yes, getting sick can increase sx's and cause a pseudo-exacerbation as others suggested. the stress on your body of being sick can be a reason and/or an increase in your body temp.

MS'ers can be very sensitive to increases in body temp, as evidenced in summer months. the heat slows down nerve impulses and can make you weak.

i would suggest with the sore throat that you get in to see your pcp, hopefully by the end of the wk. just to make sure you don't have something like strep throat. if it's viral and you need to ride it thru at least you'll know.

taking something like tylenol (always follow the directions), keeping up on fluid intake and resting will all help you heal.

if the sx's con't after you're well i would call your neuro.
and, you might need to use a cane temporarily to help with your balance.

i hope you get well soon.