We thank Iwasaki and colleagues for sharing the results of their neurophysiological studies in 4 patients with SCA6, which seem to support our observation that peripheral nerve abnormalities are not a prominent disease feature in SCA6.1 The results of our single-fiber electromyographic studies in patients with SCA6 were published separately.2 That study indicated normal function of the neuromuscular junction in SCA6. Therefore, current evidence suggests that the disease mechanism in SCA6 involves only central nervous system structures. Morphologic studies of the neuromuscular junction in SCA6 postmortem tissue are being performed to confirm our neurophysiological observations.
van de Warrenburg BPC, Schelhaas HJ, Zwarts MJ, Kremer BPH. Spinocerebellar Ataxia and Peripheral Neuropathy—Reply. Arch Neurol. 2004;61(10):1626. doi:10.1001/archneur.61.10.1626