Can aspartame cause neurological disorders?

Yes. I had a patient who drank 1-2 gallons of diet soda every day and had a pretty bad peripheral neuropathy. When he cut back, his symptoms improved.
Doubtful, but? Aspartame can chemically be converted to toxins if exposed to heat, and some have speculated that "gulf war syndrome" may be associated with diet pepsi. I have a few migraine pts who get headaches after diet drinks, and some ms pts may get worse temporarily. Personally, i will not touch the stuff, but there is little science to confirm dangers.