Medical negligence. An overview of legal theory and neurosurgical practice: causation.

This article discusses the principles of the law in relation to legal causation as applied to neurosurgical practice. Causation is a causal link between a breach of duty of care and the final harm. The fundamental "but-for" test for causation will be discussed, together with Chester v Afshar modified causation, prospective and retrospective probabilities of harm, loss of a chance, causation following breach of duty of care by omission, breaking the chain of causation, material contribution and the law in relation to multiple defendants, with neurosurgical examples.