Epidermoid of the retromastoidal region with cutaneous wound infection, fistula and epidural abscess.
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Cerebellar Diseases↗
Biomedical subjects
Jürgen Meixensberger
Publications and source records attributed to Jürgen Meixensberger.
Intracranial dural arteriovenous fistula associated with progressive cervical myelopathy and normal venous drainage of the thoracolumbar cord: case report and review of the literature.
BACKGROUND: Intracranial dural arteriovenous malformations draining into the perimedullary venous system are rare lesions. In these cases, the selective spinal catheterization of all vessels with potential of causing that malformation was negative, and additional cerebral angiography usually reveals the fistula. Because of venous congestion of the cord caused by the DAVF, a delayed drainage or stagnation of contrast material in the artery of Adamkiewicz was considered as a compelling angiographic disorder so far. CASE DESCRIPTION: We report about a 58-year-old patient with a DAVF of the right posterior fossa draining into the cervical and upper thoracic plexus of medullary veins, followed by progressive cervical myelopathy and a normal venous drainage of the artery of Adamkiewicz. Because of the failing endovascular treatment option, the neurosurgical intervention was performed. The fistula was explored and clipped without any complications. Immediately after operation, the patient reported an improvement of his neurological deficits. CONCLUSION: About 38 cases of intracranial DAVFs draining into the perimedullary venous system are reported, but to our knowledge, this is the second one with a normal drainage of the artery of Adamkiewicz. The pathophysiological mechanisms, diagnostic procedures, and treatment modalities are discussed.
Arteriovenous Fistula↗
Continuous assessment of cerebrovascular autoregulation after traumatic brain injury using brain tissue oxygen pressure reactivity.
OBJECTIVE: To evaluate whether two newly developed indexes of brain tissue oxygen pressure reactivity (ORx and bPtio2) provide information on the status of cerebrovascular autoregulation after traumatic brain injury. This was accomplished by analyzing the relationship between these indexes and an index of cerebrovascular pressure reactivity (PRx). PRx is an established parameter for estimation of cerebrovascular autoregulation. DESIGN: Retrospective analysis of prospectively collected data. SETTING: Neurosurgical intensive care unit of a university hospital. PATIENTS: Twenty-seven patients suffering from severe traumatic brain injury. INTERVENTIONS: Continuous monitoring of mean arterial blood pressure, intracranial pressure, cerebral perfusion pressure, and partial pressure of brain tissue oxygen (Ptio2) was performed for an average of 6.5 days. ORx was calculated as a moving correlation coefficient between values of cerebral perfusion pressure and Ptio2. The bPtio2 was calculated as a moving value of the slope of the linear regression function between cerebral perfusion pressure and Ptio2. PRx was calculated as a moving correlation coefficient between values for intracranial pressure and mean arterial blood pressure. Outcome was assessed at 6 months after traumatic brain injury (Glasgow Outcome Scale). MEASUREMENTS AND MAIN RESULTS: Both ORx and bPtio2 correlated significantly with PRx (r=.55 for ORx, r=.52 for bPtio2, p<.01). PRx and ORx showed a significantly negative correlation to the monitored Ptio2 values (r=-.42 for PRx, r=-.41 for ORx, p<.05) and outcome (r=-.52 for PRx, r=-.62 for ORx, p<.01), whereas bPtio2 did not. CONCLUSIONS: ORx and, to a lesser extent, bPtio2 correlated with the autoregulatory marker PRx and provide additional information about the status of cerebrovascular autoregulation after traumatic brain injury. The data also suggested that patients with impaired autoregulation are at increased risk for secondary cerebral hypoxia.
Adolescent↗
Surgical PACS for the digital operating room. Systems engineering and specification of user requirements.
For better integration of surgical assist systems into the operating room, a common communication and processing plattform that is based on the users needs is needed. The development of such a system, a Surgical Picture Aquisition and Communication System (S-PACS), according the systems engineering cycle is oulined in this paper. The first two steps (concept and specification) for the engineering of the S-PACS are discussed.A method for the systematic integration of the users needs', the Quality Function Deployment (QFD), is presented. The properties of QFD for the underlying problem and first results are discussed. Finally, this leads to a first definition of an S-PACS system.
Computer Simulation↗
Holiday heart syndrome possibly triggered after the start of radiochemotherapy for glioblastoma multiforme.
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Adrenergic beta-Antagonists↗
[Structure of an interdisciplinary pituitary outpatient care unit at the University Hospital of Leipzig and results for treatment of prolactin and growth hormone secreting pituitary tumors].
BACKGROUND: Treatment of patients with pituitary adenomas is complex and involves several medical specialties. At the Medical Center of the University of Leipzig, Germany, an interdisciplinary pituitary outpatient care unit has been established for 6 years. METHODS: The interdisciplinary collaboration and the outcome of patients with growth hormone-(GH-) and prolactin-secreting pituitary adenomas are described. Moreover, therapeutic strategies for patients with hormonally active pituitary adenomas are presented and discussed. RESULTS: In patients suffering from GH-producing adenomas, a remission could be achieved in 80% (microadenomas) and 40% (macroadenomas) of the cases, respectively. This is comparable to major published studies. Furthermore, prolactinomas decreased in size during treatment in at least 75% of all cases depending on the initial size of the lesion which is also comparable to data from other groups. CONCLUSION: Taken together, an interdisciplinary approach improves outcome and quality of care of patients with hormonally active pituitary adenomas.
Acromegaly↗
[The reliability of stereotaxy in diagnosis of intracranial space occupying lesions].
A total of 79 patients with a suspect space occupying intracranial lesion was operated stereotactically. After CT and MR image acquisition, entry and target coordinates were defined and biopsy trajectories were simulated preoperatively using a special planning software. Biopsy specimens allowed a satisfactory neuropathological examination and diagnostic result in 74 of 79 (93.7%) cases. In the remaining 5 of 79 (6.3%) patients, a glioses was diagnosed in three cases; in only two patients could no pathological process be proved. 10 of 79 (12.7%) patients showed an intraoperative bleeding out of the biopsy-cannula during serial stereotaxy, which was associated with a CT-detectable hematoma up to 7 mm in diameter in only three cases (3.8%). In no patient was the detection of intracerebral bleeding the reason for any neurological deficit. In summary, the high percentage of satisfactory neuropathological diagnoses, the low rate of stereotaxy-associated morbidity and the comfortable and safe use of computer and stereotactic devices justify this kind of minimally invasive diagnostic measure as a routine method.
Adolescent↗
Experimental therapy of allogeneic solid tumors induced in athymic mice with suicide gene-transducing replication-competent foamy virus vectors.
A replication competent foamy virus derived retroviral vector expressing suicide genes has been constructed and characterized in vitro. Here we used vectors expressing the purine nucleoside phosphorylase (FOV-7/pnp), the nitroreductase (FOV-7/ntr), or the thymidine kinase (FOV-7/tk) suicide gene in an in vivo athymic (nude) mice/human glioblastoma tumor model. Gliomas were induced by subcutanous injection of U87 tumor cells. The virus vector was injected when the tumor became visible. Mice with vector virus-injected tumors were treated with the respective prodrug. The treatment resulted in significant inhibition of tumor growth. Surprisingly, in mice with vector virus-injected tumors without prodrug treatment a similar suppression of tumor growth was observed. In 65% (pnp vector), 75% (ntr vector) and 37% (tk vector) of these mice the tumors stopped growing or vanished and the animals remained tumor free for the 25 weeks of the experiment, whereas all mice of the control groups had to be killed because of the tumor growth. In control experiments, the suppression of tumor growth could also be observed when wild-type foamy virus was injected instead of the suicide gene-transducing vectors. Similar results were obtained using the nude mice/G59 human glioblastoma tumor model. In conclusion, the experiments demonstrate an oncolytic activity of foamy virus replication in a nude-mice glioblastoma xenograft tumor model. The analysis of vector virus DNA by PCR revealed that the vector persisted in different organs of the animals irrespective of the use of a prodrug or the elimination of a tumor.
Animals↗
Unusual penetrating cranio-orbital injury by a cut-off wheel.
The rare case of a penetrating cranio-orbital injury and the surgical treatment is presented. A 38-year-old woman was brought to the Emergency Unit of the University of Leipzig Hospital after suffering a severe craniocerebral injury from a broken cut-off wheel. A computed tomography (CT) scan demonstrated the entrance of the cut-off wheel with extension from the left sinus maxillaris and frontalis through the median part of the left-sided orbit to the anterior skull base. After removing the cut-off wheel and metal splinters, the neurosurgeon performed an osteoplastic bifrontobasal trepanation with revision of the wound channel. Three years later, the patient has no neurological deficit and the CT scan shows a small hypodensity behind the sinus frontalis on the left side.
Accidents, Occupational↗
Post-operative hematoma after surgery for intracranial meningiomas: causes, avoidable risk factors and clinical outcome.
Intracranial meningiomas are mainly benign lesions amenable for surgical resection. However, removal of an intracranial meningioma carries a higher risk of post-operative hemorrhage compared to surgery for other intracranial neoplasms. Because avoidance of post-operative hematoma is of vital interest for neurosurgical patients, the aim of this retrospective study was to analyze risk factors of post-operative hematoma associated with meningioma surgery. Two hundred and ninety six patients with intracranial meningiomas, operated between June 1998 and June 2002, were included in this study. Patients who developed a space-occupying post-operative intracranial hemorrhage and were treated surgically were identified. Data of patients with and without hematoma were retrospectively analyzed to identify risk factors associated with post-operative hematoma. Variables analyzed included patients' age, invasion of venous sinus by the meningioma, tumor vascularization, arachnoidal infiltration, pre-operative prophylaxis of thromboembolic events, peri-operative coagulation abnormalities, residual tumor, location and histology of the tumor. Outcome of patients with post-operative hematoma was assessed according to the Glasgow Outcome Scale (GOS) at discharge and at three months. 21 patients (7.1 %) of 296 patients developed a post-operative intracranial hematoma requiring surgical evacuation. Age was significantly higher in the hematoma group 62.4 +/- 14.0 years compared to patients without post-operative hematoma 56.1 +/- 12.0 (p < 0.05; t-test). Patients older than 70 years had a six-fold increased risk to develop a post-operative hematoma (Chi2 test, 95% CI 1.949-13.224). Patients with post-operative hemorrhage had significant lower post-operative prothrombin time, fibrinogen and platelets immediately after surgery and lower platelets at day 1. None of the other parameters, including pre-operative routine coagulation values, differed significantly between patients with and without post-operative hemorrhage. Three patients with post-operative hematoma showed platelet dysfunction and three patients showed decreased FXIII activity. Of those patients with post-operative hemorrhage at three months follow up three patients (13%) succumbed from reasons not directly related to hemorrhage, one patient remained GOS 2 (4.3%), four patients (17.4%) were GOS 3 and 15 (65.4%) patients had favorable outcome (GOS 4 [one patient] and GOS5 [14 patients]). Meningioma surgery carries a higher risk for post-operative hematoma in the elderly. Thrombocytopenia and other hemostatic disorders were frequently associated with post-operative hemorrhage after meningioma surgery, while no surgical factors could be defined. Extending coagulation tests and specific replacement therapy may prevent hematoma formation and improve the patients outcome.
Adult↗
NEUROGATE: a new MR-compatible device for realizing minimally invasive treatment of intracerebral tumors.
The authors report on the handling and the practicability of a newly developed MR-compatible device, the NEUROGATE (Daum GmbH, Germany), which allows precise planning, simulation and control of stereotactic biopsy in patients with suspect intracranial lesions, and which allows minimally invasive maneuvers to be performed in a comfortable way. Twenty-eight patients were examined stereotactically in the Signa SP interventional 0.5 Tesla MRI (General Electric Medical Systems, USA), including 15 patients with malignant intracerebral tumors and poor general medical conditions (8 gliomas, 7 metastases) who were treated by laser-induced interstitial thermotherapy (LITT) after definite intraoperative neuropathological diagnosis. As a special stereotactic holding device, the NEUROGATE was favored as a reliable tool for stereotaxy and minimally invasive procedures.
Adult↗
Quantitative assessment of parenchymal and ventricular readjustment to intracranial pressure relief.
A 26-year-old patient underwent endoscopic third ventriculostomy for the treatment of obstructive hydrocephalus. 3D volume data sets were obtained at 3 T before surgery and three times after surgery. Off-line analysis of individual imaging data (initial linear registration, intensity adjustment, and final nonlinear registration of pre- to postoperative MR images) yielded 3D displacement fields representing the postoperative structural brain change. In principle, such an analysis technique can be used in any clinical follow-up for which careful observation of tissue readjustment is of particular importance.
Adult↗
Metabolic patterns in meningiomas.
The aim of this investigation was to define characteristic properties of cellular energy metabolism in meningiomas in vitro dependent on the histological subtype. We analysed marker enzymes of representative metabolic pathways localized in the mitochondria (respiratory chain, citric acid cycle, beta-oxidation of fatty acids) and in the cytoplasm (glycolysis, pentose phosphate shunt). The activities of the intramitochondrial enzymes were significantly reduced in the meningiomas compared to normal cortex tissue. Glycolytic enzymes were not significantly different, but the marker enzyme of the pentose phosphate shunt was increased by a factor of 3.5-6 in the tumours. Further analysis of the histological subtypes showed that phosphofructokinase and lactate dehydrogenase were significantly increased in the anaplastic meningiomas compared to the benign subtypes.
Biomarkers, Tumor↗
Investigation of time-dependency of intracranial brain shift and its relation to the extent of tumor removal using intra-operative MRI.
The object of the paper is to investigate intra-operative brainshift and its relation to the extent of tumor removal. Repeated T1w 3D datasets were acquired at different time points intra-operatively (T0; T1; T2...Tx) using a vertical open 0.5T MR scanner in six patients with intracranial tumor. An offline analysis with initial linear registration, intensity adjustment and finally nonlinear registration of the first versus subsequent time points (T0/T1; T0/T2...To/Tx) was performed, yielding a 3D displacement vector field that describes the brainshift. Brainshift was analysed qualitatively and quantitatively. A semi-automatic segmentation technique was used for calculation of the tumor size and the size of tumor remnants. Semi-automatic segmentation was reliable in all but two cases. Segmentation was difficult and unreliable in astrocytomas grade II. The shift basically followed gravity. The major shift reached levels up to 25 mm. Significant shift was observed at the first time point (T0). Intra-operative brainshift can be analysed qualitatively and also captured quantitatively. Neuronavigation that is based on pre-operatively acquired datasets is associated with a significant risk of surgical morbidity at a very early time point. Parallelisation on a workstation cluster may reduce computation time so that information about the displacement can facilitate updated navigation.
Adult↗
Online assessment of brain tissue oxygen autoregulation in traumatic brain injury and subarachnoid hemorrhage.
Monitoring of brain tissue oxygenation (ptiO2) enables early diagnosis of secondary cerebral ischemia and may guide a cerebral perfusion pressure (CPP) orientated therapy. The purpose of our study was to explain the concept of ptiO2-autoregulation, defined as the ability of the brain to maintain ptiO2 despite changes in CPP, and to show the different states of ptiO2-autoregulation we found. Microcatheters to assess ptiO2 and intracranial pressure were implanted into cerebral 'tissue at risk' of patients suffering from traumatic brain injury or subarachnoid hemorrhage. By using a multimodal neuromonitoring setup and in-house built software we assessed and displayed online the relationship between ptiO2 and CPP based on a data buffer consisting of 12 h. Depending on the linear regression slope (bptiO2 = delta ptiO2/delta CPP), we defined the state of ptiO2-autoregulation as present (0 < or = bptiO2 < or = 1/6), moderate (1/6 < bptiO2 < or = 1/3), impaired (bptiO2 > 1/3) or inverse (bptiO2 < 0). When ptiO2-autoregulation is present, an elevation in CPP is ineffective to raise ptiO2. In contrast, an increase in CPP elevates ptiO2 more pronounced in impaired than in moderate ptiO2- autoregulation, but decreases ptiO2 in inverse ptiO2-autoregulation. We conclude that online assessment of ptiO2-autoregulation gives valuable information on which patient will benefit from an increase in CPP and which CPP should be achieved to do so.
Adult↗
Monitoring of brain tissue oxygenation following severe subarachnoid hemorrhage.
The purpose of this prospective observational study was to investigate the relation between the frequency of critical neuromonitoring parameters (brain tissue pO2, (PtiO2) < or = 10 mmHg, intracranial pressure (ICP) > 20 mmHg, cerebral perfusion pressure (CPP) < or = 70 mmHg) and outcome after severe aneurysmal subarachnoid hemorrhage (SAH). In a prospective study on 42 patients monitoring of ICP, CPP, and PtiO2 (in the area at risk for vasospasm) was performed. All patients were primarily classified as Hunt and Hess grade 4 or with secondary deterioration to this grade. Relative proportions of PtiO2 < or = 10 mmHg (n = 42), ICP > 20 mmHg (n = 25) and CPP < or = 70 mmHg (n = 23) were derived from multimodal neuromonitoring data sets for different time intervals, i.e. 1. the total monitoring time; 2. the total monitoring time without the last two monitoring days; 3. the second last monitoring day; and 4. the last monitoring day. Patients were divided into nonsurvivors (GOS = 1) and survivors (GOS = 3-5). For the total monitoring time, significant differences in the relative proportion of critical values were found for all neuromonitoring parameters (p < 0.05). The detailed analysis of consecutive time intervals revealed significantly increased proportions of critical values in nonsurvivors for all neuromonitoring parameters during the last day only. Additionally, ICP > 20 mmHg was significantly more frequent during the second last day (p < 0.01). For other time periods no differences were observed. We conclude, that critical neuromonitoring values are not early predictors of nonsurvival in patients suffering from severe SAH.
Adult↗
Iterative neuronavigation using 3D ultrasound. A feasibility study.
Intra-operative ultrasound (iUS) can generate 2D images in real-time as well as near real-time 3D datasets of the current situation during an intervention. Tracked ultrasound can locate the images in 3D space and relate them to patient, devices, andpre-operative planning data. Therefore, tracked US is an efficient means for controlling the validity of pre-operative planning, recognition of changes (brain shift) during the intervention, replanning of the operational path due to situational changes (iterative navigation), and finally, controlling the results (residual tumor). This paper describes a neuronavigation system exploiting this potential of interventional tracked US for permanent control of intervention progress and iterative adaptation of the planned procedure to the current situation.
Brain Mapping↗