Cluster headache and the hypothalamus – causal relationship or epiphenomenon?

Abstract

Typical clinical features of cluster headache (CH) include trigeminal distribution of pain, circadian/circannual rhythmicity, and ipisilateral cranial autonomic features. This presentation led to the assumption that the hypothalamus plays a pivotal role in this primary headache disorder. Several studies using neuroimaging techniques or measuring hormone levels supported the hypothesis of a hypothalamic involvement in the underlying pathophysiology in CH. Animal studies added further evidence regarding this hypothesis. Based on previous data even invasive treatment methods such as hypothalamic deep brain stimulation (DBS) were tried for therapy. However, the principal question whether these alterations are pathognomonic for CH or whether they might be detected in trigeminal pain disorders in general in terms of an epiphenomenon is still unsolved. This review summarizes studies on hypothalamic involvement in CH pathophysiology, demonstrates the involvement of the hypothalamus in other diseases, and tries to illuminate the role of the hypothalamus based on this synopsis.