Catheter for endovascular sympathetic denervation of spasmed intracranial arteries

An apparatus includes a catheter assembly having a catheter with a catheter body and an end effector connected with a distal end of the catheter. The catheter assembly optionally includes an outer sheath or introducer tool. The end effector includes a spine assembly having a plurality of spines. An electrode is associated with each spine of the spine assembly. The electrodes are longitudinally staggered along their respective spines. The spines extend outward from a longitudinal axis of the catheter body such that the spine define a circular arrangement. This arrangement with the longitudinally spaced electrodes defines a helical array such that an elongated circumferential ablation pattern is achieved.