Hmmm. Been doing a bit of Googling since I posted.
Hallucinations were an “infrequent” but recorded event during clinical trials of Fampyra.
Don’t know if that actually gets you any further, as they record any adverse event that was observed, even if it’s not necessarily proved to have been related. So in a large enough trial, you don’t know how many participants might have had hallucinations by complete coincidence.
Also it’s strange that you would start having side effects after two years.
On the other hand, some drugs are like that. I take quinine, which can have some quite rare and severe side effects, but not linked to length of use. In other words, it’s NOT a drug where if you take it for a month and nothing happens, you can confidently say it never will.
There is always a small chance patients might develop a severe quinine side effect, even if they’ve used it harmlessly for years - which is kind of creepy, but I try not to think about it too much.
I don’t know if Fampyra is one like that, which could randomly start having side effects, after being fine for years.
Having read that there have been reported cases, I definitely suspect it above the MS, though.
I haven’t checked out LDN, to see if that has ever been associated with hallucinations.