If you hit the railing on the shoulder, you necessarily must have driven on the shoulder for at least *some* distance (and it's possible that based on angle of the impact, skid marks or tracks, etc. that they can determine that you--possibly without realizing it; e.g. as the seizure came on--may have driven for some distance on the shoulder). Therefore, the authorities may legitimately believe that the facts show that you committed the offense and may be ticketed. It is not a legal defense to a traffic infraction to say that you had a medical condition, but it is highly likely that, in light of the circumstances, that the prosecutor will, when you speak with him/her on the day of trial, agree to reduce the offense or penalty, or possibly even dismiss the case, especially if you otherwise have a clean driving record.