Epilepsy surgery is defined as any neurosurgical intervention whose pri- mary objective is to relieve medically intractable epilepsy (European Fed- eration of Neurological Societies Task Force 2000). The aim of epilepsy surgery is to reduce the number and intensity of seizures, minimise neuro- logical morbidity and antiepileptic drug (AED) toxicity, and improve quality of life. By definition, epilepsy surgery does not include normal surgical treatment of intracranial lesions where the primary goal is to di- agnose and possibly remove the pathological target, often an advancing tumour. In these patients, epileptic seizures are only one symptom of the lesion and will be treated concomitantly as part of the procedure. Temporal lobe epilepsy (TLE) is recognised as the most common type of refractory, focal epilepsy. In one third of all cases the neuronal systems responsible for the seizures that characterise this form of epilepsy fail to respond to currently available AEDs (Andermann F 2002). New imaging methods, especially magnetic resonance imaging (MRI), identify localising abnormalities in an increasing proportion of patients with intractable focal epilepsy. Consequently, the accuracy of the preoperative diagnostic pro- cedures has been significantly improved during the last decade; and suit- able candidates for surgery can be selected more reliably. Currently the main resources in most epilepsy surgery centres have been used to evaluate candidates for TLE surgery.

As an addition to the European postgraduate training system for young neurosurgeons we began to publish in 1974 this series of Advances and Technical Standards in Neurosurgery which was later sponsored by the European Association of Neurosurgical Societies. This series was first discussed in 1972 at a combined meeting of the Italian and German Neurosurgical Societies in Taormina, the founding fathers of the series being Jean Brihaye, Bernard Pertuiset, Fritz Loew and Hugo Krayenbiihl. Thus were established the principles of European co operation which have been born from the European spirit, flourished in the European Association, and have throughout been associated with this series. 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 publi cation 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.

As an addition to the European postgraduate training system for young neurosurgeons, we began to publish in 1974 this series of Advances and Technical Standards in Neurosurgery which was later sponsored by the European Association of Neurosurgical Societies. This series was first discussed in 1972 at a combined meeting of the Italian and German Neurosurgical Societies in Taormina, the founding fathers of the series being Jean Brihaye, Bernard Pertuiset, Fritz Loew and Hugo Krayenbuhl. Thus were established the principles of European co operation which have been born from the European spirit, flourished in the European Association, and have been associated throughout with this senes. The fact that the English language is now the international medium for communication at European scientific conferences is a great asset in terms of mutual understanding. Therefore we have decided to publish all contri butions in English, regardless of the native language of the authors. All contributions are submitted to the entire editorial board before publication of any volume for scrutiny and suggestions for revision. 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.

Epilepsy surgery is defined as any neurosurgical intervention whose pri- mary objective is to relieve medically intractable epilepsy (European Fed- eration of Neurological Societies Task Force 2000). The aim of epilepsy surgery is to reduce the number and intensity of seizures, minimise neuro- logical morbidity and antiepileptic drug (AED) toxicity, and improve quality of life. By definition, epilepsy surgery does not include normal surgical treatment of intracranial lesions where the primary goal is to di- agnose and possibly remove the pathological target, often an advancing tumour. In these patients, epileptic seizures are only one symptom of the lesion and will be treated concomitantly as part of the procedure. Temporal lobe epilepsy (TLE) is recognised as the most common type of refractory, focal epilepsy. In one third of all cases the neuronal systems responsible for the seizures that characterise this form of epilepsy fail to respond to currently available AEDs (Andermann F 2002). New imaging methods, especially magnetic resonance imaging (MRI), identify localising abnormalities in an increasing proportion of patients with intractable focal epilepsy. Consequently, the accuracy of the preoperative diagnostic pro- cedures has been significantly improved during the last decade; and suit- able candidates for surgery can be selected more reliably. Currently the main resources in most epilepsy surgery centres have been used to evaluate candidates for TLE surgery.

As an addition to the European postgraduate training system for young neurosurgeons, we began to publish in 1974 this series of Advances and Technical Standards in Neurosurgery which was later sponsored by the European Association of Neurosurgical Societies. This series was first discussed in 1972 at a combined meeting of the Italian and German Neurosurgical Societies in Taormina, the founding fathers of the series being Jean Brihaye, Bernard Pertuiset, Fritz Loew and Hugo Krayenbuhl. Thus were established the principles of European co operation which have been born from the European spirit, flourished in the European Association, and have been associated throughout with this senes. The fact that the English language is now the international medium for communication at European scientific conferences is a great asset in terms of mutual understanding. Therefore we have decided to publish all contri butions in English, regardless of the native language of the authors. All contributions are submitted to the entire editorial board before publication of any volume for scrutiny and suggestions for revision. 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.