Introduction

In 1863, Nicholaus Friedreich, Professor of Medicine in Heidelberg, Germany, wrote three articles about a ‘degenerative atrophy of the posterior columns of the spinal cord’ causing progressive ataxia, sensory loss, and muscle weakness (Friedreich, 1863a, 1863b, 1863c). It could strike several siblings with normal, unaffected parents. Friedreich reported additional cases in 1876 and 1877. Charcot suspected for some time that Friedreich had described a form of tabes, but eventually he recognized that it was a new disease entity. Brousse (1882) was the first to use the name ‘Friedreich ataxia.’ After a few years, Ladame (1890) reported more than 100 cases. In the years that followed, more and more descriptions of inherited degenerative diseases causing ataxia were published. Many of these cases were noted to have some characteristics resembling Friedreich's ataxia, eventually blurring the definition of the disease (Bell and Carmichael, 1939). Only in the late 1970s did landmark studies establish the autosomal recessive pattern of inheritance (Geoffroy et al., 1976; Harding, 1981; Harding and Zilkha, 1981) and define rigorous diagnostic criteria (Geoffroy et al., 1976; Harding, 1981). It was realized that the disease shows variability in the clinical picture, sometimes with atypical presentations coexisting in the same family with typical cases (Winter et al., 1981; Filla et al., 1990, 1991; Muller-Felber et al., 1993). Specific variants, such as the so-called Acadian ataxia (Barbeau et al., 1984; Richter et al., 1996), were recognized in some ethnic groups.