Hirntumorresektionen in einem offenen 0,5 T-MRT Zweijährige Erfahrungen aus neuroradiologischer Sicht

After two years clinical experience using an open 0.5 T-MRI, which make it possible to control all steps of a brain tumor resection, the high expense in relation to the effect is proofed. In 80 MRI-guided brain tumor resections the indication, the degree of resection, the appearance of operative induced changes, complications and clinical state are analysed. The advantage of the method consists in safety of localisation and detection especially of intra-axial cerebral tumors, recording of intraoperative invisible tumor parts and saving eloquent areas during tumor resection. To have optimal results, all over the operation time, the participation of a special experienced radiologist is necessary. The best results are shown in treatment of low grade gliomas and tumors near eloquent areas.     

Die Magnetresonanztomographie in der Dentalradiologie (Dental-MRT)

Zusammenfassung Ziel dieses Beitrags ist die Vorstellung der Untersuchungsm?glichkeiten des Ober- und Unterkiefers mittels Magnetresonanztomographie (Dental-MRT) und ihre Anwendung bei der Diagnose zahnmedizinischer Erkrankungen. Sieben gesunde Probanden, 5 Patienten mit Pulpitis, 9 Patienten mit dentogenen Zysten, 5 Patienten nach Zahntransplantationen und 12 Patienten mit atrophem Unterkiefer wurden untersucht. Axiale T1- und T2-gewichtete Gradientenecho- und Spinecho-Sequenzen in 2D und 3D-Technik wurden durchgeführt. Nach der Untersuchung wurden zus?tzliche Panoramaschnitte und orhoradiale Rekonstruktionen des Ober- und Unterkiefers, unter Verwendung einer gebr?uchlichen Dental-Software, angefertigt. Der gesamte Ober- oder Unterkiefer, Z?hne, Pulpa und der Inhalt des Mandibularkanals k?nnen gut dargestellt werden. Patienten mit einer Entzündung der Zahnwurzel k?nnen ein deutliches Knochenmarks?dem in der Periapikalregion zeigen. Bei Patienten mit odontogenen Zysten ist die Beziehungen zu den umgebenden Kieferstrukturen gut darstellbar. Nach Kontrastmittelgabe zeigt sich ein Enhancement in der Zahnpulpa. Die Dental-MRT ist ein nützliches Verfahren zur anatomischen Darstellung des Kieferbereichs und zahnmedizinischer Erkrankungen.      

Präimplantationsdiagnostik: Antrag und Entscheidungsfindung der Ethik-Kommission Lübeck

In 1995 the Ethics Commission of the Medical University of Lübeck was asked to rule on whether a preimplantation diagnostic procedure (PID) could be performed on a husband and wife who were both carriers of the cystic fibrosis mutation Δ F508. The couple had previously given birth to a child with cystic fibrosis and had twice terminated a pregnancy following prenatal screening. Ethically, the performance of a PID was certainly warranted for this couple. The risk of violating §§8 Section 1 and/or 2 Section 1 (“totipotent cells shall not be removed for diagnostic purposes”) of the Law for the Protection of Embryos (ESchG) was judged to be nonexistent in written statements from two expert witnesses (Prof. K.V. Hinrichsen and Prof. H.M. Beier, both embryologists). In the view of the Ethics Commission, only §1 Section 2 (“an ovum shall be fertilized only for the purpose of inducing pregnancy”) of the ESchG currently prohibits PIDs. In light of the social and biological arguments in favor of PIDs, however, the Ethics Commission questioned whether this section of the ESchG is still morally justifiable.     

Anästhesie bei geriatrischen Patienten Die Bedeutung physiologischer Variablen für die kognitive Leistungsfähigkeit geriatrischer Patienten nach Regional- oder Allgemeinanästhesie

Objective: The aim of the present study was to show the influence of the parameters of gas exchange (arterial oxygen pressure paO₂, arterial oxygen saturation SatO₂) and haemodynamics (arterial systolic and mean blood pressure RRs and MAP) on the restitution of cognitive functions in geriatric patients scheduled for elective hip arthroplasty. Methods: A total of 30 patients (70 years, ASA II) were randomized to be operated either in regional anaesthesia (n=15) or general anaesthesia (n=15). PaO₂ (by capillary blood gas analysis), RRs and MAP (by oscillometry) were measured 15 and 90 minutes after arrival in the recovery unit (t1 and t2), 24 and 72 hours postoperatively (t3 and t4), and cognitive functions were tested. Intraoperatively, throughout the day and the first night after surgery we measured satO₂ by continous pulse oximetry. We recorded MAP and RRs by oscillometry every 3 minutes during the operation and every15 minutes for the rest of that day and night. Results: The parameters of gas exchange and haemodynamics did not differ among the groups. PaO₂ was significantly reduced in both groups compared to baseline 24 hours postoperatively (t3) and remained low until 72 hours postoperatively (t4). Nearly all cognitive functions were significantly reduced in both groups compared to baseline 15 and 90 minutes after arrival in the recovery unit (t1 and t2), but recovered on the first postoperative day (t3). Both groups kept deficits in verbal memory and reading capacity up to the third postoperative day (t4). There was no correlation between the physiological parameters and the restitution of the tested cognitive functions. Conclusion: The restitution of cognitive functions during the first three postoperative days in geriatric patients scheduled for elective hip surgery does not depend on the anaesthetic technique. According to our results regional anaesthesia does not show any advantage for geriatric patients undergoing elective hip arthroplasty.     

Entwicklung eines neuen Closed-Loop Systems Regelung einer Mivacurium-induzierten neuromuskulären Blockade

There are many closed-loop control systems for muscle relaxants reported, but only a few could cope with the introduction of the latest shorter acting neuromuscular blocking drugs. These new muscle relaxants such as mivacurium require a fast adapting closed-loop system for controlling an adequate infusion. METHODS: After approval of the local ethics committee and having the patients' informed consent a total number of 75 patients [ASA I and II] were included in the study and assigned either to a training-, prediction-, prediction-/feedback- or a validation phase, as needed. Anaesthesia was induced and maintained with propofol in a TCI-mode with a plasma level of 3 to 5 micrograms/ml and 0.1 mg fentanyl boli as needed in all patients. In the last validation phase, having 20 patients, the prediction error and the error of the whole system was taken and analysed. RESULTS: A closed-loop system using a neural network as a predictor could be established. In the final validation phase consisting of 20 patients the mean square prediction error was found to be 0.1% +/- 0.2% [mean +/- SD]. The mean square error of the whole system was 0.55% +/- 0.59% [mean +/- SD]. CONCLUSIONS: A closed-loop system for control of a mivacurium infusion could be established. The system proofed to be reliable for a closed-loop infusion of mivacurium in order to maintain a predefined degree of neuromuscular blockade of 95% during routine surgery. The performance of the described controller is comparable to all recent attempts and could therefore be useful for scientific studies. It should be further validated and established for other muscle relaxants, as well.     

Sauerstoffangebot in der Sepsis Seit 10 Jahren mehr Fragen als Antworten

Object of this review is to present the physiological principles, diagnostic techniques and therapeutic options that are related to modifications of oxygen delivery in sepsis. Despite intense research activities in this area, many topics regarding oxygen transport and oxygen consumption in sepsis are still not clear. For example, the often discussed shift of the critical value of oxygen delivery to higher values in sepsis has not been proven, yet. Beside an impaired regional perfusion also disturbances in the cellular oxygen utilization may be responsible for organ failure in sepsis. Until now, it was not shown, whether the increase of oxygen delivery to supranormal levels reduces mortality in septic patients. It is also unknown, which catecholamine and which infusion solution is suitable for the treatment of septic patients. In future further research is necessary to solve the problems associated with sepsis therapy.     

Koinzidenz von schizophrener Psychose und Panikstörung mit Agoraphobie

The coincidence between panic disorder and depression is a well known phenomenon. However, only few studies investigated the coincidence of panic disorder with schizophrenia. This may in part be explained by the fact that both positive and negative symptoms of schizophrenia may mask the clinical symptoms of a panic disorder. We report on a female patient suffering both from agoraphobia with panic disorder and paranoid schizophrenia according to ICD-10. The productive psychotic symptoms responded well to treatment with a low dose of zotepine, whereas the panic disorder was effectively treated with a combined therapy with imipramine and cognitive behavioral therapy. Although it has to be questioned whether the coincidence between panic disorder and schizophrenia reflects two different diagnostic entities, the occurrence of symptoms of a panic disorder in schizophrenia deserve further attention because these may be treated efficiently by a specific pharmacotherapy and psychotherapy.     

Erbliche Ursachen und Risikofaktoren der Alzheimer-Krankheit

A multifactorial etiology underlies the majority of cases of Alzheimer's disease (AD). Both ill-defined environmental and genetic factors contribute to the development of the disease. Allele epsilon 4 of ApoE is a genetic risk factor. Its presence increases the risk of developing AD. However, presence of e4 is neither necessary nor sufficient for the disease to arise. Apart from the common multifactorial forms of the disease, there are rare variants which are inherited as Mendelian traits. To date three genes are known that can be mutated in these rare forms of AD. Of these, mutations in the gene presenilin 1 on chromosome 14 are most frequent. In addition, mutations in the gene presenilin 2 on chromosome 1 and in the amyloid precursor protein gene (APP on chromosome 21) occur in autosomal dominant AD. This article reviews our present knowledge of the genetics of AD and discusses its relevance for patients with AD and their relatives.     

Neuropsychologie des Normaldruckhydrozephalus

Although dementia is described as one of the constituent characteristics of normal pressure hydrocephalus (NPH), alongside gait disturbances and urinary incontinence, there is a rather limited number of controlled studies concerning neuropsychological deficits in the disease. A wide range of psychopathologically relevant symptoms have been described, but the common features of most cases include mental and motor slowing, apathy, emotional indifference, anosognosia, memory and attentional impairment. A number of other functional deficits such as dyslexia, dysgraphia, acalculia, apraxia can also frequently be found. Some emphasis is put on the work of J. de Mol (Brussels) which appears to be most important for the study of neuropsychological symptoms in NPH patients. The methodological standard of a number of studies has been found to be rather low, and yet a sound neuropsychological investigation may be of utmost importance for the diagnosis and neurosurgical outcome assessment. Concerning morphological correlates of the functional deficits in NPH, various hypotheses have been formulated, but it is argued that symptoms can neither be described as predominantly "diffuse" in nature, nor can they be reduced to unilocular dysfunctions. Recommendations for future research strategies are formulated.     

Biomechanics and functional anatomy of the upper ankle

Dorsoplantar motion in the upper ankle joint is around one "transverse" rotational axis. In relation to the lower leg this axis is oblique joining the tips of the malleoli. Talocrural motion is highly precise compared to other human joints. Most of the stability and undisturbed motion in the loaded joint is afforded by the intimate osteocartilagineous contact. The rule of the collateral ligaments is secondary stabilisation, buffering of abnormal stresses and centering the talus in the extremes of motion. The posterior talofibular ligament is the universal lateral stabilizer, the deep portion of the deltoid ligament is the predominant medial ligament structure. Ligament tension without strain and under valgusabduction load as a rule makes only a difference in a quantitative way. Under varusadduction-stress load patterns are usually changed. Fibula and the distal syndesmotic ligaments, in the presence of valgusabduction- and external rotation stress, predominate over the medial joints structures. Remaining joint steps, especially in Volkmanns triangle (posterior malleolus) are prearthritic deformities. Nevertheless primary traumatic lesion of the cartilage has a major prognostic meaning. In cadaver joints as in vivo permanent lesions of only a singular fasciculus of the deltoid or lateral collateral ligament result in clearly detectable motion abnormalities. Concerning clinical therapy at present as in the past complete reconstruction of all that damaged singular structures must be claimed for. There is generally only a small tolerance against instability and malposition in the upper ankle joint. Even after one hundred years of research today factors defining the individual breadth of tolerance are not fully understood. In the presence of treatment regimes, that stood the test of time, it is therefore difficult to recommend treatment alternatives, relaying on individual biomechanical tolerance.