Book excerpt: Gives specialists in the clinical neurosciences a detailed and authoritative instrument for coding virtually all recognized neurological conditions. Both neurological diseases and neurological manifestations of general diseases and injuries are included in this comprehensive coding tool. The volume is part of a growing family of specialty-based adaptations of ICD-10 which retain the core codes of the parent classification while providing extended detail at the fifth character and beyond. Now in its second edition ICD-NA has been revised to reflect current clinical concepts in the neurosciences as well as the new coding system introduced with ICD-10. The classification was finalized following extensive consultation with numerous professional organizations and international experts thus ensuring the representation of as many viewpoints as are practical and consistent. While remaining directly compatible with ICD-10 ICD-NA offers clinicians and researchers much greater precision allowing them to match an explicit diagnosis with a detailed code at the five- six or seven-character level. In addition a comprehensive alphabetical index and the extensive use of inclusion and exclusion terms provide considerable assistance in finding the correct category for any condition diagnosed. Apart from these opportunities for recording greater diagnostic detail the direct compatibility with ICD-10 facilitates comparisons between statistics compiled according to ICD-NA and national morbidity and mortality statistics compiled according to ICD-10. These features enhance the flexibility of ICD-NA making it suitable for use in morbidity statistics hospital record indexing and epidemiological research by government and other health agencies collecting statistical data under relatively few main headings or by individual physicians and researchers requiring a convenient tool for indexing their clinical and teaching material in sufficient detail. The revised classification should also facilitate the collection of epidemiological data comparisons of the prevalence of individual neurological diseases and identification of the risk factors for these diseases at both national and international levels. In addition to the detailed tabular list of neurological and related disorders the volume includes an explanation of the basic principles of classification and instructions for coding morphology codes for neoplasms relevant to neurology and neurosurgery and a 90-page index of diagnostic terms given in standard or official nomenclatures together with synonyms and eponyms.