Repeated GON Injections in CCH

Background: \- The effect of repeated GON-injections has never been studied in a double-blind randomized trial as a prophylactic therapy in a well-documented group of chronic patients. As such, (repeated) GON-injection has not yet found its place in current (inter)national treatment protocols for chronic cluster headache. Objectives: \- The primary objective is to determine if repeated GON-injection result in effective control of cluster headache attacks for more days compared to placebo in chronic cluster headache. Eligibility: \- Patients will be selected from the LUMC (Leiden University Medical Center) and CWZ (Canisius Wilhelmina Hospital) chronic cluster headache populations, diagnosed based upon the ICHD-3. Design: \- Bi-centre, randomized, double-blind, placebo-controlled retention trial with a maximum follow-up of one year.