The results of a long-term prospective follow-up of 104 Friedreich ataxia patients are reported from the Salpetriere Hospital, Paris, and other centers in France. Patients were examined every 6 months for a median period of 5 years (range, 6 months to 7 years). Eighty-eight were treated with the antioxidant, idebenone and 16 declined. The neurologic status, evaluated using the International Cooperative Ataxia Rating Scale (ICARS) and a quantitative writing test, showed worsening even in patients treated with idebenone and especially in those with onset before age 15 years. The ataxia posture subscore increased faster in ambulant patients with shorter disease durations at baseline. In patients with long disease durations, the ICARS scores reached a plateau, and neurological progression was underestimated. Oculomotor function evaluated by electro-oculography deteriorated slightly, and cardiac function evaluated by echocardiography, electrocardiography, and Holter monitor showed cardiac hypertrophy at baseline and significant decreases in left ventricular mass and ejection fraction at follow-up. Patients with severe neurologic impairment at baseline also had severe cardiac hypertrophy. Although cardiac hypertrophy decreased with treatment, cardiac function showed no improvement. [1]

COMMENT. All patients in this study had typical Friedreich ataxia (FA) with confirmed molecular diagnosis mapped to chromosome 9ql3. FA is an autosomal recessive disease with onset between 5 and 25 years of age. The prevalence is estimated at 1/30,000 to 1/50,000 in most populations. Clinical manifestations include progressive limb and truncal ataxia, dysarthria, absent reflexes, Babinski signs, and impaired vibration and proprioceptive sense. Asymptomatic cardiac disease with left ventricular hypertrophy is present in 66% of patients, and nystagmus or fixation instability occur in 25%. FA with retained reflexes (FARR), a variant phenotype of FS, is reported in some families [2]. The ICARS, with a possible maximum score of 100 and 4 subscores (posture, kinetic function, speech, and oculomotor dysfunction) that increase with severity, has interrater reliability but is not appropriate to evaluate progression of FA in patients with long disease duration.