Brain vascularization in deep brain stimulation surgeries: epilepsy, Parkinson's disease, and obsessive-compulsive disorder.

BACKGROUND: In our experience, we encountered more blood vessels during deep brain stimulation (DBS) surgeries in epilepsy. In this study, we have quantified and compared the cerebral vascularization in epilepsy, Parkinson's disease (PD) and obsessive-compulsive disorder (OCD). METHODS: A retrospective observational study in 15 epilepsy and 15 PD patients was performed. The amount, location, and size of blood vessels within 5 millimeters (mm) of all DBS electrode trajectories (N.=120) for both targets (anterior nucleus of the thalamus: ANT and subthalamic nucleus: STN) in both patient groups were quantified and compared on a Medtronic workstation (Dublin, Ireland). Additionally, blood vessels in the trajectories (N.=120) of another group of 15 PD (STN) and 15 OCD (ventral capsule-ventral striatum [VC-VS]) patients were quantified and compared (trajectories N.=120), also to the first group. Statistical analyses were performed with SPSS version 27.0 (descriptive statistics, independent samples t-tests, Mann Whitney U Test, ANOVA Test and post-hoc Tukey Test). A P value <0.05 was considered statistically significant. RESULTS: Our results showed a significant greater amount of cerebral blood vessels in epilepsy patients (10 SD±4) compared to PD (PD1 6 SD±1 and PD2 5 SD±3) and OCD (5 SD±1) with P<0.0001. Also, all other subanalyses showed more vascularization in the epilepsy group. CONCLUSIONS: Our results show that the brain of epilepsy patients seems to be more vascularized compared to PD and OCD patients. This can make the surgical planning for DBS more challenging, and the use of multiple trajectories limited.

Surgical and Hardware-Related Adverse Events of Deep Brain Stimulation: A Ten-Year Single-Center Experience.

INTRODUCTION: Although deep brain stimulation (DBS) is effective for treating a number of neurological and psychiatric indications, surgical and hardware-related adverse events (AEs) can occur that affect quality of life. This study aimed to give an overview of the nature and frequency of those AEs in our center and to describe the way they were managed. Furthermore, an attempt was made at identifying possible risk factors for AEs to inform possible future preventive measures. MATERIALS AND METHODS: Patients undergoing DBS-related procedures between January 2011 and July 2020 were retrospectively analyzed to inventory AEs. The mean follow-up time was 43 ± 31 months. Univariate logistic regression analysis was used to assess the predictive value of selected demographic and clinical variables. RESULTS: From January 2011 to July 2020, 508 DBS-related procedures were performed including 201 implantations of brain electrodes in 200 patients and 307 implantable pulse generator (IPG) replacements in 142 patients. Surgical or hardware-related AEs following initial implantation affected 40 of 200 patients (20%) and resolved without permanent sequelae in all instances. The most frequent AEs were surgical site infections (SSIs) (9.95%, 20/201) and wire tethering (2.49%, 5/201), followed by hardware failure (1.99%, 4/201), skin erosion (1.0%, 2/201), pain (0.5%, 1/201), lead migration (0.52%, 2/386 electrode sites), and hematoma (0.52%, 2/386 electrode sites). The overall rate of AEs for IPG replacement was 5.6% (17/305). No surgical, ie, staged or nonstaged, electrode fixation, or patient-related risk factors were identified for SSI or wire tethering. CONCLUSIONS: Major AEs including intracranial surgery-related AEs or AEs requiring surgical removal or revision of hardware are rare. In particular, aggressive treatment is required in SSIs involving multiple sites or when Staphylococcus aureus is identified. For future benchmarking, the development of a uniform reporting system for surgical and hardware-related AEs in DBS surgery would be useful.

Stereotactic accuracy and frame mounting: A phantom study.

BACKGROUND: Frame mounting is considered one of the most critical steps in stereotactic neurosurgery. In routine clinical practice, the aim is to mount the frame as symmetrical as possible, parallel to Reid's line. However, sometimes, the frame is mounted asymmetrically often due to patient-related reasons. METHODS: In this study, we addressed the question whether an asymmetrically mounted frame influences the accuracy of stereotactic electrode implantation. A Citrullus lanatus was used for this study. After a magnetic resonance imaging scan, symmetric and asymmetric mounting of the frame, which could occur in clinical scenarios, was performed with computed tomography (CT). Three different stereotactic software packages were used to analyze the results. In addition, manual calculations were performed by two different observers. RESULTS: Our results show that an asymmetrically mounted frame (deviated, tilted, or rotated) does not affect the accuracy in the mediolateral axis (X-coordinate) or the anteroposterior axis (Y-coordinate). However, it can lead to a clinically relevant error in the superoinferior axis (Z-coordinate). This error was largest with manual calculations. CONCLUSION: These results suggest that asymmetrical frame mounting can lead to stereotactic inaccuracy in the superoinferior axis (Z coordinate).

Perioperative Technical Complications in Deep Brain Stimulation Surgeries.

AIM: Deep brain stimulation (DBS) surgeries are multi-faceted and the various steps are interconnected. Since its first implementation, the method of DBS surgery has undergone changes. We have encountered several expected and also non-expected perioperative technical complications in the past seventeen years. Here, we describe the stereotactic frame, stereotactic localizer and planning station related complications and how we have managed them as much as possible. MATERIAL AND METHODS: This study is a retrospective qualitative analysis of the documented technical events encountered during DBS surgeries from 1999 onwards. We have collected these events from a cohort of approximately 921 DBS electrodes implantations from the centers of the authors. RESULTS: Stereotactic frame related complications included movement related fixation problems, head anatomy related problems, and lack of maintenance related issues. Localizer related complications were compatibility issues of the stereotactic localizer and planning station, field of view effect on fiducials, air bubbles in localizers using liquid solutions, and disengaged localizer effect. Planning station related complications included image fusion failures and cerebrospinal fluid signal effect on image fusion. CONCLUSION: The road to success in DBS therapy passes through the ability to cope with surgical and technical complications. Each step is unconditionally connected to the other, and detection of the problems that can be encountered in advance and preparations for these negative conditions are the key to success for the group responsible for executing the therapy. We are still learning from these events and advance our surgical approaches.

Infections in deep brain stimulation: Shaving versus not shaving.

BACKGROUND: To report our experience of infections in deep brain stimulation (DBS) surgeries comparing shaving versus no shaving of cranial hair. Nonshaving is strongly preferred by patients due to aesthetic and psychological factors. METHODS: This study is a prospective follow-up of the infection rate in 43 nonshaven DBS cases between April 2014 and December 2015 compared to our former infection rate with shaving in our center. Minimum follow-up was 6 months. All patients, except 7 epilepsy patients, received implantation of the electrodes together with the extension cables and internal pulse generator in one session. RESULTS: In 43 nonshaven patients, a total of 81 electrodes were implanted or revised with a mean follow-up of 16 months. One patient (2.32%) developed an infection of the implanted DBS-hardware and was treated with antibiotics. CONCLUSION: In our experience nonshaving of cranial hair in DBS surgery does not lead to more infections when compared to shaving. We have changed our protocol to nonshaving based on these findings.

A case of a brain stem abscess with a favorable outcome.

BACKGROUND: A brain stem abscess is a rare and severe medical condition. Here, we present a rare case of a brain stem abscess in a young pregnant woman, requiring acute stereotactic intervention. CASE DESCRIPTION: A 36-year-old woman presented with a headache, nausea, and vomiting, and computed tomography showed a space-occupying lesion in the brain stem. She became shortly after comatose, and we decided to perform an acute stereotactic aspiration of the abscess. Soon after surgery, her neurological condition improved dramatically. CONCLUSION: A brainstem abscess is a life-threatening condition with a potentially good outcome if treated adequately.