Reduced I waves facilitation by a paired-pulse TMS in patients with SCA6

摘要

In patients with cerebellar neurodegeneration, various changes in the intracortical facilitation and/or inhibition have been observed. Using TMS under a paired-pulse paradigm of Kujirai, a reduced intracortical facilitation was seen, whereas intracortical inhibition was shown to be unchanged [1-3]. Recently, facilitatory I waves interaction has been demonstrated with a suprathreshold first stimulus (S1) followed by a subthreshold to threshold second stimulus (S2) [4,5]. This novel technique can clearly show the serial facilitatory peaks of I waves. And also, this can visualize the relationship between the intracortical facilitation (ICF) and intracortical inhibition (ICI) on the same time course. The aim of our study was to investigate abnormalities in the intracortical inhibition and I waves facilitation in SCA6 patients with pure cerebellar ataxia syndrome by a paired-pulse transcranial magnetic stimulation (TMS).