Willemijn Naber (Leiden/ NL), Roemer Brandt (Leiden/ NL), Rosa-Lin Ouwehand (Leiden/ NL), Joost Haan (Leiden/ NL), Michel Ferrari (Leiden/ NL), Rolf Fronczek (Leiden/ NL)
Abstract text (incl. figure legends and references)
Objectives: Attacks of cluster headache (CH) are usually side-locked in most, but not all patients. In a few patients, the side may alternate between or, rarely, within cluster episodes.
Methods: We observed 7 cases in whom the side of CH attacks shifted immediately or shortly after unilateral injection of the greater occipital nerve (GON) with steroids. Side-shift was defined as a temporary or persistent displacement of CH attacks to the contralateral side of the regular headache attack previous to the GON-injection.
Results: In five patients with previously side-locked CH attacks and in two patients with previously side-alternating CH attacks, a side-shift occurred immediately (N=6) or shortly (N=1) after GON-injection.
Conclusion: Unilateral GON-injections might cause a side-shift of CH attacks, illustrating the complex role of the GON in CH pathophysiology.