Primary lateral sclerosis natural history study – planning, designing, and early enrollment. - Mitsumoto, Hiroshi; Jang, Grace; Lee, Ikjae; Simmons, Zachary; Sherman, Alexander V.; Heitzman, Daragh; Sorenson, Eric; Cheung, Ken; Andrews, Jinsy; Harms, Matthew; Shneider, Neil A.; Santella, Regina; et al. (Amyotrophic Lateral Sclerosis & Frontotemporal Degeneration, 2023)