The application of the International Statistical Classification of Diseases to neurology: ICD-10 NA

Rapid advances in the clinical neurosciences in the last decade have led to considerable amplification of our ability to classify neurological diseases. For these classifications to be widely used, they must be compatible with the 'International Statistical Classification of Diseases and related health problems' (ICD) of the World Health Organization (WHO), which system is used throughout the world for classification of diseases and reasons of death. The 'Ninth' revision of the ICD (ICD-9), published in 1976, is currently in use in a number of Member States of the World Health Organization, including the United States. However, it is expected that by the end of this decade virtually all Member States will have introduced the 10th Revision of the ICD (ICD-10), published in 1992. An 'Application of ICD-10 to neurology' (ICD-10 NA) has been developed, with a specific coding system for virtually every neurological disease currently recognized. This article describes the structure and background of this work, that is offered as a definitive international classification of neurological disease to be used by clinical and research organizations, governmental and nongovernmental bodies, and for epidemiological and research purposes. It is concordant with the new and proposed classifications of subspecialty neurological organizations.