Quebec cooperative study of Friedreich's ataxia: design of the investigation

The general outline of the complete prospective study of 50 cases of spino-cerebellar degeneration is given. The general protocol followed, the criteria for inclusion and the mode of analysis are described. The aim of this study was to establish a base of clinical, physiological and biochemical facts upon which a logical and systematic approach to pathogenesis and treatment of Friedreich's ataxia could be attempted.