Use of Compressed Sensing Accelerated, Low-Velocity Encoded, Isotropic Resolution, Phase Contrast Magnetic Resonance Angiography for SEEG Electrode Implantation

OBJECTIVE

We assessed the feasibility of using compressed sensing accelerated, low-velocity encoded, isotropic resolution phase contrast (CLIP) magnetic resonance angiography (MRA) for avascular trajectory planning of stereoelectroencephalography.

METHODS

Ten healthy subjects (1 woman and 9 men; age, 33.6 ± 9.0 years) and 20 consecutive patients (12 female patients; age, 22 ± 13.6 years) were enrolled in the present study. The healthy subjects underwent CLIP-MRA, and 3 other phase contrast MRA protocols with conventional parallel imaging (PI) acceleration, including low resolution with twofold PI (PI2), high resolution (HR) with fivefold PI (PI5), and HR-PI2. The patients underwent CLIP-MRA and computed tomography angiography (CTA). The image qualities were evaluated. The numbers and locations of trajectory-vessel conflict detected using CLIP-MRA were noted.

RESULTS

With similar scan durations, CLIP-MRA achieved higher spatial resolution compared with low resolution with PI2 and detected significantly more branches compared with HR-PI5. With the same spatial resolution, the signal/noise and contrast/noise ratios of CLIP-MRA were higher than those with HR-PI2 with a shorter scan duration. For the 12 adult patients (10 female patients; 28.8 ± 12.7 years), CLIP-MRA had better signal/noise and contrast/noise ratios than CTA. The trajectory had required modification for 14 of the 20 patients (70%), with a proportion of trajectory modification of 10.7% (23 of 215 electrodes). The middle meningeal artery, cortical vessel, and skull vessel were the main vessels with conflict (n = 11, n = 7, and n = 5, respectively).

CONCLUSIONS

In the present study, CLIP-MRA provided a clear cortical vascular display noninvasively without intravascular contrast and radiation. The middle meningeal artery and diploic and emissary veins were the main conflict vessels and could be clearly displayed using CLIP-MRA but not CTA.

Role of deep brain stimulation (DBS) in addiction disorders

Background

Addiction disorders pose significant challenges to public health, necessitating innovative treatments. This assesses deep brain stimulation (DBS) as a potential intervention for addiction disorders.

Methods

A literature review was carried out with a focus on the role of DBS in addiction disorders and its future implications in neurosurgical research.

Results

The online literature shows that DBS precisely modulates certain brain regions to restore addiction-related neural circuits and promote behavioral control.

Conclusion

Preclinical evidence demonstrates DBS's potential to rebalance neural circuits associated with addiction, and early clinical trials provide encouraging outcomes in enhancing addiction-related outcomes. Ethical considerations, long-term safety, and personalized patient selection require further investigation.

Combining ultrasound and microelectrode recordings for postoperative localization of subthalamic electrodes in Parkinson's disease

OBJECTIVE

To assess transcranial sonography (TCS) as stand-alone tool and in combination with microelectrode recordings (MER) as a method for the postoperative localization of deep brain stimulation (DBS) electrodes in the subthalamic nucleus (STN).

METHODS

Individual dorsal and ventral boundaries of STN (n = 12) were determined on intraoperative MER. Postoperatively, a standardized TCS protocol was applied to measure medio-lateral, anterior-posterior and rostro-caudal electrode position using visualized reference structures (midline, substantia nigra). TCS and combined TCS-MER data were validated using fusion-imaging and clinical outcome data.

RESULTS

Test-retest reliability of standard TCS measures of electrode position was excellent. Computed tomography and TCS measures of distance between distal electrode contact and midline agreed well (Pearson correlation; r = 0.86; p < 0.001). Comparing our "gold standard" of rostro-caudal electrode localization relative to STN boundaries, i.e. combining MRI-based stereotaxy and MER data, with the combination of TCS and MER data, the measures differed by 0.32 ± 0.87 (range, -1.35 to 1.25) mm. Combined TCS-MER data identified the clinically preferred electrode contacts for STN-DBS with high accuracy (Coheńs kappa, 0.86).

CONCLUSIONS

Combined TCS-MER data allow for exact localization of STN-DBS electrodes.

SIGNIFICANCE

Our method provides a new option for monitoring of STN-DBS electrode location and guidance of DBS programming in Parkinson's disease.

Pruritus and urticaria induced by neurostimulation: A case report and review of literature

BACKGROUND

Spinal cord stimulation (SCS) consists of the implantation of neuromodulatory devices in the spinal cord to treat refractory neuropathic pain. Although SCS technology has been proven of immense clinical benefit, complications remain including refractory pain, infection risk, and electrode migration or displacement. Till date, there are minimal reports of allergic side effects following SCS implantation.

CASE DESCRIPTION

In the first case, a 36-year-old male with chronic axial and radicular neuropathic pain in underwent implantation of an open paddle lead and generator. Within 1-3 h of activating the SCS, he developed diffuse raised erythematous hives. Over time, the SCS had immense clinical benefit for his pain reduction; however, he continued to experience recurrent hives and various other allergic reactions including facial flushing and photosensitivity. Four years later, he ultimately opted to retain the device for its clinical pain benefits. In the second case, a 35-year-old female with acute, intractable bilateral occipital neuralgia and a past medical history of Type 1 Chiari Malformation status-post-posterior fossa decompression underwent implantation of an occipital nerve stimulator (ONS). At 1-month follow-up, she began to experience pruritus across the back of her head and along the subcutaneous course of the lead. At 8 months, she continued to experience persistent symptoms, ultimately opting for device removal.

CONCLUSION

Although allergic reactions to implanted neurostimulation systems are rare, and mechanisms not completely understood, existing studies posit multiple theories surrounding the pathophysiology of allergic reactions to these devices, such as delayed hypersensitivity reactions or contact dermatitis. Further research is needed to elucidate the cutaneous and immunologic side effects of SCS and ONS devices.

Stereotactic neurosurgery as a symptomatic treatment for autism spectrum disorders: A systematic review

Stereotactic neurosurgery has been employed in autism spectrum disorders (ASD). However, its safety and effectiveness remain unclear owing to limited sample size and other methodological limitations. We aimed to systematically investigate the safety and efficacy of stereotactic neurosurgery for ASD. Eleven studies with 36 patients were included. Stereotactic neurosurgery alleviated the obsessive-compulsive disorder and aggressive behavior symptoms in ASD, with a mean improvement of 42.74% and 59.59% in the Yale-Brown Obsessive Compulsive Scale and Overt Aggression Scale scores, respectively. Systematic studies are necessary to explore the role of deep brain stimulation for social and communication difficulties in ASD.

Pilot study of a new type of machine vision-assisted stereotactic neurosurgery for EVD placement

BACKGROUND

The usage of machine vision technologies for image-based analysis and inspection is increasing. With the advent of the ability to process high-dimension data instantly, the possibilities of machine vision multiply exponentially. Robots now use this technology to assist in surgery.

OBJECTIVE

The aim of this study is to explore the efficacy of Surgical Navigation Robot NaoTrac (Brain Navi Biotechnology Co., Ltd.), which utilizes machine vision-inspired technology for patient registration and stereotactic external ventricular drainage (EVD) by the robotic arm.

METHODS

Preoperative and postoperative computed tomography (CT) scans were acquired for each case. The surgeons planned the targets and trajectories with the preoperative CT images. The postoperative CT images were utilized in the accuracy measurements.

RESULTS

All 14 cases had cerebrospinal fluid drained through the catheter. The NaoTrac placed the catheter into the frontal horn in one attempt in 13 cases and was able to drain CSF in 12 cases. Not a single case had any bleeding or intraoperative complications. The average time spent on the patient registration was 142.8 s. The mean target deviation was 1.68 mm, and the mean angular deviation was 1.99°, all within the accepted tolerance for minimal tissue damage.

CONCLUSION

The results of this report demonstrate that machine vision-inspired patient registration is feasible and fast. NaoTrac has demonstrated its accuracy and safety in performing frameless catheter placement in 13 clinical cases. Other stereotactic neurosurgical operations such as stereotactic biopsy, depth electrode placement, deep brain stimulation electrode positioning, and neuroendoscopy may also be benefited from the assistance of NaoTrac.

Pushing the boundaries of accuracy and reliability during stereotactic procedures: A prospective study on 526 biopsies comparing the frameless robotic and Image-Guided Surgery systems

INTRODUCTION

A 12-year long, prospective, single center study was conducted, comparing two frameless systems for brain biopsies: ROSA robotic-assisted stereotaxy and BrainLab Varioguide image-guided stereotaxy (Image Guided Surgery, IGS).

METHOD

All consecutive adult and pediatric patients undergoing frameless brain biopsies were included. Successfully achieving diagnosis was the primary endpoint, analysis of all periprocedural complications was the secondary endpoint, and the tertiary endpoint was the length of the procedure, with the aim of assessing of the learning curve for each operator over time. The results for the ROSA robot and the Varioguide system were compared and benchmarked to data from the literature.

RESULTS

We performed 526 on 516 patients, 314 with the ROSA robot (Group A) and 212 with the IGS Varioguide (Group B). Histological diagnosis was achieved in 97.4% of cases in Group A, versus 93.3% in Group B (p < 0.05). No statistically significant difference was found for secondary and tertiary endpoints. The complication rate appeared similar between the 2 frameless systems, with a hemorrhagic complications rate of 3.5% in Group A and 4.7% in Group B. Permanent neurological deterioration was only recorded in 0.8% of cases from Group B. Mortality was recorded in 0.3% in Group A and 0.4% in Group B.

CONCLUSION

This study provides evidence to confirm that robotic surgery lives up to its promises of increased safety, accuracy, and reliability.

Mobile intraoperative CT-assisted frameless stereotactic biopsies achieved single-millimeter trajectory accuracy for deep-seated brain lesions in a sample of 7 patients

Background

Brain biopsies are crucial diagnostic interventions, providing valuable information for treatment and prognosis, but largely depend on a high accuracy and precision. We hypothesized that through the combination of neuronavigation-based frameless stereotaxy and MRI-guided trajectory planning with intraoperative CT examination using a mobile unit, one can achieve a seamlessly integrated approach yielding optimal target accuracy.

Methods

We analyzed a total of 7 stereotactic biopsy trajectories for a variety of deep-seated locations and different patient positions. After rigid head fixation, an intraoperative pre-procedural scan using a mobile CT unit was performed for automatic image fusion with the planning MRI images and a peri-procedural scan with the biopsy cannula in situ for verification of the definite target position. We then evaluated the radial trajectory error.

Results

Intraoperative scanning, surgery, computerized merging of MRI and CT images as well as trajectory planning were feasible without difficulties and safe in all cases. We achieved a radial trajectory deviation of 0.97 ± 0.39 mm at a trajectory length of 60 ± 12.3 mm (mean ± standard deviation). Repositioning of the biopsy cannula due to inaccurate targeting was not required.

Conclusion

Intraoperative verification using a mobile CT unit in combination with frameless neuronavigation-guided stereotaxy and pre-operative MRI-based trajectory planning was feasible, safe and highly accurate. The setting enabled single-millimeter accuracy for deep-seated brain lesions and direct detection of intraoperative complications, did not depend on a dedicated operating room and was seamlessly integrated into common stereotactic procedures.

Extended stereotactic brain biopsy in suspected primary central nervous system angiitis: good diagnostic accuracy and high safety

OBJECTIVE

To evaluate the diagnostic accuracy and safety of extended stereotactic brain biopsy (ESBB) in a single center cohort with suspected primary angiitis of the central nervous system (PACNS).

METHODS

A standardized stereotactic biopsy targeting MRI-positive lesions and collecting samples from the meninges and the cortex as well as from the white matter was performed in 23 patients with clinically suspected PACNS between 2010 and 2017. The relationship between biopsy yield and clinical characteristics, cerebrospinal fluid parameters, MR-imaging, time point of biopsy and exact localization of biopsy as well as number of tissue samples were examined.

RESULTS

PACNS was confirmed in 7 of 23 patients (30.4%). Alternative diagnoses were identified in 7 patients (30%). A shorter time period between the onset or worsening of symptoms (p = 0.018) and ESBB significantly increased the diagnostic yield. We observed only minor and transient postoperative complications in 3 patients (13.0%). ESBB led to a direct change of the therapeutic regime in 13 of 23 patients (56.5%). Careful neuropathological analysis furthermore revealed that cortical samples were crucial in obtaining a diagnosis.

CONCLUSION

ESBB is a safe approach with good feasibility, even in critically ill patients, and high diagnostic accuracy in patients with suspected PACNS changing future therapies in 13 of 23 patients (56.5%). Early biopsy after symptom onset/worsening is crucial and (sub)acute MRI-lesions should be targeted with a particular need for biopsy samples from the cortical layer.

Accuracy and Safety of Customized Stereotactic Fixtures for Stereoelectroencephalography in Pediatric Patients

Stereoelectroencephalography (SEEG) in children with intractable epilepsy presents particular challenges. Their thin and partially ossified cranium, specifically in the temporal area, is prone to fracture while attaching stereotactic systems to the head or stabilizing the head in robot's field of action. Postponing SEEG in this special population of patients can have serious consequences, reducing their chances of becoming seizure-free and impacting their social and cognitive development. This study demonstrates the safety and accuracy offered by a frameless personalized 3D printed stereotactic implantation system for SEEG investigations in children under 4 years of age. SEEG was carried out in a 3-year-old patient with drug-resistant focal epilepsy, based on a right temporal-perisylvian epileptogenic zone hypothesis. Fifteen intracerebral electrodes were placed using a StarFix patient-customized stereotactic fixture. The median lateral entry point localization error of the electrodes was 0.90 mm, median lateral target point localization error was 1.86 mm, median target depth error was 0.83 mm, and median target point localization error was 1.96 mm. There were no perioperative complications. SEEG data led to a tailored right temporal-insular-opercular resection, with resulting seizure freedom (Engel IA). In conclusion, patient-customized stereotactic fixtures are a safe and accurate option for SEEG exploration in young children.

Oculomotor effects of medical and surgical treatments of Parkinson's disease

Oculomotor abnormalities are fast becoming a proxy for disease diagnosis and progression. Saccades-ballistic eye movements-are known to be affected by dopaminergic cell loss in the basal ganglia, caused by Parkinson's disease. Pharmaceutical and neurosurgical interventions such as deep brain stimulation and functional neurosurgery have both been noted to have an effect on saccades. Comparing and contrasting these effects may yield insights into Parkinson's disease pathophysiology, and the mechanisms of pharmacological and neurosurgical treatments. Computational models of saccadic control, such as the LATER model, can help to interpret the distribution of saccadic latencies, providing a framework for objectively comparing the effects of pharmaceutical interventions and deep brain stimulation.

Amygdala and Hypothalamus: Historical Overview With Focus on Aggression

Aggressiveness has a high prevalence in psychiatric patients and is a major health problem. Two brain areas involved in the neural network of aggressive behavior are the amygdala and the hypothalamus. While pharmacological treatments are effective in most patients, some do not properly respond to conventional therapies and are considered medically refractory. In this population, surgical procedures (ie, stereotactic lesions and deep brain stimulation) have been performed in an attempt to improve symptomatology and quality of life. Clinical results obtained after surgery are difficult to interpret, and the mechanisms responsible for postoperative reductions in aggressive behavior are unknown. We review the rationale and neurobiological characteristics that may help to explain why functional neurosurgery has been proposed to control aggressive behavior.

Stereotactic Systems for MRI-Guided Neurosurgeries: A State-of-the-Art Review

Recent technological developments in magnetic resonance imaging (MRI) and stereotactic techniques have significantly improved surgical outcomes. Despite the advantages offered by the conventional MRI-guided stereotactic neurosurgery, the robotic-assisted stereotactic approach has potential to further improve the safety and accuracy of neurosurgeries. This review aims to provide an update on the potential and continued growth of the MRI-guided stereotactic neurosurgical techniques by describing the state of the art in MR conditional stereotactic devices including manual and robotic-assisted. The paper also presents a detailed overview of MRI-guided stereotactic devices, MR conditional actuators and encoders used in MR conditional robotic-assisted stereotactic devices. The review concludes with several research challenges and future perspectives, including actuator and sensor technique, MR image guidance, and robot design issues.

Before and after the veterans affairs cooperative program 468 study: Deep brain stimulator target selection for treatment of Parkinson's disease

INTRODUCTION

The Veterans Affairs Cooperative Study Program 468 study (CSP 468) produced significant findings regarding deep brain stimulation (DBS) target selection for Parkinson's Disease (PD) treatment, yet its impact on clinical practices has not been described. Here we assess how CSP 468 influenced target selection at a high-volume movement disorders treatment center.

METHODS

We compared DBS target site selection between 4-year periods that immediately preceded and followed CSP 468 publication. Additionally, we examined how baseline clinical features influenced target selection following CSP 468.

RESULTS

The STN was the predominant site of DBS implantation before and after CSP 468 publication (93.2% of cases, and 60.4%, respectively), but GPi targeting increased significantly following CSP 468 publication (from 5.3% to 37.4%; p < .001). Patients who underwent GPi stimulation following CSP 468 exhibited worse indices of depression (p < .001), less responsiveness to medications (p < .05), and a trend towards worse pre-operative cognitive performance (p = .06). In multi-variate analysis, advanced patient age and depression were independent predictors of GPi targeting (p < .01).

CONCLUSIONS

Key findings of CSP 468 were reflected in our target selection of DBS for Parkinson's Disease. Following CSP 468, GPi targeting increased, and it was selected for patients with poorer cognitive and mood indices.

Feasibility of stereotactic catheter ventriculocisternostomy for cisternal lavage therapy in patients with subarachnoid hemorrhage

OBJECTIVE

Delayed cerebral infarction (DCI) confers considerable morbidity and mortality after aneurysmal subarachnoid hemorrhage (aSAH). Available prevention strategies are insufficient. Cisternal blood clearance by stereotactic catheter ventriculocisternostomy (STX-VCS) and cisternal lavage therapy is a novel concept for DCI prevention. Here, we assess the general feasibility, pitfalls and imaging requirements of STX-VCS after aSAH.

PATIENTS AND METHODS

73 aSAH patients admitted between 2008 and 2015 with appropriate imaging for simulation of stereotactic procedures were included. Surgical feasibility of a transventricular trajectory to the basal cisterns was assessed.

RESULTS

Transventricular catheter access to the basal cisterns was feasible in 94% of cases. In 6% vascular obstacles precluded a transventricular approach and access to the basal cisterns could be simulated via a transparenchymal trajectory. CT-artifacts that interfered with stereotactic planning were observed in 58% after coiling and 5% after clipping. In these cases stereotactic planning was enabled by MRI. Logistic regression of aneurysm size and distance-to-target allowed for precise prediction whether MRI was required for stereotactic planning of STX-VCS after coiling.

CONCLUSIONS

Stereotactic catheter access to the basal cisterns after aSAH appears to be generally feasible. Coil artifacts compromising CT-based planning can be precisely anticipated and planning enabled by MRI.

Accuracy of Intraoperative Computed Tomography during Deep Brain Stimulation Procedures: Comparison with Postoperative Magnetic Resonance Imaging

OBJECTIVE

To determine the accuracy of intraoperative computed tomography (iCT) in localizing deep brain stimulation (DBS) electrodes by comparing this modality with postoperative magnetic resonance imaging (MRI).

BACKGROUND

Optimal lead placement is a critical factor for the outcome of DBS procedures and preferably confirmed during surgery. iCT offers 3-dimensional verification of both microelectrode and lead location during DBS surgery. However, accurate electrode representation on iCT has not been extensively studied.

METHODS

DBS surgery was performed using the Leksell stereotactic G frame. Stereotactic coordinates of 52 DBS leads were determined on both iCT and postoperative MRI and compared with intended final target coordinates. The resulting absolute differences in X (medial-lateral), Y (anterior-posterior), and Z (dorsal-ventral) coordinates (ΔX, ΔY, and ΔZ) for both modalities were then used to calculate the euclidean distance.

RESULTS

Euclidean distances were 2.7 ± 1.1 and 2.5 ± 1.2 mm for MRI and iCT, respectively (p = 0.2).

CONCLUSION

Postoperative MRI and iCT show equivalent DBS lead representation. Intraoperative localization of both microelectrode and DBS lead in stereotactic space enables direct adjustments. Verification of lead placement with postoperative MRI, considered to be the gold standard, is unnecessary.

Ultra-High Field Template-Assisted Target Selection for Deep Brain Stimulation Surgery

BACKGROUND

Template and atlas guidance are fundamental aspects of stereotactic neurosurgery. The recent availability of ultra-high field (7 Tesla) magnetic resonance imaging has enabled in vivo visualization at the submillimeter scale. In this Doing More with Less article, we describe our experiences with integrating ultra-high field template data into the clinical workflow to assist with target selection in deep brain stimulation (DBS) surgical planning.

METHODS

The creation of a high-resolution 7T template is described, generated from group data acquired at our center. A computational workflow was developed for spatially aligning the 7T template with standard clinical data and furthermore, integrating the derived imaging volumes into the surgical planning workstation.

RESULTS

We demonstrate that our methodology can be effective for assisting with target selection in 2 cases: unilateral internal pallidum DBS for painful dystonia and bilateral subthalamic nucleus DBS for Parkinson's disease.

CONCLUSIONS

In this article, we have described a workflow for the integration of high-resolution in vivo ultra-high field templates into the surgical navigation system as a means to assist with DBS planning. The method does not require any additional cost or time to the patient. Future work will include prospectively evaluating different templates and their impact on target selection.

History and Technical Approaches and Considerations for Ablative Surgery for Epilepsy

The history of epilepsy surgery is generally noted to have begun in 1886 with Victor Horsley's first report of craniotomies for posttraumatic epilepsy. With increased understanding of brain function and development of electroencephalographic methods, nonlesional epilepsy began to be treated with resection in the 1950s. Methodological improvements and increased understanding of pathophysiology followed, and the advent of stereotaxy and ablative technology in the 1960s and 1970s heralded a new era of minimally invasive, targeted procedures for lesional and nonlesional epilepsy. Current techniques combine stereotactic methods, improved ablative technologies, and electroencephalographic methods for a multidisciplinary approach to the neurosurgical treatment of epilepsy.

The role of imaging in the development of neurosurgery

The development of modern neurosurgery was, and remains, intimately associated with developments in radiology. Neuroimaging advances have been instrumental in improving patient care and reducing both morbidity and mortality for neurosurgical patients. The purpose of this narrative review is to provide the contemporary neurosurgeon with an overview of the history of the development of radiology as applied to neurosurgery. The focus is on cranial imaging but the spine is also discussed. This article demonstrates the remarkable advancements that have shaped our modern surgical specialty. Today, almost 120 years after the discovery of the X-ray, the neurosurgeon has a wide array of neuroimaging tools at their disposal, that have led to better knowledge to inform diagnosis and management, selection of appropriate patients and surgical targets, as well as optimal surgical approaches. Modern neurosurgery is based on the appropriate use of these investigations. The pace of neuroimaging and neurosurgical advances continues and the future promises to be as, if not more, exciting as the past and present described in this paper.