The Collaborative International Dictionary of English v.0.48:

Fulgurating \Ful"gu*ra`ting\, a. (Med.)
   Resembling lightning; -- used to describe intense lancinating
   pains accompanying locomotor ataxy.
   [1913 Webster]

WordNet (r) 3.0 (2006):

fulgurating
    adj 1: sharp and piercing