Subcortical Dementia-Reply

In Reply.—  We would like to thank Drs Mayeux and Stern for their excellent comments.When our study¹ was designed, we felt it was quite reasonable to compare patients with cortical and subcortical dementia as they tend to present in a typical outpatient practice, since the value of this distinction is primarily a clinical one. We are also well aware of the value of equating disease severity, as Mayeux and Stern have already done,² and we alluded to this in our article.¹ We agree that because dementia is often progressive, it is generally appropriate to match patient groups prior to examination of qualitative differences in various syndromes of dementia. This approach may not, however, be appropriate to evaluate the cortical/subcortical hypothesis. One of the previously recognized features of subcortical dementia is that "the intellectual impairment is more mild... than [in] the cortical dementias."³ Mayeux and Stern agree that