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Dive into the research topics where Ralph König is active.

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Featured researches published by Ralph König.


Neurosurgery | 2009

Patient satisfaction and disability after brachial plexus surgery.

Thomas Kretschmer; Sarah Ihle; Gregor Antoniadis; Julia A. Seidel; Christian Heinen; Wolfgang Börm; Hans-Peter Richter; Ralph König

OBJECTIVELittle is known about patient satisfaction and disability after brachial plexus surgery. Would patients undergo the procedure again, if they knew the current result beforehand? How do they rate their result and their disability? METHODSOf 319 plexus patients who had undergone surgery between 1995 and 2005, 199 received a 65-item questionnaire. Measurement instruments included a new plexus-specific outcome questionnaire (Ulm Questionnaire) with categories of satisfaction, functionality, pain, comorbidities, and work; and the disability of the arm, shoulder, and hand questionnaire (DASH; scale, 0–100). RESULTSOf 99 returned questionnaires, 70 were returned in a useful form for evaluation. The results of patients with C5–C6 lesions (21 of 70) are as follows: 90% (19 of 21) would undergo surgery again, 95% (20 of 21) were satisfied with the result, and 86% (18 of 21) subjectively improved. The mean DASH score was 41 (standard deviation [SD], 24). The results of patients with C5–C7 lesions (6 of 70) are as follows: 50% (3 of 6) were satisfied and would undergo surgery again, and 67% (4 of 6) improved. The mean DASH score was 46 (SD, 13). The results of patients with C5–T1 lesions (43 of 70) are as follows: 67% (29 of 43) would undergo surgery again, 81% (35 of 42) were satisfied, and 74% (32 of 43) reported improvement. The mean DASH score was 58 (SD, 26). The overall mean DASH score was 52 (SD, 26). Pain since the injury was prevalent in 86% of patients (60 of 70), back pain in 53%, and depression/anxiety in 21%. Fifty-two percent of those who worked before their injury (27 of 53 patients) remained unemployed or incapacitated for work. Forty-five percent of previous workers (24 of 53) returned to their former occupation. Occupational retraining was successful for 70% of patients (16 of 23). The mean duration until return to work was 9 months overall and 5 months for those who returned to their previous occupation. CONCLUSIONEighty-seven percent of patients were satisfied with the results and 83% would undergo the procedure again. Despite a high satisfaction rate, patients remained considerably disabled, and half of the previous workers did not return to work. Occupational retraining is effective.


Neurosurgery Clinics of North America | 2009

Iatrogenic Nerve Injuries

Thomas Kretschmer; Christian Heinen; Gregor Antoniadis; Hans-Peter Richter; Ralph König

As long as humans have been medically treated, unfortunate cases of inadvertent injury to nerves afflicted by the therapist have occurred. Most microsurgically treated iatrogenic nerve injuries occur directly during an operation. Certain nerves are at a higher risk than others, and certain procedures and regions of the body are more prone to sustaining nerve injury. A high degree of insecurity regarding the proper measures to take can be observed among medical practitioners. A major limiting factor in successful treatment is delayed referral for evaluation and reconstructive surgery. This article on iatrogenic nerve injuries intends to focus on relevant aspects of management from a nerve surgeons perspective.


PLOS ONE | 2015

Surgery for Glioblastoma: Impact of the Combined Use of 5-Aminolevulinic Acid and Intraoperative MRI on Extent of Resection and Survival.

Jan Coburger; Vincent Hagel; Christian Rainer Wirtz; Ralph König

Background There is rising evidence that in glioblastoma(GBM) surgery an increase of extent of resection(EoR) leads to an increase of patient’s survival. Based on histopathological assessments tumor depiction of Gd-DTPA enhancement and 5-aminolevulinic-acid-fluorescence(5-ALA) might be synergistic for intraoperative resection control. Objective To assess impact of additional use of 5-ALA in intraoperative MRI(iMRI) assisted surgery of GBMs on extent of resection(EoR), progression free survival(PFS) and overall survival(OS). Methods We prospectively enrolled 33 patients with GBMs eligible for gross-total-resection(GTR) and performed a combined approach using 5-ALA and iMRI. As a control group, we performed a retrospective matched pair assessment, based on 144 patients with iMRI-assisted surgery. Matching criteria were, MGMT promotor methylation, recurrent surgery, eloquent location, tumor size and age. Only patients with an intended GTR and primary GBMs were included. We calculated Kaplan Mayer estimates to compare OS and PFS using the Log-Rank-Test. We used the T-test to compare volumetric results of EoR and the Chi-Square-Test to compare new permanent neurological deficits(nPND) and general complications between the two groups. Results Median follow up was 31 months. No significant differences between both groups were found concerning the matching criteria. GTR was achieved significantly more often (p <0.010) using 5-ALA&iMRI (100%) compared to iMRI alone(82%). Mean EoR was significantly(p<0.004) higher in 5-ALA&iMRI-group(99.7%) than in iMRI-alone-group(97.4%) Rate of complications did not differ significantly between groups(21% iMRI-group,27%5-ALA&iMRI-group,p<0.518). nPND were found in 6% in both groups. Median PFS (6mo resp.;p<0.309) and median OS(iMRI:17mo;5-ALA&iMRI-group:18mo;p<0.708)) were not significantly different between both groups. Conclusion We found a significant increase of EoR when combining 5-ALA&iMRI compared to use of iMRI alone. Maximizing EoR did not lead to an increase of complications or neurological deficits if used with neurophysiological monitoring in eloquent lesions. No final conclusion can be drawn whether a further increase of EoR benefits patient’s progression free survival and overall survival.


World Neurosurgery | 2014

Navigated High Frequency Ultrasound: Description of Technique and Clinical Comparison with Conventional Intracranial Ultrasound

Jan Coburger; Ralph König; Angelika Scheuerle; Jens Engelke; Michal Hlavac; Dietmar R. Thal; Christian Rainer Wirtz

OBJECTIVE Conventional curved or sector array ultrasound (cioUS) is the most commonly used intraoperative imaging modality worldwide. Although highly beneficial in various clinical applications, at present the impact of linear array intraoperative ultrasound (lioUS) has not been assessed for intracranial use. We provide a technical description to integrate an independent lioUS probe into a commercially available neuronavigation system and evaluate the use of navigated lioUS as a resection control in glioblastoma surgery. METHODS We performed a prospective study assessing residual tumor detection after complete microsurgical resection using either cioUS or lioUS in 15 consecutive patients. We compared the imaging findings of both ultrasound modalities in 44 sites surrounding the resection cavity. The respective findings were correlated with the histopathologic findings of tissue specimen obtained from those sites. RESULTS Use of cioUS leaded to an additional resection in 9 patients, whereas lioUS detected residual tumor during all surgeries. A further resection was performed at 33 of 44 intraoperative sites (75%) based on results of lioUS alone. Resected tissue was solid tumor in 66% and infiltration zone in 34%. No false-positive or false-negative findings were seen using lioUS. There was no case of a tumor detection in cioUS combined with a negative finding in lioUS. The difference of imaging results between cioUS and lioUS was significant (sign test, P<0.001). CONCLUSIONS lioUS can be used as a safe and precise tool for intracranial image-guided resection control of glioblastomas. It can be integrated in a commercially available navigation system and shows a significant higher detection rate of residual tumor compared with conventional cioUS.


Childs Nervous System | 2006

Role of intraoperative neurophysiology in primary surgery for obstetrical brachial plexus palsy (OBPP)

Ralph König; Gregor Antoniadis; Wolfgang Börm; Hans-Peter Richter; Thomas Kretschmer

ObjectiveManagement of conducting neuroma-in-continuity in primary surgery for obstetrical brachial plexus palsy (OBPP) is still discussed controversially. We present our experience with intraoperative neurophysiological recordings in the management of lesions in continuity in OBPP.MethodsA series of ten children with lesions in continuity of the upper brachial plexus is presented. Due to recordable compound nerve action potentials (CNAPs) and muscle response to motor stimulation across the neuroma, five children underwent external neurolysis of neuroma only (neurolysis group). Due to lack of recordable CNAPs or muscle response, resection of neuroma and interpositional nerve grafting were performed in another five children (resection and grafting group). Functional recovery after at least 30 months of follow-up was assessed.ResultsThere was a marked difference in functional recovery between the neurolysis and the resection and grafting group. Especially, recovery of shoulder function was disappointing after external neurolysis of conducting neuroma-in-continuity. At the end of follow-up, results of shoulder and elbow function after resection of neuroma followed by interpositional nerve grafting were better without exception.ConclusionIntraoperative neurophysiological recordings face certain difficulties when used in small children with OBPP. Due to overoptimistic assessment of prognosis after intraoperative CNAP recordings and motor stimulation, the functional results after neurolysis of conducting neuroma-in-continuity are disappointing. Resection of neuroma-in-continuity, conducting or not, offers the best opportunity for maximal functional recovery of the compromised upper limb in OBPP. The role of intraoperative neurophysiological techniques should be confined to the diagnosis of root avulsions.


Neurosurgery Clinics of North America | 2009

Avoiding Iatrogenic Nerve Injury in Endoscopic Carpal Tunnel Release

Thomas Kretschmer; Gregor Antoniadis; Hans-Peter Richter; Ralph König

In the hands of the inexperienced, endoscopic carpal tunnel release bears a substantial risk for neurovascular injury. For those thoroughly trained in this technique, it is a fast and elegant but also more expensive way to achieve carpal tunnel release. If performed uneventfully, it minimizes trauma and avoids a substantial palmar skin incision. The authors think that some basic considerations are useful to prevent complications. This article focuses on some points that are relevant to the safe use of this technique.


Neurology Research International | 2014

Desmopressin Acetate in Intracranial Haemorrhage

Thomas Kapapa; Stefan Röhrer; Sabine Struve; Matthias Petscher; Ralph König; Christian Rainer Wirtz; Dieter Woischneck

Introduction. The secondary increase in the size of intracranial haematomas as a result of spontaneous haemorrhage or trauma is of particular relevance in the event of prior intake of platelet aggregation inhibitors. We describe the effect of desmopressin acetate as a means of temporarily stabilising the platelet function. Patients and Methods. The platelet function was analysed in 10 patients who had received single (N = 4) or multiple (N = 6) doses of acetylsalicylic acid and 3 patients (control group) who had not taken acetylsalicylic acid. All subjects had suffered intracranial haemorrhage. Analysis was performed before, half an hour and three hours after administration of desmopressin acetate. Statistical analysis was performed by applying a level of significance of P ≤ 0.05. Results. (1) Platelet function returned to normal 30 minutes after administration of desmopressin acetate. (2) The platelet function worsened again after three hours. (3) There were no complications related to electrolytes or fluid balance. Conclusion. Desmopressin acetate can stabilise the platelet function in neurosurgical patients who have received acetylsalicylic acid prior to surgery without causing transfusion-related side effects or a loss of time. The effect is, however, limited and influenced by the frequency of drug intake. Further controls are needed in neurosurgical patients.


World Neurosurgery | 2013

Health-Related Quality of Life After Spontaneous Subarachnoid Hemorrhage Measured in a Recent Patient Population

Martin Tjahjadi; Christian Heinen; Ralph König; Eckhard Rickels; Christian Rainer Wirtz; Dieter Woischneck; Thomas Kapapa

OBJECTIVE This study sought to determine the impact of spontaneous subarachnoid hemorrhage (SAH) on health-related quality of life (HRQOL). METHODS Data were taken retrospectively from 601 patients (219 male, 382 female) treated between 1998 and 2008. Questionnaires concerning HRQOL were circulated prospectively, and the responses from 253 patients (81 male, 172 female) were analyzed. The questionnaires comprised the standardized Short-Form 36 (SF-36) and Short-Form 12 (SF-12) Health Surveys, a number of nonstandardized questions, and visual analogue scales. Statistical analysis of the results was exploratory, using unifactorial ANOVA (Scheffe), multivariate analyses of variance. RESULTS The HRQOL is reduced considerably by SAH and remains so for a period of 10 years. Physical and emotional domains are primarily affected, but also cognitive functions, including memory and concentration in particular. Similarly, certain roles are affected that prove difficult to rehabilitate after acute care and cause serious debility in the long term. The Hunt and Hess Scale, Glasgow Outcome Scale, and seizures were found to have the greatest impact on HRQOL. CONCLUSIONS Documentation of HRQOL after 6 to 12 months is useful because patients are often found to have a diminished HRQOL in the absence of a clear physical impairment. Because psychological, emotional, cognitive, and social functioning influence HRQOL in the long term, efforts at rehabilitation should focus in particular on improving such factors. Documentation of HRQOL is a useful, additive tool for consolidating and evaluating the outcome, and a treatment end point after SAH, respectively.


British Journal of Neurosurgery | 2014

Cognitive performance following spontaneous subarachnoid haemorrhage versus other forms of intracranial haemorrhage.

Christine Brand; Burkhard Alber; Anne-Katharina Fladung; Katharina Knauer; Ralph König; Annette Oechsner; Inga L. Schneider; Hayrettin Tumani; Bernhard Widder; Christian Rainer Wirtz; Dieter Woischneck; Thomas Kapapa

Abstract Objective. The exact cause of cognitive deficits following intracranial haemorrhage is unclear. This prospective study examines the abilities after spontaneous subarachnoid haemorrhage (SAH), intracerebral haemorrhage (ICH) and chronic subdural haematoma (SDH) to elucidate the cognitive outcome. Patients and methods. Ninety-nine patients with SAH (N = 60), ICH (N = 25), and SDH (N = 14) were followed up for an average of 6 and 12 months post-haemorrhage. Cognitive tests were used to examine attention, memory, concentration, and executive function. Following were used for analysis: 1. the percentage of patients falling below the 25th percentile per test, 2. the general development from the first to second test point and 3. the incidence of significant changes between the test points. Significance was established as p ≤ 0.05. Results. All three types of haemorrhage resulted in deficits as concerns abstract language (53%–75%). The processing speed was below the normal levels in more than 70% of the patients tested. The cognitive performance of SAH patients was similar to that of patients with SDH and ICH patients after 6 months. The number of patients with outcomes falling below the 25th percentile (to some extent more than 75% in patients post-SAH) is high in all patient groups and mostly decreases over the course. Nevertheless, patients with SAH reveal improvements in many more areas than with ICH and SDH (p ≤ 0.006). Conclusions. The cognitive impairments following SAH, ICH and SDH deficits appear to develop in a similar way regardless of the type of haemorrhage. Cognitive improvement is most pronounced in patients with SAH.


Acta neurochirurgica | 2011

Lows and highs: 15 years of development in intraoperative magnetic resonance imaging.

T. Schmidt; Ralph König; Michal Hlavac; Gregor Antoniadis; Christian Rainer Wirtz

Intraoperative magnetic resonance imaging (ioMRI) during neurosurgical procedures was first implemented in 1995. In the following decade ioMRI and image guided surgery has evolved from an experimental stage into a safe and routinely clinically applied technique. The development of ioMRI has led to a variety of differently designed systems which can be basically classified in one- or two-room concepts and low- and high-field installations. Nowadays ioMRI allows neurosurgeons not only to increase the extent of tumor resection and to preserve eloquent areas or white matter tracts but it also provides physiological and biological data of the brain and tumor tissue. This article tries to give a comprehensive review of the milestones in the development of ioMRI and neuronavigation over the last 15 years and describes the personal experience in intraoperative low and high-field MRI.

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Michal Hlavac

University of Erlangen-Nuremberg

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Dieter Woischneck

Otto-von-Guericke University Magdeburg

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