Olly, good stuff but you scare me with your quote of 50% of PLS'ers going on to develop
ALS. I've read that same statistic. The V.A. has sent me paperwork treating me as if I already have
ALS.
I concur with Olly in that PLS may start in the legs, the arms or in the bulbar region.
I have PLS, so I am told. As Olly stated, a hard diagnosis of PLS is usually given after a 5 year "wait and see" period. In some cases,
ALS starts with only upper motor neuron death. It can take up 3 to 5 years for lower motor neuron death to become evident if it indeed is
ALS.
As mentioned before, PLS is extremely rare compared to
ALS. So, as in my case, PLS can be considered a differential diagnosis until it becomes clear that it is going to stay that way. Kind of a tease, if you ask me.
A big difference, physically, between
ALS and PLS is muscle atrophy.
Zaphoon