Classification of tremor

Abstract

The classification most widely used throughout the world is that published by the World Health Organisation and revised every 10 years. The Ninth International Statistical Classification of Diseases, Injuries and Causes of Death (ICD 9) was revised in 1974 and volume 1 published in 1977 and volume 2 in 1978. In the United Kingdom all hospital discharge summaries have up to five diagnoses listed and each diagnosis is coded using the WHO classification. This information is collected regionally and forms the basis for the Hospital Inpatient Activities Analysis. It has not yet been extended to outpatient clinics or general practitioner surgeries. The WHO classification is based on a four-digit code. The Ninth Revision has been strongly criticised by Kurtzke (1979) who has demonstrated that ICD 9 is ‘a regression toward a less specific and more symptom-orientated code than its predecessors. It is particularly poor in the category of neurologic disorders with admixtures of disparate entities even at the fourth-digit level. This holds also for neurologic states coded under circulatory, musculo-skeletal and congenital anomalies sections.’