Biomedical subjects
Publications and source records attributed to S Kunze.
Reducing the cerebrospinal flow is the task of siphon-reducing devices (SRD). This paper shows test results with SRD, with special reference to the aspect of dysfunction of shunt valves in combination with anti-siphon. The local influences acting on the anti-siphon at the place of implantation and the dependence of the pressure range were examined as possible causes of dysfunction.
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In the vast majority of studies that address the role of surgery in the management of high-grade gliomas, the degree of tumor removal accomplished is solely based on the intraoperative perception of the neurosurgeon. Despite its fundamental importance for a comparison of different treatment modalities, little systematic effort has been made to evaluate the residual gross tumor by neuroimaging methods immediately after surgery. We report the results of a prospective study using contrast-enhanced computed tomography and magnetic resonance imaging (MRI) to monitor 60 patients after the resection of a high-grade glioma. In each case, the first scans were obtained between Days 1 and 5 after surgery, followed by serial imaging every 2 to 3 months, usually until the condition of the patient deteriorated severely or the patient died. Gadolinium-enhanced MRI proved to be extremely valuable for assessing gross residual tumor when performed during Days 1 to 3 after the resection of a preoperatively enhancing high-grade glioma. This timing avoided surgically induced contrast enhancement and minimized interpretative difficulties. In delineating residual tumor, MRI was vastly superior to computed tomography. About 80% of tumor "recurrences" emerged from definitely enhancing remnants, as revealed by early postoperative MRI. The neurosurgeon's estimation of gross tumor burden reduction could be shown to be much less accurate (by a factor of 3) than the postoperative assessment by modern neuroimaging. In our series, residual tumor enhancement was the most predictive prognostic factor of survival in patients with glioblastoma, followed by radiotherapy. Patients with a residual tumor postoperatively had a 6.595-times higher risk of death in comparison to patients without a residual tumor. Patients undergoing radiotherapy had a 0.258-times lower risk of death in comparison to patients who were not treated with radiation. Concerning survival, the prognostic significance of both variables surpassed age and performance.
The introduction of early aneurysm surgery in subarachnoid hemorrhage in the beginning of the eighties diminished the frequency of rebleeding. However, there are some objectives against early surgery due to its supposed higher morbidity. The present retrospective data elucidates the advantage of early aneurysmal surgery. In 1990 and 1991 we treated 175 patients with subarachnoid hemorrhage, of which 9 had no vascular malformation. In 166 patients a total of 190 aneurysmal malformations could be found. Of 60 patients with preoperative good clinical grades I and II (according to Hunt and Hess) 59 patients (99%) showed good or very good results classified by the Glasgow Outcome scale (GOS). Only one patient did not survive. Even in 61% of patients with poor grade aneurysms (III to V by Hunt and Hess) the outcome was good to very good; 15 patients (14%) survived with a distinct neurological deficit (grade 3 by GOS). Only one patient remained in a vegetative state. The total mortality of these 106 patients with grades III to V (Hunt and Hess) was 24%, among them 15 patients with preoperative grade V (Hunt and Hess). Overall it can be established, that there are no definite disadvantages of early aneurysmal surgery. The benefits of early surgery are a minimized risk of rebleeding, some effects of ameliorated conditions for intensive care treatment still have to be proven. Not only patients in good clinical condition (I and II by Hunt and Hess) show a good prognosis, even for patients with poor grade aneurysms (III to V by Hunt and Hess) a very good or at least good result can be achieved in 61%.
Postoperative magnetic resonance imaging (MRI) of glioblastomas to assess residual tumour should be performed within the first 4 days following surgery. Early methaemoglobin formation near the resection site may mimic residual tumour if only gadolinium-DTPA-enhanced images are obtained. In a prospective study 24 of 54 patients (44%) showed well-defined areas of increased signal intensity on unenhanced T1-weighted images performed soon after surgery. By in vitro experiments we showed that hydrogen peroxide used in neurosurgery as a styptic agent accelerates formation of methaemoglobin when added to whole blood samples.
A method is described in which we use a combined endovascular balloon-catheter technique and open microneurosurgical approach for clipping aneurysms of the proximal paraclinoidal intracranial segment of the internal carotid artery. By temporary occlusion of the cervical carotid artery and continuously retrograde sucking of blood from the distal vessel via a double-lumen balloon-catheter, clip application to large and critically located aneurysms is facilitated applying evacuation-decompression to the trapped arterial segment under intra-operative SEP-monitoring.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Thirty patients with lesions due to the rupture and repair of an aneurysm of the anterior communicating artery were compared neuropsychologically with 27 patients with ruptures but no lesions and 30 normal control subjects. Patients with combined lesions in the basal forebrain and striatum (n = 5), or basal forebrain, striatum, and ventral frontal cortex (n = 7), had severe memory deficits, whereas patients with lesions in the basal forebrain (n = 7) or the striatum (n = 5) alone showed virtually no deficits. Patients with lesions of the basal forebrain and ventral frontal cortex together (n = 6) showed mild memory deficits. In contrast to the memory effects, emotional changes were most pronounced in patients with striate lesions alone. Basal forebrain or ventral frontal lesions ameliorated rather than aggravated the emotional effects of striate lesions. It is suggested that the basal forebrain and the striatum form links of different pathways related to mnemonic information processing. Both systems may be able to compensate for a dysfunction of the other, but lesions of both systems together may lead to strong and unrecoverable memory deficits.
"Radiosurgery" is the term for a special concept in radiotherapy. It describes a percutaneous, stereotactically guided irradiation delivering a single high dose with collimated narrow beams. The precise stereotactic localization of the target point and a steep dose gradient outside the target volume allow the administration of high doses to a lesion without damage to adjacent normal tissue. Risk of necrosis, due to a dose volume relationship represents the limits of radiosurgery. Units for radiosurgery were designed at Stockholm using multiple external cobalt-60-gamma sources, at Boston operating with protons of a cyclotron, at Berkeley operating with helium ions accelerated by a synchrocyclotron. An attractive alternative to these complicated and expensive facilities is the use of a modified linear accelerator. At the German Cancer Research Center in Heidelberg such a system was developed and has been available for the treatment of patients since 1984. Though, data of over 100,000 patients with vascular malformations and cancer disease are available worldwide, the indication for this therapy is validated only for a minority of entities. In cases of inoperable arteriovenous malformations favourable results in achieving obliteration range between 60% and 100% were obtained. Median survival for solitary brain metastases with controlled, extracerebral tumor diseases were between nine and twelve months. Up to now, advantages of stereotactic irradiation for benign tumor masses could not be proven. Therefore, randomized trials should be initiated in this field, considering decisive improvements in local tumor control with techniques of microsurgery and fractionated, postoperative radiotherapy during the last few years.
Twelve commercially available sets for drainage of cerebrospinal fluid were tested for handling, design, features for fixation of the ventricular catheter, reliability of the anti-reflux valve, obstruction, efficiency of the air ventilation filter caps, accuracy of flow measurement and adjustment of flow, quality of material, adjustment, and cost. All systems showed considerable deficiencies in their reliability and handling. None of them can be recommended without certain restrictions and they should all be revised.
This study was designed to assess the diagnostic value of 3D time-of-flight MR-angiography in cerebral cavernomas. In seven patients, nine out of ten cavernomas were removed by microsurgery. While MR-angiography demonstrated well branches of brain arteries adjacent to the lesions, no flow signal in the vascular malformations was observed. On the other hand, there was a high intensity signal induced by methaemoglobin in those three patients with brainstem cavernomas who had experienced a significant bleeding attack seven months prior to admission. It had a spotted appearance in MR-angiography with volumes of the largest spots around 1.8 cm3. It is suggested that this spot signal could be used as a path marker for the surgical approach in brainstem cavernomas.
A rare case of a true hernia of the spinal cord through a dural defect without evidence of acute trauma is presented. The cause and the differentiation from other congenital and traumatic spinal cord lesions, especially arachnoid cysts, are discussed.
Anti-Siphon devices need a siphon length of about 25 cm H2O to activate them. SCD and ASD show a dependence on the prepressure. The subcutaneous pressure can obstruct Anti-Siphon devices.
In a population-based case-control study in the Rhein-Neckar-Odenwald area (containing 1.3 million inhabitants) of the Federal Republic of Germany (FRG), risk factors were assessed for brain tumor development in 226 cases with primary brain tumors (ICD-9 191, 192.1, 192.0) and 418 population controls, interviewed by a standardized questionnaire. The analysis of occupational risk factors and smoking is presented. No elevated risk was found for smoking. Similarly, no significant effects were found for most occupations. Five specific occupational groups were examined because of a priori determination that they were of interest. Some categories showed slightly elevated risks but in none was the elevation statistically significant. A significant increase in risk for brain tumor development was found associated with working in electrical occupations for women (relative risk [RR] = 5.2; 95 percent confidence interval [CI] 1.4-20.1) but not for men (RR = 0.9, 95 percent CI 0.3-2.3).
Nimodipine, now widely used for treatment and prevention of cerebrovascular spasm, is regarded as a safe drug. Despite a preferential action on cerebral vessels, there is clinical and experimental evidence of effects on systemic vascular and intestinal smooth muscle cells. Gastro-intestinal side-effects, however, have not been reported in clinical studies dealing with treatment of vasospasm following subarachnoid haemorrhage. We report on a patient with subarachnoid haemorrhage who developed an acute life-threatening pseudo-obstruction of the colon, a variant of adynamic ileus, while being treated with intravenous nimodipine. The relationship between this complication and calcium antagonist therapy is discussed and therapeutic strategies are presented. We conclude that neurosurgeons and neurologists should be aware of calcium antagonist--related ileus in patients treated with nimodipine.
A case of supratentorial hemangioblastoma combined with two hemangiomas of the liver without manifestation of von Hippel-Lindau disease is presented. The cerebral cystic hemangioblastoma was localized in the right parietal lobe and contained a calcified area but no visible mural solid nodules. The CT and MRT differential diagnosis (arachnoidal cyst, glioma, Echinococcosis, hamartoma and metastasis) is discussed, and the literature on the subject is reviewed.