To the Editor: In the report by Kang et al. (Feb. 25 issue)1 regarding genetic abnormalities in the lysosomal enzyme–targeting pathway in persistent developmental stuttering, it would have been important to relate the results to recent neuroimaging findings in patients with this disorder. Contrary to the authors' statement that "the underlying causes of stuttering are unknown," studies using diffusion tensor imaging, a technique sensitive to subtle abnormalities in brain white matter, have consistently revealed left-hemisphere white-matter abnormalities in patients with this disorder.2,3,4 Together with studies showing a speech-timing abnormality in such patients, these data strongly suggest a disconnection syndrome.Looks to me as if Büchel and Watkins are not happy that the genetics paper has left the causes of stuttering unclear. For them, stuttering is clearly a disconnection syndrome. I have never heard that term before, but a similar tone was hit in a recent Chinese brain imaging article. Clearly connectivity issues would lead to a less effective system which leads to occasional speech delay.
But yet again, we are deprived from an open debate. Yet again it is happening behind subscription-closed doors.