I have it as well. I was on Neudexta for it. It is specifically for PBA for ALS and MS patients.
I was taken off of it last month when I was in the hospital...they thought it caused bradycardia. When I saw my neuro the week after, he was very angry with them for taking me off, because he knows it doesn't cause this.

I saw my cardiologist today and she told me to go back on it. She was confused as to why I was taken off of it. She feels the benefits far outweigh any risks the med might cause.

I have been extremely weepy since being off of it...sobbing at the first sighting of a robin, for instance...the drug really helps, and also reduces neuropathic pain. I am going back on it.