I have heard of a few cases of als being triggered by Lyme disease.
As far as a natural cure goes, the answer is yes. Als can be solved at any stage by using holistic and mind body methods.
The key thing to understand is that als is the manifestation of a cycle of processes that progressively impair functioning.
So to change that one has to change the internal process from a degeneration process to a healing process.
This change can be achieved by learning to understand healing responses and by using mind body methods to apply healing responses on a cellular level.