I urge you to find a LLMD and schedule an appt for your brother. There is usually a wait - sometimes a few months..or longer.
Then work on convincing your brother to go.
Would he consider coming on here?
ALS is one of the misdiagnoses.
We encourage new members to take a look through the thread at the top of the page titled: "New to Lyme?...Start Here!"
It's packed full of useful information.
RMSF is a tick borne illness...and it's likely he has other coinfections.
Does he not want to treat the RMSF? (Since he did test positive?)
Ask him what does he have to lose? There is no good treatment for ALS.
Here's a video of Dr. Martz - he was diagnosed with ALS - Treated for Lyme disease and is now doing well.
/m.youtube.com/watch?v=UY9FdULDV6M