More than 800 papers were presented by neurosurgeons from 66 countries during the 7th International Congress of Neurological Surgery, held in Munich on 12-18 July 1981. With the present scope and problems of neurosurgery as its theme, the congress achieved its aims in making possible the exchange and dissemination of new knowledge and ideas and in facilitating personal contact between neurosurgeons from aU parts of the world. Of such importance are the regional differences within our branch of science that we should spare no effort in acquainting ourselves with those neurosurgical problems which lie beyond the boundaries of our local horizons. From the vast number of papers the editor has selected those whose high scientific standard merits greater exposure than that given by the conference itself. I should like to thank the editor for his work and Springer-Verlag for their involvement in our disci pline. It is to be hoped that this book will find a worldwide audience, in accordance with the intentions of the World Federation of Neurosurgical Societies. Prof. Dr. K.-A. Bushe President of the Congress v Editor's Preface This is the first volume of a new series which aims to provide an overview of the state of the art of neurosurgery every four years. It will contain papers covering various fields of our specialty, selected from among those presented at each International Congress of Neurological Surgery."

This volume contains selected works from the 25th Anniversary of the International Conference on Intracranial Pressure (ICP) held in Williamsburg, Virginia. The theme of the meeting was Intracranial Pressure and Neuromonitoring and focused on all the current state of the art brain monitoring methodologies and their application to brain injury. The brain monitoring techniques covered a wide spectrum from neurochemical monitoring of the injured brain to specialized techniques for assessing shunt function in normal pressure hydrocephalus. It also includes the most recent advances in monitoring of the brain oxygen levels using electrodes or the less invasive Near Infrared Sprectroscopy devices. Controversial issues regarding the management of ICP and CPP or both are also addressed and there are several works dealing with this topic. Of particular interest is the group of papers describing diagnosis and outcome in normal pressure hydrocephalus. It is the first compilation of papers which covers all the latest brain monitoring studies in both ischemia, trauma and hydrocephalus. The manuscripts in this volume have been selected from over 300 abstracts submitted to this international symposium. The abstracts are also published in order to provide the most comprehensive view of the progress made in brain injury research.

This book is a survey of some aspects of current knowledge on regional Cerebral Blood Flow (rCBF), mainly as studied by the isotope clearance method. Although both theoretical and methodological problems are discussed, attention is mainly dedicated to data obtained from clinical studies. The papers which make up this book were presented at the International Symposium on the Clinical Applications of Isotope Clearance Measurement of Cerebral Blood Flow, held in Mainz, Western Germany, on April 10-12, 1969. The previous meetings on Cerebral Blood Flow, held in Lund in 1964* and in Lund and Copenhagen 1968**, had shown that the moment had come to concentrate on the possibilities of introducing rCBF measurements into clinical routine. This is why in the Mainz Symposium attention was initially focused on methodological aspects. This is also why theoretical problems of physiology of CBF were not emphasized. Finally, this explains why such topics as cerebrovascular disease, head trauma, coma, carotid surgery, brain tumors and intracranial pressure were given pride of place. However a survey of the clinical aspects of rCBF measurements would not be complete without an account of the application of such measurements to monitor cerebral circulatory changes during anesthesia and therapeutic procedures like, for instance, hyperventilation and hyperbaric treatment. Furthermore, it is now possible to obtain data from correlative rCBF studies per formed before, during and after surgical operations on the human brain."

Percutaneous lumbar discectomy is a new surgical method for treating lumbar disc diseases. The goal of the procedure is decompression of the spinal nerve root by percutaneous removal of the nucleus pulposus under local anesthesia. Probably 20 % of all patients requiring lumbar disc surgery can be successfully treated by this method. During the past two years, percutaneous discectomy has spread rapidly, and it is now performed in most clinical departments engaged in spinal surgery. The first International Symposium on Percutaneous Lumbar Discectomy, held in Berlin in August 1988, covered all current procedures known as "percutaneous discectomy" and the entire range of percutaneous techniques, both clinical and experimental. Its publication is important because of the recency of this new surgical procedure, the outstanding experience of the speakers - including the Japanese, American, and European "pioneers" of the technique - and last but not least the gaps in the knowledge of physicians concerning this topic. This procedure opens up new perspectives in the surgical treatment of degenerative diseases of the lumbar spine.

This volume contains the papers presented at the First International .ijm posium on Intracranial Pressure, held at the Neurosurgical Clinic of the Medizi nische Hochschule Hannover (Hannover Medical School), July 27 to 29, 1972. The texts submitted have been included in their original form whenever possible. The editors have made only minor corrections and rearrangements, since rapid publication was considered to be more important than homoge neity in style. The sessions of this book correspond to the sessions of the sym posium. At the end of each session the reader will find a summary of the topics presented and discussed, especially prepared by the chairman and co-chairman concerned. Three main aspects ofICP were dealt with at the Symposium: Methodology (Sessions 1 and 2), Pathophysiology (Sessions 3 to 6), and Clinical Aspects (Ses sions 7 to 10). Following the symposium a special round table was held on the major topics covered by the meeting. The participants of this round table discussed drafts prepared by T. W. LANGFITT, B. JENNETT and N. LUNDBERG. These contributions have also been included as special chapters at the end of this book, and are believed to reflect the current attitudes as to the topics discussed."

"Advances in Neurosurgery 22" is devoted to three main topics, the first one being Cerebellar Infarcts. Following the introduction with the microsurgical anatomy and the neuropathology of cerebellar infarction, the indication for operative treatment and its results are then discussed. The neuroradiological treatment with local and antifibrinolytic therapy for vertebrobasilar occlusion completes this section. The management and surgical approaches to the various forms of midline lesions are then presented. Special interest is centred on minimal invasive endoscopic neurosurgery (MIEN), (intraventricular tumors, optic pathway gliomas, endoscopic brainstem tumors and vascular malformations). Furthermore the special equipment and fields of indications are extensively discussed.

Advances in Neurosurgery presents the experience and research results of modern neurosurgeons confronted with urgent diagnostic and therapeutic problems. The first topic here is spontaneous intracerebral hematomas, whose localization determines the form of treatment and usually its outcome. Newer therapeutic approaches such as stereotactic removal, endoscopy and fibrinolysis supplement the results of standard operative methods. Secondly, the hydrocephalus malresorptivus is covered, presenting experience with the diagnostic value of intrathecal infusion tests, CT-cisternography, evoked potentials, and MRI CSF-flow studies, as well as aspects of neurosurgical intensive care such as barbiturate treatment, respiratory problems in head injury patients, auto-regulation mechanisms, and hospital infection. The last section is devoted to peripheral nerve surgery, reports on experience with microsurgery and various forms of anastomosis in both traumatic and tumorous nerve lesions.

Three topics of major interest for neursurgeons are covered in this volume of the Advances in Neurosurgery series, as the title suggests. First, neurosurgical standards of diagnosis and treatment are viewed from several points of view, including the legal one. Second, the many aspects of aneurysm surgery are dealt with: timing and grading, monitoring during the operation, postoperative vasospasm, Doppler sonography and new research in subarachnoid hemorrhage. Third, the diagnosis and treatment of malignant gliomas are discussed; there are preliminary reports on interstitial laser-assisted thermal therapy, immunotherapy and radiopharmaceutical substances as well as the standard forms of neurosurgical and radiation treatment.

Demands on a Neurosurgeon Under Routine Clinical Conditions' "Hardly any other field of surgery requires such meticulous asepsis. No other field requires such a protection of the tissue and such reliable hemostasis. No one will question that neurosurgery makes exceedingly high demands. However, the degree of the demands on the personal ity of the surgeon who has to carry out very serious operations to the exclusion of all others and has little opportuinity to recover psycholog ically by working on simpler cases is concealed from the outer world. The mental strain which the coworkers and staff have to tolerate may not be denied." So wrote Wilhelm Tonnis in 1939. Although fifty years have now elapsed, his appraisal is still relevant today - hence my intention to discuss the everyday demands placed on neurosurgeons. My aim is not self-glorification to engender sympathy; rather it is to highlight the effects and repercussions of such demands for the well-being of the patients entrusted to us. The major onerous demands include: - those in the operating theater - those resulting from staff problems in nursing - those resulting from legal developments - those resulting from the increasing administrative tasks that cost valuable time and energy which are lost to our actual work in look ing after patients: science and research also suffer from this. I shall not go into the latter point within this preface. Let me first turn to the strains occurring in the operating theater."

The 17th volume of the "Advances in Neurosurgery" contains a selection of the scientific reports of the 39th annual meeting of the German Society for Neurosurgery, which was held in Cologne from May 8-11, 1988. The first section deals in particular with the "long-term results of severe head " "injuries," as well as with problems of the acute traumatic hematomas and brain edema. The second section covers "microsurgical experiences." Attention is focused on the anatomy and operative technique for lesions in and around the "jugular foramen" and the craniospinal transition. The third section describes the special new results of "brain " "death determination." Beyond this, numerous contributions on clinical and research results were presented in a poster exhibition which was systematically studied in order to give younger neurosurgeons the opportunity for extensive discussion. The volume contains new information which will bring specialists up-to-date on the latest clinical and research developments in the field.

This 16th volume of Advances in Neurosurgery contains a selection of pa pers presented at the 38th Annual Meeting of the German Society of Neurosurgery, held in Munster on 3-6 May 1987. The program committee had to choose these contributions from a total of 161 presentations. I am very much obliged to the members of the committee who contributed their experience and effort to the organization of the scientific pro gram: Prof. Dr. R.A. Frowein, Prof. Dr. W.J. Bock, Prof. Dr. E. Kazner, Prof. Dr. G. Lausberg, Prof. Dr. M. Klinger, and Prof. Dr. M. Brandt. The aim of the Meeting was to exchange experiences regarding modern diagnostic and therapeutic achievements. The first main topic was new technical methods in neurosurgery. Refinements in laser technology were introduced; different laser devices have been recognized as use ful tools in microsurgery and some peripheral nerve problems. The Ca vitron ultrasonic aspirator has proven its value in a great variety of intracranial and spinal tumors within a few years. Its technical advance is impressively demonstrated by some of the papers in this book. With growing experience we have recognized the great value of these additional instruments in limited surgical fields and learned not to overestimate them in the hands of a skilled neurosurgeon."

This 13th volume of Advances in Neurosurgery presents thos.e papers held at the 35th Annual Meeting of the German Society of Neurosurgery in Hannover, June 13-16, 1984. Of 150 papers submitted, the program com mittee of the Society chose 69 for presentation. I would like to thank Professors Bock, Brock, Jensen, Wenker, and Wlillenweber for their as sistance in the selection. It was the intention of the President of the Congress at this meeting to lay special scientific emphasis on discussion. For this reason the number of papers had to be limited even more than usual in order to give all participants the opportunity for questions and the presenta tion of their own experience. The main topic of the first day was Extra-Intracranial Anastomoses. Here the operative experience and the long-term results of these operations in the German-speaking countries were reviewed. This discussion was preceded a day earlier by a satellite symposium on the possibilities of the prophylaxis and treatment of ischemic neurological deficits fol lowing subarachnoid hemorrhage by means of calcium antagonists. Microsurgery at the Edge of the Tentorium was the second main topic. In co operation with the SOCiety's microneurosurgery working group, only a small number of lectures were planned, but the topic was covered thor oughly in a round-table discussion."

The computer tomograms of the brain were investigated in 195 patients in whom a primary carcinoma was known to be present. Metastases of bronchial and mammary carcinomas are most frequent. It is not possible to achieve a definite differentiation of brain metastases from known primary tumors. References 1. Kazner, E. , Wende, S. , Grumme, Th. , Lanksch, W. , Stochdorph, 0. : Computertomographie intrakranieller Tumoren. Berlin, Heidelberg, New York: Springer 1981 2. Nadjmi, M. , Piepgras, U. , Vogelsang, H. : Kranielle Computertomo- graphie. Stuttgart: Thieme 1981 3. Penzholz, H. : Die metastatischen Erkrankungen des Zentralnerven- systems bei besartigen Tumoren. Acta neurochir. Suppl. ~, 1968 4. ZUlch~ K. J. : Pathologische Anatomie der raumbeengenden intra- kraniellen Prozesse. In: Handbuch der Neurochirurgie, Bd. III, Hrsg. Krenkel, W. , Olivecrona, H. , Tennis, W. Berlin: Springer 1956 18 Epileptic Seizures in Brain Metastases B. Neundorfer Klinik fUr Neurologie, Medizinische Hochschule LUbeck, Ratzeburger Allee 160, D-2400 LUbeck 1 Epileptic seizures are a frequent symptem ef intracranial space- eccupying lesiens (4). The reperted frequency in the literature var- ies between 13% and-abeut 50%. This apparent discrepancy can be ex- plained by the different cempesitien ef different series with regard to. the patient's age, turner histelegy and lecatien (4). The mest frequently enceuntered finding in patients with symptematic seizures is a primary brain turner: at the tep ef the list eligedendregliemas, astrecytemas and meningiemas - at the bettem glieblastemas. Brain metastases are also.

This volume of ADVANCES IN NEUROSURGERY presents the original texts of 60 papers delivered at the 33rd annual meeting of the German Neuro surgical Society held in Kiel from May 16th to 20th, 1982. These papers represent a selection from some 162 papers submitted and 96 actually given. The selection was made by the society's programme committee, of which Professor W. J. BOCK, Professor H. DIETZ and Professor W. GROTE are also members. I would like to take this opportunity to express my sincere thanks to them for their untiring cooperation. The scientific programme dealt with three main themes: 1. Acute, non-traumatic intracranial hemorrhages, a subject that has always been of importance for neurological surgeons since the ana tomist Giovanni Battista MORGAGNI in 1791 first described in detail the clinical picture and the pathological and anatomical causes of a brain hemorrhage he had observed in his servant. Indeed, at our 31st annual meeting in Erlangen in 1980 "Timing Problems in Sub arachnoid Hemorrhages" was one of the main topics of discussion. For this year's meeting a cooperative study in which 27 university and hospital departments of neurosurgery participated enabled us to look into the causes and the diagnostic and therapeutic measures involved in a great number of cases of intracranial hemorrhage."

W.DRIESEN This volume contains the original text of 60 papers delivered at the 32nd Annual Meeting of the German Society for Neurosurgery, held in TUbingen, 22nd to 25th April, 1981. They represent a selection from 91 papers submitted, a third of which had to be excluded on critical analysis. This was deemed necessary on account of costs, and in order to keep the volume of a size and standard usually achieved within the last few years. Three main subjects were considered: 1. changes in methods of investigation and treatment of neurosurgi cal.conditions, brought about by the use of computerised axial tomography (C.A.T . scanning); 2. papers dealing with fundamental research concerned with normal and abnormal cerebral metabolism; 3. trauma to the vertebral column and spinal cord, and its sequelae; and, 4. free communications. The organisers of this meeting tried, in contradistinction to pre vious custom, to shift the emphasis away from highlighting major communications, and so to remain true to their intention to allow experts in their fields to introduce their subjects and pin-point problems, to which subsequent speakers could then address them selves in detail in their own papers. In my view, this did occur in a meaningful way, although not to perfection; a goal always difficult to attain."

W. SCHIEFER The 31st annual meeting of the Deutsche Gesellschaft fur Neurochirurgie was held in Erlangen on May 1 - 4,1980. The numerous participants obviously enjoyed the opportunity to be co me acquainted with the attractive city of gardens, lecture theatres and workshops surrounded by a lovely countryside and a historic environment. The pro gram included a visit to the neighboring city of Nurnberg, to the old Reichsstadt Regensburg and an opening ceremony in the orangerie of the Erlangen palace, where the "Bamberger Ensemble fur alte Musik" presented interesting and little-known early music. The annual meeting was held in the newly-built "Kopfklinik" of the University of Erlangen-Nurnberg, which houses the departments of neurosurgery, neurology and ophthalmology. As far as possible, many functions of this hospital were centralized because this has economic advantages and saves personell. Other functional units, such as the operating theatres, the intensive care units, research laboratories and units specific to the individual disciplines remained decentralized and independent. This concept has proved to be a happy solution. At the membership meeting of the Deutsche Gesellschaft fur Neurochirurgie, Prof. Dr. K. J. Zulch of Cologne was made an honorary member of this society, of which he is a founding member."

The 28th annual conference of the German Society for Neurosurgery was held in Cologne, West Germany, from the 18th to the 21st of September 1977. The conference dealt with problems concerning craniocerebral injuries and space-occupying processes in the posterior cranial fossa as well as general topics on clinical practice and research with special attention paid to the work of younger neurosurgeons. This volume is a presentation of the conference results. Within the scope of the general topics, special interest was directed toward the que stion of the current status of cytostatic treatment for brain tumors. In addition to experimental investigations, the results concerning cerebral tumors and medulloblas tomas are reported. Cerebellar tumors represent two further focal points: 1. From the diagnostic viewpoint, specific results from computerized tomography are discussed, especially with regard to the more extensive anatomic difficulties involved in the posterior cranial fossa. 2. With emphasis on cerebellar processes, the results of long-term measurements of intracranial pressure during the postoperative follow-up period are reported."

Recent topics of interest in neurosurgery are discussed in selected papers in this volume. The first major topic deals with vascular malformations of the brain, where neuroradiological interventions and microneurosurgical treatment present major advances. The second major topic covers treatment patterns for various supratentorial tumors in Ahildhood. The interdisciplinary aspects of neurosurgical intensive care, particularly electrophysiology and anesthesia, are treated extensively.

Had we ever guessed the historical importance of this day, had we expected the impressive and touching episode of German history that took place on November 9, 1989, had we dared to hope that a dream three decades old would come true on precisely that day, we would have held our symposium in the immediate vicinity of the Branden burg Gate! While it is difficult to describe the atmosphere on that evening, when the news suddenly spread that "the wall had opened", it is almost impossible to describe the feeling of fraternity and sense of belonging that overcame everyone, a feeling that had been repressed (but never suppressed) for three decades! Berlin M. BROCK H. M. MAYER K. WEIGEL Contents Introductory Remarks M. BROCK, H. M. MAYER and K. WEIGEL. . . . . . . . . . . . . . . . . . . 1 . . . . Functional Anatomy of the Lumbar Spine R. LOUIS (With 4 Figures) . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 . . . . . . . . Implant Materials H. STALLFORTH, W. WINKLER-GNIEWEK and M. UNGETHUM (With 4 Figures) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 . . . . . . . . . . . Performance of Alloplastic Materials and Design of an Artificial Disc H. J. SCHMITZ, B. KADEN, R. T. FRITZ, U. GROSS and G. FUHRMANN (With 9 Figures) . . . . . . . . . . . . . . . . . . . . . 23 . . . . . . Intradiscal Implants in 1989: Concepts and Possibilities J . A. N. SHEPPERD (With 4 Figures) . . . . . . . . . . . . . . . . . . . . . 35 . . . . . . . Intradiscal Polymerization: Preliminary Results of Chemical and Biomechanical Studies A. GARCIA, B. LAVIGNOLLE, P. MORLIER, D. DUCASSOU and C. BAQUEY (With 2 Figures) . . . . . . . . . . . . . . . . . . . . . . . 39 . . . . . . . Intervertebral Implants for Fixation and Disc Replacement J. A. N. SHEPPERD (With 6 Figures) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Lumbar Interbody Threaded Prostheses C. D. RAY (With 5 Figures) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

This book contains the papers delivered at the Symposium on "Medical Treatment of Brain Ede- ma" at the Seventh International Congress ofNeu- rological Surgery, held in Munich in 1981. The aim of each speaker was to give a short review of current knowledge in his or her field. In addition, most of the authors presented their own data. The symposium . was divided into two parts. The experimental part focused on pathophysiological and biochemical findings, while the clinical part dealt with therapy for brain edema, with particular emphasis on steroids. We wish to acknowledge the technical support of Springer-Verlag, Merck Company, Darmstadt and the help of Miss Scholz, Secretary of the Depart- ment of Neurology at the University of Heidel- berg. Heidelberg/Berlin A. Hartmann M. Brock v Contents K. -A. Hossmann Pathophysiology of Va so genic and Cytotoxic Brain Edema . . . . . . . . . . . . . . . . . . . A. Marrnarou, K. Tanaka, and K. Shulmann The Brain Response to Infusion Edema: Dynamics of Fluid Resolution . . . . . . . . . . 11 M. D. O'Brien 19 Ischemic Cerebral Edema A. Baethmann, W Oettinger, K. Moritake, L. Chaussy, andF. Jesch Metabolic Effects of Corticosteroids in Central Nervous Tissue . . . . . . . . . . . . . 24 K. Maier-Hauff, O. Kempski, A. Unterberg, U. Gross, M. Lange, L. Schurer, and A. Baethmann The Kallikrein-Kinin-System as Mediator in Cerebral Edema, Recent Progress . . . . . . . . . . . . . 31 S. F. Berndt 36 Symptoms of Cerebral Edema W R. Lanksch The Diagnosis of Brain Edema by Computed Tomography . . . . . . . . . . . . . . 43 H. J. Klein and K. Schmidt Hyperosmolar Solutions and Diuretics in the Treatment of Brain Edema . . . . . . . .