Evaluating the progression of Friedreich ataxia and its treatment.

Friedreich ataxia is characterised by slowly progressive neurodegeneration and cardiomyopathy. Currently, no treatments have been proven to delay, prevent, or reverse the inexorable decline that occurs in this condition; however, several pharmaceutical agents are undergoing clinical assessment. Because initial beneficial therapies are likely to slow disease progression rather than reverse morbidity, the need for accurate measurement tools that will detect such subtle benefits is critical. The impact of Friedreich ataxia on the nervous system has been assessed largely through the use of rating scales and functional composite measures, and a number of patient reported outcome measures in Friedreich ataxia have been studied. However, on the basis of published reports on the performance of these measures, none clearly stands out as the best for use in clinical trials. Refinement of existing tools and development of new tools will be needed to maximise the chance of detecting small but clinically significant benefits of therapeutic agents in patients with Friedreich ataxia.