Time filter

Source Type

Mirzayan M.J.,Hannover Medical School | Probst C.,Hannover Medical School | Samii M.,International Neuroscience Institute Hanover | Krettek C.,Hannover Medical School | And 4 more authors.
Experimental and Toxicologic Pathology | Year: 2012

Object: Among the various introduced experimental traumatic brain injury models, there is a clear paucity of proper experimental polytrauma models. To overcome this experimental gap we introduced such a polytrauma model in the mouse including traumatic brain injury. Here, we report on the histopathological features of the brain, lung, kidney, spleen and liver. Materials and methods: 20 male C57BL mice with a mean weight of 23. g were anesthetized with ketamine and xylazine. The anaesthetized animals were subjected to a controlled cortical impact (CCI) over the left parieto-temporal cortex using rounded-tip impounder for application of a standardized brain injury. Following fracture of the right femur using a guillotine, a volume-controlled hemorrhagic shock was induced. The control groups included animals with CCI only (n=20) and animals with femur fracture plus hemorrhagic shock without CCI (n=20). Subjects were sacrified at 96. h following trauma. Brain, lung, kidney, spleen and liver of the animals underwent histopathological examinations. Results: The mortality rate at 96. h was 25% in the polytrauma group versus 10% in the control groups. Within the histopathological investigations, polytraumatized animals differ from those with a single trauma (traumatic brain injury or femur fracture with hemorrhagic shock) with various severity. Conclusion: The findings of this study show that such a polytrauma model can be standardized resulting in a reproducible damage. This model fulfills the requirements of a standardized animal model. It allows adequate analogies and inferences to the clinical situation of a polytrauma in humans. © 2010 Elsevier GmbH.


Dukatz T.,Universitatsklinikum Giessen und Marburg GmbH | Sarnthein J.,UniversitatsSpital Zurich | Sitter H.,University of Marburg | Bozinov O.,UniversitatsSpital Zurich | And 3 more authors.
Neurosurgery | Year: 2011

Background: Symptomatic patients with a brainstem cavernoma are treated surgically with increasing frequency. Generally, the patient's benefit from this difficult surgical intervention is quantified by the assessment of neurological symptoms. Objective: To document the beneficial effect of surgery in a larger patient population by assessing the postoperative quality of life (QoL). Methods: In a series of 71 surgically treated patients, a detailed neurological status was assessed by Patzold Rating and Karnofsky Performance Status Scale. Patients rated their QoL with the Short Form 36 Health Survey. To document the effect of surgery on QoL, we devised a supplementary questionnaire. The last 24 patients completed Short Form 36 Health Survey pre- and postoperatively. Results: Karnofsky Performance Status Scale improved in 44 of 71 surgical patients (62%), remained unchanged in 19 (27%), and deteriorated in 8 (11%) individuals. Patzold Rating showed a more detailed picture of the neurological symptoms. It correlated significantly with Karnofsky Performance Status Scale, which underscores its usefulness for patients with brainstem lesions. In the Short Form 36 Health Survey score, the Mental Component Summary improved with surgery (paired test, P = .015). In addition, 58 individuals (82%) declared a clear subjective benefit of surgery. Conclusion: The results of this large series support the notion that microsurgical removal of a brainstem cavernoma represents an effective therapy in experienced hands and is generally associated with good clinical outcome, both neurologically and in terms of QoL. Copyright © 2011 by the Congress of Neurological Surgeons.


Stieglitz L.H.,Inselspital Bern | Ludemann W.O.,International Neuroscience Institute Hanover | Giordano M.,International Neuroscience Institute Hanover | Raabe A.,Inselspital Bern | And 2 more authors.
Neurosurgery | Year: 2011

BACKGROUND: Fiber tracking (FT) of the optic pathways (OPs) is difficult because there is no standard for the parameters of diffusion tensor imaging (DTI), placement of seed volumes, or interpreting the results. OBJECTIVE: To determine optimal conditions and parameters for DTI and FT of the optic radiation under intraoperative conditions, we performed a multivariate prospective study. METHODS: A healthy man underwent magnetic resonance imaging and DTI scans using various scan parameters. The slice thicknesses were 2.7 mm, 5 mm, and 7 mm, and the gantry of the slices was 0 degrees and 44 degrees. The OPs were tracked using different settings for focal anisotropy and minimal length of the visualized fibers. The time needed for DTI, image processing, and uploading as well as the difficulty of depicting the OPs, the time needed for FT, quality, and volume of the tracked fiber object were registered and analyzed. RESULTS: The DTI took between 2 minutes 14 seconds for the axial scan with 7-mm slice thickness and 6 minutes 14 seconds for the 44-degree angulated scan with 2.7-mm slice thickness. Splitting the data into a 3-dimensional mosaic data set took between 1 minute 42 seconds (44 degrees, 7 mm; 0 degrees, 7 mm) and 4 minutes 21 seconds (44 degrees, 2.7 mm). The best results were achieved using 44-degree, 2.7-mm DTI. The optimal setting for focal anisotropy was 0.1 and 11 mm for minimal length. Using these parameters, tracking of the OPs was possible in 1 minute 22 seconds and with high quality and correlating with anatomic studies. CONCLUSION: The use of anteriorly angulated DTI improves the FT work flow and the results of tractography of the OP. The quality of the resulting objects can be judged by anatomic landmarks. Copyright © 2011 by the Congress of Neurological Surgeons.


Probst C.,Witten/Herdecke University | Mirzayan M.J.,Hannover Medical School | Mommsen P.,Hannover Medical School | Zeckey C.,Hannover Medical School | And 5 more authors.
Mediators of Inflammation | Year: 2012

Objective. Despite broad research in neurotrauma and shock, little is known on systemic inflammatory effects of the clinically most relevant combined polytrauma. Experimental investigation in an animal model may provide relevant insight for therapeutic strategies. We describe the effects of a combined injury with respect to lymphocyte population and cytokine activation. Methods. 45 male C57BL/6J mice (mean weight 27g) were anesthetized with ketamine/xylazine. Animals were subjected to a weight drop closed traumatic brain injury (WD-TBI), a femoral fracture and hemorrhagic shock (FX-SH). Animals were subdivided into WD-TBI, FX-SH and combined trauma (CO-TX) groups. Subjects were sacrificed at 96h. Blood was analysed for cytokines and by flow cytometry for lymphocyte populations. Results. Mortality was 8, 13 and 47 for FX-SH, WD-TBI and CO-TX groups (P<0.05). TNF (11/13/139 for FX-SH/WD-TBI/CO-TX; P<0.05), CCL2 (78/96/227; P<0.05) and IL-6 (16/48/281; P=0.05) showed significant increases in the CO-TX group. Lymphocyte populations results for FX-SH, WD-TBI and CO-TX were: CD-4 (31/21/22; P= n.s.), CD-8 (7/28/34, P<0.05), CD-4-CD-8 (11/12/18; P= n.s.), CD-56 (36/7/8; P<0.05). Conclusion. This study shows that a combination of closed TBI and femur-fracture/ shock results in an increase of the humoral inflammation. More attention to combined injury models in inflammation research is indicated. Copyright 2012 C. Probst et al.


Teramoto S.,Juntendo University | Bertalanffy H.,International Neuroscience Institute Hanover
Acta Neurochirurgica | Year: 2016

Background: The anterior communicating artery (ACoA) often limits surgical exposure in the anterior interhemispheric approach. Although division of the ACoA has been proposed occasionally, it is rarely practiced, and criteria for such a surgical maneuver remain unknown. Our purpose was to identify key factors that allow for predicting the necessity of controlled ACoA division in the bifrontal basal interhemispheric approach. Method: Twenty-two consecutive patients who underwent surgery via the bifrontal basal interhemispheric approach for removal of various pathologic brain lesions were examined. First, tumors were dichotomized into central and lateral lesions. Next, three tumor parameters were compared between cases with and without ACoA division in each, the central and lateral lesion groups, respectively: tumor volume, tumor depth (defined as distance between the ACoA and posterior tumor margin) and tumor laterality angle (defined as the geometric angle between the lateral tumor margin and sagittal midline). Results: Tumor volume was not related in a statistically significant manner to ACoA division in both the central (P = 0.06) and lateral (P = 0.13) lesion groups, respectively. However, tumor depth was significantly correlated with ACoA division in the central lesion group (P = 0.01), whereas in the lateral lesion group, the tumor laterality angle showed a significant correlation with ACoA division (P = 0.04). Conclusions: Our results suggest that controlled ACoA division may be required in central lesions with a depth of 38 mm or more and in lateral lesions with an angle of 23 degrees or more as defined in this study. Two key factors were thus identified that may predict the necessity of controlled ACoA division before surgery. © 2016 The Author(s)


Fahlbusch R.,International Neuroscience Institute Hanover
Acta neurochirurgica. Supplement | Year: 2011

The initial attempts at intraoperative image guidance and imaging dates back to early 1980s. Since then Neuronavigation and intraoperative imaging technologies were developed in parallel. This works aims at summarizing the developments and giving an insider's view into the beginning stage of these technologies. The successes and obstacles encountered in the first few decades are relayed from the angle of one of the initial developers.


Paterno' V.,International Neuroscience Institute Hanover | Fahlbusch R.,International Neuroscience Institute Hanover
Acta Neurochirurgica | Year: 2014

Background: Intraoperative high-field magnetic resonance imaging (iMRI) is used as an immediate intraoperative quality control, evaluating the extent of tumor removal during the surgical procedure and allowing us to extend resections in those cases where tumor remnants are documented. The aim of the study was to analyze the typical localization of residual tumor remnants, detected by iMRI during transsphenoidal surgery of pituitary adenomas. Methods: We reviewed a series of 72 patients. All patients presented with macroadenomas with or without suprasellar extension. After high-field MRI investigation, we divided the series preoperatively into totally resectable (TR) and non-totally resectable (NTR) tumors. Tumor remnants were documented by iMRI, obtained directly after tumor removal, as well as by intraoperative surgical inspection of the sellar content. Results: In the TR group, we observed 23 cases suspicious for tumor remnants, located anteriorly, laterally, posteriorly, and suprasellar under descending folds of the diaphragm. Continuing surgery, upon a "second inspection", tumor resection could be completed in all cases. Conclusions: Incomplete removal of resectable pituitary adenomas could be avoided in a higher number of cases with the knowledge of the location of the typical remnant tumors. In those cases where it is not possible to achieve a complete resection of adenoma, further treatment can be planned at an earlier stage, without any need to wait for the conventional postoperative MRI scan performed 2 to 3 months after surgery. © 2014 Springer-Verlag Wien.


Giordano M.,International Neuroscience Institute Hanover | Gerganov V.M.,International Neuroscience Institute Hanover | Metwali H.,International Neuroscience Institute Hanover | Fahlbusch R.,International Neuroscience Institute Hanover | And 3 more authors.
Neurosurgical Review | Year: 2014

Intraoperative magnetic resonance imaging (iopMRI) actually has an important role in the surgery of brain tumors, especially gliomas and pituitary adenomas. The aim of our work was to describe the advantages and drawbacks of this tool for the surgical treatment of cervical intramedullary gliomas. We describe two explicative cases including the setup, positioning, and the complete workflow of the surgical approach with intraoperative imaging. Even if the configuration of iopMRI equipment was originally designed for cranial surgery, we have demonstrated the feasibility of cervical intramedullary glioma resection with the aid of high-field iopMRI. This tool was extremely useful to evaluate the extent of tumor removal and to obtain a higher resection rate, but still need some enhancement in the configuration of the headrest coil and surgical table to allow better patient positioning. © 2013 Springer-Verlag Berlin Heidelberg.


Stieglitz L.H.,International Neuroscience Institute Hanover | Giordano M.,International Neuroscience Institute Hanover | Samii M.,International Neuroscience Institute Hanover | Luedemann W.O.,International Neuroscience Institute Hanover
Neurosurgery | Year: 2010

BACKGROUND: The accurate position of the ventricular catheter inside the frontal horn of the lateral ventricle is essential to prevent proximal failure in shunt surgery. For optimal placement, endoscopic-and image-guided techniques are available. OBJECTIVE: We introduce a newly constructed tool for quick and safe placement of ventricular catheters. It is mounted on a fixation device and therefore allows the surgeon's optimal concentration on the catheter insertion and feeling for the penetrated tissue. To check the feasibility of the new device, we performed a study with 4 patients. METHODS: Two patients with communicative and 2 patients with noncommunicative hydrocephalus underwent ventricular catheter placement using the new shunt placement tool. Three patients had a complex anatomy of the ventricular system. RESULTS: In all 4 procedures, correct placement of the ventricular catheters was achieved. The additional time needed for preparations did not exceed 15 minutes. The comparison of the postoperative computed tomography scans with the preoperative planning showed good accuracy of the instrument with a mean deviation of the catheter tips from the planned position of 1.5 mm (range 1.0-2.1 mm). CONCLUSION: The new tool allows safe and quick placement of ventricular catheters. The adjustment of the tool to the planned trajectory is performed before catheter insertion and allows optimal concentration on the insertion procedure and the fingertip feeling for the penetrated tissue. Copyright © 2010 by the Congress of Neurological Surgeons.


PubMed | International Neuroscience Institute Hanover
Type: Journal Article | Journal: Experimental brain research | Year: 2013

In our study we examined acute and chronic changes in c-Fos expression patterns in the visual system of the rat after complete visual deafferentation. In 20 male Lewis rats, the retro-bulbar part of the optic nerve was sectioned bilaterally. Ten animals underwent c-Fos immunohistochemistry after 3 days and 10 animals after 3 weeks examining time-dependent changes. The control group consisted of 10 animals, which did not undergo any surgical manipulation. c-Fos expression in the rat visual system experienced significant changes after acute and chronic bilateral complete visual deafferentation. Acute decrease in c-Fos level was observed in the ventral lateral geniculate nucleus, intergeniculate leaflet, superficial gray layer of the superior colliculus and layers IV and V of the primary visual cortex. After chronic deafferentation, c-Fos expression was also found to be decreased in the optic and deep layers of the superior colliculus and layer VI of the primary visual cortex. No change in c-Fos expression was observed in the dorsal lateral geniculate nucleus and layers I, II and III of the primary visual cortex. This work shows that secondary complete blindness does not lead to uniform decrease in c-Fos levels in all subcortical and cortical brain regions related to vision. These findings provide important information concerning expression of the immediate-early gene product c-Fos in secondary blind rodent models. It may further serve as a relevant baseline finding when electrical stimulation of the visual system is performed, aiding the assessment of visual neuroprosthesis using c-Fos as a functional mapping tool when evaluating different stimulus parameters in blind rodent models.

Loading International Neuroscience Institute Hanover collaborators
Loading International Neuroscience Institute Hanover collaborators