The jump between the past and present revealed that Picard potentially contracted Irumodic Syndrome, which was first seen as a possibility by Dr. Beverly Crusher in the episode’s present timeline, when she spotted an anomaly in his brain’s parietal lobe.
In “All Good Things,” Q took Picard on a journey through time, though it was not immediately known that was the case.
Crusher said it was possible Picard could live his whole life without developing the defect, though future timelines in the episode alleged he had contracted it.