The period that followed World War II has witnessed a dramatic change in neurology. From being a discipline in which its partici- pants were castigated for being interested solely in diagnosis, usually of disorders of unknown causation without effective therapy, neurology has evolved into a highly active treatment- orientated subject. This transition is clearly reflected in the ap- proach to diseases of the peripheral nervous system, and to the Guillain-Barre syndrome (GBS) in particular. In a state-of-the- art review made in 1952, Elkington (1952) observed that no less than 56% of neuropathies remained undiagnosed, and amongst those of unknown causation he listed GBS. With intensive in- vestigation and follow-up, the proportion of neuropathies seen at tertiary referral centres which elude diagnosis is now as little as 13% (McLeod et al. 1984). Overall, of course, the proportion is even less. This change is partly because of the introduction of new diagnostic techniques and partly because of the application of the great expansion in knowledge evident throughout medicine. In this book, Professor Richard Hughes has assembled current information on GBS and related disorders, including chronic in- flammatory demyelinating polyneuropathy (CIDP), the existence of which was not appreciated until Austin's perspicacious study published in 1958. In the Introduction, Professor Hughes gives an account of the way in which recognition of the GBS emerged and matured, and shows that it followed, pari passu, with the realisation that paral- ysis and sensory loss may result from peripheral nerve disorders.