between image-to-patient registration strategies, depending on the type of surgery at hand.

Neuronavigation has become an intrinsic part of preoperative surgical planning and surgical procedures. However, many surgeons have the impression that accuracy decreases during surgery. To quantify the decrease of neuronavigation accuracy and identify possible origins, we performed a retrospective quality-control study. Between April and July 2011, a neuronavigation system was used in conjunction with a specially prepared head holder in 55 consecutive patients. Two different neuronavigation systems were investigated separately. Coregistration was performed with laser-surface matching, paired-point matching using skin fiducials, anatomic landmarks, or bone screws. The initial target registration error (TRE1) was measured using the nasion as the anatomic landmark. Then, after draping and during surgery, the accuracy was checked at predefined procedural landmark steps (Mayfield measurement point and bone measurement point), and deviations were recorded. After initial coregistration, the mean (SD) TRE1 was 2.9 (3.3) mm. The TRE1 was significantly dependent on patient positioning, lesion localization, type of neuroimaging, and coregistration method. The following procedures decreased neuronavigation accuracy: attachment of surgical drapes (DTRE2 = 2.7 [1.7] mm), skin retractor attachment (DTRE3 = 1.2 [1.0] mm), craniotomy (DTRE3 = 1.0 [1.4] mm), and Halo ring installation (DTRE3 = 0.5 [0.5] mm). Surgery duration was a significant factor also; the overall DTRE was 1.3 [1.5] mm after 30 minutes and increased to 4.4 [1.8] mm after 5.5 hours of surgery. After registration, there is an ongoing loss of neuronavigation accuracy. The major factors were draping, attachment of skin retractors, and duration of surgery. Surgeons should be aware of this silent loss of accuracy when using neuronavigation.

Background Optical neuronavigation systems using infrared light to create a virtual reality image of the brain allow the surgeon to track instruments in real time. Due to the high vulnerability of the brain, neurosurgical interventions must be performed with a high precision. The aim of the experimental cadaveric study was to determine the application accuracy of a frameless optical neuronavigation system as guide for craniotomies by determining the target point deviation of predefined target points at the skull surface in the area of access to the cerebrum, cerebellum and the pituitary fossa. On each of the five canine cadaver heads ten target points were marked in a preoperative computed tomography (CT) scan. These target points were found on the cadaver skulls using the optical neuronavigation system. Then a small drill hole (1.5 mm) was drilled at these points. Subsequently, another CT scan was made. Both CT data sets were fused into the neuronavigation software, and the actual target point coordinates were identified. The target point deviation was determined as the difference between the planned and drilled target point coordinates. The calculated deviation was compared between two observers. Results The analysis of the target point accuracies of all dogs in both observers taken together showed a median target point deviation of 1.57 mm (range: 0.42 to 5.14 mm). No significant differences were found between the observers or the different areas of target regions. Conclusion The application accuracy of the described system is similar to the accuracy of other optical neuronavigation systems previously described in veterinary medicine, in which mean values of 1.79 to 4.3 mm and median target point deviations of 0.79 to 3.53 mm were determined.

Purpose Neurosurgical biopsies require high accuracy and precision and are executed with image-guided surgical navigation. The current state-of-the-art techniques require markers, are displayed on a 2D screen, and have a time-consuming setup. We propose an AR-driven surgical navigation method that automatically projects a 3D virtual overlay onto a patient in real-time, without the use of any markers. Method Baseline accuracy of the proposed system and the StealthStation S8 was measured on a 3D printed human head phantom in a lab-based setting. For the measurements in the operating room, seventeen participants who underwent a neurosurgical biopsy with the StealthStation S8 were included. Prior to the clinical procedure, our proposed markerless AR system provided an automated three-dimensional virtual overlay onto the patient to the surgeon. By measuring the difference in the planned biopsy trajectory between the state-of-the-art StealthStation S8 and our experimental system, a comparison was made between the two systems. Results The average clinical error for the entry point of the proposed system was 4.5 ± 2.2 mm, which is lower than the total error of the current clinical gold standard found in literature. Conclusion The total error of the system proposed in this study reaches the gold standard for image-guided neuronavigation, in both lab-controlled and clinical settings. These initial results highlight the potential and advantages of AR over other methods, offering promising AR opportunities for future clinical applications.