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Biomedical subjects

J Schöche

Publications and source records attributed to J Schöche.

At least 19 recordsLinked to original sources
PubMed1999

Lamotrigine concentrations in human serum, brain tissue, and tumor tissue.

PURPOSE: Although lamotrigine (LTG) has been used for years as an antiepilepic drug (AED), there are no data on penetration into the brain with the exception of a single case report. It was our aim to determine the LTG content in the brain and the tumor tissue and to bring the same into relation to the serum concentration and protein binding in neurosurgically operated patients. METHODS: Neurosurgical intervention was performed on 11 patients with brain tumors. Tumor tissue was removed, and LTG kinetics was carried out for 12 h. LTG was determined by means of (HPLC) and the protein binding by means of ultrafiltration. RESULTS: At the time of the section of the tumor, the LTG concentrations in the serum were an average of 3.7 microg/ml (range, 1.1-9.8); in the brain, an average of 6.8 microg/g (range, 1.0-14.9); and in the tumor, an average of 4.4 microg/g (range, 2.0-8.3). Brain/serum and tumor/serum ratios of 2.8 and 1.9, respectively, result from these data. The protein binding was on average 68% (range, 46-96). CONCLUSIONS: LTG is a lipophile AED with a moderate protein binding that penetrates brain tissue well and can be proven even in the tumor tissue.

Adult↗
PubMed1998

An avoidable methodological failure in intracranial pressure monitoring using fiberoptic or solid state devices.

Failure of intraventricular pressure (IVP) measurement in case of catheter blockage is believed to be eliminated by using intraventricular microtransducers. We report about an avoidable methodological error, which may affect the reliability of IVP measurement with these devices. Intraventricular fiberoptic or solid state devices were implanted in 43 patients considered to be at risk for catheter occlusion. Two different types were used: devices where the transducer is placed inside the ventriculostomy catheter (Type A), and devices where the transducer is integrated in the external surface of the catheter (Type B). Of the 15 patients treated with Type A devices, no reliable pressure recording could be obtained in three patients where ventricular puncture was not successful. In four cases of the remaining 12 patients, periods of erroneous pressure readings were revealed. After opening of CSF drainage, all Type A devices failed to reflect real IVP. In patients treated with Type B devices, no erroneous pressure recording could be identified, irrespective if CSF drainage was performed or not. Transducers, which are simply placed inside the ventriculostomy catheter require fluid coupling. They may fail, either during CSF drainage or when the catheter is blocked or placed within the parenchyma.

Catheters, Indwelling↗
PubMed1998

Reliability of intraventricular pressure measurement with fiberoptic or solid-state transducers: avoidance of a methodological error.

OBJECTIVE: The failure of intraventricular pressure measurement in cases of catheter blockage or dislodgement is thought to be eliminated by using intraventricular microtransducers. We report on an avoidable methodological error that may affect the reliability of intraventricular pressure measurement with these devices. METHODS: Intraventricular fiberoptic or solid-state devices were implanted in 43 patients considered to be at risk for developing catheter occlusion. Two different types were used, i.e., devices in which the transducer is placed inside the ventriculostomy catheter (Type A) and devices in which the transducer is integrated in the external surface of the catheter (Type B). Type A devices were used in 15 patients and Type B devices in 28 patients. Pressure recordings were checked at bedside for the validity and reliability of the measurement. RESULTS: Of the 15 patients treated with Type A devices, no reliable pressure recordings were able to be obtained in three patients in whom ventricular punctures were not successful. In 4 of the remaining 12 patients, periods of erroneous pressure readings were detected. After opening of cerebrospinal fluid drainage, all Type A devices failed to reflect real intraventricular pressure. In patients treated with Type B devices, no erroneous pressure recordings were able to be identified, irrespective of whether cerebrospinal fluid drainage was performed. Even when ventricular puncture failed, pressure measurement was correct each time. CONCLUSION: Transducers that are simply placed inside the ventriculostomy catheter require fluid-coupling. They may fail, either during cerebrospinal fluid drainage or when the catheter is blocked or placed within the parenchyma.

Catheters, Indwelling↗
PubMed1998

Reliability of epidural pressure measurement in clinical practice: behavior of three modern sensors during simultaneous ipsilateral intraventricular or intraparenchymal pressure measurement.

OBJECTIVE: In recent years, new devices for epidural pressure (EDP) measurement have been developed, with claims of improved accuracy. However, there have been no new data from simultaneous pressure measurements to reverse the skepticism regarding this technique. METHODS: The reliability of EDP recording was investigated in 26 patients with severe head injuries, during simultaneous measurement of ipsilateral intraventricular pressure (IVP) or intraparenchymal pressure (IPP). RESULTS: Periods of simultaneous measurement ranged from 3.3 to 168 hours. Technical failure occurred in five cases. Clinically significant erroneous pressure values (defined as differences of >10 mm Hg between EDP and IVP or IPP, lasting for >10 min) occurred in 7 of 21 measurements (33%). In three of these seven cases (43%) the difference between the EDP and the IVP or IPP remained nearly stable throughout the period of observation, whereas in four cases (57%) significant drifting over time was observed. Analysis of the transfer function calculated for the first to sixth harmonics between the EDP and the IVP or IPP showed no significant differences between the pulse pressure waveforms, even when significant drifting of more than 20 mm Hg occurred. CONCLUSION: The reliability of EDP measurement has not improved, compared with 10 years ago. Using this technique, one must be aware of the possibility of overestimating intracranial pressure by more than 10 mm Hg and the possibility of significant drifting of EDP over time, which argues against the use of this method even for trend analysis.

Brain Edema↗
PubMed1990

[External fixation in the treatment of cervical fractures].

A report is given on the application of external fixateurs for the treatment of complicated fractures of the cervical vertebral column and fractures of the dens. Basic principles of application and construction are represented. The effectiveness of the method if an intraspinal space occupation is excluded is proved by means of X-ray pictures.

Cervical Vertebrae↗
PubMed1990

[Histomorphologic findings of suction material following removal of brain tumor using ultrasound aspiration].

In the cellular examination of suction material of 100 brain tumour operations, which was obtained by means of ultrasound aspiration, the following essential findings were obtained: Homogenisation, cavitation, cellular changes, effects on the vascular walls, and very rarely small-area haemorrhages. The determination of the tumour type was possible in all cases, the results were checked by independently performed biopsies.

Astrocytoma↗
PubMed1986

[Tumor removal using performance ultrasound. Report of 50 brain tumor operations].

A report is given on the method of the tumour aspiration of cerebral tumours by means of power ultrasound. After classical exposure of the tumour--obligatory performance with physical-pharmacological reduction of the metabolism and in most cases under hypotension--the tumour is destroyed by ultrasonic power and simultaneously aspirated. A report is given on 50 cerebral tumour operations, which were carried out in Karl-Marx-Stadt within two years, using the tumour aspiration system "Aspirus 120". Finally the advantages of the method are summarised and dangers interpreted. At the end a valuation of the method is attempted and an outlook is given.

Brain↗
PubMed1986

[Operations of vascular brain tumors using pharmacologico-physical metabolic depression and hypotension. Report of experiences in 50 operations].

On the basis of experience gained in operations for cerebral tumours rich in blood vessels in 50 patients the advantages of the combination of a pharmacological-physical reduction of the metabolism and hypotension is dealt with. Nitroprusside sodium hypotension is inferior to this procedure. The experience gained in the different groups is broken down in detail.

Adult↗
PubMed1984

[Brain tumor removal with an ultrasound aspirator].

A report is given on the application of an ultrasound aspirator for the removal of cerebral tumours. After the description of physical and surgical fundamentals, a report is given on the respective patients. Then hazards an advantages are described as far as they can be summarized already today.

Brain Neoplasms↗
PubMed1982

[Angioarchitecture of gliomas. 2. Vessel models from experimental brain tumors in experimental animals].

The paper submits the results of the study of vascular models of experimental brain tumours in 20 Wistar rats and 20 rabbits from inbred races. These were transplantation tumours of the type of the dedifferentiated astrocytomas. First, the authors give a survey of the transplantation technique, the preparation of the vascular models and the advantages and disadvantages of the individual injection methods. The individual findings of the change in the blood supply of the brain, the vascular transformation by the tumour and the new formations of the tumour vessels are described and illustrated by pictures. Signs of true tumour vessels were: I. Caliber fluctuations, vascular occlusions and breaks; 2. Loss of direction property of the vessels, normal division and anastomosing; 3. Insufficiency of the vascular wall with extravasates and short-circuits; 4. Vascular bulgings with formation of pseudoaneurysms, meanders and blood puddles. The individual tumour vessel signs were found in a typical arrangement which permitted a classification of the tumour. Especially in the region of necroses and in the periphery of the tumour, the changes of the tumour vessels could not be strictly differentiated from reactive changes especially in the venous region.

Animals↗
PubMed1980

[Angioarchitecture of gliomas. 1: Models of cerebral vessels, casting materials, preparation methods, changes in tumor vessels].

A report is given on the study of cerebrovascular systems in experimental animals and corpses and the demonstration of cerebral tumours be means of models of vascular system. After a survey of the development of model representation, the technique of the vessel injection, the various injection materials and methods of preparation are described in detail. Advantages and disadvantages of the individual methods and certain peculiarities in model representations of transplantation tumours and various human brain tumours are presented. Besides, a multitude of pictures which document the results of the experiments, general laws of the tumour development, angioarchitectufe of the cerebral tumours and the changes in pre-existing and newly formed vessels in and around the tumour are briefly dealth with. The individual results of systematic investigations into the vascular system of cerebral tumours--of human brain vessel models, of transplantation tumours and special angioarchitecture of gliomatous brain tumours--will be published in individual articles appearing later.

Animals↗
PubMed1980

[Clinical picture of malignant extradural tumors of the spine].

The postoperative prognosis of malignant extradural spinal tumours still is unfavourable with regard to both functional restitution and postoperative survival time. Short anamnestic times and severe neurological attacks developing within a short period of time up to a complete transverse paraplegia syndrome characterise the clinical picture. In addition to the usually existing increase in the lumbar cerebrospinal protein level (86 per cent), pathological native X-ray findings are found condierably more frequently than in processes of other topical localisations (72 per cent). In three quarters of the cases the pantopaque myelogram shows complete contrast medium passage disturbances. In 10.8 per cent of the cases, an improvement of the findings could be achieved by an operation, 76.9 per cent showed an unchanged condition up to four weeks post operationem and in 12.3 per cent a deterioration of the condition had occurred. The average survival times of the deceased patients was 4.1 months. Prolonged survival times between three and six years were only seen in two retothelial sarcoma patients and one sarcoma patient. The cause of the unfavourable functional results are believed to be due to medullary circulation disturbances which are caused by the tumour and can non longer be influenced by an operation. In spite of the results being frequently unfavourable, a general rejection of the operation does not seem to be justified. It should, however, be rejected when (I) a complete transverse lesion syndrome has been present for several months, (2) extensive vertebral destruction can be demonstrated, (3) multiple destruction foci are present and (4) there ist an advanced stage of the primary process with a highly reduced general condition.

Humans↗
PubMed1980

[Follow-up study of benign tumors of the spine].

A report is given on long-term results after the removal of spinal mengiomas and neurinomas. A total of 150 patients with meningiomas and 80 patients with spinal neurinomas were operated on within a period of 25 years at the Neurosurgical Clinic in the Division Medicine of the Karl-Marx-University Leipzig. The primary results of the operations are secertained by a comparison of the preand portoperative ability to walk. Improvements were found in one third of all patients after meningioma operations and in more than ten per cent of the patients after removal of a neurinoma. The long-term rests were ascertained by means of questioning all patients that could be contracted after 2 to 25 years, sending them a questionaire in the form of a reply card. The number of patients who had become able to walk had doubles as compared with the condition before the operation: 56 per cent of all patients after meningioma operations and 64 per cent of all patients after removal of a spinal neurinoma. The long-term results have not been mainly influenced by the age of the patients and by the duration of the anamnesis. The greatest threat for patients with benign spinal tumours are the misjudging of the disease and a certain loss of time when paralysis was threatening. The prognosis in operations for relapses was considerably worse. So radical surgery in the first intervention must be attached the greatest importance. A tendency to infiltrations in case of meningiomas, especially in juvenile patients, and the overlooking of the smallest parts of extradural tumours in case of neuromas are frequent causes of the development of relapses and should be taken into account when carrying out the first ingervention.

Adolescent↗
PubMed1979

[X-ray diagnosis of meningiomas in childhood and adolescence].

In a period of 15 years, 16 intracranial meningiomas of the childhood and adolescence were examined radiologically. The neuroradiological findings obtained are analysed and compared with those obtained in adults. The particularities resulting from this comparison, which above all concern the angiographic picture of meningiomas in juvenile patients, are worked out and discussed. As a result, some conclusions can be drawn which may be of practical importance: As is the case with other cerebral tumours in childhood, meningiomas in most cases give rise to reliable radiological signs of an increase in intracranial pressure. The changes of the cranial bones indicating the presence of a meningioma, which are well-known signs in adults, are found in children almost as frequently. While pneumo-encephalography in most cases permits a reliable localisation of the tumour, it does not permit a diagnostic statement with respect to the kind of the tumour. In three patients the air filling made larger cysts visible which obviously occur more frequently in children than in adults. The angiographic picture of meningiomas in childhood often differs from that in adults with regard to the vascularisation type as well as the phase course, so that differential-diagnostic difficulties may arise. However, when considering the above mentioned peculiarities of the vascular picture of memingiomas in children, it appears to be possible to make a preoperative diagnosis of the kind of the tumour with the help of the angiogram also for children. The increased vascular supply via branches of the A. carotis externa, which is frequently found in neningiomas, cannot in our opinion be considered as a decisive type-diagnostic criterion; it must be considered as an expression of an increased participation of the dura and thus also occurs in other space-occupying intracranial processes.

Adolescent↗
PubMed1979

[Sciatic pain and intervertebral disc prolapse after gynecologic operations].

Among 65 patients operated by lumbar disc in 1977 we encountered 5 women after gynecological tumour operations. 4 of those patients not became symptom free. The relation of mechanical factors, obstruction and circulation changes seemed to be of importance for the evaluation of ischialgia in those cases and led to spinal root and root sheath damages.

Castration↗
PubMed1978

[Deadly brain injuries (author's transl)].

Among 503 deadly brain injuries 71% have been caused by traffic accidents. In 93 patients the brain injury was not the direct cause of death. Total observations included: 170 intracranial haemorrhages; 106 smashes of the skull and 104 contusions. In patients with subdural and epidural haematomas angiography and trepanation were used in few cases.

Accidents, Home↗