I understand that some of this is a

I understand that some of this is a judgement call by both the subject and the investigator as something like seizures may not happen in a consistent frequency (i.e. someone who has seizures roughly 6-8 times a year may not necessarily get them every 7-8 weeks and may have a few closer to one another than others) and it would be up to the subject to gauge if the seizures were more serve or had a change in their character. However, it would be the responsibility of the investigator to re-assess the pre-existing condition throughout the trial to determine if eventually there is a change in severity, frequency or character and thus should be reported as an AE, often being conveyed by a “worsening of the event”, “more frequent event”, or if it is a new AE in the case of changes in the character of the event.