Your friend might want to get checked for Lyme Disease because chronic Lyme Disease can mimic several neurological diseases.
Dr. David Martz was diagnosed with ALS. And when he was tested for Lyme Disease his test results came back positive. Dr. Martz was then treated for Lyme Disease and his "ALS" symptoms improved dramatically.
Dr. Martz recovery from diagnosed ALS was featured in the documentary film "Under Our Skin" and in the book "Cure Unknown: Inside the Lyme Epidemic".
You can read a little more about Dr. Martz and his recovery here:
Also, the average doctor doesn't have the slightest clue as how to correctly diagnose chronic Lyme Disease so your friend will need to go see a "Lyme Literate Medical Doctor" aka LLMD. And he needs to be tested through Igenex labs.