The non-hallucinogen 2-bromo-lysergic acid diethylamide as preventative treatment for cluster headache: An open, non-randomized case series

Cluster headache (CH) is a stereotyped primary headache characterized by strictly unilateral severe orbital or periorbital pain and categorized as either episodic or chronic (1,2). Its prevalence is 0.1% (3). Oxygen and sumatriptan are the treatments of choice for individual attacks, whereas verapamil, lithium, corticosteroids and other neuromodulators can suppress attacks during cluster periods (1)