Sandro M. Krieg

Universität Heidelberg · University Clinic for Neurosurgery

The use of intraoperative MRI (ioMRI) contributes to an improved extent of resection. Hybrid operating room MRI suites have been established, with the patient being transferred to the MRI scanner. In the present descriptive analysis, we compared the rate of surgical site infections (SSI) after intracranial tumor surgery with and without the use of...

This study tests the generalisability of three Brain Tumor Segmentation (BraTS) challenge models using a multi-center dataset of varying image quality and incomplete MRI datasets. In this retrospective study, DeepMedic, no-new-Unet (nn-Unet), and NVIDIA-net (nv-Net) were trained and tested using manual segmentations from preoperative MRI of gliobla...

Introduction The resection of brainstem cerebral cavernous malformations (CCM) harbors the risk of damaging the corticospinal tract (CST) and other major tracts. Hence, visualization of eloquent fiber tracts supports pre- and intraoperative planning. However, diffusion tensor imaging fiber tracking at brainstem level suffers from distortion due to...

BACKGROUND Intraoperative magnetic resonance imaging (ioMRI) is applied to improve the extent of resection in patients suffering from primary brain tumors, especially glioblastoma (GBM). While some older randomized trials reported data on safety and feasibility, ioMRI’s actual impact in a modern neurosurgical setting has not been sufficiently inves...

Introduction Decompressive craniectomy (DC) is the ultimate intervention to lower intracranial pressure (ICP) following severe traumatic brain injury (TBI). However, this intervention is associated with considerable adverse events and a higher proportion of survivors with poor functional outcomes. Research question In a multicompartment system ICP...

The neural representation of language can be identified cortically using navigated repetitive transcranial magnetic stimulation and subcortically using the fiber tracking of diffusion tensor imaging. We investigated how cortical locations of language and language-eloquent white matter pathways differ in 40 brain lesion patients speaking various lan...

Background and objectives: Three-dimensional imaging-based navigation in spine surgery is mostly applied for pedicle screw placement. However, its potential reaches beyond. In this study, we analyzed the incorporation of spinal navigation for lateral instrumentation of the thoracolumbar spine in clinical routine at a high-volume spine center. Met...

Intraoperative magnetic resonance imaging (ioMRI) aims to improve gross total resection (GTR) in glioblastoma (GBM) patients. Despite some older randomized data on safety and feasibility, ioMRI’s actual impact in a modern neurosurgical setting utilizing a larger armamentarium of techniques has not been sufficiently investigated to date. We therefor...

Introduction Lateral lumbar interbody fusion (LLIF) and lateral thoracic interbody fusion (LTIF), supported by intraoperative neuromonitoring (IONM), gained popularity as a mini-invasive alternatives for standard interbody fusion. The objective of this study was to investigate the clinical outcome in a large elderly patient cohort who underwent LTI...

OBJECTIVE Language-related networks have been recognized in functional maintenance, which has also been considered the mechanism of plasticity and reorganization in patients with cerebral malignant tumors. However, the role of interhemispheric connections (ICs) in language restoration remains unclear at the network level. Navigated transcranial mag...

OBJECTIVE Multiple solutions for navigation-guided pedicle screw placement are currently available. Intraoperative imaging techniques are invaluable for spinal surgery, but often there is little attention paid to patient radiation exposure. This study aimed to compare the applied radiation doses of sliding gantry CT (SGCT)– and mobile cone-beam CT...

Magnetic resonance imaging (MRI) in therapy-naïve intracranial glioma is paramount for neuro-oncological diagnostics, and it provides images that are helpful for surgery planning and intraoperative guidance during tumor resection, including assessment of the involvement of functionally eloquent brain structures. This study reviews emerging MRI tech...

Background Non-invasive measurement of intracranial pressure (ICP) has failed for decades. Yet, it would allow for proper evaluation of unconscious patients suffering from non-penetrating traumatic brain injury (TBI). Transcranial transmission ultrasound (TTUS) measurements provided promising experimental data via brain pulsatility. This study inve...

There are vast gaps in our understanding of the organization and operation of the human nervous system at the level of individual neurons and their networks. Here, we report reliable and robust acute multichannel recordings using planar microelectrode arrays (MEAs) implanted intracortically in awake brain surgery with open craniotomies that grant a...

Introduction: Intraoperative neuromonitoring (IOM) of motor/somatosensory evoked potentials is a well-established approach for reducing ischemic complications after aneurysm clipping. Research question: To determine the predictive validity of IOM for postoperative functional outcome and its perceived added value for intraoperative real-time feed...

Objective: Treatment strategies of patients suffering from pyogenic spondylodiscitis are a controverse topic. Percutaneous dorsal instrumentation followed by surgical debridement and fusion of the infectious vertebral disc spaces is a common approach for surgical treatment. Technical advances enable spinal navigation for dorsal and lateral instrum...

The review provides a comprehensive update (previous report: Chen R, Cros D, Curra A, Di Lazzaro V, Lefaucheur JP, Magistris MR, et al. The clinical diagnostic utility of transcranial magnetic stimulation: report of an IFCN committee. Clin Neurophysiol 2008;119(3):504-32) on clinical diagnostic utility of transcranial magnetic stimulation (TMS) in...

Purpose Radiolucent anterior and posterior implants by carbon fiber–reinforced polyetheretherketone (CFR PEEK) aim to improve treatment of primary and secondary tumors of the spine during the last years. The aim of this study was to evaluate clinical and radiological outcomes after dorsoventral instrumentation using a CFR PEEK implant in a cohort o...

BACKGROUND AND PURPOSE: Tractography of the corticospinal tract is paramount to presurgical planning and guidance of intraoperative resection in patients with motor-eloquent gliomas. It is well-known that DTI-based tractography as the most frequently used technique has relevant shortcomings, particularly for resolving complex fiber architecture. Th...

Purpose Patients undergoing spinal surgery require postoperative pain management to alleviate wound pain. Pain medication includes WHO grade 1 analgesic as well as potent opioids, potentially leading to cognitive decline. Up until now, the cognitive impairment is only poorly studied and difficult to monitor. We hereby investigate the feasibility of...

Purpose: Uncertainties remain about the safety and efficacy of therapies for managing intracranial hypertension in acute brain injured (ABI) patients. This study aims to describe the therapeutical approaches used in ABI, with/without intracranial pressure (ICP) monitoring, among different pathologies and across different countries, and their assoc...

Background: Resection of brain metastases (BM) close to motor structures is challenging for treatment. Navigated transcranial magnetic stimulation (nTMS) motor mapping, combined with diffusion tensor imaging (DTI)-based fiber tracking (DTI-FTmot.TMS), is a valuable tool in neurosurgery to preserve motor function. This study aimed to assess the pra...

Background: Resection followed by local radiation therapy (RT) is the standard of care for symptomatic brain metastases. However, the optimal technique, fractionation scheme and dose are still being debated. Lately, low-energy X-ray intraoperative RT (lex-IORT) has been of increasing interest. Method: Eighteen consecutive patients undergoing BM...

Objective Pedicle screw-based posterior instrumentation of the spine.IndicationsInstability of the spine due to trauma, infection, degenerative spinal disease or tumor.ContraindicationsNone.Surgical techniqueRobot-assisted navigated pedicle screw placement.Postoperative managementEarly functional mobilization starting on the first postoperative day...

Objective: In adult patients, an increasing group of neurosurgeons specialize entirely in the treatment of highly eloquent tumors, particularly gliomas. In contrast, extensive perioperative neurophysiological workup for pediatric cases has been limited essentially to epilepsy surgery. Methods: The authors discuss radio-oncological and general on...

COVER ILLUSTRATION A landmark work that first extracts and constructs spatio‐temporal features to diagnose dementia based on Graph Neural Network.

Background Although the world is experiencing a deficit in the neurosurgical workforce, the number of neurosurgeons in Germany has increased within the last two decades. The aim of the present study was to assess the neurosurgical workforce in Germany, compare it to European countries, and assess structures in neurosurgical departments in Germany....

BACKGROUND Resection of brain metastases (BM) close to the motor cortex and the corticospinal tract (CST) bears a significant risk for treatment-related morbidity. Navigated transcranial mapping (nTMS) combined with diffusion-tensor-imaging (DTI) based fiber tracking (DTI-FTTMS) is a valuable tool to guide the neurosurgeon along the CST to preserve...

Human single-unit studies currently rely on neurosurgical procedures that provide only limited brain coverage and on recording devices that do not integrate easily into established surgical routines. Here, we report reliable and robust acute multi-channel recordings with broad cortical access using planar microelectrode arrays (MEA) implanted intra...

Background: Management of high-grade gliomas (HGGs) close to motor areas is challenging due to the risk of treatment-related morbidity. Thus, for resection, functional mapping of the corticospinal tract (CST) with navigated transcranial magnetic stimulation (nTMS) combined with diffusion tensor imaging (DTI)-based fiber tracking (nTMS-DTI-FT) is in...

Background Fast-track surgical treatment of neurooncology patients is a multimodal approach aimed at reducing the length of hospital stay, and is gaining more and more importance in a resource-limited health care system.Objective This study aimed to analyze current evidence on fast-track surgery in neurooncology patients.Materials and methodsA syst...

Background Patients with lower-grade glioma (LGG) are often of working age. For LGG patients post-surgical work resumption is at risk from treatment including resective surgery. However, little is known on determinants of returning to work. In this study we examined determinants of post-surgical work resumption after nine months using patient- and...

Purpose The Working Group for Neurooncology of the German Society for Radiation Oncology (DEGRO; AG NRO) in cooperation with members of the Neurooncological Working Group of the German Cancer Society (DKG-NOA) aimed to define a practical guideline for the diagnosis and treatment of radiation-induced necrosis (RN) of the central nervous system (CNS)...

Purpose The Working Group for Neuro-Oncology of the German Society for Radiation Oncology in cooperation with members of the Neuro-Oncology Working Group of the German Cancer Society aimed to define a practical guideline for the diagnosis and treatment of radiation-induced necrosis (RN) of the central nervous system (CNS). Methods Panel members of...

Background: Repetitive neuromuscular magnetic stimulation (rNMS) of the trapezius muscles showed beneficial effects in preventing episodic migraine. However, clinical characteristics that predict a favorable response to rNMS are unknown. The objective of this analysis is to identify such predictors. Methods: Thirty participants with a diagnosis of...

Glioma resection within language‐eloquent regions poses a high risk of surgery‐related aphasia (SRA). Preoperative functional mapping by navigated transcranial magnetic stimulation (nTMS) combined with diffusion tensor imaging (DTI) is increasingly used to localize cortical and subcortical language‐eloquent areas. This study enrolled 60 nonaphasic...

Navigated repetitive transcranial magnetic stimulation (nrTMS) is an innovative technique that provides insight into language function with high accuracy in time and space. So far, nrTMS has mainly been applied in presurgical language mapping of patients with intracranial neoplasms. For the present study, nrTMS was used for language mapping in prim...

OBJECTIVE Healthcare digitization has led to increasing tablet-based apps to improve diagnostics, self-discipline, and well-being in patients. Moreover, patient-reported outcome measures are crucial for optimized treatment, with superior applicability if independent from patient visits. Whereas most uses cover health maintenance, only a few studies...

Purpose In the surgical treatment of osteoporotic spine fractures, there is no clear recommendation, which treatment is best for the individual patient with vertebra plana and/or neurological deficit requiring instrumentation. The aim of this study was to evaluate clinical and radiological outcomes after dorsal or 360° instrumentation of osteoporot...

Background: Management of high-grade gliomas (HGGs) close to motor areas is challenging due to the risk of treatment-related morbidity. Thus, for resection, functional mapping of the corticospinal tract (CST) with navigated transcranial magnetic stimulation (nTMS) combined with diffusion tensor imaging (DTI)-based fiber tracking (DTI-FTTMS) is inc...

COVER ILLUSTRATION The image shows a left frontal glioma (brown) with cortical language areas identified via navigated transcranial magnetic stimulation (nTMS) (purple) non‐invasively. Language‐involved subcortical fiber tracts, such as the superior longitudinal fascicle I‐III, uncinate fascle, inferior frontooccipital fascicle and corticobulbar fi...

Introduction Surgical treatment for CCS in patients with an underlying cervical stenosis without instability remains controversial. Research question The aim was to assess the incidence of concomitant discoligamentous injury (DLI) in patients with CCS and underlying degenerative cervical spinal stenosis and to determine the sensitivity of MRI by c...

Objective: Preoperative fiber tracking (FT) enables visualization of white matter pathways. However, the intraoperative accuracy of preoperative image registration is reduced due to brain shift. Intraoperative FT is currently considered the standard of anatomical accuracy, while intraoperative imaging can also be used to correct and update preoper...

We present three cases fulfilling diagnostic criteria of hemorrhagic variants of acute disseminated encephalomyelitis (acute hemorrhagic encephalomyelitis, AHEM) occurring within 9 days after the first shot of ChAdOx1 nCoV-19. AHEM was diagnosed using magnetic resonance imaging, cerebrospinal fluid analysis and brain biopsy in one case. The close t...

We present three cases fulfilling diagnostic criteria of hemorrhagic variants of acute disseminated encephalomyelitis (acute hemorrhagic encephalomyelitis, AHEM) occurring within 9 days after the first shot of ChAdOx1 nCoV-19. AHEM was diagnosed using magnetic resonance imaging, cerebrospinal fluid analysis and brain biopsy in one case. The close t...

Intraoperative neurophysiological monitoring of transcranial motor-evoked potentials (tcMEPs) may fail to produce a serviceable signal due to displacements by mass lesions. We hypothesize that navigated placement of stimulation electrodes yields superior potential quality for tcMEPs compared to the conventional 10–20 placement. We prospectively inc...

Purpose Due to the lack of consensus on the management of glioblastoma patients, there exists variability amongst surgeons and centers regarding treatment decisions. Though, objective data about the extent of this heterogeneity is still lacking. We aim to evaluate and analyze the similarities and differences in neurosurgical practice patterns. Met...

Background Mapping techniques are frequently used to preserve neurological function during glioma surgery. There is however no consensus regarding the use of many variables of these techniques. Currently, there is almost no objective data available about potential heterogeneity between surgeons and centers. The goal of this survey is therefore to g...

Background Perioperative assessment of language function in brain tumor patients commonly relies on administration of object naming during stimulation mapping. Ample research, however, points to the benefit of adding verb tasks to the testing paradigm in order to delineate and preserve postoperative language function more comprehensively. This rese...

Argon has shown neuroprotective effects after traumatic brain injury (TBI) and cerebral ischemia in vitro and in focal cerebral ischemia in vivo. The purpose of this study is to show whether argon beneficially impacts brain contusion volume (BCV) as the primary outcome parameter, as well as secondary outcome parameters, such as brain edema, intracr...

Introduction To achieve a maximum extent of resection, intraoperative MRI (ioMRI) scan is frequently performed. Intraoperative diffusion-weighted imaging (DWI) is not standardly performed and has been described to be inferior to early postoperative MRI regarding the detection of ischemia. Research question This feasibility study evaluates the dete...

Over the past years navigated repetitive transcranial magnetic stimulation (nrTMS) had become increasingly important for the preoperative examination and mapping of eloquent brain areas. Among other applications it was demonstrated that the detection of neuropsychological function, such as arithmetic processing or face recognition, is feasible with...