Retraction ========== Y Sato, T Asoh, N Metoki *et al*. Authors’, reply. *J Neurol Neurosurg Psychiatry* 2004;75:511ret. We are retracting this letter in light of the retraction of the article to which it relates. This is an Open Access article distributed in accordance with the terms of the Creative Commons Attribution (CC BY 4.0) license, which permits others to distribute, remix, adapt and build upon this work, for commercial use, provided the original work is properly cited. See:[http://creativecommons.org/licenses/by/4.0/](http://creativecommons.org/licenses/by/4.0/)