What significance do the phenotypes have for the prognosis of ALS?

The ALS phenotypes can be associated with different ALS progression rates and survival times. For example, phenotypes with an onset in the legs, with slow propagation and with exclusive involvement of the first or second motor neuron are associated with a more favorable prognosis.

The phenotypes can thus help to further individualize the prognosis in the expected course and supplement other established prognostic factors such as the ALS progression rate, NfL, body mass index or respiratory parameters.

Phenotypes are also determined in clinical trials in order to reduce the clinical heterogeneity of study groups or to target drug development to specific phenotypes. It should be emphasized that phenotypes must always be evaluated and weighed in conjunction with other prognostic factors.