A Raabe

Goethe-Universität Frankfurt am Main, Frankfurt am Main, Hesse, Germany

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Publications (53)104.59 Total impact

  • Article: Erythropoietin neuroprotection is enhanced by direct cortical application following subdural blood evacuation in a rat model of acute subdural hematoma.
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    ABSTRACT: Recombinant human erythropoietin (EPO) has been successfully tested as neuroprotectant in brain injury models. The first large clinical trial with stroke patients, however, revealed negative results. Reasons are manifold and may include side-effects such as thrombotic complications or interactions with other medication, EPO concentration, penetration of the blood-brain-barrier and/or route of application. The latter is restricted to systemic application. Here we hypothesize that EPO is neuroprotective in a rat model of acute subdural hemorrhage (ASDH) and that direct cortical application is a feasible route of application in this injury type. The subdural hematoma was surgically evacuated and EPO was applied directly onto the surface of the brain. We injected NaCl, 200, 2000 or 20,000IU EPO per rat i.v. at 15min post-ASDH (400μl autologous venous blood) or NaCl, 0.02, 0.2 or 2IU per rat onto the cortical surface after removal of the subdurally infused blood t at 70min post-ASDH. Arterial blood pressure (MAP), blood chemistry, intracranial pressure (ICP), cerebral blood flow (CBF) and brain tissue oxygen (ptiO2) were assessed during the first hour and lesion volume at 2days after ASDH. EPO 20,000IU/rat (i.v.) elevated ICP significantly. EPO at 200 and 2000IU reduced lesion volume from 38.2±0.6mm3 (NaCl-treated group) to 28.5±0.9 and 22.2±1.3mm3 (all p<0.05 vs. NaCl). Cortical application of 0.02IU EPO after ASDH evacuation reduced injury from 36.0±5.2 to 11.2±2.1mm3 (p=0.007), whereas 0.2IU had no effect (38.0±9.0mm3). The highest dose of both application routes (i.v. 20,000IU; cortical 2IU) enlarged the ASDH-induced damage significantly to 46.5±1.7 and 67.9±10.4mm3 (all p<0.05 vs. NaCl). In order to test whether Tween-20, a solvent of EPO formulation 'NeoRecomon®' was responsible for adverse effects two groups were treated with NaCl or Tween-20 after the evacuation of ASDH, but no difference in lesion volume was detected. In conclusion, EPO is neuroprotective in a model of ASDH in rats and was most efficacious at a very low dose in combination with subdural blood removal. High systemic and topically applied concentrations caused adverse effects on lesion size which were partially due to increased ICP. Thus, patients with traumatic ASDH could be treated with cortically applied EPO but with caution concerning concentration.
    Neuroscience 02/2013; · 3.38 Impact Factor
  • Article: Serum S100B as a biochemical marker of neurological complications in intensive care patients
    Critical Care 04/2012; 6:1-1. · 4.93 Impact Factor
  • Article: Decompressive hemicraniectomy in subarachnoid haemorrhage: the influence of infarction, haemorrhage and brain swelling.
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    ABSTRACT: To analyse decompressive hemicraniectomy (DHC) in patients with aneurysmal subarachnoid haemorrhage (SAH) with regard to infarction, haemorrhage or brain swelling. DHC was performed in 43 of 787 patients with SAH. Patients were stratified according to (1) primary brain swelling without and (2) with additional intracerebral haematoma, (3) secondary brain swelling without rebleeding or infarcts and (4) with infarcts or (5) with rebleeding. Outcome was assessed according to the modified Rankin scale at 6 months Overall, 36 of 43 patients (83.7%) with DHC and 241 of 744 patients (32.4%) without DHC have been of a poor grade on admission (World Federation of Neurological Societies grading 4-5; p<0.0001). Favourable outcome was achieved in 11 of 43 (25.6%) patients with DHC. There was no difference in favourable outcome after primary (25%) versus secondary (26.1%) DHC (p = 1.0). Subgroup analysis (brain swelling vs bleeding vs infarcts) revealed no difference in the rate of favourable outcome. In a multivariate analysis, acute hydrocephalus (p = 0.02) and clinical herniation (p = 0.03) were significantly associated with unfavourable outcome. We conclude that primary and secondary hemicraniectomy may be warranted, irrespective of the underlying aetiology-infarction, haemorrhage or brain swelling. The time from onset of intractable ICP to DHC seems to be crucial, rather than the time from SAH to DHC.
    Journal of neurology, neurosurgery, and psychiatry 08/2009; 80(7):799-801. · 4.87 Impact Factor
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    Article: Laser Doppler imaging for intraoperative human brain mapping.
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    ABSTRACT: The identification and accurate location of centers of brain activity are vital both in neuro-surgery and brain research. This study aimed to provide a non-invasive, non-contact, accurate, rapid and user-friendly means of producing functional images intraoperatively. To this end a full field Laser Doppler imager was developed and integrated within the surgical microscope and perfusion images of the cortical surface were acquired during awake surgery whilst the patient performed a predetermined task. The regions of brain activity showed a clear signal (10-20% with respect to the baseline) related to the stimulation protocol which lead to intraoperative functional brain maps of strong statistical significance and which correlate well with the preoperative fMRI and intraoperative cortical electro-stimulation. These initial results achieved with a prototype device and wavelet based regressor analysis (the hemodynamic response function being derived from MRI applications) demonstrate the feasibility of LDI as an appropriate technique for intraoperative functional brain imaging.
    NeuroImage 12/2008; 44(4):1284-9. · 5.89 Impact Factor
  • Article: A rare anomaly of the anterior communicating artery complex hidden by a large broad-neck aneurysm and disclosed by three-dimensional rotational angiography.
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    ABSTRACT: Double fenestration of the anterior communicating artery (ACoA) complex associated with an aneurysm is a very rare finding and is usually caused by ACoA duplication and the presence of a median artery of the corpus callosum (MACC). We present a patient in whom double fenestration was not associated with ACoA duplication or even with MACC, representing therefore, a previously unreported anatomic variation. A 43 year old woman experienced sudden headache and the CT scans showed subarachnoid haemorrhage (SAH). On admission, her clinical condition was consistent with Hunt and Hess grade II. Conventional digital subtraction angiography (DSA) was performed and revealed multiple intracranial aneurysms arising from both middle cerebral arteries (MCA) and from the ACoA. Three-dimensional rotational angiography (3D-RA) disclosed a double fenestration of the ACoA complex which was missed by DSA. The patient underwent a classic pterional approach in order to achieve occlusion of both left MCA and ACoA aneurysms by surgical clipping. The post-operative period was uneventful. A rare anatomical variation characterised by a double fenestration not associated with ACoA duplication or MACC is described. The DSA images missed the double fenestration which was disclosed by 3D-RA, indicating the importance of 3D-RA in the diagnosis and surgical planning of intracranial aneurysms.
    Acta Neurochirurgica 04/2008; 150(3):279-84; discussion 284. · 1.52 Impact Factor
  • Article: Transcranial and direct cortical stimulation for motor evoked potential monitoring in intracerebral aneurysm surgery.
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    ABSTRACT: To analyse the parallel use of transcranial electrical stimulation (TES) and direct cortical stimulation (DCS) for eliciting muscle motor evoked potentials (MMEPs) in intracranial aneurysm surgery; to correlate permanent or transient TES- and/or DCS-MMEP changes with surgical maneuvers and clinical motor outcome. TES and DCS were intraoperatively performed in 108 patients (51.5+/-14.7 years); MMEPs were obtained in muscles belonging to the vascular territory of interest. Monopolar, anodal stimulation was achieved with a train of five stimuli consisting of an individual pulse width of 0.5ms, an interstimulus interval of 4ms, a train repetition rate of 0.5-2Hz, and maximum stimulation intensities up to 200mA (TES) versus 25mA (DCS). In 95/108 (88%) patients, no changes in MMEPs occurred and none of these patients suffered a permanent severe motor deficit. In 14/108 (12%) patients, we observed nine (64%) temporary changes, four (29%) permanent deteriorations and one (7%) permanent MMEP loss. Out of 14 MMEP changes, nine (64%) occurred with TES, compared to 13 (93%) with DCS (Fishers'p=0.165). Parallel changes in TES- and DCS-MMEPs occurred in 8/14 patients (57%), in which case a permanent loss was always followed by a permanent severe motor deficit. Sixty-seven percent of all permanent changes occurred with DCS-MMEPs, compared to 33% with TES-MMEPs (p=0.567, NS). In aneurysm surgery, provided that close-to-motor-threshold stimulation and the most focal stimulating electrode montage are used, TES- and DCS-MMEPs do not differ in their capacity to detect an impending lesion of the motor cortex or its efferent pathways. TES stimulation can cause significant muscular contraction during surgery, potentially disrupting the operating surgeon. DCS maintains the singular advantage of stimulating a very focal and superficial motor cortex stimulation that does not result in patient movement.
    Neurophysiologie Clinique/Clinical Neurophysiology 01/2008; 37(6):391-8. · 1.98 Impact Factor
  • Conference Proceeding: Laser Doppler Imaging Opens New Perspectives for Intra-Operative Brain Mapping
    Fortieth Annual Meeting of the Union of Swiss Societies for Experimental Biology (USGEB'08); 01/2008
  • Chapter: Perfusion/diffusion-weighted imaging protocol for the diagnosis of cerebral vasospasm and management of treatment after subarachnoid haemorrhage
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    ABSTRACT: BacgkroundTo describe our protocol of perfusion/diffusion weighted imaging (PWI/DWI) for the diagnosis of cerebral vasospasm and for monitoring the effects of transluminal balloon angioplasty (TBA) in patients with subarachnoid haemorrhage (SAH). MethodCerebral vasospasm was diagnosed using a PWI/DWI protocol. TBA was used to dilate vasospastic arteries, and the PWI/DWI protocol was repeated after transluminal balloon angioplasty in 13 patients. Evaluation of the contrast medium passage with the bolus tracking method allowed for the calculation of the time to peak (TTP). Tissues at risk were diagnosed by perfusion delays in individual vessel territories as compared to reference territories. FindingsFollow-up PWI/DWI after angioplasty showed disappearance or decrease of the PWI/DWI mismatch. Reduction of a perfusion delay of 6.2 ± 0.85 sec (mean ± SEM) by TBA to 1.6 ± 0.40 sec resulted in the complete prevention of infarction; reduction of a delay of 6.2 ± 2.7 to 4.1 ± 1.9 sec resulted in the survival of the parts of brain tissue with only small infarcts. Without TBA, however, the perfusion delay remained or even increased (11.1 ± 3.7 sec) and complete territory infarcts developed. ConclusionsWith PWI/DWI, one is able to diagnose cerebral vasospasm leading to misery perfused tissue at risk. Based on the PWI/DWI results, one is able to control treatment, including TBA. PWI/DWI in SAH is a feasible, safe and effective tool for diagnoses and treatment decisions in cerebral vasospasm.
    12/2007: pages 241-244;
  • Chapter: A pharmacokinetic study of clazosentan in patients with aneurysmal subarachnoid haemorrhage
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    ABSTRACT: The objective of this study was to evaluate the pharmacokinetics of clazosentan, an endothelin receptor antagonist, in patients with aneurysmal subarachnoid haemorrhage (aSAH) intravenous. Blood samples were taken at different time points during and following infusion with 0.2–0.4mg/kg/h clazosentan, which lasted for up to 14 days. The results show that the pharmacokinetic properties of clazosentan in patients with aSAH are similar to those in healthy subjects. With increasing body weight, higher plasma concentrations were reached, suggesting that clazosentan in future clinical studies can be dosed on a mg/h rather than a mg/kg/h basis.
    12/2007: pages 125-126;
  • Article: Serum GFAP is a diagnostic marker for glioblastoma multiforme.
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    ABSTRACT: A serum marker for malignant cerebral astrocytomas could improve both differential diagnosis and clinical management of brain tumour patients. To evaluate whether the serum concentration of glial fibrillary acidic protein (GFAP) may indicate glioblastoma multiforme (GBM) in patients with single supratentorial space-occupying lesions, we prospectively examined 50 consecutive patients with histologically proven GBM, World Health Organization (WHO) grade IV, 14 patients with anaplastic astrocytoma (WHO grade III), 4 patients with anaplastic oligodendroglioma, 13 patients with diffuse astrocytoma (WHO grade II), 17 patients with a single cerebral metastasis and 50 healthy controls. Serum was taken from the patients before tumour resection or stereotactic biopsy. Serum GFAP levels were determined using a commercially available ELISA test and were detectable in 40 out of the 50 GBM patients (median: 0.18 microg/l; range: 0-5.6 microg/l). The levels were significantly elevated compared with those of the non-GBM tumour patients and healthy controls (median: 0 mug/l; range: 0-0.024 microg/l; P < 0.0001, respectively). Non-GBM tumour patients and all healthy subjects showed zero serum GFAP levels. There was a significant correlation between tumour volume (Spearman Rho, CC = 0.47; 95% confidence interval, 0.2-0.67; P < 0.001), tumour necrosis volume (CC = 0.49; 95% confidence interval, 0.2-0.72; P = 0.004), the amount of necrotic GFAP positive cells (CC = 0.61; 95% confidence interval, 0.29-0.81; P = 0.007) and serum GFAP level among the GBM patients. A serum GFAP level of >0.05 microg/l was 76% sensitive and 100% specific for the diagnosis of GBM in patients with a single supratentorial mass lesion in this series. Therefore, it can be concluded that serum GFAP constitutes a diagnostic biomarker for GBM. Future studies should investigate whether serum GFAP could also be used to monitor therapeutic effects and whether it may have a prognostic value.
    Brain 12/2007; 130(Pt 12):3336-41. · 9.46 Impact Factor
  • Article: Active secretion of S100B from astrocytes during metabolic stress.
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    ABSTRACT: In patients suffering from cerebrovascular diseases and traumatic brain damage, increases in serum levels of protein S100B are positively correlated with the severity of the insult. Since high concentrations of S100B have been shown to exert neurotoxic effects, the objective of this study was to characterize the regulatory mechanisms underlying control of S100B release from astrocytes. To that end, we analyzed the kinetics and amount of S100B release in correlation with regulation of S100B gene expression in an in vitro ischemia model. Astrocyte cultures were treated with combined oxygen, serum and glucose deprivation, serum and glucose deprivation or hypoxia alone for 6, 12 and 24 h, respectively. While oxygen, serum and glucose deprivation triggered the most rapid release of S100B, serum and glucose deprivation provoked comparable levels of released S100B at the later time points. In contrast to oxygen, serum and glucose deprivation and serum and glucose deprivation, hypoxia alone elicited only marginal increases in secreted S100B. Parallel analysis of extracellular lactate dehydrogenase and the number of viable cells revealed only moderate cell death in the cultures, indicating that S100B was actively secreted during in vitro ischemia. Interestingly, S100B mRNA expression was potently downregulated after 12 and 24 h of oxygen, serum and glucose deprivation, and prolonged oxygen, serum and glucose deprivation for 48 h was associated with a significant reduction of S100B release at later time intervals, whereas lactate dehydrogenase levels remained constant. Our data suggest that secretion of S100B during the glial response to metabolic injury is an early and active process.
    Neuroscience 10/2006; 141(4):1697-701. · 3.38 Impact Factor
  • Article: Serum glial fibrillary acidic protein as a biomarker for intracerebral haemorrhage in patients with acute stroke.
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    ABSTRACT: Biomarkers of stroke are an evolving field of clinical research. A serum marker which can differentiate between haemorrhagic and ischaemic stroke in the very early phase would help to optimise acute stroke management. To examine whether serum glial fibrillary acidic protein (GFAP) identifies intracerebral haemorrhage (ICH) in acute stroke patients. A pilot study assessing 135 stroke patients admitted within six hours after symptom onset. Diagnosis of ICH (n = 42) or ischaemic stroke (n = 93) was based on brain imaging. GFAP was determined from venous blood samples obtained immediately after admission, using a research immunoassay. GFAP was detectable in the serum of 39 patients (34 of 42 (81%) with ICH, and five of 93 (5%) with ischaemic stroke). Serum GFAP was substantially raised in patients with ICH (median 11 ng/l, range 0 to 3096 ng/l) compared with patients with ischaemic stroke (median 0 ng/l, range 0 to 14 ng/l, p<0.001). Using receiver operating characteristic curve analysis, a cut off point of 2.9 ng/l provided a sensitivity of 0.79 and a specificity of 0.98 for the identification of ICH in acute stroke (positive predictive value 0.94, negative predictive value 0.91; p<0.001). Serum GFAP can reliably detect ICH in the acute phase of stroke. Further evaluation of the usefulness of GFAP as an early diagnostic marker of ICH is now required, with the aim of optimising cause specific emergency management.
    Journal of Neurology Neurosurgery &amp Psychiatry 02/2006; 77(2):181-4. · 4.76 Impact Factor
  • Article: [Recommendations for the management of patients with aneurysmal subarachnoid hemorrhage].
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    ABSTRACT: After SAH, primary and secondary complications are frequent and often require neurosurgical interventions to avoid secondary brain damage. The authors of the present paper have summarized the available data about the treatment modalities often used for patients with SAH. The present recommendations have been developed as a neurosurgical and neuroanestesiological consensus. Evidence from prospective, randomized, double blind, placebo-controlled studies support grade A recommendations (standard) for the prophylaxis and treatment of cerebral vasospasm with oral Nimodipine in good grade patients. For intravenous Nimodipine or for oral nimodipine treatment in poor grade patients, available data only support grade C recommendations (options). Despite the lack of data supporting standards (grade A) or guidelines (grade B), avoidance and rigorous treatment of hypotension and hypovolemia remains the mainstay in the prophylaxis and treatment of a delayed ischemic neurological deficit (DIND). Prophylactic hypervolemia or prophylactic hypertension and hypervolemia was shown to be ineffective in reducing symptomatic vasospasm and improving outcome (grade B). Therapeutic hypertensive hypervolemic hemodilution is recommended as a treatment of symptomatic vasospasm but no prospective studies are available (grade C recommendation). Suggested target values for moderate triple-H-therapy are CPP 80- 120 mmHg (MAP 90-130), CVP > 7 mmHg and Hk 0.25-0.40. Balloon angioplasty should be considered for treatment of DIND cause by focal, proximal cerebral vasospasm. There is no evidence supporting the routine use of antifibrinolyticals, steroids or anticonvulsive prophylaxis. Clinical data indicate that current prophylaxis and treatment of cerebral vasospasm is still insufficient and aggressive triple-H-therapy is associated with an increased incidence of complications.
    Zentralblatt für Neurochirurgie 05/2005; 66(2):79-91. · 0.63 Impact Factor
  • Article: Technique and image quality of intraoperative indocyanine green angiography during aneurysm surgery using surgical microscope integrated near-infrared video technology.
    A Raabe, J Beck, V Seifert
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    ABSTRACT: To describe the technical integration of indocyanine green (ICG) near-infrared technology into the optical path of the surgical microscope and to report on the image quality achieved by this method. We hypothesized that ICG angiography permits a simple and quick intraoperative assessment of vessel patency and aneurysm occlusion after clip placement. A special arrangement of filters was designed to allow the passage of near-infrared light required for the excitation of ICG fluorescence (700-850 nm) from a modified microscope light source into the surgical field and the passage of ICG fluorescence (780-950 nm) from the surgical field back into the optical path of the surgical microscope (Carl Zeiss, Oberkochen, Germany). Thus, ICG angiography could be completely performed with a surgical microscope. 20 patients with intracranial aneurysms were included in the technical evaluation of the new method. Image quality and spatial resolution were excellent and permitted a real-time assessment of vessel patency and aneurysm occlusion if the structures of interest were visible to the surgeon's eye under the microscope, including perforating arteries with a diameter of less than 1 millimeter. In 1 patient, vessel occlusion by the clip was found and in 1 case residual filling of the aneurysm was diagnosed. Both cases could be treated by clip correction within 2 minutes after primary placement of the clip. In all cases, the intraoperative findings correlated with the postoperative digital subtraction angiography. ICG angiography using a surgical microscope is valuable for the intraoperative imaging of arterial and venous flow in all visible vessels including small perforating arteries. The simplicity of the method and the speed with which the investigation can be performed indicate that this technique may help to improve the quality and outcome of surgical procedures and reduce the need for intra- or postoperative angiography in selected cases.
    Zentralblatt für Neurochirurgie 03/2005; 66(1):1-6; discussion 7-8. · 0.63 Impact Factor
  • Article: Tissue at risk concept for endovascular treatment of severe vasospasm after aneurysmal subarachnoid haemorrhage.
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    ABSTRACT: To report a case of severe vasospasm after subarachnoid haemorrhage (SAH) where "tissue at risk" was identified by magnetic resonance imaging (MRI), and to demonstrate the haemodynamic consequences with either resolution of the perfusion-diffusion mismatch by balloon angioplasty or evolution of an infarct. A 45 year old women with SAH underwent surgical treatment of a ruptured middle cerebral artery (MCA) aneurysm. On day 3 she became obtunded and developed a right hemiparesis. Diffusion weighted (DWI) and perfusion weighted (PWI) imaging were done before and after transluminal balloon angioplasty (TBA) of multifocal proximal vasospasm. The initial MRI revealed no DWI lesion but PWI showed a severe perfusion deficit of 6.7 to 16.4 seconds in the complete left MCA territory. Digital subtraction angiography confirmed severe segmental narrowing of left C1 and M1. The spastic segments were successfully dilated by TBA. Follow up MRI showed that the PWI-DWI mismatch resolved in the anterior and middle MCA territory with no tissue infarction, whereas in the terminal dorsal MCA territory a severe mismatch remained and cerebral infarction evolved. PWI/DWI can identify tissue at risk for infarction in severe vasospasm following SAH. This may allow selection of patients for angioplasty and the monitoring of treatment effects.
    Journal of Neurology Neurosurgery &amp Psychiatry 01/2005; 75(12):1779-81. · 4.76 Impact Factor
  • Article: Robot-assisted navigated endoscopic ventriculostomy: implementation of a new technology and first clinical results.
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    ABSTRACT: Important landmarks in the evolution of advanced neurosurgical techniques during the past decades include microneurosurgery, neuro-endoscopy and its minimally invasive nature, as well as neuronavigation and advanced intra-operative imaging. With conventional neuroendoscopic techniques, e.g. free-hand endoscopy or the use of mechanical or pneumatic holding devices, a definitive and controlled movement of the endoscope within the brain does depend on the experience and manual skill of the individual neurosurgeon. Therefore, the development of robotic systems to assist surgeons in performing complex neurosurgical procedures is a growing field of interest. With the precision robot "Evolution 1" (U.R.S. Universal Robot Systems, Schwerin, Germany) a new neurosurgical tool has just become available for the precise steering of instruments within the cranium. After preclinical anatomical as well as precision studies the system was used for robot-assisted navigated endoscopic third ventriculostomies in six patients with hydrocephalus related to aqueductal stenosis. All robot-assisted navigated endoscopic procedures were successfully completed. The time for the registration procedure and setup of the robot decreased from 60 min. for the first procedure down to 30 min. The time for the surgical part of the neuro-endoscopic procedure itself ranged from 17 to 35 min. During all procedures no system-related complications occurred. The use of robotic technology for neuro-endoscopic third ventriculostomies is a major step towards the controlled movement of the neuro-endoscope within the cranium. The start up procedure and calibration of the robot is still time consuming, but the real operation time is comparable to free hand neuro-endoscopy. The steering of the endoscope is facilitated and the precision of the endoscopic movements is noteworthy.
    Acta Neurochirurgica 08/2004; 146(7):697-704. · 1.52 Impact Factor
  • Article: Severe delayed diffuse cerebral vasospasm and cerebral infarctions following spinal subdural hemorrhage.
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    ABSTRACT: We report a rare case of severe delayed cerebral vasospasm with cerebral infarctions after spinal subdural hemorrhage. A 56-year-old woman presented with an acute onset of paraplegia. MR-imaging revealed an extensive intraspinal hemorrhage reaching from T1 to L1. The hematoma was evacuated via a T8-laminectomy. At the 7th postoperative day the patient developed visual disturbances. MR-scanning revealed extensive infarctions and cerebral angiography showed severe diffuse vasospasms. This case demonstrates that cerebral vasospasm may be caused by a spinal subdural hemorrhage, supporting the hypothesis that cerebral vasospasm may be triggered by factors from a remote site and that a direct contact of blood clots with the vessel is not mandatory.
    Acta Neurochirurgica 06/2004; 146(5):517-20. · 1.52 Impact Factor
  • Conference Proceeding: Functional neuronavigation - risk grading for surgery in close proximity to eloquent motor cortex.
    CARS 2004. Computer Assisted Radiology and Surgery. Proceedings of the 18th International Congress and Exhibition, Chicago, USA, June 23-26, 2004; 01/2004
  • Conference Proceeding: Accuracy and applicability of laser surface scanning as new registration technique in image-guided neurosurgery.
    R. Krishnan, A. Raabe, V. Seifert
    CARS 2004. Computer Assisted Radiology and Surgery. Proceedings of the 18th International Congress and Exhibition, Chicago, USA, June 23-26, 2004; 01/2004
  • Article: Functional magnetic resonance imaging-integrated neuronavigation: correlation between lesion-to-motor cortex distance and outcome
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    ABSTRACT: OBJECTIVE: The integration of functional magnetic resonance imaging (fMRI) data into neuronavigation is a new concept for surgery adjacent to the motor cortex. However, the clinical value remains to be defined. In this study, we investigated the correlation between the lesion-to-fMRI activation distance and the occurrence of a new postoperative deficit. METHODS: fMRI-integrated "functional" neuronavigation was used for surgery around the motor strip in 54 patients. During standardized paradigms for hand, foot, and tongue movements, echo-planar imaging T2* blood oxygen level-dependent sequences were acquired and processed with BrainVoyager 2000 software (Brain Innovation, Maastricht, The Netherlands). Neuronavigation was performed with the VectorVision(2) system (BrainLAB, Heimstetten, Germany). For outcome analysis, patient age, histological findings, size of lesion, distance to the fMRI areas, preoperative and postoperative Karnofsky index, postoperative motor deficit, and type of resection were analyzed. RESULTS: In 45 patients, a gross total resection (>95%) was performed, and for 9 lesions (low-grade glioma, 4; glioblastoma, 5), a subtotal resection (80-95%) was achieved. The neurological outcome improved in 16 patients (29.6%), was unchanged in 29 patients (53.7%), and deteriorated in 9 patients (16.7%). Significant predictors of a new neurological deficit were a lesion-to-activation distance of less than 5 mm (P < 0.01) and incomplete resection (P < 0.05). CONCLUSION: fMRI-integrated neuronavigation is a useful concept to assess the risk of a new motor deficit after surgery. Our data suggest that a lesion-to-activation distance of less than 5 mm is associated with a higher risk of neurological deterioration. Within a 10-mm range, cortical stimulation should be performed. For a lesion-to-activation distance of more than 10 mm, a complete resection can be achieved safely. The visualization of fiber tracks is desirable to complete the representation of the motor system.
    Neurosurgery. 01/2004; 55(4):904-14.