I’m bi-lingual since childhood and writes both in English and Swedish. Unfortunately, after the stroke, I lost plenty of my vocabulary and started to mix the languages. At the stroke unit they asked me if I prefered to speak Swedish or English. I didn't understand why, I was so sure I spoke Swedish.
This complicated my writing and for a long time I had to learn to write again, and found a new way to use my language. I sometimes, accidentally switch language without noticing it, it usually takes a page or two before I realize it. My writing process is a little bit more complicated these days, but on the other hand I have parts of a translation ready from the beginning.
You can read excerpts from most of my English books here.