Friedreich's ataxia in 13 children: presentation and evolution with neurophysiologic, electrocardiographic, and echocardiographic features.
Thirteen children with Friedreich's ataxia were reviewed. The clinical presentation and evolution of the disease was compared to that observed in large series--based mainly on adult patients--and the few studies in children. The mean age of onset (5.3 +/- 2.7 years) was lower than that reported in the former studies. Progressive unremitting ataxia of all four limbs was the earliest and most consistent finding, whereas dysarthria and loss of joint or vibration sense occurred with less frequency than that reported in adult series. The tendon jerks were absent or reduced in the lower limbs in almost all children. The universal absence of lower limb reflexes was shown to be too rigid to be obligatory for the diagnosis of early cases of Friedreich's ataxia. Electrophysiologic investigations revealed typical findings, ie, normal or low-normal motor conduction velocities and absent sensory responses. Electromyography showed more features of denervation in the lower limbs than in the upper limbs. Cardiac symptoms and signs were minimal, whereas electrocardiographic abnormalities occurred in 92% of patients, presenting mostly as significant T-wave changes. Concentric symmetric thickening of both the interventricular and left ventricular posterior walls was the major echocardiographic finding.