Sorry you had this scary experience. I had very similar thing happen and ended in the back of ambulance for a late night jaunt to ER knowing full well tha tit was probably an AS side effect--- what Tim correctly classified under the heading of neuropathy.
I never got a great explanation on why I got the sensation so scary that night. SO I have no great ideas to offer. Just be careful not to always assume it is AS caused and get someone to give you a medical lookover just in case.
