• Survival rates for patients with neurosurgical pathology are improving, resulting in more of these patients presenting for incidental surgery. The non-specialist can safely anaesthetize neurosurgical patients by adhering to general neurophysiological principles. • Cerebrospinal fluid diversion devices (shunts) used to treat hydrocephalus are not only ventriculoperitoneal, the distal end may be placed into the intrapleural space or the right atrium. The proximal end can also arise from the lumbar spine.