What is meant by ALS propagation?

Propagation describes the temporal and spatial pattern in which the motor symptoms spread from the region of symptom onset to another region of the body (for example, from the arms to the legs or to the muscles of the head).

Propagation is determined on the basis of the patient’s medical history and/or neurological physical examinations over a period of at least 12 months. Propagation can only be better estimated after this observation period.

Recording propagation can be important for prognosis assessment and treatment and care planning, as the propagation pattern can result in adjustments to mobility or respiratory support.