Shortly after Brian Wallach was first diagnosed with amyotrophic lateral sclerosis, he flew from Chicago to Massachusetts to get a second opinion.

It was November 2017, and the then-37-year-old assistant U.S. attorney was hoping that a general neurologist may have a different explanation for the muscle twitches in his arm or the difficulty he'd had grasping a pen. He wanted to hear that he wasn't suffering from ALS, a disease that is perhaps best known by references to Lou Gehrig and the ice bucket challenge.

That's not what the doctor told him and family members. Wallach was suffering from a disease that is typically fatal within three to five years. But there was more to the visit.