Comparative analysis of intraoperative thermal and optical imaging for identification of the human primary sensory cortex.

Significance: The precise identification and preservation of functional brain areas during neurosurgery are crucial for optimizing surgical outcomes and minimizing postoperative deficits. Intraoperative imaging plays a vital role in this context, offering insights that guide surgeons in protecting critical cortical regions.

Aim: We aim to evaluate and compare the efficacy of intraoperative thermal imaging (ITI) and intraoperative optical imaging (IOI) in detecting the primary somatosensory cortex, providing a detailed assessment of their potential integration into surgical practice.

Clinical confocal laser endomicroscopy for imaging of autofluorescence signals of human brain tumors and non-tumor brain.

Purpose: Analysis of autofluorescence holds promise for brain tumor delineation and diagnosis. Therefore, we investigated the potential of a commercial confocal laser scanning endomicroscopy (CLE) system for clinical imaging of brain tumors.

Methods: A clinical CLE system with fiber probe and 488 nm laser excitation was used to acquire images of tissue autofluorescence.

Technical challenges and outcomes of stereotactic biopsies in the posterior fossa: Experience with ZD-inomed and leksell vantage frames.

Introduction: Stereotactic brain biopsies are essential for obtaining tissue samples from brain lesions, crucial for comprehensive histological analysis and subsequent adjuvant therapies. While most biopsies target supratentorial lesions, those involving the posterior fossa are less frequent but pose significant technical and surgical challenges, necessitating careful patient management.

Methods: We present our experience with stereotactic biopsies of the posterior fossa using the Leksell Vantage frame (Elekta, Stockholm, Sweden) and the ZD Inomed frame (Inomed Medizintechnik GmbH, Emmendingen, Germany).

Raman and autofluorescence spectroscopy for in situ identification of neoplastic tissue during surgical treatment of brain tumors.

Purpose: Raman spectroscopy (RS) is a promising method for brain tumor detection. Near-infrared autofluorescence (AF) acquired during RS provides additional useful information for tumor identification and was investigated in comparison with RS for delineating brain tumors in situ.

Methods: Raman spectra were acquired together with AF in situ within the solid tumor and at the tumor border during routine brain tumor surgeries (218 spectra; glioma WHO II-III, n = 6; GBM, n = 10; metastases, n = 10; meningioma, n = 3).

Morbidity Milestones Demonstrate Long Disability-Free Survival in Parkinson's Disease Patients with Deep Brain Stimulation of the Subthalamic Nucleus.

Background: Deep brain stimulation of the subthalamic nucleus (STN-DBS) is an effective treatment for Parkinson's disease (PD). The long-term benefit in PD patients with STN-DBS in comparison to medical treatment (MT) alone has not yet been demonstrated conclusively.

Objectives: To judge the long-term outcome of patients with STN-DBS.

A new approach for clinical translation of infrared spectroscopy: exploitation of the signature of glioblastoma for general brain tumor recognition.

Purpose: Infrared (IR) spectroscopy has the potential for tumor delineation in neurosurgery. Previous research showed that IR spectra of brain tumors are generally characterized by reduced lipid-related and increased protein-related bands. Therefore, we propose the exploitation of these common spectral changes for brain tumor recognition.

Topographic Mapping of the Primary Sensory Cortex Using Intraoperative Optical Imaging and Tactile Irritation.

The determination of exact tumor boundaries within eloquent brain regions is essential to maximize the extent of resection. Recent studies showed that intraoperative optical imaging (IOI) combined with median nerve stimulation is a helpful tool for visualization of the primary sensory cortex (PSC). In this technical note, we describe a novel approach of using IOI with painless tactile irritation to demonstrate the feasibility of topographic mapping of different body regions within the PSC.

Serum neurofilament indicates that DBS surgery can cause neuronal damage whereas stimulation itself does not.

Deep brain stimulation (DBS) is a potent symptomatic therapy for Parkinson's disease, but it is debated whether it causes or prevents neurodegeneration. We used serum neurofilament light chain (NFL) as a reporter for neuronal damage and found no difference between 92 patients with chronic STN-DBS and 57 patients on best medical treatment. Serum NFL transiently increased after DBS surgery whereas the initiation of STN stimulation did not affect NFL levels, suggesting that DBS surgery can be associated with neuronal damage whereas stimulation itself is not.

Characterization of cortical hemodynamic changes following sensory, visual, and speech activation by intraoperative optical imaging utilizing phase-based evaluation methods.

Alterations within cerebral hemodynamics are the intrinsic signal source for a wide variety of neuroimaging techniques. Stimulation of specific functions leads due to neurovascular coupling, to changes in regional cerebral blood flow, oxygenation and volume. In this study, we investigated the temporal characteristics of cortical hemodynamic responses following electrical, tactile, visual, and speech activation for different stimulation paradigms using Intraoperative Optical Imaging (IOI).

Vestibular Schwannoma Surgery: Outcome and Complications in Lateral Decubitus Position versus Semi-sitting Position-A Personal Learning Curve in a Series of 544 Cases over 3 Decades.

Objective: To retrospectively evaluate influence of intraoperative positioning (semisitting vs. lateral decubitus) and surgeon's learning curve with regard to functional outcome of patients with vestibular schwannoma.

Methods: This study included 544 patients (median age 57 years) and spanned 3 decades: 1991-1999 (n = 103), 2000-2009 (n = 210), and 2010-2019 (n = 231).

Parcellation of the Subthalamic Nucleus in Parkinson's Disease: A Retrospective Analysis of Atlas- and Diffusion-Based Methods.

Background: Deep brain stimulation (DBS) is an established method of treatment for Parkinson's disease (PD). A stimulation sweet spot at the interface between the motor and associative clusters of the subthalamic nucleus (STN) has recently been postulated. The aim of this study was to analyze the available clustering methods for the STN and their correlation to outcome.

Workflow and hardware for intraoperative hyperspectral data acquisition in neurosurgery.

To prevent further brain tumour growth, malignant tissue should be removed as completely as possible in neurosurgical operations. Therefore, differentiation between tumour and brain tissue as well as detecting functional areas is very important. Hyperspectral imaging (HSI) can be used to get spatial information about brain tissue types and characteristics in a quasi-continuous reflection spectrum.

Comparison of Automatic Segmentation Algorithms for the Subthalamic Nucleus.

Introduction: Various automatic segmentation algorithms for the subthalamic nucleus (STN) have been published recently. However, most of the available software tools are not approved for clinical use.

Objective: The aim of this study is to evaluate a clinically available automatic segmentation tool of the navigation planning software Brainlab Elements (BL-E) by comparing the output to manual segmentation and a nonclinically approved research method using the DISTAL atlas (DA) and the Horn electrophysiological atlas (HEA).

Mapping of language and motor function during awake neurosurgery with intraoperative optical imaging.

Intraoperative optical imaging (IOI) is a marker-free, contactless, and noninvasive imaging technique that is able to visualize metabolic changes of the brain surface following neuronal activation. Although it has been used in the past mainly for the identification of functional brain areas under general anesthesia, the authors investigated the potential of the method during awake surgery. Measurements were performed in 10 patients who underwent resection of lesions within or adjacent to cortical language or motor sites.

[Accreditation and digitization - just a load of crap? Systematic risk analysis among medical employees - today and 12 years ago].

Background: The aim of this study was to elucidate whether measures of quality management and digitization have the potential to reduce treatment risks in patients of a surgical clinic.

Methods: All health professional involved in the treatment of patients were asked to participate in a systematic, process-orientated and anonymous survey to assess the probability of occurrence of 69 treatment risks in stationary patients. The surveys were conducted in 2006 before establishing quality management (QM) and digitization, and recently after various certification activities have been performed and the digitization has been completed.

Somatosensory functional MRI tractography for individualized targeting of deep brain stimulation in patients with chronic pain after brachial plexus injury.

Background: The optimal targets for deep brain stimulation (DBS) in patients with refractory chronic pain are not clearly defined. We applied sensory functional MRI (fMRI)- and diffusion tensor imaging (DTI)-based DBS in chronic pain patients into 3 different targets to ascertain the most beneficial individual stimulation site.

Methods: Three patients with incapacitating chronic pain underwent DBS into 3 targets (periventricular gray (PVG), ventroposterolateral thalamus (VPL), and posterior limb of the internal capsule according to fMRI and DTI (PLIC).

Clinical Validation of Quality Improvements Using the Six Sigma Concept: A Case Study for Deep Brain Stimulation in Parkinson's Disease.

Background: The Six Sigma concept allows for the evaluation of quality changes after the implementation of new technical equipment or adjustment of perioperative procedures. Exemplarily, we applied this method for quality assessment in deep brain stimulation surgery (DBS) for Parkinson's disease.

Methods: The medical procedure and possible errors were registered.

Application of the Six Sigma concept for quality assessment of different strategies in DBS surgery.

Background: For quality analysis, we applied the Six Sigma concept to define quality indicators and their boundaries as well as to compare treatment-dependent outcome data of deep brain stimulation (DBS) of the subthalamic nucleus (STN) in patients with Parkinson's disease (PD).

Methods: The Unified Parkinson Disease Rating Scale (UPDRS) III with on medication and on stimulation, the reduction of daily levodopa equivalence doses (LED), and the stimulation amplitude 1 year after surgery were registered. Regarding the results of the EARLYSTIM study, sigma values for applicable studies were calculated and compared.

Intraoperative optical imaging of metabolic changes after direct cortical stimulation - a clinical tool for guidance during tumor resection?

Brain tumor resection is even today one of the most challenging disciplines in neurosurgery. The current state of the art for the identification of tumor tissue during the surgical procedure comprises a wide variety of different tools, each with its own limitations and drawbacks. In this paper, we present a novel approach, the use of optical imaging in connection with direct electrical cortical stimulation (DCS), for identification of impaired tumor tissue and functional intact normal brain tissue under intraoperative conditions.

Probabilistic Tractography of the Cranial Nerves in Vestibular Schwannoma.

Objective: Multiple recent studies have reported on diffusion tensor-based fiber tracking of cranial nerves in vestibular schwannoma, with conflicting results as to the accuracy of the method and the occurrence of cochlear nerve depiction. Probabilistic nontensor-based tractography might offer advantages in terms of better extraction of directional information from the underlying data in cranial nerves, which are of subvoxel size.

Methods: Twenty-one patients with large vestibular schwannomas were recruited.

Comparison of probabilistic and deterministic fiber tracking of cranial nerves.

OBJECTIVE The depiction of cranial nerves (CNs) using diffusion tensor imaging (DTI) is of great interest in skull base tumor surgery and DTI used with deterministic tracking methods has been reported previously. However, there are still no good methods usable for the elimination of noise from the resulting depictions. The authors have hypothesized that probabilistic tracking could lead to more accurate results, because it more efficiently extracts information from the underlying data.

ActiGait implantable drop foot stimulator in multiple sclerosis: a new indication.

OBJECTIVE Direct stimulation of the peroneal nerve by the ActiGait implantable drop foot stimulator is a potent therapy that was described previously for stroke-related drop foot. The authors report here successful long-term application of the ActiGait implantable drop foot stimulator in patients with multiple sclerosis (MS). METHODS Six patients with MS and 2 years of persisting central leg paresis received an implantable ActiGait drop foot stimulator after successful surface test stimulation.