Is there a benign form of ALS?

The course of ALS varies greatly from person to person. Within the spectrum of disease progression, it is also possible for ALS to progress at a very slow rate. However, the term “benign” should not be applied even to these cases, since even with very slow progression, ALS always continues to advance and—albeit at a slower pace—leads to severe or complete paralysis. Slow-progressing ALS occurs in about 10% of all people with ALS. In these cases, the motor symptoms spread much more slowly from the initially affected region to other muscle groups.