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Dive into the research topics where Kerim Beseoglu is active.

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Featured researches published by Kerim Beseoglu.


Neurology | 2015

The unruptured intracranial aneurysm treatment score A multidisciplinary consensus

Nima Etminan; Robert D. Brown; Kerim Beseoglu; Seppo Juvela; Jean Raymond; Akio Morita; James C. Torner; Colin P. Derdeyn; Andreas Raabe; J. Mocco; Miikka Korja; Amr Abdulazim; Sepideh Amin-Hanjani; Rustam Al-Shahi Salman; Daniel L. Barrow; Joshua B. Bederson; Alain Bonafe; Aaron S. Dumont; David Fiorella; Andreas Gruber; Graeme J. Hankey; David Hasan; Brian L. Hoh; Pascal Jabbour; Hidetoshi Kasuya; Michael E. Kelly; Peter J. Kirkpatrick; Neville Knuckey; Timo Koivisto; Timo Krings

Objective: We endeavored to develop an unruptured intracranial aneurysm (UIA) treatment score (UIATS) model that includes and quantifies key factors involved in clinical decision-making in the management of UIAs and to assess agreement for this model among specialists in UIA management and research. Methods: An international multidisciplinary (neurosurgery, neuroradiology, neurology, clinical epidemiology) group of 69 specialists was convened to develop and validate the UIATS model using a Delphi consensus. For internal (39 panel members involved in identification of relevant features) and external validation (30 independent external reviewers), 30 selected UIA cases were used to analyze agreement with UIATS management recommendations based on a 5-point Likert scale (5 indicating strong agreement). Interrater agreement (IRA) was assessed with standardized coefficients of dispersion (vr*) (vr* = 0 indicating excellent agreement and vr* = 1 indicating poor agreement). Results: The UIATS accounts for 29 key factors in UIA management. Agreement with UIATS (mean Likert scores) was 4.2 (95% confidence interval [CI] 4.1–4.3) per reviewer for both reviewer cohorts; agreement per case was 4.3 (95% CI 4.1–4.4) for panel members and 4.5 (95% CI 4.3–4.6) for external reviewers (p = 0.017). Mean Likert scores were 4.2 (95% CI 4.1–4.3) for interventional reviewers (n = 56) and 4.1 (95% CI 3.9–4.4) for noninterventional reviewers (n = 12) (p = 0.290). Overall IRA (vr*) for both cohorts was 0.026 (95% CI 0.019–0.033). Conclusions: This novel UIA decision guidance study captures an excellent consensus among highly informed individuals on UIA management, irrespective of their underlying specialty. Clinicians can use the UIATS as a comprehensive mechanism for indicating how a large group of specialists might manage an individual patient with a UIA.


Stroke | 2014

Multidisciplinary consensus on assessment of unruptured intracranial aneurysms: proposal of an international research group.

Nima Etminan; Kerim Beseoglu; Daniel L. Barrow; Joshua B. Bederson; Robert D. Brown; E. Sander Connolly; Colin P. Derdeyn; Daniel Hänggi; David Hasan; Seppo Juvela; Hidetoshi Kasuya; Peter J. Kirkpatrick; Neville Knuckey; Timo Koivisto; Giuseppe Lanzino; Michael T. Lawton; Peter D. LeRoux; Cameron G. McDougall; Edward W. Mee; J Mocco; Andrew Molyneux; Michael Kerin Morgan; Kentaro Mori; Akio Morita; Yuichi Murayama; Shinji Nagahiro; Alberto Pasqualin; Andreas Raabe; Jean Raymond; Gabriel J.E. Rinkel

Background and Purpose— To address the increasing need to counsel patients about treatment indications for unruptured intracranial aneurysms (UIA), we endeavored to develop a consensus on assessment of UIAs among a group of specialists from diverse fields involved in research and treatment of UIAs. Methods— After composition of the research group, a Delphi consensus was initiated to identify and rate all features, which may be relevant to assess UIAs and their treatment by using ranking scales and analysis of inter-rater agreement (IRA) for each factor. IRA was categorized as very high, high, moderate, or low. Results— Ultimately, 39 specialists from 4 specialties agreed (high or very high IRAs) on the following key factors for or against UIA treatment decisions: (1) patient age, life expectancy, and comorbid diseases; (2) previous subarachnoid hemorrhage from a different aneurysm, family history for UIA or subarachnoid hemorrhage, nicotine use; (3) UIA size, location, and lobulation; (4) UIA growth or de novo formation on serial imaging; (5) clinical symptoms (cranial nerve deficit, mass effect, and thromboembolic events from UIAs); and (6) risk factors for UIA treatment (patient age and life expectancy, UIA size, and estimated risk of treatment). However, IRAs for features rated with low relevance were also generally low, which underlined the existing controversy about the natural history of UIAs. Conclusions— Our results highlight that neurovascular specialists currently consider many features as important when evaluating UIAs but also highlight that the appreciation of natural history of UIAs remains uncertain, even within a group of highly informed individuals.


Neurosurgery | 2008

Dependence of subarachnoid hemorrhage on climate conditions: a systematic meteorological analysis from the dusseldorf metropolitan area.

Kerim Beseoglu; Daniel Hänggi; Walter Stummer; Hans-Jakob Steiger

OBJECTIVE A number of publications suggest that there are seasonal influences on the incidence of subarachnoid hemorrhage (SAH). Most series agree on a peak incidence during springtime. Meteorological influences have been assumed to be obvious explanations for seasonal variations. Furthermore, the perceived clustering of the incidence of subarachnoid hemorrhage is also intuitively related to meteorological influences. The present study was initiated to determine whether specific meteorological conditions are related to the occurrence of SAH in the mild climatic zone of North Rhine Westphalia. METHODS We retrospectively examined 183 patients (107 women and 76 men) treated at our department between January 2003 and June 2005 for SAH that had occurred within the Düsseldorf metropolitan area. We correlated the date of SAH (Day 0) and of the week preceding the incident (Days -1, -3, -5, and -7) with the meteorological key parameters from Düsseldorf International Airport. Parameters analyzed were mean daily temperature (7C), relative humidity (%), barometric pressure (hPa), and weather condition (divided into 6 groups: clear, cloudy, rain, thunderstorms, snow, and not available). RESULTS A relative peak incidence of SAH was found for the month of April. In addition, a diurnal rhythm with two peaks during morning and in the evening, and a statistically significant nadir during forenoon and midday was evident (P <0.002). None of the average meteorological key parameters of the day of SAH differed from the annual average, and no general trends during the days preceding hemorrhage could be identified. Apparent clustering of the occurrence of SAH could not be related to short-term meteorological trends. CONCLUSION The results of the present study demonstrate a trend toward a seasonal distribution in the incidence of SAH with a peak during spring in the metropolitan area of Düsseldorf. Furthermore, weather variables, such as temperature, barometric pressure, and humidity, were shown to be without influence on aneurysm rupture within the patient population. Therefore, the result indicates the need to validate further parameters in detail to isolate risk circumstances to achieve a risk pattern for patients with SAH.


Stroke | 2013

Early Perfusion Computerized Tomography Imaging as a Radiographic Surrogate for Delayed Cerebral Ischemia and Functional Outcome After Subarachnoid Hemorrhage

Nima Etminan; Kerim Beseoglu; Hi-Jae Heiroth; Bernd Turowski; Hans Jakob Steiger; Daniel Hänggi

Background and Purpose— To date, there is no immediate radiographic surrogate to quantify primary cerebral injury to identify patients at risk for delayed cerebral ischemia and poor clinical outcome after aneurysmal subarachnoid hemorrhage. Therefore, we investigated the relation of early cerebral perfusion–computerized tomography and clot volume with radiological events of delayed cerebral ischemia and clinical outcome in patients with aneurysmal subarachnoid hemorrhage. Methods— Data from 2 cohorts of patients (51 in main, 28 patients in control cohort) with aneurysmal subarachnoid hemorrhage, receiving computerized tomography and perfusion-computerized tomography scanning <12 hours after ictus, were included. A risk group model for functional outcome was developed on the basis of early mean transit time (MTT) and volumetric blood clot measurements. The relation of the risk group model with subsequent MTT, angiographic vasospasm, new cerebral infarction, and functional outcome was analyzed. Actual and predicted functional outcomes based on the risk group model were compared in the control cohort. Results— The risk group model correlated significantly with subsequent MTT measurements, cerebral infarction, and functional outcome. Odds for poor outcome were significantly higher in case of concomitant increase of early MTT and clot volumes, as opposed to exclusive early MTT or clot volume increase. For patients in the high- or low-risk groups, neurological outcome in the control cohort correlated significantly with predicted outcomes. Conclusions— Assessment of early cerebral perfusion and intracranial blood clot may serve as a radiographic surrogate for delayed cerebral ischemia and functional outcome in patients with aneurysmal subarachnoid hemorrhage using risk group modeling.


Clinical Neurology and Neurosurgery | 2008

Feasibility and safety of intrathecal nimodipine on posthaemorrhagic cerebral vasospasm refractory to medical and endovascular therapy

Daniel Hänggi; Kerim Beseoglu; Bernd Turowski; Hans-Jakob Steiger

OBJECTIVE The effectiveness of balloon angioplasty and intra-arterial infusion of vasodilating agents for patients suffering from severe vasospasm following aneurysmal subarachnoid haemorrhage (SAH) is often unsatisfying and there is still demand for further last resort treatment strategies. In the current prospective study, we attempted the intrathecal lavage administration of nimodipine in cases of severe cerebral vasospasm that were refractory to medical and endovascular therapy. METHODS Eight of 146 patients with aneurysmal SAH were included in the prospective study, which had been approved by the local ethics committee. Treatment was instituted by intraventricular nimodipine bolus (0.4 mg), followed by a continuous lumbar intrathecal infusion (0.4 mg/h). Effectiveness was monitored angiographically, with transcranial Doppler (TCD), perfusion CT (pCT), and by neurological examination during treatment course and follow-up. RESULTS The neurological condition improved directly in three patients and remained unchanged in four patients. Seventeen (70.8%) CT perfusion analyses revealed improved perfusion. A reduction of vasospasm was seen angiographically by digital subtraction angiography (DSA) in seven (66.6%) investigations. Additional ischaemic infarction after onset of the intrathecal therapy was documented in two (25%) patients. There were no serious adverse effects observed. CONCLUSION The present study has for the first time demonstrated the feasibility and safety of intrathecal nimodipine lavage in patients with severe vasospasm resistant to the established medical and endovascular treatment strategies. The results of the study are therefore encouraging, and further experimental and clinical trials should be carried out so as to investigate the efficacy of intrathecal nimodipine lavage in vasospasm therapy.


Stroke | 2013

Prospective, Randomized, Open-Label Phase II Trial on Concomitant Intraventricular Fibrinolysis and Low-Frequency Rotation After Severe Subarachnoid Hemorrhage

Nima Etminan; Kerim Beseoglu; Sven O. Eicker; Bernd Turowski; Hans-Jakob Steiger; Daniel Hänggi

Background and Purpose— The goal of this randomized, open-label phase II study was to investigate the effect of concomitant low-frequency head-motion therapy and intraventricular fibrinolysis in patients after surgical or endovascular treatment for aneurysmal subarachnoid hemorrhage. Methods— Sixty patients experiencing subarachnoid hemorrhage were randomized into treatment with intraventricular application of recombinant tissue-type plasminogen activator and lateral rotational therapy (experimental) or treatment as usual (control). The primary end point was defined as functional outcome, measured by Glasgow Outcome Scale at discharge and at 3-month follow-up. Clot clearance rate, radiographic features of delayed cerebral ischemia, and posthemorrhagic hydrocephalus were defined as secondary end points. Results— The majority of patients (78.3%) experienced severe subarachnoid hemorrhage. Although there was a higher incidence of subgaleal hematomas in the experimental group, there was no difference in the incidence of adverse or severe adverse events between the 2 groups. Despite significantly higher clot clearance rates, there was no beneficial effect on the incidence of delayed cerebral ischemia and poor functional outcome, as well as posthemorrhagic hydrocephalus after experimental treatment. Conclusions— Despite the ineffectiveness on reduction of delayed cerebral ischemia or poor functional outcome, intraventricular fibrinolysis and kinetic therapy seems to be a safe and effective concept for therapeutic reduction of subarachnoid clot in a patient collective experiencing predominately severe subarachnoid hemorrhage. Therefore, future studies should investigate this treatment in a larger patient collective with a lower degree of primary brain injury and until full clot clearance on serial imaging. Clinical Trial Registration— URL: http://www.controlled-trials.com. Unique identifier: ICRCTN13230264.


Acta Neurochirurgica | 2006

Supratentorial meningeal melanocytoma mimicking a convexity meningioma

Kerim Beseoglu; C. B. Knobbe; Guido Reifenberger; Hans Jakob Steiger; Walter Stummer

SummaryObjective and importance. Meningeal melanocytomas are rare benign neuro-ectodermal tumors arising from melanocytic cells in the leptomeninges. These leptomeningeal melanocytes are found at highest density underneath the brain stem and along the upper cervical spinal cord. Thus, most reported cases of meningeal melanocytomas are located in the posterior fossa and the spinal cord, respectively.Clinical presentation. We report on the rare case of a 55-year-old male patient with a large supratentorial meningeal melanocytoma mimicking a convexity meningioma and a smaller, similarly dura based lesion in the posterior fossa.Intervention. Tumor control to date was achieved by surgery of the large lesion and radiosurgery of the small lesion.Conclusion. Complete tumor resection may be advantageous and second or recurrent lesions may be managed by repeat surgery or stereotactic radiosurgery.


Stroke | 2014

Age of Collagen in Intracranial Saccular Aneurysms

Nima Etminan; Rita Dreier; Bruce A. Buchholz; Kerim Beseoglu; Peter Bruckner; Christian Matzenauer; James C. Torner; Robert D. Brown; Hans Jakob Steiger; Daniel Hänggi; R. Loch Macdonald

Background and Purpose— The chronological development and natural history of cerebral aneurysms (CAs) remain incompletely understood. We used 14C birth dating of a main constituent of CAs, that is, collagen type I, as an indicator for biosynthesis and turnover of collagen in CAs in relation to human cerebral arteries to investigate this further. Methods— Forty-six ruptured and unruptured CA samples from 43 patients and 10 cadaveric human cerebral arteries were obtained. The age of collagen, extracted and purified from excised CAs, was estimated using 14C birth dating and correlated with CA and patient characteristics, including the history of risk factors associated with atherosclerosis and potentially aneurysm growth and rupture. Results— Nearly all CA samples contained collagen type I, which was <5 years old, irrespective of patient age, aneurysm size, morphology, or rupture status. However, CAs from patients with a history of risk factors (smoking or hypertension) contained significantly younger collagen than CAs from patients with no risk factors (mean, 1.6±1.2 versus 3.9±3.3 years, respectively; P=0.012). CAs and cerebral arteries did not share a dominant structural protein, such as collagen type I, which would allow comparison of their collagen turnover. Conclusions— The abundant amount of relatively young collagen type I in CAs suggests that there is an ongoing collagen remodeling in aneurysms, which is significantly more rapid in patients with risk factors. These findings challenge the concept that CAs are present for decades and that they undergo only sporadic episodes of structural change.


Stroke | 2012

Perfusion CT in Patients With Spontaneous Lobar Intracerebral Hemorrhage Effect of Surgery on Perihemorrhagic Perfusion

Nima Etminan; Kerim Beseoglu; Bernd Turowski; Hans-Jakob Steiger; Daniel Hänggi

Background and Purpose— The aim of the present study was to investigate cerebral hemodynamics in patients requiring surgical treatment for lobar intracerebral hemorrhage. Methods— Twenty patients who underwent surgery to remove a lobar spontaneous intracerebral hemorrhage were scanned before and after surgery using perfusion CT mapping. Mean transit time, time to peak of the residue function, cerebral blood volume, and cerebral blood flow were measured in 4 defined regions of interest. Results— Preoperatively, time to peak of the residue function, cerebral blood volume, and cerebral blood flow were significantly impaired in the perihemorrhagic zone as compared with the ipsilateral and contralateral hemisphere. Perihematomal perfusion improved significantly after clot evacuation and there was no difference in time to peak of the residue function, cerebral blood flow, and cerebral blood volume values between the perihemorrhagic zone and ipsilateral as well as contralateral hemisphere after surgical treatment. Conclusions— Our findings illustrate distinct perihemorrhagic perfusion impairments in a selected patient population with lobar intracerebral hemorrhage as evident by impaired time to peak of the residue function, cerebral blood flow, and cerebral blood volume and their improvement after early surgical treatment. Whether these early improvements in hemodynamic measurements may influence secondary neuronal injury and ultimately clinical outcome, as opposed to the natural course of spontaneous intracerebral hemorrhage remains unclear.


Journal of Neurosurgery | 2011

The transorbital keyhole approach: early and long-term outcome analysis of approach-related morbidity and cosmetic results. Technical note.

Kerim Beseoglu; Sabrina Lodes; Walter Stummer; Hans-Jakob Steiger; Daniel Hänggi

OBJECT In 2003 the authors introduced a minimally invasive transorbital keyhole approach. Because this approach requires removal of the orbital rim and orbital roof, there have been concerns regarding perioperative morbidity, long-term morbidity, and cosmetic results. The authors evaluated approach-related morbidity and cosmetic results in their patients to determine the rate of complications and compared this to published reports of similar approaches. MATERIAL Seventy-one patients (41 female, 30 male) underwent operations using this approach between 2004 and 2008. Immediate approach-related morbidity was recorded after the operation. Late morbidity was determined after 7 months by an independent examiner while cosmetic results were self-rated by the patient using a questionnaire. RESULTS Fifty-one (72%) of 71 patients had no postoperative complications and 12 (16.9%) had minor complications, the most common of which was subgaleal CSF collection (7.0%). Other minor complications included facial nerve palsy (2.8%), hyposphagma (2.8%), periorbital swelling due to periorbital hematoma (2.8%), and subdural hematoma (1.4%). Major complications requiring surgical revision occurred in 4 patients (5.6%); these were CSF fistulas in 2 patients, pneumocephalus in 1 patient, and a hematoma in 1 patient. Forty-nine (90.7%) of all 54 examined patients rated the cosmetic results as very good or good. Major long-term morbidity was hyposmia or anosmia (14 patients) followed by hypoesthesia around the scar (9 patients). CONCLUSIONS The transorbital keyhole approach is a feasible approach with a low-risk profile for postoperative or long-term morbidity and excellent cosmetic outcome.

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Nima Etminan

University of Düsseldorf

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Bernd Turowski

University of Düsseldorf

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Marcel A. Kamp

University of Düsseldorf

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Sven O. Eicker

University of Düsseldorf

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Jason Perrin

University of Düsseldorf

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James C. Torner

University of Iowa Hospitals and Clinics

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