Can the ALS progression rate change during the course of ALS?

The rate of progression of ALS (ALSPR) remains relatively constant over the course of the disease. With slower progression, there is rarely a sudden acceleration, just as a significant slowdown is unusual with faster progression. The “basic speed” of the disease usually shows only minor fluctuations and is particularly noticeable in the early and middle stages. As the disease progresses, the ALSPR may appear to decrease – a methodical effect known as the “floor” effect. This occurs when only minimal changes can be measured on the ALS Functional Scale (ALSFRS-R) with a pronounced motor deficit. Especially after the start of invasive ventilation, the lowest scale value is often reached, which means that progression is not adequately mapped.