neurological side effects of 5-FU

I just started my third cycle of M-F chemotherapy and my oncologist wants me to have a brain MRI. I had a mastectomy and clear lymph nodes. I've noticed since I started the chemotherapy that I get shaky, my right hand tingles and sometimes my hands start shaking. I'm 42 years old and in otherwise excellent health. What's going on?

[CCF-RN,MSN-JS]

Dear johyvaa, It's difficult to say.  These symptoms can be related to a number of things such as: 5-FU does have some neurologic side effects associated with it but these are rare and depend greatly on dose and how the drug is given.  You could be having some electrolyte imbalances particularly if you are having diarrhea, are dehydrated or anything like that.  The MRI is likely being done just to be on the safe side to make sure there is nothing there causing your symptoms.

[johyvaa]

Thank you. I haven't been dehydrated from diarrhea, so we'll see what the MRI shows.