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.