We have already seen evidence that AVXL trials have generated more information-data than what is required/described by basic trial criteria. So, as long as additional data gathering does not interfere w/trial protocols-information gathering then it is allowed. Gathering todays trial data by inference and correlations/interviews and picture(MRI) over time has less scientific value than direct data and real time measurements. IMO, unless how trials are done changes, we will never escape the CNS disease forest.
Based on the FDA paper attached it would seem they are in the same place.