Functional neurosurgery procedures are long and specific. Cooperation of the patient may be necessary during surgery. The interference of anaesthetic agents with electrophysiological monitoring should be as little as possible. Local anaesthesia combined with intravenous sedation is often used, but general anaesthesia is more comfortable and secure. Since awakening during the procedure is generally planed, it has to be quick, reliable and of excellent quality. These requirements are fulfilled by the association of propofol by target-controlled infusion (TCI) and a continuous infusion of remifentanil.