In 1981, the Norwegian physiologist and cyberneticist, Rune Aaslid, developed a device which made it possible to apply the transcranial Doppler sonographic technique in man. In 1983, Dr. Albrecht Harders took on the project of working out a clinically practicable method that would allow atraumatic measurements to be made of the blood flow velocity in the large branches ofthe circle of Willis. The technique has now become a competitor of the conventional methods of measuring the intracranial hemodynamics, including angiography and the xenon method of cerebral blood flow measurement. Harders proceeded from the assumption that the measurement of the blood flow velocity is more relevant for clinical diagnoses than the usual volume flow measurements. He stresses the very valuable application of the technique in detecting cerebral vasospasm before and after aneurysm surgery. The changes in the blood flow velocities measured by transcranial Doppler sonography in the individual vessel segments of the circle of Willis are interpreted with respect to the various factors that can effect such changes (collateral circulation in the circle of Willis, diameter of the vessel, vascular resistance, the general cardiovascular situation, arterial partial CO pressure, autoregulatory factors, position of body). The rate of 2 complications associated with angiography has thus been reduced, since the best time both for angiography and for surgery can be determined, and continuous TCD examinations show when the patient is out of a critical phase of cerebral vasospasm.

The first mention of moyamoya disease as a distinct disease entity was in a paper I published in 1965. The abnormal net like vessels at the base of the brain seen in cerebral angio grams of this disease were described by most native speakers of Japanese as "moyamoya," a Japanese expression for some thing hazy, such as a puff of cigarette smoke drifting in the air. In fact, prior to my advocacy of this term, this type of vascular network was often referred to as "moyamoya vessels" by Japanese researchers. In 1969, Dr. A. Takaku and I submitted a paper to the Ar chives of Neurology entitled "A Disease Showing Abnormal Net-like Vessels at the base of the Brain," with a subtitle of "Moyamoya Disease." The editor, however, interchanged the main title and the subtitle and brought this term "moyamoya" to fame! Since then, researchers throughout the world have been using this poetic word! For a nicknaming godfather like me, it is a special joy to have this Japanese word enter the honored ranks ofmedica1 terminology. My first publication concerning this lesion was a report discussing six cases in 1963. Therefore it is now 20 years since I first became aware of and started to study moyamoya dis ease. At first, I merely thought that it was a strange vascular network, unique to these first few patients, and I reported these cases as being cases of acquired collateral vessels.

This supplement to "Acta Neurochirurgica" contains a selection of papers which were presented at the 9th Scientific Meeting of the European Society for Paediatric Neurosurgery on Space Occupying Lesions of the Cerebral Midline in Vienna, October 10-13,1984. This meeting was arranged at the same location where the ESPN was founded exactly seventeen years ago. Although the presentations in this meeting dealt with numerous important problems encountered in paediatric neurosurgery, the main emphasis was on that special problem which exemplifies the extraordinary advances in paediatric neurosurgery and its related fields. Therefore the main topic of this scientific meeting was dedicated to the subject of "Space Occupying Lesions of the Cerebral Midline." Recent diagnostic procedures, such as computerized axial tomography and magnetic resonance imaging, now enable the neurosurgeon preoperatively, to obtain precise data on the location, and in many cases also on the nature of a lesion deep within the brain. Fundamental new knowledge in neuroanatomy and neurotopography has now transformed previous high-risk procedures into routine ones for the neurosurgeon, and an abundance of new surgical techniques has improved the success rate in the treatment of many patients. The scientific meetings of the ESPN have proved to be a successful forum for the exchange of experiences, opinions and even critical discussions. The present selection of papers will undoubtedly support this endeavour. Wolfgang T. Koos Gerhard Pendl Contents A. Statistics Koos, Wo To, Horaczek, Ao: Statistics of Intracranial Midline Tumors in Children 0 1 B.

This series of yearly books on Advances in Neurotraumatology is being published under the auspices of the Scientific Committee of Neuro traumatology of the World Federation of Neurological Surgeons. For some years neurotraumatology was perhaps too much looked upon as a secondary part of neurosurgery. But the constant increase of cases has provoked a renewal of interest all over the world, involving not only neurosurgeons but also any surgeon who has to take care of such patients. Each volume, in order to cover the whole of neurosurgery, will be concerned with a special topic, the various chapters of which being envisaged in detail, and followed by a practical "How to do it." Every volume will also contain chapters outside the envisaged topic regarding some up-to-date problems. The authors, chosen from various countries for their special competence, will try to offer an efficient contribution to the knowledge of neuro traumatology, and also to present a bedside series of handy books helping those who tend these cases. The first volume will deal with "Extracerebral Collections," the second "Dorsal and Lumbar Spine and Spinal Cord Injuries," the third "Cerebral Contusions, Lacerations and Hematomas," and the next ones will continue to successively approach all the other neurotraumatological topics."

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."

This book contains the contributions to the symposium "Functional Mapping of the Brain in Vascular Disorders", held at the Thirteenth World Congress of Neurology, Sep- tember 1-6, 1985 in Hamburg, FRG. I have to thank the contributors to this symposium for submitting their manu- scripts long before the congress so that the printed procee- dings could be distributed to the audience. I hope that this will enable the participants in this symposium not only to recall the vivid presentation of the lectures and the highlights of the discussions, but also to widen their knowlegde of the topics dealt with during the symposium by rereading the chapters on the various issues. I would also like to express my thanks to the company UCB, Kerpen, FRG, who sup- ported the symposium and the printing of these proceedings. W. -D. HEISS Cologne, July 1985 Contents The Purpose of Functional Mapping in Focal Cerebral Ischemia W. -D. Heiss ...1 Positron Emission Tomography Versus Nuclear Magnetic Resonance Imaging? M. M. Ter-Pogossian (With 1 Figure) ...5 Aims on Phosphorus-3l Magnetic Resonance Imaging K. Kogure, H. Ohtomo, S. Matsui, and H. Kohno (With 10 Figures) ...1 5 In Vivo Nuclear Magnetic Resonance Imaging of Sodium-23 in the Human Head S. K. Hilal, A. A. Maudsley, J. B. Ra, H. E. Simon, P. Roschmann, S. Wittekoek, Z. H. Cho, and S. K. Mun (With 5 Figures) ...29 Uncoupling of Flow and Metabolism in Infarcted Tissue T. Jones, R. J. S. Wise, R. S. J. Frackowiak, J. M.

Evolved from working with head injured groups at Headway and those attempting to return to work, this is a rich, comprehensive and photocopiable workbook for professionals, carers and clients. It contains over 140 cognitive rehabilitation exercises - tailored for memory, thinking skills, executive functions, awareness and insight, and emotional adjustment. It provides more than 40 information sheets on key problem areas, with questions for the reader, designed to educate and stimulate thinking and discussion. Suitable for both individuals and groups, it includes questionnaires for clients to complete with or without help and quizzes to evaluate and encourage information retention. Primarily for professionals where exercises or handout sheets can be photocopied and used therapeutically, The Brain Injury Workbook can also be used by carers or family members to provide stimulating activities for a head-injured person. In addition, the head-injured person themselves can work through the book on their own.

Almost a hundred years passed from the time of the first description of an intracranial aneurysm by Morgagni in 1761 to the year 1859, when Sir William Withey Gull arrived at the conclusion that haemorrhage in the subarachnoid space is caused by ruptured aneurysms. The introduction of lumbar puncture by Quincke 1891 and cerebral angiography by Moniz 1927 made it possible to establish the diagnosis of haemorrhage and its source. In recent decades the problems of treatment have come into prominence, first of all because of the inadequacy of conservative methods of treatment in most of the cases, and from surgical experience and its limitations which became apparent before very long. Because of the erratic development of neurosurgery and vascular surgery, above all, since the technique of microsurgery has been used, the entire removal of the source of haemorrhage has become a possibility, even though there were still quite different views taken regarding the most convenient time for surgical intervention, apart from the prevailing local conditions 134, 143, 144,261. In an up-to-date plan of treatment of subarachnoid haem orrhage (SAH) conservative measures are appropriate for bridging the pre-operative period, and must be considered the only solution in those cases in which the source of haemorrhage cannot be found. As far as the effectiveness of such conservative therapy is con cerned, the rate of re bleeding and the mortality provide sufficient comment.

Awareness and preparedness for potential complications in the aftermath of acute stroke is as important as initial treatment to achieve good clinical outcomes. Complications of Acute Stroke: A Concise Guide to Prevention, Recognition, and Management is the first book to focus exclusively on specific post-acute stroke complications that require timely and urgent attention. This practical, evidence-based guide is written for clinicians who provide in-hospital care to stroke patients and covers the broad range of medical and neurological issues that may manifest in the first 24 to 72 hours following ischemic or hemorrhagic stroke. This book will assist neurologists, neurosurgeons, intensivists, hospitalists, and other team members in the optimal management of acute stroke patients. It provides a roadmap for assessing risk and monitoring, recognizing, and managing emergent problems that can lead to neurological deterioration or worsening. Chapters by specialists on the frontlines are formatted with structured headings that detail pathophysiology, preventive measures, identification, and management strategies. For quick and targeted reference at the point of care, boxed "Key Points", tables, flowcharts or algorithms, and associated imaging are also included. Key Features: Practical guide to identify complications in acute stroke patients Easy to understand description of the pathophysiology underlying various complications Structured format for quick access to essential content Three-pillar approach of prevention, recognition, and effective management Detailed prevention strategies and treatment interventions for each complication Includes free digital access to the book on your mobile devices or computer

Local interstitial radiation therapy of intrinsic and inaccessible brain tumors is confronted with two major problems: 1. The tolerance of normal brain tissue, which is usually involved in local tumor irradiation, i.e. perifocal white matter edema and demyelinating effects, is crucial. 2. Data on radiation effects of implanted radioactive sources on neoplastic tissue, i.e. data on the radiosensitivity and on the biology of tumors, are still widely unavailable. In clinical practice the dose with which to achieve a given volume of tumor necrosis is roughly estimated. This report deals with the experimental findings of Iodine-125 and Iridium-I92 permanent implants in healthy and neoplastic brain tissue. Our own experimental findings are correlated with experimental data on Yttnul11-l)O irradiation from the literature. The study is directed to collect data on the tolerance non-tumoral brain tissue and to attempt to establish a dose-response relationship. Morphologic Changes in the Dog Brain Following Interstitial Iodine-125 Irradiation Iodine-I25 seeds (manufactured by 3 M Company, St. Paul, M. N.) with an activity of 3.55 mCi were permanently implanted under stereotactic conditions into the subcortical white matter of the gyrus coronalis of the left hemisphere in 6 beagle dogs. One animal with a non-radioactive seed implanted under similar operative conditions served as a control. The animals were allowed to survive 25, 46, 71, 94, 248, 368 days, respectively, after the implantation. The control animal survived 46 days. A detailed description of the experimental procedure is given elsewhere 16. 17.

This volume is the latest in the series Exercises in Radio logical Diagnosis, launched by the Strasbourg School of Radio logy. Further volumes on the facial bones, senology, and abdominal tomography are in preparation. Jean-Louis Dietemann has over a decade's experience of radiodiagnosis of the skull, and has already proven his talents as a teacher with his earlier books on the sella turcica and on carotid angiography. The present volume will assuredly be a great success and will enhance the series. Professor A. W ACKENHEIM Hospices Civils de Strasbourg Centre Hospitalier Regional Service de Radiologie I Strasbourg v Contents Part One: Iconography . . . . . . . . . . . . .. . . 1 . Part Two: Commentary with Corresponding Schemata. 85 References . . 165 Subject Index 167 VII Part One Iconography 1 1 a b 3 2 a b 4 3 4 5 6 6 a b 7 7 8 8 a b 9 9 10 10 11 a b 11 12 13 a b 13 a b 14 b 15 16 17 16 17 20 18 21 a b 19 22 a b 20 21 24 a b 22 b 23 26 27 24 a 25 26 29 27 31 32 28 33 34 29 35 36 30 37 a b 31 38 39 32 40 41 33 42 43 34 44 a b 35 44 c 45 a 36 45 b ~----~------~~ c 37 46 47 38 48 49 39 50 a b 40 41 52 53 a 42 53 b 54 a 43 54 b 55 44 56

This book is written by an author whose knowledge of the subject is based on vast surgical experience. A reliable assessment of the success or failure of a micro- vascular anastomosis or an aneurysm operation has until now been possible only postoperatively by angiography and transcutaneous Doppler sonography. Of particular impor- tance are the stenoses and occlusions which can occur dur- ing the operation, but which are frequently not detected un- til after surgery. This induced the neurosurgeons in Freiburg, as well as those in several other hospitals, to carry out a rou- tine control with postoperative transcutaneous Doppler fol- lowing extracranial-intracranial bypass operations and an- giography while still under anesthesia following aneurysm operations. The stenoses and occlusions detected were often not apparent intraoperatively. The reasons for this are that from the outside we see only the surface - and not the lu- men - of a v~ssel, and that stenoses caused by thrombosis, indentation of the vessel wall during anastomosis or by plaque on the vessel wall are not externally obvious. Even arterial pulsation is no guarantee of patency. The necessity to be able to detect stenoses during the op- eration is obvious. The microvascular Doppler sonography adopted by Dr. Gilsbach provides an expedient and safe method of recognizing such lumen narrowings.

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.

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."

In the clinic at Giessen during the last few years there has been an extensive programme of research into the various aspects of lesions of the diencephalon and brain stem and the associated autonomic and metabolic disturbances. As a continuation of this research programme Ernst Grote has investigated the central neuronal and hormonal factors acting on the peripheral regulation of glucose metabolism and their diverse inter-relationships. This research was made possible not only by the availability of well-documented clinical and experi mental material with primary and secondary lesions of the hypo thalamus and brain stem, but also by the advances in clinical endo crinology and the development of radio-immuno-assays. By continuous systematic investigation of the basic values and their reaction to stress-tests, as well as to trauma and operation, he has elucidated the basic facts of the central and peripheral mechanisms which are concerned in the regulation of glucose, and also their disturbances. Of particular significance are his descriptions and interpretations of the characteristic hypothalamic syndromes, as combinations of hyperglycaemia, hyperinsulinaemia and hyperglucagonaemia; dif ferent syndromes are produced by lesions at various levels of the brain stem and in central brain death. From this starting point it was possible to develop a rational treatment of this hormonal dys regulation by means of somatostatin."

Thus instead of being synonymous with specific procedures per- formed at the level of the basal ganglia, stereotaxis is in fact a general diagnostic and therapeutic concept, which has as its aim the precise three-dimensional representation of the patient's brain in its entirety. This three-dimensional representation is based on anatomical, neuro- radiological and other localizing information, the spatial integration Prof. Jean Talairach with friends and coworkers at the congress dinner in the Royaumont Abbey near Paris. (From left to right: Drs. ]. Bancaud, N. T. Zervas, B. Nashold, ]. Talairach, G. Szikla, F. Mundinger, P. Tournoux, ]. Peeker) of which allows a more precise "anatomical" approach to the human brain and to the surgical management of localized pathologic proces- ses. Literally, stereotaxis means "orientation in space". Taken in this general sense, all surgical procedures obviously should be stereo- tactic, at least in their principle! Two of the main themes of our meeting, namely the topic of the first day, "Surgery of Epilepsy" and that of the second "Stereotactic Cerebral Irradiation" of small brain tumours correspond to this evolution toward a global "whole brain" concept of stereotaxis. The same philosophy inspired the scientific efforts of the stereotactic group Introduction 3 of the Sainte Anne Hospital, under the leadership of its promoter, Professor Jean Talairach. This is the reason why the present Meeting is dedicated in honor of his scientific work.

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."

Fifty-two patients operated on for this type of spondylogenic myelo- pathy by the anterior approach were reexamined. The male: female re- lation was 2 : 1. Fifty percent were males in the 5th decade. About 20% had a congenital narrow spinal canal with an ap-diameter below the minimal standard values (3). The maximum of spondylogenic narrow- ing was found between C4 and C6 in 2/3 of the cases. Results: good 44%, satisfactory 31%, unchanged 13%, deteriorated 12%, mortality O. The duration of the neurological symptoms before operation had no in- fluence on the surgical results. Final neurological restitution was reached within 1 week to 3 months after the operation. The operative results in patients with congenital narrow spinal canal showed the same percentual distribution as the results of the entire group. No factors could be found to explain the groups of unsatisfactory results. References 1. DECKING, D. , STEEGE, W. ter: Rontgenologische ParametAr der Hals- wirbelsaule im seitlichen Strahlengang. Die Wirbelsaule in Forschung und Praxis, ~ (1975) 2. HERRMANN, H. D. : Neurologie in Praxis und Klinik. HOPF, H. C. , POECK, K. , SCHLIACK, N. (Hrsg. ). Stuttgart: Thieme (in press) 3. PIEPGRAS, U. : Neuroradiologie. S. 88-89. Stuttgart: Thieme 1977 114 Classification and Prognosis of Cervical Myelopathy E. HAMEL, R. A FROWEIN, and A KARIMI-NEJAD Introduction Up to the present, 104 patients with cervical myelopathy caused by cervical disk lesions, have been operated on in our clinic.

The main aim of this study is to define the clinical criteria which must be considered in order to come to an adequate decision whether a patient with intracranial arteriovenous malformation (AVM) should be operated upon or treated conservatively. A special method was used to reduce the effects of selection. This method made it possible to evaluate the therapeutic efficacy of conservative treatment versus surgery. The method implies that patients with equal combinations of variables (risk profiles) were compared in the two treatment lines. The variables building up the risk-profile pattern were chosen by analysing the decision process, as it was originally practiced by the surgeon who selected and treated the patients of this study. The risk profiles thus described relevant characteristics of the patient and his malformation. The variables were assigned numerical values accord ing to their prognostic value. Summation of the variables making up the risk profile then gives each risk profile a certain value. A low value symbolizes a bad prognosis and a high value a good prognosis in both treatment groups. There were many risk profiles with the same value in both groups and a comparison could be made over a large part of the risk-profile scale. This comparison showed that surgical treatment of A VM can always be justified, although the indications for surgery are less strong in patients with low risk profile values."

Authored by experienced surgeons and key innovators in the fast-moving field of LIF surgery, Lumbar Interbody Fusions provides an in-depth, focused approach to recent advances in surgical techniques and technology. Covering both minimally invasive and open procedures, this comprehensive reference provides step-by-step details for proven techniques, including extreme lateral, oblique lateral, and direct lateral approaches; intertransverse approaches; axial approaches; and endoscopic approaches. Focuses on the technical nuances, pearls and pitfalls of each procedure, as well as complication avoidance and management. Features high-quality radiographs and intraoperative images for superb visual guidance throughout. Covers topics that have as-yet unsettled surgical management, such as thoracolumbar and lumbosacral overlap diseases. Includes a concise review of evidence-based spine literature at the end of each procedural chapter. Features chapters on adjunct instrumentation such as pedicle screw and facet fixation, as well as graft selection and revision surgeries. Provides real-time guidance in video: Open Transforaminal Lumbar Interbody Fusion, MIDLIF Operative Technique, L5-S1 OLIF, Aspen Surgical Technique, and many more. Enhanced eBook version included with purchase. Your enhanced eBook allows you to access all of the text, figures, and references from the book on a variety of devices.

The Neurosurgeons of Berlin are happy to welcome their colleagues from Germany and from foreign countries to our Annual Meeting, being held in this city once again after many years. The external appearance of the city may have changed in many respects since our winter meeting in 1965. This ist not the case, however, as concerns the outstanding quality of its cultural life. We hope that you take as much profit of it as possible. When choosing the scientific themes of this congress, we were led by the idea that problems should be discussed which are not dealt with at special symposia this year. Thus, the problems related to lumbar disc surgery and its complications were chosen as one main topic. This important chapter of neurosurgery worries (and not seldom depresses) us in our daily work. A joint statistic analysis has been made, for which we are indebted to the colleagues from the following university clinics: Essen, Freiburg, Graz, Hannover, Heidelberg, Kiel, Koln, Mainz, Wiirzburg, Berlin-Charlottenburg, Berlin Steglitz, of the Neurosurgical Department of the BG-U nfallklinik Frankfurt/Main, of the Neurosurgical Department Wagner-J auregg-Krankenhaus Linz, of the Neurosurgical Clinic of the Katharinen-Hospital Stuttgart, and of the Neurosurgical Clinic of the Stadt. Krankenhaus Berlin-N eukolln."

A workshop on Dynamic Aspects of Cerebral Edema was organized to pro vide an opport nitY, for interdisciplinary and detailed consideration of this subject, so crucial in neurology and neurosurgery. The previ ous workshops were held in Vienna in 1965 and in Mainz in 1972. In the meantime, our ideas on mechanisms of resolution of cerebral edema had been changing drastically. Controversy had arisen regarding the role of biogenic amines in the development of edema. Active work in several centers had indicated the possibility of a reversible compo nent in edematous changes associated with ischemia, the control of which could be of therapeutic significance in the problem of stroke. It was felt that a thorough discussion, at this time, by those involv ed in these various studies should help to resolve the controversies, to crystallize the implications of the new findings, and to evaluate their application for patient care. In preparing the proceedings for publication we have edited the manu scripts and selected the discussions with an aim to highlight new find ings, to make this volume readable, and to eliminate duplication. We gratefully acknowledge financial support from the institutions and organizations previously listed. Many individuals contributed to the success of the workshop and the preparation of the proceedings for publication. Doctors J.B. Brierley, I. Klatzo, H.J. Reulen, and A.G."

On this occasion we look back on 25 years of the Deutsche Gesellschaft fur Neuro chirurgie. They hold a great deal: founding and development of the society, comple tion and extension, communication between the individual members and contacts to other societies beyond our borders. They also stand for close co-operation with those who transfer their patients to u- the neurologists and specialists in internal medicine, the ophthalmologists and ear nose-and throat specialists as well as the general surgeons. This 25th annual meeting will deal with two examples of diseases that present common problems to the neurologist and to the neurosurgeon, namely meningiomas and multiple sclerosis. In view of their long histories often going back over many years, both of these lesions lead to diagnostic errors and indequate treatment. And yet it should be possible to recognize meningiomas at an early date and to initiate the only possible treatment, the operation, if all diagnostic measures are repeatedly carried out. The diagnosis MS, on the other hand, with the multiplicity of symptoms which are peculiar to this disease, should continue to be re-examined until every other lesion has been excluded with certainty. The increasing number of legal proceedings because of diagnostic and therapeutic measures as well as the doctor-patient talk preceding the written consent for these measures are further problems in need of discussion. For this reason, the topic "medical liability in special reference to the neurosurgeon" was chosen for this meeting. Many questions necessitate many answers."

This volume contains the papers presented at the 26th Annual Meeting of the Deutsche Gesellschaft fUr Neurochirurgie, held in Heidelberg, Western Germany, on May 1-3,1975. Since at recent meetings of the German Neurosurgical Society central pathophysiological problems such as "central dysregulation" and "brain edema" had been discussed extensively, it seemed appropriate to choose another major area of cerebral patho- physiology for the meeting in Heidelberg. CEREBRAL HYPOXIA is, as LANGFITT once emphasized, "the final common denominator" of various cerebral lesions with which the neurosurgeon is confronted every day. Raised intracranial pressure, respiratory disorders and disturbances in systemic arterial blood pressure, etc. may lead, if not treated, to a focal or global lack of oxygen in the brain tissue. Anoxia finally results in cell death and thus in irreversible cerebral damage or even death. Main interest has therefore been focussed on disturbances in cerebral perfusion pressure ("ischemic hypoxia") and in arterial oxygenation ("hypoxic hypoxia"). The importance of cerebral autoregulatory mechanisms protecting the brain against tissue hypoxia, of patho- morphological alterations of the cerebral vessels (e. g. the "no-reflow-phenomenon") in the course of severe hypoxia, and of changes in brain metabolism have been discussed on a large scale. The organizing committee was particularly happy to have obtained internationally well-known scientists who presented their work in the field of cerebral hypoxia.

This volume contains the papers presented at the 24th Annual Meeting of the Deutsche Gesellschaft fur Neurochirurgie, held in Mainz, Western Germany, on April 30 - May 3, 1973. Deliberate choice was made of two crucial still hotly debated subjects which, for ages, have meant a source of constant worry, and nights without sleep to every neurosurgeon. Just as long as our special field exists, there have been the problems of how to control brain edema and .of how to reduce lethality and the secondary lesions in surgery of cerebello-pontine angle tumors. Concerning the first subject, new pathological, pathophysiological and chemical aspects, the mechanisms of brain edema formation and resolution are presented in the hope for better understanding. Furthermore, the relationship between brain edema, intracranial pressure, cerebral blood flow and metabolism are discussed. Finally, the therapeutical consequences as well as the results of experimental and clinical work are presented, and a comparison of effects between different methods (hypertonic solutions, diuretics, steroids, controlled hyperventilation, hyperbaric oxygen) is given. Concerning the second main subject, any important contributions to the early diagnosis of cerebello-pontine angle tumors have been included. Nevertheless, it is of utmost interest for the neurosurgeon to know which approach he is to prefer for the different stages of tumor size and to be familiar with the trans labyrinthine approach or the posterior craniotomy, as well as with the importance of the use of the microscope in neurosurgery, the preservation of the facial nerve and, in certain cases, its repair."