We read with interest the article by Urbanet al. Using transcranial magnetic stimulation, the authors demonstrated electrophysiological evidence for a central monoparesis of the tongue in patients with isolated dysarthria from stroke.1 As in their patients transcranial magnetic stimulation induced absent or delayed corticolingual responses at the tongue, the authors ascribed isolated dysarthria to interruption of the corticolingual pathways. On the whole, these results seem plausible, but we would like to comment on the underlying mechanism of isolated dysarthria.

As in the case of isolated dysarthria reported by Urbanet al, all of our patients with isolated dysarthria had lacunar infarctions involving the internal capsule and corona radiata.2 Measurement of …