I had similar experience. I have IgM MGUS, anti-MAG and WM but after almost two years of the peripheral neuropathy I quickly got numbness in my face. I told my neurologist, and he immediately ordered a brain MRI (small chance but my WM has possibility of Bing-Neel CNS involvement). Concerning but it was symmetrical, so after a clean scan it came down to just more neuropathy that is atypical. So, we can't just rely on what is typical.