References of "Hertel, Frank 50009071"
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See detailA new rechargeable device for deep brain stimulation: a prospective patient satisfaction survey.
Timmermann, Lars; Schupbach, Michael; Hertel, Frank UL et al

in European Neurology (2013), 69(4), 193-9

BACKGROUND: Deep brain stimulation (DBS) is highly successful in treating Parkinson's disease (PD), dystonia, and essential tremor (ET). Until recently implantable neurostimulators were nonrechargeable ... [more ▼]

BACKGROUND: Deep brain stimulation (DBS) is highly successful in treating Parkinson's disease (PD), dystonia, and essential tremor (ET). Until recently implantable neurostimulators were nonrechargeable, battery-driven devices, with a lifetime of about 3-5 years. This relatively short duration causes problems for patients (e.g. programming and device-use limitations, unpredictable expiration, surgeries to replace depleted batteries). Additionally, these batteries (relatively large with considerable weight) may cause discomfort. To overcome these issues, the first rechargeable DBS device was introduced: smaller, lighter and intended to function for 9 years. METHODS: Of 35 patients implanted with the rechargeable device, 21 (including 8 PD, 10 dystonia, 2 ET) were followed before and 3 months after surgery and completed a systematic survey of satisfaction with the rechargeable device. RESULTS: Overall patient satisfaction was high (83.3 +/- 18.3). Dystonia patients tended to have lower satisfaction values for fit and comfort of the system than PD patients. Age was significantly negatively correlated with satisfaction regarding process of battery recharging. CONCLUSIONS: Dystonia patients (generally high-energy consumption, severe problems at the DBS device end-of-life) are good, reliable candidates for a rechargeable DBS system. In PD, younger patients, without signs of dementia and good technical understanding, might have highest benefit. [less ▲]

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See detailSide population in human glioblastoma is non-tumorigenic and characterizes brain endothelial cells.
Golebiewska, Anna; Bougnaud, Sebastien; Stieber, Daniel et al

in Brain : a journal of neurology (2013), 136(Pt 5), 1462-75

The identification and significance of cancer stem-like cells in malignant gliomas remains controversial. It has been proposed that cancer stem-like cells display increased drug resistance, through the ... [more ▼]

The identification and significance of cancer stem-like cells in malignant gliomas remains controversial. It has been proposed that cancer stem-like cells display increased drug resistance, through the expression of ATP-binding cassette transporters that detoxify cells by effluxing exogenous compounds. Here, we investigated the 'side population' phenotype based on efflux properties of ATP-binding cassette transporters in freshly isolated human glioblastoma samples and intracranial xenografts derived thereof. Using fluorescence in situ hybridization analysis on sorted cells obtained from glioblastoma biopsies, as well as human tumour xenografts developed in immunodeficient enhanced green fluorescence protein-expressing mice that allow an unequivocal tumour-stroma discrimination, we show that side population cells in human glioblastoma are non-neoplastic and exclusively stroma-derived. Tumour cells were consistently devoid of efflux properties regardless of their genetic background, tumour ploidy or stem cell associated marker expression. Using multi-parameter flow cytometry we identified the stromal side population in human glioblastoma to be brain-derived endothelial cells with a minor contribution of astrocytes. In contrast with their foetal counterpart, neural stem/progenitor cells in the adult brain did not display the side population phenotype. Of note, we show that CD133-positive cells often associated with cancer stem-like cells in glioblastoma biopsies, do not represent a homogenous cell population and include CD31-positive endothelial cells. Interestingly, treatment of brain tumours with the anti-angiogenic agent bevacizumab reduced total vessel density, but did not affect the efflux properties of endothelial cells. In conclusion our findings contribute to an unbiased identification of cancer stem-like cells and stromal cells in brain neoplasms, and provide novel insight into the complex issue of drug delivery to the brain. Since efflux properties of endothelial cells are likely to compromise drug availability, transiently targeting ATP-binding cassette transporters may be a valuable therapeutic strategy to improve treatment effects in brain tumours. [less ▲]

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See detailMethod for identification of anatomical landmarks
Gielen, F. L. H.; Hertel, Frank UL; Gemmar, P. et al

Report (2012)

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See detailMethod for planning a surgical procedure
Gielen, Frans L. H.; Hertel, Frank UL; Gemmar, Peter et al

Report (2012)

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See detailSystem for navigating a planned procedure within a body
Gielen, F. L. H.; Hertel, Frank UL; Gemmar, P. et al

Report (2012)

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See detailImpaired performance on the Wisconsin Card Sorting Test under left- when compared to right-sided deep brain stimulation of the subthalamic nucleus in patients with Parkinson's disease.
Lueken, Ulrike; Schwarz, Michaela; Hertel, Frank UL et al

in Journal of neurology (2008), 255(12), 1940-8

Over the past decade, deep brain stimulation (DBS) has become an effective treatment option for managing severe Parkinson's disease (PD). However, evidence is accumulating that DBS of target sites like ... [more ▼]

Over the past decade, deep brain stimulation (DBS) has become an effective treatment option for managing severe Parkinson's disease (PD). However, evidence is accumulating that DBS of target sites like the subthalamic nucleus (STN) can result in unintended cognitive effects that lie beyond motor control. The aim of the present study was to evaluate whether changes in executive task performance after chronic DBS might be predominantly associated with the stimulation of only one hemisphere. Eight patients with PD who had undergone DBS treatment of the STN were selected to participate in the study. Using a repeated measurements design, they underwent a neuropsychological examination under unilateral left- and right-sided stimulation in order to investigate laterality effects in their performance on the Wisconsin Card Sorting Test. All patients showed a significant improvement in motor symptoms postoperatively. Selected aspects of executive task performance were compromised under left- when compared to right-sided stimulation. Performance measures were unrelated to demographic, neurological, and behavioral characteristics of the patients. Findings are consistent with the emerging evidence that the STN is not only involved in motor control, but also participates in functions of the cognitive domain. Moreover, results raise the possibility that the left and right hemisphere might differ in their vulnerability to tolerate side effects on executive functions of DBS treatment. Potential consequences for future research questions and the management of cognitive side effects are discussed. [less ▲]

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See detailUnilateral Holmes tremor, clearly responsive to cerebrospinal fluid release, in a patient with an ischemic midbrain lesion and associated chronic hydrocephalic ventricle enlargement. Case report.
Hertel, Frank UL; Zuchner, Mark; Decker, Christian et al

in Journal of Neurosurgery (2006), 104(3), 448-51

The authors describe a 58-year-old man with sudden onset of a unilateral tremor caused by a midbrain lesion that affected the substantia nigra and the cerebellothalamic pathway. There were also clinical ... [more ▼]

The authors describe a 58-year-old man with sudden onset of a unilateral tremor caused by a midbrain lesion that affected the substantia nigra and the cerebellothalamic pathway. There were also clinical and neuroimaging signs of a communicating chronic hydrocephalus. The patient was severely handicapped by this tremor, which was a typical Holmes tremor with rest, posture, and intention components. Parkinson disease or multiple-system atrophy as causes for the tremor could be ruled out by DaTSCAN and 123I iodobenzamide and single-photon emission computerized tomography (SPECT), respectively. The tremor was completely supressed by temporary and permanent cerebrospinal fluid release after ventriculoperitoneal shunt placement, without any additional medication, for a period of 6 months. Afterward, the tremor returned, and the patient had to be treated by a stereotactic electrode implantation in the contralateral ventralis intermedius nucleus, which led to complete tremor suppression during the 1.5-year follow-up period. In this case report, the authors present the clinical description and the electrophysiological, SPECT, and magnetic resonance imaging data of a rare combination of symptoms and their surgical treatment. [less ▲]

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See detailKapitel 19 - ZNS-Tumoren
Bettag, Martin; Hertel, Frank UL; Preiß, Joachim et al

in Pfeifer, Ben; ???; Preiß, Joachim (Eds.) et al Onkologie integrativ (2006)

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See detailPerfusion-weighted Magnetic Resonance Imaging in Patients with Vasospasm: A Useful New Tool in the Management of Patients with Subarachnoid Hemorrhage.
Hertel, Frank UL; Walter, Christof; Bettag, Martin et al

in Neurosurgery (2006), 58(3), 590

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See detailImplantation of electrodes for deep brain stimulation of the subthalamic nucleus in advanced Parkinson's disease with the aid of intraoperative microrecording under general anesthesia.
Hertel, Frank UL; Zuchner, Mark; Weimar, Inge et al

in Neurosurgery (2006), 59(5), 11381138

OBJECTIVE: Deep brain stimulation (DBS) is widely accepted in the treatment of advanced Parkinson's disease (PD) and other movement disorders. The standard implantation procedure is performed under local ... [more ▼]

OBJECTIVE: Deep brain stimulation (DBS) is widely accepted in the treatment of advanced Parkinson's disease (PD) and other movement disorders. The standard implantation procedure is performed under local anesthesia (LA). Certain groups of patients may not be eligible for surgery under LA because of clinical reasons, such as massive fear, reduced cooperativity, or coughing attacks. Microrecording (MER) has been shown to be helpful in DBS surgery. The purpose of this study was to evaluate the feasibility of MER for DBS surgery under general anesthesia (GA) and to compare the data of intraoperative MER as well as the clinical data with that of the current literature of patients undergoing operation under LA. CLINICAL PRESENTATION: The data of nine patients with advanced PD (mean Hoehn and Yahr status, 4.2) who were operated with subthalamic nucleus (STN) DBS under GA, owing to certain clinical circumstances ruling out DBS under LA, were retrospectively analyzed. All operations were performed under analgosedation with propofol or remifentanil and intraoperative MER. For MER, remifentanil was ceased completely and propofol was lowered as far as possible. INTERVENTION: The STN could be identified intraoperatively in all patients with MER. The typical bursting pattern was identified, whereas a widening of the baseline noise could not be as adequately detected as in patients under LA. The daily off phases of the patients were reduced from 50 to 17%, whereas the Unified Parkinson's Disease Rating Scale III score was reduced from 43 (preoperative, medication off) to 19 (stimulation on, medication off) and 12 (stimulation on, medication on). Two patients showed a transient neuropsychological deterioration after surgery, but both also had preexisting episodes of disorientation. One implantable pulse generator infection was noticed. No further significant clinical complications were observed. CONCLUSION: STN surgery for advanced PD with MER guidance is possible with good clinical results under GA. Intraoperative MER of the STN region can be performed under GA with a special anesthesiological protocol. In this setting, the typical STN bursting pattern can be identified, whereas the typical widening of the background noise baseline while entering the STN region is obviously absent. This technique may enlarge the group of patients eligible for STN surgery. Although the clinical improvements and parameter settings in this study were within the range of the current literature, further randomized controlled studies are necessary to compare the results of STN DBS under GA and LA, respectively. [less ▲]

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See detailAlteration of cerebral perfusion in patients with idiopathic normal pressure hydrocephalus measured by 3D perfusion weighted magnetic resonance imaging.
Walter, Christof; Hertel, Frank UL; Naumann, E. et al

in Journal of neurology (2005), 252(12), 1465-71

OBJECTIVE: It is controversial whether alteration of cerebral perfusion plays an important role in the pathophysiology of patients with idiopathic normal pressure hydrocephalus (NPH) and can help to ... [more ▼]

OBJECTIVE: It is controversial whether alteration of cerebral perfusion plays an important role in the pathophysiology of patients with idiopathic normal pressure hydrocephalus (NPH) and can help to predict the outcome after shunt surgery. MATERIALS AND METHODS: 28 patients with suspected NPH were examined clinically (Homburg Hydrocephalus Scale, walking test, incontinence protocol) and by 3D dynamic susceptibility based perfusion weighted magnetic resonance imaging (PWI-MRI) before and after cerebrospinal fluid release (spinal tap test, STT). The perfusion parameters (negative integral (NI), time of arrival (T0), time to peak (TTP), mean transit time, and the difference TTP-T0 were analysed. RESULTS: Three different groups of patients were identified preoperatively: In group 1 seven patients showed an increase in the cerebral perfusion and a clinical improvement after STT. The second group (9 patients) also revealed an increase of the cerebral perfusion, but no significant alteration of the clinical assessment could be found. In the third group neither the cerebral perfusion nor the clinical assessment changed. 14 of the 16 patients (group 1 and 2) were examined three months after shunt placement. 11 patients showed a good or excellent result, 2 patients revealed a fair assessment, and only 1 patient had transiently improved. No patient was downgraded after shunting. In the patient group 1 and 2 the NI increased significantly (effect size: 34%), whereas in group 3 no significant alteration of NI was observed. CONCLUSION: PWI-MRI improves the prediction of outcome after shunt placement in patients with NPH and can offer new insights into the pathophysiology. [less ▲]

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See detailPerfusion-weighted magnetic resonance imaging in patients with vasospasm: a useful new tool in the management of patients with subarachnoid hemorrhage.
Hertel, Frank UL; Walter, Christof; Bettag, Martin et al

in Neurosurgery (2005), 56(1), 28-3535

OBJECTIVE: Cerebral vasospasm (VSP) is one of the most important risk factors for the development of a delayed neurological deficit after subarachnoid hemorrhage (SAH). Perfusion-weighted magnetic ... [more ▼]

OBJECTIVE: Cerebral vasospasm (VSP) is one of the most important risk factors for the development of a delayed neurological deficit after subarachnoid hemorrhage (SAH). Perfusion-weighted magnetic resonance imaging (pwMRI) provides the possibility of detecting tissue at risk for infarction. The objective of our study was to evaluate the feasibility and impact of pwMRI in the management of SAH patients. METHODS: From a consecutive series of 180 patients experiencing SAH and treated at our institution over a 3-year period, we identified 20 who underwent pwMRI during their acute illness. For these 20 patients, the results of pwMRI were compared with the results of diffusion-weighted MRI, transcranial Doppler sonography, and neurological examinations performed at the same time and with repeated pwMRI examinations of the same patient at different times. RESULTS: Nineteen of 20 patients showed perfusion changes predominantly in the time maps. Fifteen of 19 patients with changes in pwMRI had a neurological deficit at the same time. In 7 of 15 patients with neurological deterioration, transcranial Doppler sonography showed signs of VSP, whereas all 15 patients showed alterations in pwMRI. The areas of perfusion changes in pwMRI correlated well with the neurological deficits of the patients and were larger than the areas of changed diffusion in diffusion-weighted MRI performed at the same time. There were no clinical complications with regard to the pwMRI examinations. CONCLUSION: pwMRI is safe and helpful in the management of patients with VSP after SAH. The sensitivity of pwMRI is higher than that of transcranial Doppler sonography in the detection of decreased perfusion as a result of VSP. pwMRI can detect tissue at risk before definitive infarction occurs and therefore may lead to a change of therapy in those patients. [less ▲]

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See detailComputerassistierte Hirnoperationen
Bettag, Martin; Busert, Christoph; Hertel, Frank UL

in Laubach, Ester; Mau, Frank; Mau, Thomas (Eds.) Medizin im 21. Jahrhundert: Molekulare Medizin, Mikrotherapie und High-Tech-Operationen (2002)

Die Hirnchirurgie hat in den letzten Jahrzehnten rasante Fortschritte gemacht. Zwei Entwicklungen hatten daran wesentlichen Anteil. Die Einführung des Operationsmikroskops erlaubte es dem Operateur, durch ... [more ▼]

Die Hirnchirurgie hat in den letzten Jahrzehnten rasante Fortschritte gemacht. Zwei Entwicklungen hatten daran wesentlichen Anteil. Die Einführung des Operationsmikroskops erlaubte es dem Operateur, durch die Möglichkeit der variablen Vergrößerung und der koaxialen Lichteinstrahlung Hirnstrukturen auch in der Tiefe optimal zu visualisieren. Dies war und ist eine Grundvoraussetzung für subtile neurochirurgische Operationsmaßnahmen. Seither wurden und werden spezielle neurochirurgische Mikroinstrumente entwickelt, die den Gegebenheiten einer feinmodulatorischen Arbeit gerecht werden. Eine zweite wesentliche Entwicklung, die den Fortschritt in der Neurochirurgie begründete, war die Einführung neuer diagnostischer Verfahren. [less ▲]

Detailed reference viewed: 134 (1 UL)