To the Editor: We appreciate Dr. Swartz’s comments underscoring that the stimulus characteristics used in our study may have affected the results. As he points out, and as we discussed in our article, some reports have suggested that shorter pulse widths and a longer duration of stimuli may be more efficient at eliciting seizures. Such stimulus characteristics might be associated with fewer than 5% of the subjects having ineffective treatments because of short seizures at the maximum available stimulus level. It should be noted, however, that to our knowledge, there have been no published studies that directly address this issue with the use of precise dose-titration methodology, and this possibility therefore remains speculative. Further, other, admittedly flawed, investigations have suggested diminished efficacy with shorter pulse widths.