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Daniel Rosenthal, Gerhard Marquardt, Ruediger Lorenz and Michael Nichtweiß

✓ It is well accepted that the treatment of spinal tumors that threaten neurological integrity comprises resection, vertebral body reconstruction, and stabilization if the patient's condition is suitable. In spite of the excellent results reported using thoracotomy, the majority of investigators recommend posterolateral techniques because of lower morbidity, shorter hospitalization time, and the possibility of performing dorsal stabilization via the same incision. To overcome some of the disadvantages of thoracotomy, the authors developed an anterior procedure that permits vertebrectomy, reconstruction, and stabilization to be performed entirely by endoscopic technique. Microsurgical endoscopy and stabilization were performed in four patients with metastatic disease of the thoracic spine. All were ambulatory after surgery and at follow up; preoperative neurological and neurophysiological deficits improved as well. No complications occurred in this small series. Microsurgical endoscopy achieves a substantial reduction in trauma, use of analgesic medications, and hospitalization time. Early results seem to indicate that adequate decompression, stabilization and reduction of surgical morbidity can be achieved with this technique.

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Acute posttraumatic spinal cord herniation

Case report and review of the literature

Gerhard Marquardt, Stefan Weidauer, Friedhelm E. Zanella and Volker Seifert

✓ Transdural herniations of the spinal cord are rare, and those occurring acutely after a spinal cord injury (SCI) are particularly unusual. In this report, the authors present the case of acute posttraumatic spinal cord herniation in a patient who sustained severe polytraumatic injuries. The clinical manifestations were acute flaccid paralysis of the right leg and rapidly progressive sensorimotor deficits of the contralateral leg. The herniation was surgically reduced. Postoperatively left leg paralysis was completely resolved. The authors review the pertinent literature, and suggest that, with regard to another underlying pathophysiological mechanism, cases of acute posttraumatic spinal cord herniation should be differentiated from those “posttraumatic” cases in which herniation of the spinal cord occurs years or even decades after the traumatic event. To the best of the authors' knowledge, only one similar case has been previously reported. They conclude that acute posttraumatic spinal cord herniation should be included in the differential diagnosis of acute neurological deterioration after SCI.

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Gerhard Marquardt, Soledad M. Barduzal Angles, Fouad D. Leheta and Volker Seifert

✓ A rare case of peripheral-nerve compression in the upper arm caused by a spontaneous venous aneurysm is reported. The apparent dysfunction of the median nerve led to various vain surgical explorations of the nerve at different levels. The real localization of nerve entrapment was identified by a thorough clinical examination, and sonography yielded a correct diagnosis. Surgical resection of the venous aneurysm resulted in complete relief of pain. To the authors' knowledge, this is the first report of a spontaneous venous malformation in the upper arm causing focal neuropathy.

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Rüdiger Gerlach, Gerhard Marquardt, Heimo Wissing, Inge Scharrer, Andreas Raabe and Volker Seifert

✓ The authors report on a 64-year-old woman with a huge recurrent skull base hemangiopericytoma, in whom they encountered severe difficulty in attaining intraoperative hemostasis. Standard surgical hemostatic methods and the administration of fresh-frozen plasma and prothrombin complex concentrates failed to stop diffuse bleeding from an inoperable tumor remnant. At a critical point during the operation, the intravenous administration of recombinant activated factor VII, combined with mechanical compression, finally led to satisfactory hemostasis. The rationale for using recombinant activated factor VII in situations of uncontrolled bleeding during neurosurgical procedures is discussed, along with the literature in which the use of recombinant activated factor VII as a maneuver of last resort is reported for hemostasis in other surgical fields.

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Sebastian Herminghaus, Thomas Dierks, Ulrich Pilatus, Walter Möller-Hartmann, Jörg Wittsack, Gerhard Marquardt, Christoph Labisch, Heinrich Lanfermann, Wolfgang Schlote and Friedhelm E. Zanella

Object. In this study, 1H magnetic resonance (MR) spectroscopy was prospectively tested as a reliable method for presurgical grading of neuroepithelial brain tumors.

Methods. Using a database of tumor spectra obtained in patients with histologically confirmed diagnoses, 94 consecutive untreated patients were studied using single-voxel 1H spectroscopy (point-resolved spectroscopy; TE 135 msec, TR 1500 msec). A total of 90 tumor spectra obtained in patients with diagnostic 1H MR spectroscopy examinations were analyzed using commercially available software (MRUI/VARPRO) and classified using linear discriminant analysis as World Health Organization (WHO) Grade I/II, WHO Grade III, or WHO Grade IV lesions. In all cases, the classification results were matched with histopathological diagnoses that were made according to the WHO classification criteria after serial stereotactic biopsy procedures or open surgery. Histopathological studies revealed 30 Grade I/II tumors, 29 Grade III tumors, and 31 Grade IV tumors. The reliability of the histological diagnoses was validated considering a minimum postsurgical follow-up period of 12 months (range 12–37 months). Classifications based on spectroscopic data yielded 31 tumors in Grade I/II, 32 in Grade III, and 27 in Grade IV. Incorrect classifications included two Grade II tumors, one of which was identified as Grade III and one as Grade IV; two Grade III tumors identified as Grade II; two Grade III lesions identified as Grade IV; and six Grade IV tumors identified as Grade III. Furthermore, one glioblastoma (WHO Grade IV) was classified as WHO Grade I/II. This represents an overall success rate of 86%, and a 95% success rate in differentiating low-grade from high-grade tumors.

Conclusions. The authors conclude that in vivo 1H MR spectroscopy is a reliable technique for grading neuroepithelial brain tumors.

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Elke Hattingen, Catriona Good, Stefan Weidauer, Sebastian Herminghaus, Peter Raab, Gerhard Marquardt, Andreas Raabe, Volker Seifert and Friedhelm E. Zanella

Object. The goal of this study was to evaluate a novel form of brain surface representation that allows simple, reliable mapping of the surface neuroanatomy for the preoperative evaluation of the spatial relationship between a focal lesion and the precentral gyrus.

Methods. High-resolution three-dimensional (3D) magnetic resonance (MR) imaging data sets were postprocessed using a curved multiplanar reformatting technique to create brain surface reformatted (BSR) images. These BSR images were reconstructed in less than 5 minutes and demonstrated the entire central sulcus with adjacent surface structures in one view. Two experienced neuroradiologists determined the localization of lesions near the central sulcus in 27 patients on standard MR images in three orthogonal planes and on BSR images. In addition, these observers judged whether the lesions were easy or difficult to localize on standard MR and BSR images, and whether diagnoses based on these methods were certain or doubtful. Anatomical localization based on BSR images was compared with that based on functional MR (fMR) images or intraoperative mapping of motor function. The BSR images yielded a perfect concordance with the fMR images and intraoperative mapping (Cohen κ 1.0) and optimal diagnostic accuracy in localizing perirolandic lesions (both sensitivity and specificity were 100%). Localization was judged to be easy for 48 of 54 diagnoses based on BSR images compared with 26 of 54 based on standard MR images. Diagnoses were assessed as certain for 52 cases based on BSR images and 34 cases based on standard MR images.

Conclusions. Brain surface reformatted imaging improves the diagnostic accuracy of standard anatomical MR imaging for localizing superficial brain lesions in relation to the precentral gyrus. The complementary use of this technique with standard two-dimensional imaging is supported by the fast and simple postprocessing technique and may provide useful information for preoperative surgical planning.

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Gerhard Marquardt, Matthias Setzer, Alf Theisen, Edgar Dettmann and Volker Seifert

Object. The goal of this study was to develop a novel dynamic model for experimental spinal cord compression that closely approximates neoplastic epidural compression of the spinal cord in humans.

Methods. In 30 New Zealand white rabbits, the thoracic spine was exposed via a posterior approach. On each side of one vertebral lamina a small hole was drilled caudal to the articular process. A silicone band was passed through these holes, forming a loop. The spinal dura mater was exposed via an interlaminar approach. The loop was brought into contact with the dura mater and fixed in its position encircling 270° of the circumference of the spinal cord. Thereafter, the loop was gradually tightened at set times by pulling at the ends of the band and fixing them again in their new position. The spinal cord was thus increasingly compressed in a circular and dynamic manner.

Neurological deficits of various degrees were created in all animals in the compression group, and the compressive effect of the loop was reliably demonstrated on MR imaging. After decompression of the spinal cord, the neurological deficits were reversible in the majority of animals, and MR imaging revealed either no signal changes or only circumscribed ones within the cord. In contrast, MR images obtained in animals that did not recover revealed the occurrence of extensive chronic myelopathy.

Conclusions. This novel model features reproducibility of paresis and neurological recovery. It is a dynamic model simulating circular tumor growth and is characterized by its easy, straightforward, and cost-saving applicability.

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Matthias Setzer, Hartmut Vatter, Gerhard Marquardt, Volker Seifert and Frank D. Vrionis

Object

In this report, the authors describe their experience in the surgical management of spinal meningiomas at two neurosurgical centers. The results of a literature review are also presented.

Methods

Eighty consecutive patients (22 men and 58 women) with spinal meningiomas who had undergone an operation at two specific neurosurgical centers were included in this study. Functional outcomes were evaluated using univariate and multivariate analyses. A review of the literature yielded an additional 651 patients with spinal meningiomas from 9 large studies.

Results

On multivariate analysis, the variable of a poor preoperative neurological state (p < 0.02, odds ratio [OR] 13.6, 95% confidence interval [CI] 2.6–71.4) and invasion of the arachnoid/pia mater (p < 0.03, OR 15.2, 95% CI 2.5–90.4) were independent predictors of a poor outcome, whereas invasion of the arachnoid/pia (p < 0.02, OR 8.9, 95% CI 2.2–35) and duration of symptoms (p < 0.001, OR 1.12/month, 95% CI 1.05–1.2) predicted no improvement (stable or deteriorated condition). The Cox proportional hazards regression analysis showed three significant predictor variables for recurrence: invasion of the arachnoid/pia (p < 0.05; hazard ratio [HR] 1.8, 95% CI 1.2–3.6), Simpson resection grade (p < 0.012, HR 6.8, 95% CI 1.5–3.0), and histological tumor grade (Grade I; p < 0.001, HR 0.001–0.17).

Conclusions

Because of the excellent outcome of surgery for benign spinal meningiomas and the association between duration of symptoms and neurological compromise with a poor functional outcome, early operation is the treatment of choice. In cases of malignant transformation, adjuvant therapies must be considered.

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Hischam Bassiouni, Siamak Asgari, I. Erol Sandalcioglu, Volker Seifert, Dietmar Stolke and Gerhard Marquardt

Object

In this study, the authors' goal was to analyze a series of patients treated microsurgically for an anterior clinoid process (ACP) meningioma in regard to long-term functional outcome.

Methods

The authors retrospectively analyzed clinical data in a consecutive series of 106 patients who underwent microsurgical treatment for an ACP meningioma at 2 neurosurgical institutions between 1987 and 2005. The main presenting symptoms of the 84 female and 22 male patients (mean age 56 years) were visual impairment in 54% and headache in 28%. Physical examination revealed decreased visual acuity in 49% and a visual field deficit in 26%. Tumors were primarily resected via a pterional approach. Meningioma extensions invading the cavernous sinus, present in 29% of the patients, were not removed. Complete tumor resection (Simpson Grade I and II) was achieved in 59% of the cases.

Results

Postoperatively, visual acuity improved in 40%, was unchanged in 46%, and deteriorated in 14%. A new oculomotor palsy was observed in 8 patients (8%). Clinical and MR imaging data were available in 95 patients for a mean postsurgical period of 6.9 years (1.5–18 years) and revealed tumor recurrence in 10% and tumor progression after subtotal resection in 38%. Clinical deterioration on long-term follow-up consisting primarily of ophthalmological deficits was observed in 14% of the cases.

Conclusions

Acceptable functional results can be achieved after microsurgical resection of ACP meningiomas; however, long-term treatment remains challenging due to a high tumor recurrence and progression rate.