This headache seems to send low level electrical currents shooting back and forth right behind my lower forehead and almost behind the eyes. It happens when I move my eyes or move my head to try and focus on something to the side of me or in my peripheral field of vision. To stop this almost debilitating sensation I must either sit without turning my head or eyes. Or, go to bed in a darkened room. It sometimes lasts for two or three days. Sound familiar to anyone taking Fentynal or even those not taking the drug. I'm not sure what to attribute this sensation to and it seems to me I had the same sensation years ago when I tried Gabapentin and Lryica, at different times, though. I have never been a real victim of headaches in the past sixty years. By the way, I'm on the 100 mcg patch every 48 hours. Thanks. slimtonone