Which phenotypes of ALS propagation can be distinguished?

A basic distinction is made between early and late spread (propagation) – depending on whether this occurs within 12 months or later.

If the disease starts in the head region, the following distinction is made: P1e – onset in the head region with spread to other regions within 12 months and P1l – onset in the head region with spread to other regions after 12 months or later (also called “progressive bulbar paralysis”).

The following distinction is made at the onset of ALS in the arm: P2e – onset on the arm with spread to other regions within 12 months; P2l – onset in the arm with spread to other regions after 12 months or later also known as “flail arm syndrome”); if ALS begins on the trunk, the following distinction is made: P3e – onset on the trunk with spread to other regions within 12 months; P3l – onset on the trunk with spread to other regions after 12 months or laterThe following distinction is made at the onset of ALS in the leg: P4e – onset on the leg with spread to other regions within 12 months; P4l – onset on the leg with spread to other regions after 12 months or later (called “Flail-Leg syndrome” after 12 months of illness).