Response to Letter by Toni et al
We thank Dr Toni and colleagues for their insightful comments. We acknowledge that no clinical stroke syndrome is pathophysiologically pure, that the TOAST classification of stroke mechanism is imperfect, and that a better system is needed, yet this should not be a barrier to the development and testing of putative therapies.
The main purpose of our article was to quantify the accuracy of a syndromic diagnosis of lacunar stroke within the first 6 hours of symptom onset, given the difficulties associated with establishing a causative mechanism early on when treatment is most likely to be effective. We concluded that an OCSP LACS diagnosis made within 6 hours of stroke onset is reasonably predictive of a final diagnosis of “small vessel (lacunar)” disease made using TOAST criteria and has a similar relationship to outcome at 3 months. We believe that this information is of value in the design of clinical trials of acute-phase interventions because it can be used to help balance the different treatment arms of a trial with strokes that have a distinctly better natural history than other subtypes.