Figure 1.
Timing of SMN Restoration and Predicted Outcomes: SMA is caused by reduced levels of SMN protein. Therapies that provide early restoration of SMN are anticipated to fully rescue motor neurons and the motor unit. When SMN restoration is delayed it is anticipated that rescue will be reduced in a time-dependent fashion. CMAP: compound muscle action potential; MUNE: motor unit number estimation. *Following delayed treatment, CMAP size may be fully corrected if there is sufficient collateral reinnervation from the remaining motor neurons.