1
|
Karazapryanov PA, Gabrovski KR, Milenova Y, Pavlov VK, Karameshev A, Damianova M, Sirakov S, Minkin K. Mapping of Capsular Side Effects by using Intraoperative Motor-Evoked Potentials during Asleep Deep Brain Stimulation Surgery of the Subthalamic Nucleus for Parkinson's Disease. Stereotact Funct Neurosurg 2024; 102:248-256. [PMID: 38934180 DOI: 10.1159/000539433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 05/16/2024] [Indexed: 06/28/2024]
Abstract
INTRODUCTION The aim of this study was to present a novel technique for subthalamic nucleus (STN) deep brain stimulation (DBS) implantation under general anesthesia by using intraoperative motor-evoked potentials (MEPs) through direct lead stimulation and determining their correlation to the thresholds of postoperative stimulation-induced side effects. METHODS This study included 22 consecutive patients with advanced Parkinson's disease who underwent surgery in our institution between January 2021 and September 2023. All patients underwent bilateral implantation in the STN (44 leads) under general anesthesia without microelectrode recordings (MERs) by using MEPs with electrostimulation directly through the DBS lead. No cortical stimulation was performed during this process. Intraoperative fluoroscopic guidance and immediate postoperative computed tomography were used to verify the electrode's position. The lowest MEP thresholds were recorded and were correlated to the postoperative stimulation-induced side-effect threshold. The predictive values of the MEPs were analyzed. Five DBS leads were repositioned intraoperatively due to the MEP results. RESULTS A moderately strong positive correlation was found between the MEP threshold and the capsular side-effect threshold (RS = 0.425, 95% CI, 0.17-0.67, p = 0.004). The highest sensitivity and specificity for predicting a side-effect threshold of 5 mA were found to be at 2.4 mA MEP threshold (sensitivity 97%, specificity 87.5%, positive predictive value 97%, and negative predictive value 87.5%). We also found high sensitivity and specificity (100%) at 1.15 mA MEP threshold and 3 mA side-effect threshold. Out of the total 44 leads, 5 (11.3%) leads were repositioned intraoperatively due to MEP thresholds lower than 1 mA (4 leads) or higher than 5 mA (1 lead). The mean accuracy on postoperative CT was 1.05 mm, and there were no postoperative side-effects under 2.8 mA. CONCLUSION Intraoperative MEPs with electrostimulation directly through the contacts of the DBS lead correlate with the stimulation-induced capsular side effects. The lead reposition based on intraoperative MEP may enlarge the therapeutic window of DBS stimulation.
Collapse
Affiliation(s)
| | | | - Yoana Milenova
- Department of Neurosurgery, University Hospital St. Ivan Rilski, Sofia, Bulgaria
| | | | | | - Maria Damianova
- Department of Neurosurgery, University Hospital St. Ivan Rilski, Sofia, Bulgaria
| | - Stanimir Sirakov
- Department of Interventional Radiology, University Hospital St. Ivan Rilski, Sofia, Bulgaria
| | - Krasimir Minkin
- Department of Neurosurgery, University Hospital St. Ivan Rilski, Sofia, Bulgaria
| |
Collapse
|
2
|
Silva NA, Barrios-Martinez J, Yeh FC, Hodaie M, Roque D, Boerwinkle VL, Krishna V. Diffusion and functional MRI in surgical neuromodulation. Neurotherapeutics 2024; 21:e00364. [PMID: 38669936 PMCID: PMC11064589 DOI: 10.1016/j.neurot.2024.e00364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 04/13/2024] [Accepted: 04/15/2024] [Indexed: 04/28/2024] Open
Abstract
Surgical neuromodulation has witnessed significant progress in recent decades. Notably, deep brain stimulation (DBS), delivered precisely within therapeutic targets, has revolutionized the treatment of medication-refractory movement disorders and is now expanding for refractory psychiatric disorders, refractory epilepsy, and post-stroke motor recovery. In parallel, the advent of incisionless treatment with focused ultrasound ablation (FUSA) can offer patients life-changing symptomatic relief. Recent research has underscored the potential to further optimize DBS and FUSA outcomes by conceptualizing the therapeutic targets as critical nodes embedded within specific brain networks instead of strictly anatomical structures. This paradigm shift was facilitated by integrating two imaging modalities used regularly in brain connectomics research: diffusion MRI (dMRI) and functional MRI (fMRI). These advanced imaging techniques have helped optimize the targeting and programming techniques of surgical neuromodulation, all while holding immense promise for investigations into treating other neurological and psychiatric conditions. This review aims to provide a fundamental background of advanced imaging for clinicians and scientists, exploring the synergy between current and future approaches to neuromodulation as they relate to dMRI and fMRI capabilities. Focused research in this area is required to optimize existing, functional neurosurgical treatments while serving to build an investigative infrastructure to unlock novel targets to alleviate the burden of other neurological and psychiatric disorders.
Collapse
Affiliation(s)
- Nicole A Silva
- Department of Neurological Surgery, University of North Carolina - Chapel Hill, Chapel Hill, NC, USA
| | | | - Fang-Cheng Yeh
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - Mojgan Hodaie
- Division of Neurosurgery, University of Toronto, Toronto, Canada
| | - Daniel Roque
- Department of Neurology, University of North Carolina in Chapel Hill, NC, USA
| | - Varina L Boerwinkle
- Department of Neurology, University of North Carolina in Chapel Hill, NC, USA
| | - Vibhor Krishna
- Department of Neurological Surgery, University of North Carolina - Chapel Hill, Chapel Hill, NC, USA.
| |
Collapse
|
3
|
Smid A, Dominguez-Vega ZT, van Laar T, Oterdoom DLM, Absalom AR, van Egmond ME, Drost G, van Dijk JMC. Objective clinical registration of tremor, bradykinesia, and rigidity during awake stereotactic neurosurgery: a scoping review. Neurosurg Rev 2024; 47:81. [PMID: 38355824 PMCID: PMC10866747 DOI: 10.1007/s10143-024-02312-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 01/19/2024] [Accepted: 01/28/2024] [Indexed: 02/16/2024]
Abstract
Tremor, bradykinesia, and rigidity are incapacitating motor symptoms that can be suppressed with stereotactic neurosurgical treatment like deep brain stimulation (DBS) and ablative surgery (e.g., thalamotomy, pallidotomy). Traditionally, clinicians rely on clinical rating scales for intraoperative evaluation of these motor symptoms during awake stereotactic neurosurgery. However, these clinical scales have a relatively high inter-rater variability and rely on experienced raters. Therefore, objective registration (e.g., using movement sensors) is a reasonable extension for intraoperative assessment of tremor, bradykinesia, and rigidity. The main goal of this scoping review is to provide an overview of electronic motor measurements during awake stereotactic neurosurgery. The protocol was based on the PRISMA extension for scoping reviews. After a systematic database search (PubMed, Embase, and Web of Science), articles were screened for relevance. Hundred-and-three articles were subject to detailed screening. Key clinical and technical information was extracted. The inclusion criteria encompassed use of electronic motor measurements during stereotactic neurosurgery performed under local anesthesia. Twenty-three articles were included. These studies had various objectives, including correlating sensor-based outcome measures to clinical scores, identifying optimal DBS electrode positions, and translating clinical assessments to objective assessments. The studies were highly heterogeneous in device choice, sensor location, measurement protocol, design, outcome measures, and data analysis. This review shows that intraoperative quantification of motor symptoms is still limited by variable signal analysis techniques and lacking standardized measurement protocols. However, electronic motor measurements can complement visual evaluations and provide objective confirmation of correct placement of the DBS electrode and/or lesioning. On the long term, this might benefit patient outcomes and provide reliable outcome measures in scientific research.
Collapse
Affiliation(s)
- Annemarie Smid
- Department of Neurosurgery, University Medical Center Groningen, University of Groningen, Hanzeplein 1 HPC AB71, 9713 GZ, Groningen, Netherlands.
| | - Zeus T Dominguez-Vega
- Department of Neurology, University Medical Center Groningen, University of Groningen, Hanzeplein 1 HPC AB71, 9713 GZ, Groningen, Netherlands
| | - Teus van Laar
- Department of Neurology, University Medical Center Groningen, University of Groningen, Hanzeplein 1 HPC AB71, 9713 GZ, Groningen, Netherlands
| | - D L Marinus Oterdoom
- Department of Neurosurgery, University Medical Center Groningen, University of Groningen, Hanzeplein 1 HPC AB71, 9713 GZ, Groningen, Netherlands
| | - Anthony R Absalom
- Department of Anesthesiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1 HPC AB71, 9713 GZ, Groningen, Netherlands
| | - Martje E van Egmond
- Department of Neurology, University Medical Center Groningen, University of Groningen, Hanzeplein 1 HPC AB71, 9713 GZ, Groningen, Netherlands
| | - Gea Drost
- Department of Neurosurgery, University Medical Center Groningen, University of Groningen, Hanzeplein 1 HPC AB71, 9713 GZ, Groningen, Netherlands
- Department of Neurology, University Medical Center Groningen, University of Groningen, Hanzeplein 1 HPC AB71, 9713 GZ, Groningen, Netherlands
| | - J Marc C van Dijk
- Department of Neurosurgery, University Medical Center Groningen, University of Groningen, Hanzeplein 1 HPC AB71, 9713 GZ, Groningen, Netherlands
| |
Collapse
|
4
|
Wang D, Ashkan K. "Grass Is Always Greener on the Other Side" or Is It?! Comparison of Trend of Awake Craniotomy in Neuro-Oncology and Asleep Deep Brain Stimulation. Stereotact Funct Neurosurg 2023; 101:217-220. [PMID: 37231910 PMCID: PMC11251657 DOI: 10.1159/000530527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 03/24/2023] [Indexed: 05/27/2023]
Affiliation(s)
- Difei Wang
- Department of Neurosurgery, King's College Hospital, London, UK
| | | |
Collapse
|
5
|
Sammartino F, Yeh FC, Krishna V. Intraoperative lesion characterization after focused ultrasound thalamotomy. J Neurosurg 2022; 137:459-467. [PMID: 34972085 DOI: 10.3171/2021.10.jns211651] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 10/01/2021] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Outcomes after focused ultrasound ablation (FUSA) for essential tremor remain heterogeneous, despite therapeutic promise. Clinical outcomes are directly related to the volume and location of the therapeutic lesions, consistent with CNS ablative therapies. Recent data demonstrate that postoperative diffusion MRI, specifically the quantification of intracellular diffusion by restricted diffusion imaging (RDI), can accurately characterize focused ultrasound lesions. However, it is unclear whether RDI can reliably detect focused ultrasound lesions intraoperatively (i.e., within a few minutes of lesioning) and whether the intraoperative lesions predict delayed clinical outcomes. METHODS An intraoperative imaging protocol was implemented that included RDI and T2-weighted imaging in addition to intraoperative MR thermography. Lesion characteristics were defined with each sequence and then compared. An imaging-outcomes analysis was performed to determine lesion characteristics associated with delayed clinical outcomes. RESULTS Intraoperative RDI accurately identified the volume and location of focused ultrasound lesions. Intraoperative T2-weighted imaging underestimated the lesion volume but accurately identified the location. Intraoperative RDI revealed that lesions of the ventral border of the ventral intermediate nucleus were significantly associated with postoperative tremor improvement. In contrast, the lesions extending into the inferolateral white matter were associated with postoperative ataxia. CONCLUSIONS These data support the acquisition of intraoperative RDI to characterize focused ultrasound lesions. Future research should test the histological correlates of intraoperative RDI and test whether it can be developed as feedback to optimize the current technique of FUSA.
Collapse
Affiliation(s)
| | - Fang-Cheng Yeh
- 2Department of Neurosurgery, University of Pittsburgh, Pennsylvania
| | - Vibhor Krishna
- 1Department of Neurosurgery, The Ohio State University, Columbus, Ohio; and
| |
Collapse
|
6
|
Sammartino F, Taylor P, Chen G, Reynolds RC, Glen D, Krishna V. Functional Neuroimaging During Asleep DBS Surgery: A Proof of Concept Study. Front Neurol 2021; 12:659002. [PMID: 34262518 PMCID: PMC8273165 DOI: 10.3389/fneur.2021.659002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 05/25/2021] [Indexed: 11/30/2022] Open
Abstract
Object: A real-time functional magnetic resonance imaging (fMRI) feedback during ventral intermediate nucleus (VIM) deep brain stimulation (DBS) under general anesthesia (or “asleep” DBS) does not exist. We hypothesized that it was feasible to acquire a reliable and responsive fMRI during asleep VIM DBS surgery. Methods: We prospectively enrolled 10 consecutive patients who underwent asleep DBS for the treatment of medication-refractory essential tremor. Under general anesthesia, we acquired resting-state functional MRI immediately before and after the cannula insertion. Reliability was determined by a temporal signal-to-noise-ratio >100. Responsiveness was determined based on the fMRI signal change upon insertion of the cannula to the VIM. Results: It was feasible to acquire reliable fMRI during asleep DBS surgery. The fMRI signal was responsive to the brain cannula insertion, revealing a reduction in the tremor network's functional connectivity, which did not reach statistical significance in the group analysis. Conclusions: It is feasible to acquire a reliable and responsive fMRI signal during asleep DBS. The acquisition steps and the preprocessing pipeline developed in these experiments will be useful for future investigations to develop fMRI-based feedback for asleep DBS surgery.
Collapse
Affiliation(s)
- Francesco Sammartino
- Department of Neurosurgery, The Ohio State University, Columbus, OH, United States
| | - Paul Taylor
- Scientific and Statistical Computing Core, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, United States
| | - Gang Chen
- Scientific and Statistical Computing Core, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, United States
| | - Richard C Reynolds
- Scientific and Statistical Computing Core, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, United States
| | - Daniel Glen
- Scientific and Statistical Computing Core, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, United States
| | - Vibhor Krishna
- Department of Neurosurgery, The Ohio State University, Columbus, OH, United States
| |
Collapse
|
7
|
Jin H, Gong S, Tao Y, Huo H, Sun X, Song D, Xu M, Xu Z, Liu Y, Wang S, Yuan L, Wang T, Song W, Pan H. A comparative study of asleep and awake deep brain stimulation robot-assisted surgery for Parkinson's disease. NPJ PARKINSONS DISEASE 2020; 6:27. [PMID: 33083521 PMCID: PMC7536209 DOI: 10.1038/s41531-020-00130-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 09/02/2020] [Indexed: 01/13/2023]
Abstract
To compare the differences between asleep and awake robot-assisted deep brain stimulation (DBS) surgery for Parkinson’s Disease (PD), we conducted this retrospective cohort study included 153 PD patients undergoing bilateral robot-assisted DBS from June 2017 to August 2019, of which 58 cases were performed under general anesthesia (GA) and 95 cases under local anesthesia (LA). Procedure duration, stimulation parameters, electrode implantation accuracy, intracranial air, intraoperative electrophysiological signal length, complications, and Unified PD Rating Scale (UPDRS) measurements were recorded and compared. The clinical evaluation was conducted by two raters who were blinded to the choice of anesthesia. Procedure duration was significantly shorter in the GA group, while on stimulation off medication motor scores (UPDRS-III) were significantly improved in both the GA and LA group. ANCOVA covariated for the baseline UPDRS-III and levodopa challenge exhibited no significant differences. In terms of amplitude, frequency, and pulse width, the stimulation parameters used for DBS power-on were similar. There were no significant differences in electrode implantation accuracy, intraoperative electrophysiological signal length, or intracerebral hemorrhage (no occurrences in either group). The pneumocephalus volume was significantly smaller in the GA group. Six patients exhibited transient throat discomfort associated with tracheal intubation in the GA group. The occurrence of surgical incision infection was similar in both groups. Compared with the awake group, the asleep group exhibited a shorter procedure duration with a similar electrode implantation accuracy and short-term motor improvement. Robot-assisted asleep DBS surgery is a promising surgical method for PD.
Collapse
Affiliation(s)
- Hai Jin
- Department of Neurosurgery, The General Hospital of Northern Theater Command, 83 Wenhua Road, 110016 Shenyang, China
| | - Shun Gong
- Department of Neurosurgery, The General Hospital of Northern Theater Command, 83 Wenhua Road, 110016 Shenyang, China
| | - Yingqun Tao
- Department of Neurosurgery, The General Hospital of Northern Theater Command, 83 Wenhua Road, 110016 Shenyang, China
| | - Hua Huo
- Department of Clinical Trail Management Agency, The General Hospital of Northern Theater Command, 83 Wenhua Road, 110016 Shenyang, China
| | - Xiao Sun
- Department of Neurosurgery, The General Hospital of Northern Theater Command, 83 Wenhua Road, 110016 Shenyang, China
| | - Dandan Song
- Department of Anesthesia, The General Hospital of Northern Theater Command, 83 Wenhua Road, 110016 Shenyang, China
| | - Ming Xu
- Department of Anesthesia, The General Hospital of Northern Theater Command, 83 Wenhua Road, 110016 Shenyang, China
| | - Zhaozhu Xu
- Department of Anesthesia, The General Hospital of Northern Theater Command, 83 Wenhua Road, 110016 Shenyang, China
| | - Yang Liu
- Department of Neurosurgery, The General Hospital of Northern Theater Command, 83 Wenhua Road, 110016 Shenyang, China
| | - Shimiao Wang
- Department of Neurosurgery, The General Hospital of Northern Theater Command, 83 Wenhua Road, 110016 Shenyang, China
| | - Lijia Yuan
- Department of Neurosurgery, The General Hospital of Northern Theater Command, 83 Wenhua Road, 110016 Shenyang, China
| | - Tingting Wang
- Department of Neurosurgery, The General Hospital of Northern Theater Command, 83 Wenhua Road, 110016 Shenyang, China
| | - Weilong Song
- Department of Neurosurgery, The General Hospital of Northern Theater Command, 83 Wenhua Road, 110016 Shenyang, China
| | - He Pan
- Department of Neurosurgery, The General Hospital of Northern Theater Command, 83 Wenhua Road, 110016 Shenyang, China
| |
Collapse
|
8
|
Coenen VA, Sajonz B, Prokop T, Reisert M, Piroth T, Urbach H, Jenkner C, Reinacher PC. The dentato-rubro-thalamic tract as the potential common deep brain stimulation target for tremor of various origin: an observational case series. Acta Neurochir (Wien) 2020; 162:1053-1066. [PMID: 31997069 PMCID: PMC7156360 DOI: 10.1007/s00701-020-04248-2] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 01/23/2020] [Indexed: 01/19/2023]
Abstract
INTRODUCTION Deep brain stimulation alleviates tremor of various origins. The dentato-rubro-thalamic tract (DRT) has been suspected as a common tremor-reducing structure. Statistical evidence has not been obtained. We here report the results of an uncontrolled case series of patients with refractory tremor who underwent deep brain stimulation under tractographic assistance. METHODS A total of 36 patients were enrolled (essential tremor (17), Parkinson's tremor (8), multiple sclerosis (7), dystonic head tremor (3), tardive dystonia (1)) and received 62 DBS electrodes (26 bilateral; 10 unilateral). Preoperatively, diffusion tensor magnetic resonance imaging sequences were acquired together with high-resolution anatomical T1W and T2W sequences. The DRT was individually tracked and used as a direct thalamic or subthalamic target. Intraoperative tremor reduction was graded on a 4-point scale (0 = no tremor reduction to 3 = full tremor control) and recorded together with the current amplitude, respectively. Stimulation point coordinates were recorded and compared to DRT. The relation of the current amplitude needed to reduce tremor was expressed as TiCR (tremor improvement per current ratio). RESULTS Stimulation points of 241 were available for analysis. A total of 68 trajectories were tested (62 dB leads, 1.1 trajectories tested per implanted lead). Tremor improvement was significantly decreasing (p < 0.01) if the distance to both the border and the center of the DRT was increasing. On the initial trajectory, 56 leads (90.3%) were finally placed. Long-term outcomes were not part of this analysis. DISCUSSION Tremor of various origins was acutely alleviated at different points along the DRT fiber tract (above and below the MCP plane) despite different tremor diseases. DRT is potentially a common tremor-reducing structure. Individual targeting helps to reduce brain penetrating tracts. TiCR characterizes stimulation efficacy and might help to identify an optimal stimulation point.
Collapse
Affiliation(s)
- Volker Arnd Coenen
- Department of Stereotactic and Functional Neurosurgery, Freiburg University Medical Center, Freiburg (i.Br.), Germany.
- Faculty of Medicine, Freiburg University, Freiburg (i.Br.), Germany.
- Brain Links/Brain Tools Cluster of Excellence, Freiburg University, Freiburg (i.Br.), Germany.
- NeuroModul Basics (Center for Basics in NeuroModulation), Freiburg University, Freiburg (i.Br.), Germany.
| | - Bastian Sajonz
- Department of Stereotactic and Functional Neurosurgery, Freiburg University Medical Center, Freiburg (i.Br.), Germany
- Faculty of Medicine, Freiburg University, Freiburg (i.Br.), Germany
| | - Thomas Prokop
- Department of Stereotactic and Functional Neurosurgery, Freiburg University Medical Center, Freiburg (i.Br.), Germany
- Faculty of Medicine, Freiburg University, Freiburg (i.Br.), Germany
| | - Marco Reisert
- Department of Stereotactic and Functional Neurosurgery, Freiburg University Medical Center, Freiburg (i.Br.), Germany
- Faculty of Medicine, Freiburg University, Freiburg (i.Br.), Germany
| | - Tobias Piroth
- Faculty of Medicine, Freiburg University, Freiburg (i.Br.), Germany
- Brain Links/Brain Tools Cluster of Excellence, Freiburg University, Freiburg (i.Br.), Germany
- Department of Neurology and Neurophysiology, Freiburg University Medical Center, Freiburg (i.Br.), Germany
| | - Horst Urbach
- Faculty of Medicine, Freiburg University, Freiburg (i.Br.), Germany
- Department of Neuroradiology, Freiburg University Medical Center, Freiburg (i.Br.), Germany
| | - Carolin Jenkner
- Faculty of Medicine, Freiburg University, Freiburg (i.Br.), Germany
- Clinical Trials Unit, Freiburg University Medical Center, Freiburg, Germany
| | - Peter Christoph Reinacher
- Department of Stereotactic and Functional Neurosurgery, Freiburg University Medical Center, Freiburg (i.Br.), Germany
- Faculty of Medicine, Freiburg University, Freiburg (i.Br.), Germany
| |
Collapse
|