Since the introduction of electrosurgery the techniques of surgery on the nervous system have passed through further improvements (bipolar coagulation, microscope), even if the procedure was not substantially modified. Today, laser represents a new "discipline," as it offers a new way of performing all basic maneuvers (dissection, demolition, hemostasis, vessel sutures). Furthermore, laser offers the possibility of a special maneuver, namely reduction of the volume of a tumoral mass through vaporization. Its application is not restricted to traditional neurosurgery but extends also to stereotactic and vascular neurosurgery. Laser surgery has also influenced the anesthesiologic techniques. At the same time new instrumentation has been introduced: CUSA ultrasonic aspiration, echotomography, and Doppler flowmeter. I have had the chance to utilize these new technologies all at a time and have come to the conclusion that we are facing the dawn of a new methodology which has already shown its validity and lack of inconveniences, and whose object is to increase the precision of neurological surgery. The technological development is still going on, and some improvements are to be foreseen. Laser scalpel is splitting the initial laser surgery into NO TOUCH and TOUCH surgery with laser. As new instrumentarium will be developed, a variable and tunable beam will become available. For example, in a few years Free Electron Laser will further add to the progress in this field."

During the last decade a multitude of studies concerning the dynamic changes in cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO2), and intracranial pressure (ICP) in the acute phase after head injury have been published. These studies have been supplemented with studies of cerebral autoregulation, CO2 reactivity and barbiturate reactivity. Other investigations include studies of cerebrospinal fluid pH, bicarbonate, lactate and pyruvate. In this book experimental and clinical studies of the dynamic changes in CBF, CMRO2, CO2 reactivity and barbiturate reactivity are reviewed. The author's own clinical studies of the dynamic changes in CBF and cerebral metabolism are summarized and discussed, and the therapeutical implication as regards the use of artificial hyperventilation, sedation with barbiturate and mannitol treatment are discussed.

Das vorliegende Buch enth{lt die Beitr{ge eines internatio- nalen Symposiumszum Thema "Stimulierte Hirndurchblutung." Vorgestellt werden zun{chst neue Erkenntnisse zur Regulation der Hinrdurchblutung. Im 2. Abschnitt kommen verschiedene Methoden zur Messung der Hirndurchblutung zur Sprache, die sowohl unter experimentellen als auch unter klinischen Be- dingungengetestet wurden. Es folgt ein Abschnitt, der ver- schiedene M-glichkeiten zur Stimulation der Hirndurchblutung aufzeigt. Im letzten Abschnitt wird aufdie Bedeutung der stimulierten Hirndurchblutungsmessung zur Bestimmung der ce- rebrovascul{ren Reservekapazit{ten hingewiesen. Dieser Para- meter hat nach den vorliegenden Untersuchungen klinisch- praktische Bedeutung, beispielsweise f}r die Indikations- stellung bei cerebrovascul{ren Eingriffen zur Isch{mie-Pro- phylaxe.

It is a great honor and pleasure for cerebral infarction have been carried me to have Springer-Verlag publish out. Dr. Yoshimoto hoped that the this volume entitled "Treatment of results of research done in our depart Cerebral Infarction." I am much in ment over the last sixteen years con debted to my colleagues for my success cerning cerebral infarction could be in publishing this book. published. Moved by his enthusiasm, I have engaged in clinical work in my colleagues took their share in writ the field of neurosurgery for these few ing each article. I suggested to them decades and I have performed more that this volume should cover primarily than 5,000 major operations of intra the results of our own research, but that cranial surgery. Throughout this time, at the same time it should also include it has been my privilege to conduct a 2- the results of related work done by neurosurgical experts throughout the hour-morning research seminar in our department every Wednesday and to world. Therefore, I hope that this book supervise a great deal of research. At will interest many investigators who these seminars my fellow research have devoted themselves to research in workers and I have exchanged many the field of neuroscience. ideas about the study of neurosurgery My colleagues acknowledge that and we have designed many animal our research has been stimulated and experiments."

Neurosurgery o/the Future: Computers and Robots in Clinical Neurosurgical Practice and in Training - a Philosophical Journey into the Future Many present day neurosurgeons believe that they already obtain good results in operative surgery with the benefit of the operating microscope and other aids which have become available in the last three decades and that the introduction of computers and robots to the operating theatre is superfluous. However, it is clear from analogy with the function of the airline pilot, another profession where there are great demands on manual skill and on spatial awareness, that these devices do have much to offer neurosurgery. Classical neurosurgery, in the time of Cushing, Dandy and Scarff, was based on a three dimensional picture of the patient's brain formed in the surgeon's mind and often illustrated in elegant drawings. Such pictures were based on neuroradiological studies by pneumoencephalography, ventriculography or by angiography. Generally these stud ies showed the presence and position of a lesion by displacement of normal brain structures and the picture was built up by interference. This was then converted by the experienced neurosurgeon into a plan for the craniotomy site and the trajectory of the surgical approach. Once the brain was exposed further pre-operative information was obtained by visual inspection and by palpation with the brain needle. These classical forms ofneuroradiology have largely been superseded by computerised tomography and by magnetic resonance imaging."

More than 40 years ago British and German neurosurgeons met in Berlin and Breslau to exchange their experiences, to strengthen their friendly bonds, and to enjoy the attractions of both cities and their surroundings. In 1960 a joint meeting of the Dutch and German societies took place in Rotterdam by invitation of the Nederlandse Vereniging van Neurochirurgen. All who attended this meeting thankfully remember the great hospitality during these unforgettable days. In 1970, by courtesy of the Society of British Neurological Surgeons, German neurosurgeons had the pleasure to become acquainted with the great tradition of British sciences at one of the most famous places during the meeting in Cambridge. These impressions were deepened by visits to other famous sources of British scientific tradition during the European Congress in Oxford in 1975. The critical distance sometimes necessary towards our own discipline is implicit in the major themes of this meeting. Complications following shunting procedures for hydrocephalus have been discussed on the basis of the results of a cooperative study of some German neurosurgical departments. The second main topic was problems and diagnostic errors in computer tomography. The papers presented contain critical considerations about the findings obtained by this method, as well as on its possibilities and limitations. German neurosurgeons felt deeply indebted to their British and Dutch colleagues and wanted to return their kindness at this joint meeting in Berlin. We hope that all participants will retain pleasant memories of the days in this city.

We have witnessed a remarkable development during the past 10 years in the development of extra-intracranial anastomosis to revascularize the brain. Initially, the intention was to create ameans of performing embolectomy in small corticaI arteries after cardiac surgery. Gradually a plan was conceived to form an extra-intracranial bypass(10) to treat inaccessible lesions of the carotid and vertebral arteries as weIl as tumors and giant aneurysms that involved these arteries. The basic techniques and principles of microvascular sur- gery, which had been refined over 30 years on peripheral ar- teries(1-7, 9) were applied in 1966 to the intracerebral arteries of dogs(4). The arterial patehing and suturing were successful, while extra-intracraniallong bypasses were a constant failure. This was attributed to the damage that was inevitably inflicted on the vasa vasorum of the autogenous graft during dissec- tion(9). This situation posed a dilemma until eventually the idea of Pool and Potts(8) was adopted and an anastomosis was performed on a dog between the superficiaI temporaI artery and a cortical branch. Because of the vesseIs' small size and the doubts regarding its capacity for improving the circulation, the procedure was performed with a certain amount of apprehen- sion. It was a pleasant surprise, therefore, to discover that it was possible to attain a high rate of patency. If the middle cerebral artery was us ed and was isolated from its carotid in- flow, an even higher rate was achieved.

This volume covers, in a logical sequence, the brain neuroscience which underpins current management of malignant brain tumours. Cellular and molecular studies are considered, as well as current concepts of histopathological classification and grading. The clinical manifestations and natural history of these tumours is set in context by a discussion of the pathophysiology of intracranial mass lesions. Special attention is given to low-grade and childhood tumours. The more common cerebral gliomas and cerebral metastases are also examined. Diagnostic imaging methods are described and the differential diagnosis of benign and malignant tumours is explored. The final chapters are devoted to conventional and innovative methods, along with the results, of treatment by surgery, radiation, chemotherapy and immunotherapy.

A different kind of book! The clivus of skull base is an area difficult to reach in neurosurgery, otorhinolaryngolo- gy, maxillo-facial surgery, plastic surgery, reconstructive surgery, and orthopedic surgery. It is for this reason that the various specialities gave found different approaches for different operations.

No special field of surgery dealing with the cranial nerves exists today. This is not surprising in view of the characteristics of this group of morphologically and topo graphically heterogenous nerves. Morphologically we must differentiate between central nerves (I, II and VIII) and the so-called peripheral nerves (nn. III to VII and IX to XII), in which post-lesion rgeneration is quite different. Anatomo-topographi cally we must consider an intracranial and an extracranial part of each cranial nerve. For practical reasons at operation, further subdivisions of the intracranial course of cranial nerves are to be distinguished in the anterior, middle and posterior cranial fossae as well as within the petrous bone. This underscores the extensive tasks awaiting surgeons operating in the ventral part of the brain and facial skull as well as in the more dorsal part of the skull and neck. This very wide field cannot be covered by a single surgical discipline alone. In our opinion, considerable progress has been made in surgery of the cranial nerves only in recent years. This may be explained by the increased mastery of microsurgical techniques by all surgeons in terested in the surgery of the base of the skull as well as with the initiation of more interdisciplinary consultation and jointly performed operations. Possibilities of fu ture development can be discerned in the text. The base of the skull separating the extra-and intracranial part of cranial nerves should not be a barrier but a connect ing link."

Increasing specialisation in pathology reflects the progressive changes in medical practise. The advent of a specialist with a new interest in a hospital or clinic may present the pathologist with a need to extend his or her knowledge to be able to work closely with the clinical practi tioner in order to provide adequate clinical care. Some sub-specialisations are long established, such a one is neu ropathology. However, an exclusive specialist practise is generally con fined to neurosurgical centres and much neuropathology is of necessity, executed by geneni.l pathologists. The areas covered by this volume are those which are commonly managed by the generalist. Professor Adams' account of how the skull and brain should be examined here will give confidence to many by defining a good technique and the careful description of various kinds of vascular injury lesions resulting from raised intracranial pressure will help to clarify repeated difficulty. More subtle forms of damage are also considered in detail. Professor Weller provides a detailed account of how the central nervous system may be examined in a way which permits all of us to prepare material which will allow adequate investigation of central nervous system disease and the proper examination of peripheral nerves. This chapter will become a "handbook" and will be of interest to those in training and established practitioners. Muscle biopsy is also dealt with; this is an area of investigative concern for many gener alists. The role of that singular neuropathological technique is very clearly emphasized.

Over a mere 5 years, neonatal cranial sonography has evolved from an obscure and largely experimental imaging possibility to the modality of preference in the examination of the young brain. The almost immediate acceptance of the ultrasound examination of the neonatal brain was based on a number of coinci dent factors, the most important of which was the emergence of a burgeoning population of premature neonates who were, for the first time, surviving be yond infancy. These delicate patients were beginning to withstand the rigors of extrauterine life when not fully prepared for it; pulmonary, cardiac, and infec tious diseases no longer claimed most of them. With survival, a new specter reared its head: Would the eventual mental and neurologic status of these same children be worth the expense and time needed to bring them through their first months? This issue became increasingly pressing as evidence mounted through the 1970s that very premature neonates were at a high risk for intracranial hemor rhage and posthemorrhagic complications. An imaging modality that could evaluate the premature brain was sorely needed. The CT scanner with its proven ability to diagnose intracranial hemorrhage was of little value in this regard. So too were static gray-scale or waterpath ultrasound units. These modalities all had the same limitation, lack of portability. As neonatal intensive care units proliferated, so did the technology that would soon allow cribside neonatal neuroimaging, the real-time sector scanner."

In this volume, one of a series of monographs devoted to the problems of cerebral ischemia and related topics, we present the proceedings of an international conference on Cerebral Ischemia and Basic Mechanisms held in Bad Schachen/Lake Constance, Germany in June 1992. The enormous progress in research recently on the basic mechanisms associated with cerebral ischemia has provided greater insight into the pathophysiological mechanisms of reduced brain perfusion and decreased cerebral metabolism. The high technology instrumentation used to unravel the intricacies of cerebral blood flow and metabolism includes positron emission tomography and magnetic resonance imaging. A description of sophisticated neurophysiological techniques will give the reader insight into new models of reversible and irreversible tissue damage and changes at the molecular level have been described. The therapeutic approaches which have developed from this re search have been or will be used in clinical trials and will open new avenues in the treatment of stroke. The organizers of the meeting would like to thank the advisory board for its helpful suggestions and the Deutsche Forschungsgemeinschaft and other sponsors for their important support."

The two International Symposia on Spinal Cord Monitoring, held in Tokyo in 1981 [Homma S, Tamaki T (eds) (1984) Fundamentals and clinical appli- cation of spinal cord monitoring. Saikon Publishing, Tokyo] and Erlangen in 1984, were remarkable in that they stimulated a gathering of electro- encephalographic, neurophysiological, orthopaedic, neurosurgical, anaes- thetic and pathological practitioners, presenting experimental, clinical and surgical experiences. The factor held in common was an understanding of the need to reduce the incidence and severity of iatrogenic neurological im- pairment associated with certain surgical and radiographic procedures. In the past there has been a tendency for the study of human evoked poten- tials (EPs) to be regarded as an end in itself, or at best a discipline which can be of limited assistance in certain problems of neurological diagnosis. Symposia such as these serve the valuable function of opening electro- physiological eyes to the problems to which EP techniques might usefully be devoted in other medical spheres. They also help those who practise electrophysiology as an adjunct to their speciality to comprehend such of the more complex properties of EPs as are relevant to their particular interests. The title of the Symposia and of this volume arose as a result of an his- torical accident. The pioneers of intraoperative neuronal monitoring were mostly surgeons specialising in the correction of spinal deformities or the removal of tumours.

In June 1973, Professor George Austin invited a small group of neuroscientists from Asia, Europe, the United States, and Canada to the Loma Linda University School of Medicine in Loma Linda, California. The fundamental technique of fashioning a small vessel collateral to the brain had been pioneered by Donaghy and Yasargil 5 years before and was now gaining momentum with the increased availability of the operating microscope, fine instruments and sutures, and surgeons trained in microvascular surgery. The interchange of ideas at this first conference was magic. The handful of participants returned home stimulated with new ideas of technique, patient selection, and postoperative evaluation and resolved to meet again on a regular basis. A Second International Symposium was hosted by Howard Reichman at Loyola University in Chicago, Illinois in June of 1974; a Third Symposium at Rottach-Egern, West Germany in June of 1976 under Professor F. Marguth of the Ludwig-Maximilians-University of Munich.

It is estimated that the functionally significant body of knowledge for a given medical specialty changes radically every 8 years. New specialties and "sub-specialization" are occurring at approximately an equal rate. Historically, established journals have not been able either to absorb this increase in publishable material or to extend their readership to the new specialists. International and national meetings, symposia and seminars, workshops, and newsletters suc cessfully bring to the attention of physicians within developing spe cialties what is occurring, but generally only in demonstration form without providing historical perspective, pathoanatomical corre lates, or extensive discussion. Page and time limitations oblige the authors to present only the essence of their material. Pediatric neurosurgery is an example of a specialty that has de veloped during the past 15 years. Over this period neurosurgeons have obtained special training in pediatric neurosurgery and then dedicated themselves primarily to its practice. Centers, Chairs, and educational programs have been established as groups of neuro in different countries throughout the world organized surgeons themselves respectively into national and international societies for pediatric neurosurgery. These events were both preceded and fol lowed by specialized courses, national and international journals, and ever-increasing clinical and investigative studies into all aspects of surgically treatable diseases of the child's nervous system."

Alzheimer's disease is one the foremost health problems facing every society fortunate enough to attain a level of medical care that ensures an average lifespan of over 70 years of age. The cause of the disease remains unknown, and no single therapeutic approach has yet been found highly efficacious. Indeed, as the complexity of its effects on brain neuronal systems becomes elucidated, the concept emerges that Alzheimer's disease may be an umbrella term for multiple Alzheimer's-type syndromes that can be differentiated based on etiology (hereditary versus sporadic), neurochemical deficits, and extent of pathology. Whether one or more disease processes is involved, it seems increasingly unlikely that any single drug will provide efficacious relief across the broad spectrum of symptoms reflected in large subject populations. Rational therapeutic approaches may yield long term amelioration of many symptoms in selected groups of patients; and individual symptoms may be ameliorated in larger populations. Multiple approaches may be combined to optimize therapeutic effects. For example, a variety of approaches remain focused on restoration of cholinergic neurodegeneration and enhancing cholinergic neurotransmission, whereas other approaches attempt to retard the of the brain that occurs during Alzheimer's disease. Chapters cover continuous degeneration topics from growth factor secretion of proteases, which could modify amyloid processing, to neuronal gene delivery using viral vectors. The breadth and thoroughness of the chapters truly embrace a broad spectrurn of models, pathological mechanisms and therapeutic approaches.

This volume contains papers presented at the Fifth International Symposium on Intra cranial Pressure held on May 30-June 3,1982, in Tokyo, Japan. The Symposium has continued to grow since it began in 1972, and this year it was comprised 121 oral and 46 poster presentations. This considerable number was chosen from the more than 216 abstracts that were received, which made the selection process very difficult. We would like to thank the Program Committee for their efforts. One hundred and fifty-one of the manuscripts are printed here. The classic papers, short communications, and the presentations for the poster sessions here appear together under their appropriate topic heading. There were eleven sessions which spanned the most basic scientific descriptions of ICP dynamics to the most recent clinical advances and debate. Also included are the seven special seminars given by the invited speakers. These spe cial seminars were an innovation at this symposium as a means of reviewing the major aspects and history and of projecting the future directions of this expanding field. The organizers wish to thank the Advisory Committee for their guidance and focus, and to express their appreciation to everyone who contributed to the success of this meeting - to the Chairmen and Co-chairmen, to all of the members and participants, and not least of all to our executive staff who worked behind the scenes. We also wish to acknowledge our gratitude to Springer-Verlag for their technical aid and for their prompt publication of this volume."

This volume is dedicated to the Third International Symposium on Microneurosurgical Anastomoses for Cerebral Ischemia, which took place in Rottach-Egern, June 2&-30, 1976, under the sponsorship of Professor F. Marguth, Director of the Depart- ment of Neurosurgery, Ludwig-Maximilians-University of Munich (West Germany). It contains the continuing devel- opments of the extra- intracranial arterial bypass (EIAB) for cerebrovascular occlusive disease since the First International Symposium in Lorna Linda, California, in June, 1973, and the Second International Symposium in Chicago, Illinois, in June, 1974. The EIAB was developed by Donaghy and Yasargil, and it consists of a microsurgical anastomosis of the superficial tem- poral artery or the occipi tal branch of the external carotid artery to the middle cerebral artery on the surface of the brain and, very recently, the anastomosis of the occipital artery to the posterior-inferior cerebellar artery for the treatment of verte- brobasilar insufficiency. From the presentations at the sym- posium it became evident that the greatest potential in the pre- vention of a stroke in a susceptible patient is the presence of an adequate collateral cerebral blood flow. The basic diagnostic procedure is cerebral angiography in- cluding both carotid and vertebral arteries. Regional cerebral blood flow (rCBF) studies and computerized tomography add further diagnostic information and are particularly important in the selection of potential surgical candidates.

The rapid development of diagnostic and therapeutic procedures in the management of spinal angiomas has opened up new possibilities and provided better chances for the patients concerned. The greatest impetus to this pro gress was given by the introduction of selective and superselective spinal angiography, microsurgical technique, and embolization. These sophisticated techniques and the skill required for their use are far from being routine in the neurosurgical and neuroradiologic departments. In spite of the rarity of spinal angiomas, the application of the above-mentioned procedures is the prerequisite for improving early diagnosis and giving timely adequate treat ment. Delay in diagnosis and treatment are still the main cause of unsatisfac tory results. In the last 10 -20 years, several groups in Europe and the USA have done important and fundamental work in introducing and developing the diganos tic and therapeutic armamentarium. Based on the pioneering work of their teachers and the classic contribution of Wyburn - Mason in 1943, they simultaneously improved the morphologic, physiologic, and clinical basis of our knowledge. Although progress is going on and many problems have to be solved, the general principles of clinical diagnosis, operative treatment, and embolization have been laid down and are to be published in a special monograph on this topic."

It is estimated that the functionally significant body of knowledge for a given medical specialty changes radically every 8 years. New specialties and "sub specialization" are occurring at approximately an equal rate. Historically, estab lished journals have not been able either to absorb this increase in publishable material or to extend their readership to the new specialists. International and national meetings, symposia and seminars, workshops and newsletters success fully bring to the attention of physicians within developing specialties what is occurring, but generally only in demonstration form without providing historical perspective, pathoanatomical correlates, or extensive discussion. Page and time limitations oblige the authors to present only the essence of their material. Pediatric neurosurgery is an example of a specialty that has developed during the past 15 years. Over this period, neurosurgeons have obtained special train ing in pediatric neurosurgery, and then dedicated themselves primarily to its practice. Centers, Chairs, and educational programs have been established as groups of neurosurgeons in different countries throughout the world organized themselves respectively into national and international societies for pediatric neurosurgery. These events were both preceded and followed by specialized courses, national and international journals, and ever-increasing clinical and investigative studies into all aspects of surgically treatable diseases of the child's nervous system."

Our common interest in surgery of the vertebral artery was born in 1976, when as residents in the same hospital, we attended an attempt by two senior surgeons to treat an aneurysm of the vertebral artery at the C 3 level. Long discussions had preceded this unsuccessful trial, to decide if surgery was indicated and to choose the surgical route. Finally a direct lateral approach was performed, but access was difficult and correct treatment was impossible, resulting in only partial reduction of the aneurysmal pouch. Following this experience, we decided to seek a regular and well defined approach for exposition of the vertebral artery. Review of the literature indicated some surgical attempts, but the descriptions did not give the impression of safety and reproducibility. No landmark on the described surgical route appeared sufficiently reliable. Henry's anatomical work (1917) gave the only accurate description on vertebral artery anatomy, and it became the basis for our work. When the same patient was referred again one year later, after a new stroke in the vertebro-basilar system, we had behind us repetitive experience on cadavers of an original approach to the distal vertebral artery.

The book on Processes of Recovery from Neural Trauma contains the proceedings of an international symposium which was sponsored by the Weizmann Institute of Science and was held in June 1984 in Israel. One of the central problems in neurobiology and clinical neurology are the processes which underlie the ability of the nervous system to recover from damage. Neurons of the mammalian nervous system cannot be replaced once the generative embryonic period has ended. Thus, recovery after trauma is limited by the degree to which regeneration of damaged neural processes is possible and by the capac ity of uninjured neurons to form new synaptic contacts or to use their existing ones more effectively. The lack of successful axon regeneration in the central nervous system is the reason for the permanent damage and the very limited recovery of function seen in victims of traumatic injury. Over the past few years, research on neural trauma has witnessed significant progress, resulting from interdis ciplinary research carried out in an increasing number of laboratories throughout the world. Accordingly, the book includes reports on the progress made in the forefront of research in this field. We hope that in addition to being a source of new informa tion, readers of the book will be stimulated to work and to generate new ideas and research strategies in this field of research.

Understanding the structure and function of the blood-brain barrier (BBB) and recogniz ing its clinical relevance require a concert of scientific disciplines applied from a view point of integrative physiology rather than from only molecular or analytical approaches. It is this broad scope that is emphasized in this book. In my opinion, four original contributions define the field as it exists today. The first, a monograph by Broman,1 entitled The Permeability of the Cerebrospinal Vessels in Normal and Pathological Conditions, was the model for many subsequent clinical and 3 experimental studies on BBB pathology. Second, experiments by Davson, summarized in his book entitled Physiology of the Ocular and Cerebrospinal Fluids, indicated that passive entry of nonelectrolytes into brain from blood is governed largely by their lipid 4 solubility. This research supported the original suggestion by Gesell and Hertzman that cerebral membranes have the semipermeability properties of cell membranes. The modem era of the barrier was introduced with the 1965 paper by Crone,2 entitled "Facilitated transfer of glucose from blood to brain tissue. " This paper identified stereospecific, facilitated transport of glucose as part of a system of regulatory barrier properties at a time when only a barrier to passive diffusion had been contemplated. Finally, the 1967 paper by Reese and Kamovsky, 11 entitled "Fine structural localization of a blood-brain barrier to exogenous peroxidase," sited the barrier at the continuous layer of cerebrovascular endothelial cells, which are connected by tight junctions.

As an addition to the European postgraduate training system for young neurosurgeons we began to publish in 1974 this series devoted to Advances and Technical Standards in Neurosurgery which was later sponsored by the European Association of Neurosurgical Societies. The fact that the English language is well on the way to becoming the international medium at European scientific conferences is a great asset in terms of mutual understanding. Therefore we have decided to publish all contributions in English, regardless of the native language of the authors. All contributions are submitted to the entire editorial board before publication of any volume. Our series is not intended to compete with the publications of original scientific papers in other neurosurgical journals. Our intention is, rather, to present fields of neurosurgery and related areas in which important recent advances have been made. The contributions are written by specialists in the given fields and constitute the first part of each volume. In the second part of each volume, we publish detailed descriptions Of standard operative procedures, furnished by experienced clinicians; in these articles the authors describe the techniques they employ and explain the advantages, difficulties and risks involved in the various procedures. This part is intended primarily to assist young neurosurgeons in their post graduate training. However, we are convinced that it will also be useful to experienced, fully trained neurosurgeons."