Modafinil and Fampyra together

I think this might be a hard question to answer, but for anyone with a good knowledge of neurology, here goes. I started on Fampyra about six months ago and am now taking Modafinil as well. From what I read, they both affect how the nerves transmit messages. Does anyone know what happens if you are on both of them? Is anyone else on both of them?

My neurologist did prescribe them both at the same time, but for completely different symptoms (walking problems and excessive sleeping). I do trust him but am still wondering about the two drugs together because I think they sound as if they’re doing something similar. However, I’m not sure if I’ve really understood what I’ve read about them.

By the way, they are both great drugs and I love them both. The Modafinil especially seems to be having a mood-lightening effect (but I’ve only been on it 10 days and I know this may not last). Also, my urge incontinence is much improved since starting the Modafinil. Have other people experienced this?