A medical device for sympathetic nerve ablation includes a catheter shaft and an expandable member disposed on the catheter shaft. The balloon is configured to be able to shift between an unexpanded configuration and an expanded configuration. The medical device includes an elongate electrode assembly constructed as a flexible circuit and a protective bumper member. The elongate electrode assembly may have an outer edge and may be disposed on an outer surface of the balloon. The protective bumper member may cover at least a portion of the outer edge of the elongate electrode assembly.